ALBERT R. MANN
LIBRARY
New York State Colleges
of
Agriculture and Home Economics
Cornell UniversityCornell University Library
QK 47.B57 1888
3 1924 001 794 100
31924001794100THE
American S®ence Series
V
FOR SCHOOLS AND COLLEGES.
The principal objects of the series are to supply the lack—in some subjects
very great—of authoritative books whose principles are, so far as practicable,
illustrated by familiar American facts, and also to supply the other lack that
the advance of Science perennially creates, of text-books which at least do not
contradict the latest generalizations. The books of this series systematically
outline the field of Science, as the term is usually employed with reference to
general education. The scheme includes an Advanced Course, a Briefer Course,
and an Elementary Course.
In ordering be careful to state which course is desired—Advanced,
Briefer, or Elementary.
Physics.
By George F. Barker, Professor
in the University of Pennsylvania.
In Preparation.
Chemistry.
By Ira Remsen, Professor in the
Johns Hopkins University.
Briefer Course, 387 pp.
Elementary Course, 272 pp.
Astronomy.
By Simon Newcomb, Professor in
the Johns Hopkins University, and
Edward S. Holden, Director of the
Lick Observatory.
Advanced Course, 512 pp.
Briefer Course, 352 pp.
Biology.
By William T. Sedgwick, Pro-
fessor in the Massachusetts Insti-
tute of Technology, and Edmond
B. Wilson, Professor in Bryn Mawr
College.
Part I,—Introductory, 193 pp.
Botany.
By C. E. Besset, Professor in the
University of Nebraska; formerly
in the Iowa Agricultural College.
Advanced Course, 611 pp.
Briefer Course, 292 pp.
Zooloyy.
By A. S. Packard, Professor
of Zoology and Geology in Brown
University.
Advanced Course, 722 pp.
Briefer Course, 338 pp.
Elementary Course, 290 pp.
The Unman Body.
By H. Newell Martin, Profes-
sor in the Johns Hopkins Univer-
sity.
Advanced Course, 621 + 34 pp.
Copies without the Appendix on
Reproduction will be sent when
specially ordered.
Briefer Course, 377 pp.
Elementary Course, 261 pp.
Political Economy.
By Francis A. Walker, Presi-
dent Massachusetts Institute of
Technology.
Advanced Course, 537 pp.
Briefer Course, 415 pp.
HENRY HOLT & CO., Publishers, NEW YORK.AMERICAN SCIENCE SERIES
BOTANY
FOR
HIGH SCHOOLS AND COLLEGES
BY
CHARLES E. BESSEY, Ph.D.,
PROFESSOR OF BOTANY IN THE UNIVERSITY OF NEBRASKA; FORMERLY PROFESSOR OF
BOTANY IN THE IOWA AGRICULTURAL COLLEGE; ASSOCIATE EDITOR OF
THE “AMERICAN NATURALIST'’ (DEPARTMENT OF BOTANY)
FIFTH EDITION, REVISED
NEW YORK
HENRY HOLT AND COMPANY
1888Copyright, 1880,
BY
Hemet hoi,t & Co.PREFACE.
This book is designed to serve as an Introduction
to the Study of Plants. It does not profess to give a
complete account of the Vegetable Kingdom, but
only such an outline as will best subserve the pur-
poses of the work.
In its preparation there have been kept in view
the wants of the large number, in the schools and
out, who wish to obtain, as a branch of a liberal cul-
ture, a general knowledge of the structure of plants,
with some idea as to their classification into the
larger divisions and subdivisions of the Vegetable
Kingdom. For this class of students and general
xeaders, what is here given will in most cases be
amply sufficient to enable any one to understand the
greater part of the current biological literature, in so
far as it relates to vegetable organisms. For the
student who desires to pursue the subject further,
or who intends to make botany a special study, this
book aims to lead him to become himself an observer
and investigator, and thus to obtain at first hand his
knowledge of the anatomy and physiology of plants:
accordingly the presentation of the matter has been
made such as to tit the book for constant use in the
Laboratory, the text supplying the outline sketch,
which may be tilled up by each student, with the aid
of the scalpel and compound microscope.
This book is an expansion and considerable modi-
fication of the material of several courses of lecturesIV
PREFACE.
annually delivered to college students. In general
plan, Part I. follows pretty nearly that of Sachs’ ad-
mirable “Lehrbuch,” and in many instances it has
seemed to me that I could not do better than to
adopt the particular, treatment which a subject has
received at the hands of the distinguished German
botanist. This has been rendered possible through
the liberality of my publishers, and the courtesy of'
Engelmann of Leipzig, the publisher of many of
Sachs’ works, by which many of the cuts of the
“Lehrbuch” are here reproduced. This book will
thus, to a considerable extent, serve as an introduc-
tion to that work. Free use has also been made of
the recent works of Tie Bary, Hofmeister, Strasbur-
ger, Nageli, Schwendener, and others, to whose writ-
ings numerous references are made.
In Part II. the general disposition of the lower
plants is a considerable modification of that proposed
by Sachs ; that of the higher plants is made to con-
form to the system of classification in vogue in this
country and in England, as outlined in Dr. J. D.
Hooker’s “Synopsis of the Classes, Sub-classes, Co-
horts and Orders,” in the English edition of
Le Maout and Decaisne’s “Traite Generale de Botan-
ique,” and as given much more fully in Bentham and
Hooker’s still unfinished “ Genera Plantarum.” The
notes upon the economic values of the more impor-
tant plants of each order are based upon my own lec-
tures upon Economic Botany. I have also freely
used the similar notes in Le Maout and Decaisne’s
work, cited above; Balfour’s “Class-Book of Bot-
any,” Archer’s “Economic Botany,” Smith’s “Do-
mestic Botany,” Laslett’s “Timber and Timber
Trees,” etc., etc.
Necessarily, there is but little that is really new in a
treatise like this. Aside from a more or less important
and original arrangement of the matter, so as tofKEFAVE.
v
secure a more logical presentation of the subject,
there are but two considerable innovations, consist-
ing (I.) in the recognition (in Chapter VI.) of seven
quite well marked kinds of tissue. In this, however,
while not adopting De Bary’s classification, I have
followed his method of treating the subject, as given
in his recent work on the comparative anatomy of
plants (“ Vergleichende Anatomie der Vegetations-
organe der Phanerogamen und Fame.”) (II.) The
second considerable innovation occurs in Part II. ; it
consists in raising the Protophyta, Zygosporese, Oos-
porem and Carposporese to the dignity of Primary
Divisions of the vegetable kingdom, co-ordinate with
the Bryo] tliyta, Pteridophyta and Phanerogamia.
The usefulness of both of these departures from the
common practice has been subjected to the test of
the laboratory, and the lecture and class-room, with
the most satisfactory results ; and I am led to hope
that in the hands of others they may also serve to
give a clearer and more accurate notion of the struc-
ture of plants. Should they do this they will need no
further apology or defense.
Of the illustrations, many are entirely new ; many
others have been re-drawn, from various sources,
with slight modifications, expressly for this work,
and all from other sources are specially acknowl-
edged in their places.
I desire here to acknowledge my indebtedness to
Dr. Asa Gray, whom it is an honor to own as my
sometime teacher, for kindly aid and counsel in the
preparation of the lectures upon which this work is
based ; and in the same way I am indebted to Dr.
G. L. Goodale, Dr. W, G. Farlow and Professor A.
N. Prentiss. For aid in the immediate preparation
of the material for the press, acknowledgment is due
many of my personal friends : Mr. J. C. Arthur fur-
nished the original drawings of the water-pores ofVI
PREFACE.
Fuchsia, and of various tissues of Echinocystis;
Professor H. L. Smith, of Hobart College, New
York, contributed the sketch of the classification of
the Diatomacefe ; Dr. T. F. Allen furnished a synop-
sis of the classification of the Characese ; Dr. B. D.
Halsted also furnished material and notes upon our
native species of Characese ; my colleague, Professor
W. H. Wynn, kindly determined some of the more
difficult etymologies; to my wife I am deeply in-
debted for efficient aid in the laborious tasks of
proof-reading and indexing.
Should this book serve to interest the student in
the study of plants as living things, should it succeed
in directing him rather to the plants themselves than
to the books which have been written about them,
should it contribute somewhat to the general read-
er’s knowledge of the structure and relationship of
the plants around him, the objects kept in view in its
preparation will have been attained.
C. E. B.
April 12, 1880.
PREFACE TO THE FIFTH EDITION.
In the preceding editions, which appeared, respectively,
in 1881, 1883, and 1885, a considerable number of correc-
tions and additions were made. In the present edition that
modification of the names of the second, third, and fourth
branches of the Vegetable Kingdom (Zygophyta. Oophyta,
Carpophyta) heretofore used in the “ Essentials of Botany,”
has been adopted, and a number of important paragraphs
have been added as foot-notes.
C. E. B.
University op Nebraska,
Lincoln, December 24, 1887.CONTENTS.
PART I. GENERAL ANATOMY AND PHYSIOLOGY.
CHAPTER I.
Protoplasm.
]
General Characters—Chemical Composition—Consistence—Power
of Imbibing Water—Vacuoles—Physical Activity—Naked
Protoplasm—Protoplasm Enclosed in Cell Walls .......
CHAPTER II.
The Plant-Cell.
General Statement—Ectoplasm and Endoplasm—Bands and Strings
of Protoplasm—Nucleus—Size of Cells—Forms of Cells—The
Cell the Unit in Plants.............................
CHAPTER III.
The Cell-Wall.
Composition—Growth in Surface—Growth in Thickness—The
Markings on Cell Walls—Theories as to the Mode of Thick-
ening—Stratification of the Cell Wall—Formation of Chem-
ically Different Layers—The Formation of Mucilage—Incom-
bustible Substances in the Wall.......................
CHAPTER IV.
The Formation op New Cells.
Cell-Formation by Division: (a) Fission; (6) Internal Cell-Forma-
tion—Cell-Formation by Union—Examples.................via
CONTENTS.
CHAPTER V.
The Products of the Cell.
PAGE
| 1. Chlorophyll—§ 2. Starch, Composition, Form, Molecular
Structure—Grauulose and Starch-Cellulose — Formation of
Starch Granules in the Chlorophyll-Bodies—Formation of
Ordinary Starch Granules—§ 3. Aleurone and Crystalloids—
§ 4. Crystals in Cells—§ 5. The Cell Sap—§ 6. Oils, Resins,
Gums, Acids and Alkaloids......................:.. 50
CHAPTER VI.
Tissues.
§ 1. The Various Aggregations of Cells : (a) Single Cells ; (b) Fam-
ilies ; (c) Fusions ; (cl) Tissues ; The Cell-Wall in Tissues—
§ 2. The Principal Tissues—Parenchyma—Collencliyma—
Sclereuchyma—Fibrous Tissue—Laticiferous Tissue — Sieve
Tissue—Traclieary Tissue—§ 3. The Primary Meristem. 65
CHAPTER VII.
The Tissue Systems.
§ 1. The Differentiation of Tissues into Systems—§2. The Epi-
dermal System of Tissues—Epidermis—Tricliomes—Stomata
— § 8. The Fibro-Vascular System of Tissues—General
Structure—The Fibro-Vascular Bundles of Pteris, Polypodium,
Adiantum, Equisetum, Selaginella, Lycopodium, Zea, Acorus,
Ricinus and Ranunculus—Of Xylem and Phloem—Collateral,
Concentric, and Radial Bundles — Development of Fibro-
Vascular Bundles—§ 4. The Fundamental System—The Tis-
sues it Contains—Cork—Lenticels................. 89
CHAPTER VIII.
Intercellular Spaces, and Secretion Reservoirs..... 128.
CHAPTER IX.
The Plant-Body.
g 1. Generalized Forms—Thallome—Caulome—Trichome—Root--.
Particular Relations of Pliyllome to Caulome—General Modes
of Branching of Members—g 2. Stems—The Punctum Veget.a-
tionis—Buds—Adventitious Stems—g 3. Of Leaves in General
—g 4. The Arrangement of Leaves—g 5. The Internal Struc-
ture of Leaves—g 6. The Roots of Plants, Structure, Root-Cap,
Growth—Formation of New Roots—Arrangement of Roots... 133CONTENTS.
ix.
CHAPTER X.
The Chemical Constituents of Plants.
TAGE
§ 1. The Water in the Plant—Amount of Water in Plants—Water
in the Protoplasm—Water in the Cell Walls—Water in the
Intercellular Spaces—Equilibrium of the Water in the Plant—
Disturbance of Equilibrium—Evaporation of Water—Amount
of Evaporation—The Movement of the Water in the Plant
—§ 2. As to Solutions—§ 3. Plant Food—The Most Important
Elements—The Compounds Used—How the Food is Obtained
—How Transported in the Plant......................... 166.
CHAPTER XI.
The Chemical Processes in the Plant.
£ 1. Assimilation—§ 2. Metastasis—Its General Nature—Trans-
formation of Starch—Nutrition of Protoplasm—The Storing of
Reserve Material—The Use of Reserve Material—The Nutri-
tion of Parasites and Saprophytes—The Formation of Alkaloids
—Results of Metastasis................................ 178
CHAPTER XII.
The Relations of Plants to External Agents.
§ 1. Temperature—General Relations—Absorption of Water as Af-
fected by Temperature—Evaporation—Assimilation—Metasta-
sis-Death from too High a Temperature—Death from too
Low a Temperature—§2. Light: General Relations of Light
to Assimilation, Light, and Metastasis—£ 3. Heliotropism—
£ 4. Geotropism—§ 5. Certain Movements of Plants : General
Statement, Spontaneous Movements, Movements Dependent
upon External Stimuli, Movements of Nutation, Movements
of Torsion........................................ 184
PART II. SPECIAL ANATOMY AND PHYSIOLOGY.
CHAPTER XIII.
Classification.
Principles of a Natural Classification—Critical—A Comparison of
several Systems............................................. 202X
CONTENTS.
CHAPTER XIV.
The Protopiiyta.
§ 1. Myxomycetes—§ 2. Schizomycetes—§ 3. Cyanophyce®
CHAPTER XV.
The Zygophyta.
§ 1. Zoospore®—§ 2. Conjugate................
PAGE
206
220
CHAPTER XVI.
The Oophyta.
§ 1. Volvox and its Allies—§ 2. CEdogonie®—§ .3. Cceloblaste®—
§ 4. Fucace®..................................243
CHAPTER XVII.
The Cabpofhyta.
§ 1. Coleocltete—§ 2. Floride®—§ 3. Ascomycetes—§ 4. Basidio-
mycetes—§ 5. Charace®—§ 6. The Classification of Tliallo-
phytes........................................... 270
CHAPTER XVIII.
The Bryopiiyta.
§ 1. Hepatic®—g 2. Musci........................ 341
CHAPTER XIX.
The Pteridophyta.
§ 1. Equisetin®—§ 2. Filicin®—§ 3. Lycopodin®....... 361
CHAPTER XX.
The Phanerogamia.
§ 1. General Characters—g 2. Gytnnosperm®—g 3. Angiosperm®
—Glossology of Angiospernis—The Tissues of Angiosperms—
Classification and Economic Botany of Monocotyledons—Class-
ification and Economic Botany of Dicotyledons.389
CHAPTER XXI.
Concluding Observations.
The Number of Species of Plants—The Affinities of the Groups of
Plants—The Distribution of Plants in Time.......................566BOTANY,
PART I.
GENERAL ANATOMY AND PHYSIOLOGY.
CHAPTER I.
PKOTOPLASM.
1.—If we examine a thin slice of any growing part of a
plant (Fig. 1) under a microscope of a moderately high
power (400 to 500 diameters), there may be seen large num-
bers of cavities which are more or less filled with an almost
transparent semi-fluid substance. In very young parts, as
in buds and the tips of roots, this substance entirely fills the
cavities, and makes up almost the whole mass, while in older
parts it occurs in less quantity, and usually disappears in
quite old tissues. This substance is the living portion of
the plant, the active, vital thing which gives to it its sensi-
bility to heat, cold, and other agents, and the power of mov-
ing, of appropriating food, and of increasing its size ; it is, in
fact, that ivhich is sensitive, which moves, appropriates food,
and increases in size. This sensitive, moving, assimilating,
and growing substance is named Protoplasm.*
It is a fact of great biological interest that in animals the essential
constituent of all living parts is a substance similar to the protoplasm
of plants. We cannot distinguish the two by any chemical or physical
tests, and can only say that, taken as a whole, the protoplasm of plants
* So named by its discoverer, Dr. Hugo Von Mohl, in 1846. It is the
Bioplasm of Dr. Lionel Beale and his followers.2
BOTANY.
•differs from that of animals in its secretions. And yet these secre-
tions are not strictly confined to plants ; cellulose, starch, chlorophyll,
and other products of vegetable protoplasm formerly regarded as pe-
culiar to plants are now known to occur in undoubted animals. Botanists
and zoologists have laboredlong in vain to discover absolute differences
between the animal and tbe vegetable kingdoms; between the higher
plants and the higher animals there are great and constant differences.-
in none of the higher animals, for ex-
ample, is chlorophyll produced; but
in the lower orders of both kingdoms
not one of the differences observed to
hold between the higher plants and
animals exists.
2.—The exact chemical compo-
sition of protoplasm lias not hith-
erto been made out, but it is
known to be an albuminous,
watery substance, combined with
a small quantity of ash. It is
probably a complex mixture of
chemical compounds, and not a
single compound. It contains at
some time or another all the chem-
ical constituents of plants. Oil,
granules of starch, and other or-
ganic substances are frequently
present in it, but they are to be re-
garded as products rather than
proper constituents of protoplasm.
Fig. 1.—A little more than half of
-a longitudinal section of the apex of , v i , , ,
a young root of the Indian corn. (®) ” &ter makes up a considerable
The part above s is the body of the part of tbe bulk of ordinary protoplasm,
root, that below it is the root-cap ; , . , , , , .
v, thick outer wall of the epidermis; smd. is much more abundant in its
m young pith-cells;/, voung wood- active than in its dormant conditions,
cells ; g, a young vessel; s, a, inner _ . ,
younger part of root-cap ; a, a, out- lu the protoplasm oi Fuhqo vanans
Iach!rr part 0f root-cap'-After (one of the Slime Moulds) just before
tbe formation of its spores there is 70
per cent of water ; in dry seeds, on the other hand, the amount is not
more than about 8 to 10 per cent.
(b) As to its molecular constitution, Strasburger bolds* that proto-
plasm is composed of minute solid particles (not, however, of a crystal-
-line form), separated from each other by layers of water (see Cell-wall
* “ Studien fiber Protoplasma,” 1876.PROTOPLASM.
3
paragraph 37, and Starch, paragraph 69). The thicker the layers of
water are, the more watery is the protoplasm, and vice versa.
(c) Tests. 1. If a protoplasmic mass is moistened with a solution of
iodine, it at once assumes a deep yellow or brown color.
2. If treated with a solution of copper sulphate aud afterward-* with
potash, it assumes a dark violet color.
Fig. 2.—Parenchyma cells from the central cortical layer of the root of Frttllim ic
imperialis, longitudinal sections. A, very young cells lying close above the apex ol
the root, still without cell sap or vacuoles. B, cells of the same description about
two millimetres above the apex of the root; by the entrance of cell sap the vacuoles
a, a, s have been formed. 0. cells of the same description about seven to eight mil-
limetres above the apex of the root. In all the figures, h, cell-wall; p. protoplasm ;
k. nucleus ; Jck. nucleoli; s, vacuoles ; x y. swelling of the nucleus under the influ-
ence of the water in preparing the specimen. X 500.—After Sachs.
3. Treated with a solution of sugar, and afterwards with sulphuric
acid, it becomes rose-red.
4. The presence of protoplasm may be demonstrated in a tissue by
the application of various staining fluids, as magenta, carmine, etc.4
BOTANY.
5. In a dilute solution of potash protoplasm is dissolved ; if, how-
ever, the solution is concentrated, the form of the protoplasm remains
unaltered for weeks, but upon the addition of water it at once dissolves.
6. Protoplasm coagulates upon the application of heat (50 degrees
Centigrade), or when immersed in alcohol or dilute mineral acids.
3.—In consistence protoplasm is a soft-solid substance,
varying from an almost perfect fluidity on the one hand to
a considerable degree of hardness and even brittleness on
the other. This difference in con-
sistence is mainly due to the vary-
ing amounts of water imbibed by
it, hence the same mass may at
different times vary greatly in this
regard. Generally there may be
seen in protoplasm a large number
of minute granules enclosed in a
transparent medium (Pig. 2, A) ;
in some instances, however, the
granules are entirely wanting, or
nearly so. By the withdrawal of
these granules for a little distance
from the surface toward the cen-
tre, a mass of granular protoplasm
Fisp 3.—Optical section of a re (the endoplasm) may appear to be
tractmg branch of a large pianino- surrounded by a hyaline envelope,
dium of Fuligo varUms (.JElhalium ., . , . , . r
septicum of authors); the narrow the protoplasmic SKin, OY CCtO-
inner granular mass of protoplasm TT , 7 • 7 , £ •
is seen to be surrounded by a broad plasm (the HautSClllcIlt 01 Pl’ingS-
wtuchlnthtj^caecisradiahystmik- heim, and Hauptplasmci of Stras-
the body y the6 plaLSSfhs burger) (Pig. 3). It is almost al-
fiifo'rarnmnded^by (rh$?n”ei- ways formed when protoplasm is
veiope. x 200.—After Hofmeieter. exposed in water or air ; but it, or
something very much like it, appears to he generally
present, even in closed cells.
(a) The fine granules are probably not proper constituents of proto-
plasm, but finely divided assimilated food-materials immersed in the
proper protoplasm, whicli is itself colorless and transparent. Proto-
plasm destitute of granules may he found in the cotyledons of the
bean (Plmseolus), In other cases, e.g., in the zygospores of Spirogyra,
the granular and coloring matters are so abundant that the hyaline
basis can no longer he distinguished.PROTOPLASM.
5
(6) fetrasburger* maintains that the hyaline envelope is not simply a
portion of the basis or ground substance of the protoplasm deprived
of its granules, but that it is a definite modification of it, and endowed
with various properties quite distinct from those of the ground sub-
stance.
4. —Active protoplasm possesses the power of imbibing
water into its substance, and as a consequence, of increasing
its mass. This power varies with the changes in external,
and also in internal conditions ; many seeds, for example,
which do not swell up (through absorbing water) in cold
water, will do so when placed in that of a higher tempera-
ture ; but in some seeds it appears that imbibition of water
will not take place until after a period of rest.
5. —-When the amount of water imbibed is so great that
the protoplasm may be said to be more than saturated with
it, the excess is separated within the protoplasmic mass in
the form of rounded drops, termed Vacuoles (Vacuoli). In
closed cells these may become so large and abundant as to
be separated only by thin plates of the protoplasm (Fig. 3,
B). As such vacuoles become still larger, the plates are
broken through, and eventually we may have but one large
vacuole surrounded by a thin layer of protoplasm, which
lines the interior of the cell wall (Fig 2, C). In this way
some masses of protoplasm assume a bladder-like or vesicular
form, so unlike their original form that until very recently
their real nature has not been understood.! Frequently
when the plates which separate vacuoles break down, instead
of breaking entirely away they become pierced with several
large openings, leaving strings or bands of protoplasm which
extend across the cavity.
Occasionally, when vacuoles unite, small masses of the protoplasm
which previously separated them become detached as free rounded
* “ Studien fiber Protoplasma,” 1876. See also Qr. Jour. Mia. Science,
1877, p. 124 et seq.
f Vou Mold gave to this layer the name Primordial Utricle, and it is
still frequently used, but the term is objectionable, and Sachs’ name of
Protoplasmic Sac is to be preferred. Treatment with glycerine, strong
alcohol, or any other substance which removes the water, will cause
the protoplasmic sac to contract and be'come visible.6
BOTANY.
masses in the large vacuole ; these again may produce vacuoles within
themselves, and thus give rise to a peculiar and at first sight perplex-
ing structure (Fig. 4).
6.—The most remarkable peculiarity of living protoplasm is
its physical activity. When the proper conditions are pres-
ent, a living mass of protoplasm is apparently never at rest,
but, on the contrary,
continually altering its
shape and changing the
position of its constit-
uent parts. The move-
ments are all of the
same general nature;
each one maybe regard-
ed as the aggregate re-
sult of the chemical and
physical changes taking
place in the substance
of the protoplasm.
We may study the ac-
tivity of protoplasm
under two conditions,
which will give us the
two cases. (1.) The
Activity of Naked Pro-
Fig. 4.— Forms of the protoplasm contained in toplasm, and (2.) The
cells. A and B, of Indian Com tZea main); A, A £ -js ,
cells from the first leal’-shrarh of a germinating Activity 01 1 rotoplasni
plant, showing the frothy condition of the proto- ^r,nir.Qn)q * n Poll wall
plasm, the many vacuoles separated by thin tnciObeCL 111 a v^eil-wail.
plates. B, cells from the first internode of the 17 rn|~ft a n-HTri+Tr rtf
germinating pi nt; the protoplasm is broken up ' * J--Llv /xoiiviiy 01
into many rounded masses, in each of which there N aked Protoplasm,
is a vacuole, b ; these are the so-called “ sa, contracted protoplasm. After Sachs. ^ Slime Moulds,
present the best examples of the activity of naked vegetable
protoplasm. In their plasmodia (as the masses of naked proto-
plasm are called), many kinds of movements may be observed,
the commonest of which is streaming. In plasmodia com-
posed of thin (i.e., watery) protoplasm, streams or currents
of the latter may be seen running in various directions1 PROTOPLASM MO VEMKA'TS. . 7
(Fig. 5). The streams arc made clearly risible by the motion
of the grannies which are carried along by the moving hya-
line portion of the protoplasm. After running in one
Fig. 5.—A email mass of the naked protoplasm (plasmodium) of Didymium ser
pula ; the arrows show the direction of the currents, x 30.—After Hofmeister.
direction for some minutes (about five) the current stops,
and then it usually sets in an exactly opposite direction for
about the same length of time, and carries back the previ-
ously moved protoplasm.8 BOTANY.
i
The formation of the new current may he explained as follows:
Let A..........B he a stream in which the movement is from A
to B; clearly ihere will be an aggregation of protoplasm about B.
When the current in the direction A B stops, the new one, in the
reverse direction, B A, begins at A, by the movement toward it of the
particles nearest to it; next the particles further off move toward A ;
after this, those still further off, and so on. The current extends back-
ward. So, too, when a stream begins de now, it is propagated back,
ward from the point of beginning.
, AS *
8.—Mass-Movement (Amoeba-Movement). In the flowing
back and forth in the
streams the movement
may be greater in one
direction than in the
other; this causes a
slow motion of the
whole plasmodium in
the direction of
the greatest movement.
When this takes place
in the case of streams
which begin in the mar-
gin of the plasmodium,
protuberances of vari-
ous shapes arise; these
may be extended into
branches (pseudopo-
dia), which may again
be branched one or
Fig. 6.—Outline of a plasmodium of Didymium times. By tile
spjmla forming pseudopodla The heavy black anastomosing of these
line indicates the outline at the beginning ol the °
observation ; the pseudopodium a-b formed in 8 brandies a COmpl&X
seconds, c-d in 30, and c-e in 55 seconds. X 10. . .
—After Hofmeister. moving and changing
network is formed. (See Fig. 140, page 208) There is pos-
sibly to he separated from the above-described mass-move-
ment that more or less rapid change of external contour
which has, from its resemblance to the motions of the
Amoeba, been denominated the Amoeba-movement (Fig. 6).
It is best observed in the so-called “Amoeba-form ” stage of
the swarm-spores of the Mvxomycetes.PROTOPLASM MOVEMENTS.
9
While in thinner protoplasm the streaming and mass-
movements are always horizontal, or, at least, parallel with
the surface upon which the plasmodium rests, in the case of
tougher protoplasm they may give rise to branches which
have an upward direction, as in the formation of sporangia.
9.—Effect of External Influences. The movements of
the protoplasm of the Myxomyeetes, and probably to a
greater or less extent of all plants, are suspended by certain
external influences. Violent jarring, pressure, a thrust as
with the point of a pin or pencil, electrical discharges,
sudden changes of the temperature, and sudden changes in
the concentration of the surrounding fluid, stop the move-
ments, and cause the plasmodium to contract into one or
more spheroidal masses. When these influences cease, if
they have not been so violent as to destroy the organization
of the protoplasm, it returns after a greater or less length
of time to its original form, and the movements are resumed.
(а) The effect of mechanical disturbances (jarring, pressure, and
thrust) may be best studied in the tougher or least fluid plasmodia
(e.g., of Stemonitis fused).
(б) The effect of electrical discharges may be studied by placing a
small plasmodium (e.g., Didymium serpula) upon a glass plate provided
with platinum points which are in connection with the poles of an
induction apparatus. When a discharge takes place through a narrow
branch (pseudopodium) it contracts so violently as to be broken up into
a row of little spheres ; if it takes place through the mass of the plas-
modium it becomes more or less spherical by its contraction. In any
case, if the shock has not been too severe,the protoplasm after awhile
returns to its normal shape again.*
(c) The plasmodium of Didymium serpula, when removed from a tem-
* Kuhne performed the following curious experiment. Taking a
portion of the plasmodium of Didymium serpula., in its resting state,
he mixed it with water so as to make a pulpy or pasty mass. With
this he filled a piece of the intestine of a water-beetle, and tying the
ends, laid it across the electrodes of an induction apparatus. The pre-
paration was kept in a film of water in a damp chamber for twenty-four
hours, at the end of which time it was considerably distended. He now
allowed the electrical current to pass through it, when it contracted
itself “like a colossal muscle-fibre.’' Upon extending it by pulling at
the ends, and then sending through it a stronger electrical current, it
contracted itself one third of its length.10
BOTANY.
perature of 30° C. to one of 30° C. (68° to 80° Fahr.l. withdraws its pseud-
opodia and ceases its activity in tlie space of five minutes. In an hour
after the restoration of the normal temperature (20° C.) the movements
begin again. If the temperature is raised to 35° C. (95° Fahr.) the
organization of the plasmudium is destroyed.
The plasmodium of Euligo varians, tionimf. (JEthalium septwum,
Fr.), when placed in a chamber surrounded by ice, contracts into a
rouuded form and ceases all motion ; upon gradually raising the tem-
perature again the normal state is resumed.
(d) In glycerine, a concentrated solution of sugar, a five percent solu-
tion of potassium nitrate, or a five percent solution of sodium chloride, a
plasmodium contracts, and becomes rounded and motionless. A sudden
decrease in the concentration of the solution by which a plasmodium
is surrounded also results in a stoppage of its movements. A plasmo-
dium of Didymium serpula, when placed in a one per cent solution
of potassium nitrate, and allowed time to regain its activity, suddenly
rounds itself up and stops its movements when the preparation is
washed out with distilled water; after the lapse of a few minutes (ten
to twelve) the activity begins to show itself again, and in half an hour
the normal state is restored.
10.—Ciliary Movement. The swimming of swarm-spores,
spermatozoids, and many other naked protoplasmic bodies, is
due to the rapid vibratory motion of extremely small whip-
like extensions of the hyaline portion of the protoplasm.
Examples of ciliary movement are very common. In some swarm-
spores, as in those of Vaucheria, the whole surface is covered with short
cilia ; in others, as in CEdogonium, the cilia lorm a crown about the hya-
line anterior extremity ; those of Pandorina and Cladopliora, and the
spermatozoids of Bryophytes and Pieridophytes, have two or more cilia ;
while the swarm-spores of Myxnmycetes have but one.
The rapidity of the swimming motion produced by cilia is consider-
able, as shown by measurements made by Holmeister* in the case of
swarm-spores, viz. :
Fuligo varians (JEtlialium septicum)... .7 to .9 mm. per second.
Lycogola epidendrnm................ .33 min. “ “
CEdogonium vesicatum..................15 to .20 mm. “ “
Yauclieria sp.........................10 to .14 mm. “ “
11 .—The Activity of Protoplasm Enclosed in a Cell-wall.
The movements of protoplasm in closed cells differ but
little from those in naked ones ; the differences are such as
are due to the fact that in the latter case the protoplasm is
Lelire von der Pflanzenzelle,” p. 30.PROTOPLASM MOVEMENTS.
11
free to move in any direction, while in the former its move-
ments are greatly restricted by the surrounding walls. In
closed cells there are two general kinds of movements—one
a streaming, the other a mass movement—comparable to the
streaming and Amoeba movements of the naked cells or pro-
toplasmic masses. No movement takes place, however (at any
rate to no great extent), until the vacuoles are quite large.
12—The streaming movements occur in the protoplasmic
strings, bands, and plates which cross or separate the vacu-
oles, and in the lining layer of protoplasm which invests the
inner surface of the cell-wall. The motion, in many cases,
shows the same alternation as in the Myxomycetes, the direc-
tion of the streaming usually being reversed after the lapse
of a few minutes.
The mass-movement in closed cells is not as clearly sepa-
rated from the streaming as in naked cells. It usually con-
sists in a sliding or gliding of the protoplasm upon the inner
surface of the cell-wall, in much the same way as the naked
plasmodium of one of the Myxomycetes moves upon the sur-
face of its support. The limited space in which its move-
ment must take place in closed cells, and its disposition over
the whole inner surface of the wall, compel the protoplasm
to move in opposite directions upon opposite sides of the
cell. There is thus a kind of rotation of the protoplasm
when the movement of all its parts is uniform.
(a) Tlie streaming movements may be studied in the stamen-hairs of
Tradescantia Virginica, the stinging hairs of the nettle (Urtica), the
hairs of Cucurbita, Ecbalium, and Solatium tuberosum, the styles of
Zea mais, the easily separated cells of the ripe fruit of Symphoricar-
pus racemosus, the young pollen grains of (Emthera, and the paren-
chyma of succulent monocotyledons—e.g., in the flower peduncles and
the filaments of Tradescantia. The parenchyma cells of the leaves of
many trees and of the prothallia of ferns and Equisetums show a net-
work of hyaline strings in which a streaming may with difficulty be seen.
Among the lower plants good examples may be found in the hyphae
of some Saprolegniae, and in the cells of Spirogyra, Closterium, Denti-
cella, and Ooscinodiscus.
(b) In many cases (e.g., in the unfertilized embryo-sac of many
Phanerogams, in the young endosperm cells, and in the spore-mother-
cells of Anthoceros lavis)—where the strings and bands resemble those
in the cases cited above—no movement of the protoplasm is visible,12
BOTANY.
doubtless because of tlie mechanical injury of the cells in making1 the
preparation, and the disturbing influence of the water in which it is
mounted.
(c) In the stamen-hairs of 2'radescantia Virginica the protoplasm
Fig. 7.—An optical section of a cell of one of the stamen-hairs of Ti'adescantia
Virginica, after treatment with a solution of sugar. The protoplasmic 6ac has
partly collapsed, on account of the withdrawal of some of the interior water by the
sugar solution. At the bottom of the cell is the large nucleus ; in the strings and
bands of protoplasm there are streamings of the protoplasm, shown by the arrows.—
After Hofmeistcr.
forms a rather thick layer over the inner surface of the cell-wall, and
in some part of this layer the nucleus lies imbedded. From the nucleus
and from various parts of the protoplasmic layer there pass to the
opposite side of the cell thicker or thinner bands and strings, always.PROTOPLASM MOVEMENTS.
13
however, more or leas parallel with the longer axis of the cell (Fig. 7).
In a string there may be one, two, or three currents ; when there are
two they are in opposite directions ; when there are three the central
one takes one direction and the two outer ones the other.
The strings are not stationary in the cell, but, on the contrary, they
change their position with a consideiable rapidity, and in a prepara,
tion soon pass out of the focus of the microscope.* By this change of
place two strings may come together and fuse into one, or a string may
pass to the side of the cell and become obliterated by fusing with the
protoplasmic sac. New strings may be formed by a process exactly
opposite to the one just described. A stream in the substance of the
lining protoplasm forms a ridge projecting into the vacuole ; this ridge
gradually becomes higher, and finally breaks away from the protoplas-
mic sac, retaining its connection only at the ends. After a stream has
been running in a certain direction for from ten to fifteen minutes, the
motion suddenly becomes slower and soon stops entirely for from a few
seconds to several minutes, and then begins to move in the opposite
direction. The new movement begins and spreads as in the Myxomy-
cetes (see paragraph 7).
(d ) In the hairs of Cucurbita Pepo the arrangement of the protoplasm
is much as in Tradescantia. The strings and bands are, however,
broader, and frequently contain several currents, and the nucleus,
instead of being imbedded in the lining layer of protoplasm, is in
a centrally placed mass. There is a more rapid change in the form
and position of the bands and strings than in Tradescantia, but the
streaming motion is, on the contrary, considerably slower. The reversal
of the streaming currents takes place in from seven to twenty minutes.
(e) In most cases the streams lie in the lining protoplasmic layer of
the cell, or form low ridges upon its inner surface. This is the case
in the hairs of the style of Campanula, in liyphte (of fungi), and in the
suspensor and young embryo of Funkia ccerulea. In long cells, the
movement being parallel with the longer axis, there may be, as in the
pollen tube of Zostera marina, currents passing up one side and down
the other, f
* This fact must be borne in mind in studying the movements of pro-
toplasm in these cells, otherwise grave mistakes may be made. One
string may move out of focus, and another, with a contrary current,
may move into it, and thus a reversal of the current in the first string
may erroneously be supposed to have taken place.
f To study the movements of protoplasm in pollen tubes it is usual y
necessary only to make a thin longitudinal slice of the stigma, and to
mount and cover it in the usual way, using no water, however. After
placing it under the microscope the preparation should be carefully
crushed, when some of the pollen tubes may be distinctly seen. Their
movements frequently continue for some hours in such preparations.14
BOTANY.
(/) The passage from the condition in the last examples (the so.
called circulation of protoplasm) is an easy one to the cases where the
whole mass of protoplasm moves along the cell-wall as a broad stream,
passing up one side and down the other (the so-called rotation of pro-
toplasm). Common and well-known examples of this kind of mass-move-
ment occur in Ohara, Naias, and Vattisneria. It may also (on the
authority of Meyen) be studied in the root-lrairs of many land plants—
e.g., of Imprrtiens Balmmina, Vida faba, Ipomcea purpurea, Cucumis,
Cucurbita, Ranunculus sceleratus, and Marchantia polymorpha.
Note.—In the study of the structures treated of in Chapters I to Y
inclusive, the student will do well to consult a recent laboratory man-
ual—“Botanical Micro-Chemistry,” by V. A. Poulsen (William Tre-
lease, 1884).CHAPTER II.
THE PLANT-CELL.
13. —In some cases plant protoplasm has no definite or
constant form. This- is its permanent condition in some of
the lowest plants—e.g., the Myxomycetes. In most other
lower plants, and in all the higher ones, it has this condition
only temporarily, if at all. In the great majority of cases,
however, the protoplasm of which a plant is composed has a
definite, and, within certain limits, a constant form. It usu-
ally appears in more or less rounded or cubical masses of
minute size, and which may or may not be surrounded by a
cell-wall. In this condition it constitutes the Plant-Cell.
The undifferentiated protoplasm of the Myxomycetes reminds us of
the lower Monera among animals. In Bathybius and Protamoeba the
naked protoplasm of which they are composed has no constant form.
In Protomyxa we have a few simple transformations which are in every
respect comparable to those of the Myxomycetes.* In higher animals
the protoplasm exists in minute and definitely marked masses, termed
cells, or corpuscles, and these have been shown to be the exact homo-
logues of the cells of plants.
14. —While in young cells provided with a wall the pro-
toplasm fills the whole cavity, as in A, Eig. 2 (p. 3), in
older ones it never does so, and generally these contain only
a very small portion of it, as a thin layer covering the inner
surface of the cell-wall (B and C, Fig. 2). Close examina-
tion shows that this protoplasmic sac consists of (1) a firmer
hyaline layer, the ectoplasm, which is in contact with the
* See further on this subject in paragraph 222, Chapter XI. For a
short account of these interesting animal forms mentioned above, the
student is referred to Dr. Packard’s “ Zoology for Students and Gen-
eral Readers,” (p. 18 et neq.) in the series of which the present work
forms a part, and his “ Life-Histories of Animals,” where are also given
numerous references to fuller accounts.16
BOTANY.
cell-wall ; and (2) within this a less dense granular one, the
endoplasm ; the two layers are, however, not separated from
each other by any sharp line of demarkation.*
When the endoplasm attains a considerable thickness it becomes dif-
ferentiated into an external denser layer and an internal less dense
one. Often one of these layers may he found to be in motion while the
other is at rest.f
15. —There may almost always be seen in plant-cells bands
or strings of protoplasm which lie in or between the vacu-
oles (Fig. 2, B). They are at first thickish plates which
separate vacuoles, but afterward they become narrower as
the vacuoles enlarge, and at last they disappear entirely. In
these bands and strings, as previously stated (paragraph 12),
streaming movements are frequently to be seen.
16. —Each of the protoplasm masses constituting the cells
of most plants usually has a portion of its interior substance
differentiated into a firmer rounded body, the nucleus Its
normal position is in the centre of the cell; but it may be
displaced and pushed aside by the vacuoles, so that in an
optical section of the cell it may often appear to be in the
margin. The nucleus is to be regarded simply as a modified
part of the protoplasm of the cell, and not as something dis-
tinct from it. It may dissolve, and its substance pass into
that of the remainder of the cell; afterward a nucleus may
form again ; and this may occur a number of times. Com-
monly in each nucleus one or more small rounded granules
may be seen; these are called the nucleoli. The nucleus
may form a skin (hautschicht) about itself, and vacuoli may
be present in its interior.
17. —Cells are of very varying sizes. They differ in dif-
ferent plants, and also in the different parts of the same
plant. ' In but few cases, however, are they of great size, by
far the larger number being microscopic. The most striking;
* These two layers were first described by Pringsheiin in his “ Theorie
der Pflanzenzelle,” 1854.
t Cf. Strasburger, “ Studien fiber Protoplasma,” 1876 ; and Qr. Jr,
1lie. Science, 1877, pp. 124-132.THE PLANT-CELL.
17
examples of large cells are found in the Thallophytes ; Nitella,
dor example, has cells 50 mm. (2 inches) long, and 1 mm.
{.04 inch) thick. According to Von Mold, the bast-cells
of a species of palm (Astrocaryum) are from 3.6 to 5.6 mm.
(.13 to .21 inch) in length. For ordinary plants the average
size of the cells may be given as from .1 to .02 mm. (.004 to
.0008 inch). From this average size the dimensions of cells
decrease to exceedingly small magnitudes. In the Yeast
Plant (Saccharomyces cerevisice) the cells are about .008 mm.
(.0003 inch) in diameter. The cells of Bacterium tenno are
from .0021 to .0028 mm. long and from .0028 to .0005 mm.
broad (.0001- 00008 by .00008- 00002 inch).
The following table, taken from Hofmeister’s “ Lelire von der Piian-
aenzelle,” is useful as showing how the dimensions of similar cells
vary in different plants :
Table of Dimensions of Various Kinds of Cells of Woody
Plants.
(In decimals of a millimetre.)
• Robinia Pseudaca- cia (five year - old branch). FaGUS 6YLVATICA (49-yr.-old trunk). 3 P . ss ■'C- p _ M ~ ~ «fj p CT3 U 3*0 tf-O •• pa* ;►> & Viburnum Lantana (fonr-yr.-old branch). 1 Cinchona Calisaya. (branch 2 cm. | thick). g X3 zo 5 g 3 >> m bfl z z 2 p '-a
■Cambium-cells, average length .201 .413 .528 .339 .786 1.511
Vessel-like wood-cells, average length .308 .712 1.179 1.819 2.020
Bast-like wood-cells, average length .301 .513 .‘615
Vessel-cells of the wood, average length — .205 .404
Latticed cells of young secondary bark, aver- .212 .520
age length
Bast-cells of young secondary bark, average 1.292 .403 1.152
length .798 2.183
Cells of medullary ray in the cambium ring, .321 .437 .178 .838 .466
maximum length in tangential section .049
Do., do., maximum width in tangential sec- .011
tion .041 .076 .017 .056 .014
Cells of medullary ray in the young wood, .519 .285 .567 .630
average length in tangential section .376 .095
Do., do., average width in tangential section. 043 .077 .019 .037 .075 .019
Cells of medullary ray in the young secon- dary bark, average length in tangential .912 468 .504 .744 .172
section .342
.Do., do., average width in tangential sec- .066 031 .076 .075 .026
tion .057 18
BOTANY.
18. —Every free mass of protoplasm tends to assume a
spherical form. The free cells of the unicellular water plants
are generally more or less rounded, as are also the floating
spores of most aquatic Thallophytes. In plants composed of
masses of cells their mutual pressure gives them an angular
outline. Where the pressure is slight the cells depart but
little from the spherical shape, but as it becomes greater
they assume more and more the form of bodies bounded by
planes. If the diameters of the individual cells are equal
and the development of the mass of cells has been uniform
in every direction, we may have regular cubes, or twelve-sided
bodies, i.e., dodecahedra. It is rarely the case, however,
that the cells have a perfectly regular form. Even when
their diameters are approximately equal, they are generally
so much distorted that they are best described as irregular
polyhedra.
19. —It much more frequently happens that cells grow
more in some directions than in others, and thus give rise
to elongated and many irregular forms. In many of the
Thallophytes the long filaments composing the plants
are made up of elongated cylindrical cells placed end to
end ; while in others the cells are repeatedly and irregularly
branched.
In higher plants many elongated cells occur, but here,
by pressure, they generally become prismatic in cross-section.
(a) Many forms of cells have been enumerated, but they may all be
arranged under tbe two principal kinds 'indicated above, viz., the
short, and tbe elongated. As will be more fully shown hereafter, the
various kinds of short cells constitute what is called Parenchyma;
hence tbe cells themselves are termed Parenchymatous Cells, or Paren-
chyma cells. Similarly, certain kinds of the elongated cells constitute
Prosenchyma, and hence such are termed Prosenchymatous cells, or
Prosencliyma cells. While it is impossible to draw an exact line be-
tween parenchymatous and prosenchymatous forms, yet the terms are
valuable, and are in constant use to indicate the general form.
(b) Duchartre* has made an excellent classification of the prin-
* In his Elements de Botanique,” second edition, a large and
valuable work, which the student may profitably consult.THE PLANT-CELL.
19
cipal forms of cells, which is given below in a slightly modified
form:
Cell short
(Par enchyma--
tous).
f Cell globular or
I ovoid, in section
| round or oval .... Spheroidal.
! Cell polyhedral. Polyhedral
Outline smooth, Cell a parallelo-
or without promi--J pipedon, in section
nences. rectangular....... Cuboidal.
Cell tabular,
with an elongated
rectangular sec-
tion.............. Tabular.
f Cell ramose,
(having short and
irregular projec-
tions............. Ramose.
Cell star-shap-
I ed, having long
I projections which
[are more regular.. Stellate.
Cell elongated.
Cell cylindrical, with its ends at
right angles to its axis, or but little
inclined............................. Cylindrical.
Cell prismatic, with its ends at
right angles to its axis, or but little
- inclined............................. Prismatic.
Cell fusiform [cylindrical or pris-
matic], with its ends oblique and
pointed.............................. Fusiform
(Prosenchyma-
tous).
20. —When one or more sides of a cell are not in contact
with other cells, as is the case with those cells which com-
pose the surface of plants, the free sides are generally con-
vex, and they often become more or less prolonged, sometimes
in a curious way. The velvety appearance of the petals of
many plants is due to such prolongations of the free sides of
the surface cells (Pig. 8). Of a somewhat similar nature are
the tubular extensions of the surface cells of young roots—
the root-hairs. And here we may also place the curious star-
shaped cells which project into the intercellular spaces in the
interior of the stem of the water lily (Fig. 9), and those
which compose the pith of certain rushes (Pig. 9J).
21. —In the unicellular plants each cell is an independent20
BOTANY.
•organism ;
reproduces
it absorbs nourishment, assimilates, grows, and
its kind. In the higher plants, although this
independence is not so evident, it still
exists in a considerable degree. Here
each cell is an individual in a commu-
nity ; but it still has a life-history of its
own, a formation (genesis), growth, ma-
turity, and death. It is the unit in the
plant. Upon its changes in size, form,
and structure depend the volume, shape,
Fig. 8.—a small piece of and structural characters of the plant
the epidermis of the petal 1
or a pansy (viola tricolor), and all its parts. It is thus the Morplio-
shovviug prolongations ol . , TT T, , . ±
the free (upper) sides of the logical Unit Ot the plant.
GhartreMas'_ After Du' 22.—As the whole structure of the
plant is an aggregation of cells, so the functions of the
whole, or of any part of a plant are but the sum or result-
Fie. a
Fig. 9.—A cross-section through the petiole of Nuphar adverta ; s, «, 6tar-shaped
cells projecting into the intercellular spaces i, i ; g, a reduced flbro-vascnlar bundle.
Magnified.—After Sachs.
Fig. %. — Stellate cells from the pith of Juncus effusus, magnified.—After Du-
chartre.
ant of the physiological activities of its individual cells.
The cell is thus also the Physiological Unit of the plant.CHAPTER III.
THE CELL-WALL.
23.—In all but the lowest plants the protoplasm of every
cell surrounds itself sooner or later with a covering or wall
of cellulose. The substance of the cell-wall is a secretion
from the protoplasm. Cellulose, as such, does not exist in
the protoplasm ; it is formed on the surface when the wall is
made. On its first appearance the wall is an extremely thin
membrane, hut by subsequent additions it may acquire vary-
ing degrees of thickness. The cell-wall forms a complete
covering for the protoplasm ; there are at first no openings
in it, at least none that are visible; later in the life of the
cell pores are formed iti the wall in some cases, while quite
frequently in dead cell-walls there are large perforations of
various sizes and shapes.
(a) Cellulose is related chemically to starch and sugar. Its composi-
tion is C12 H21> O,o. It is tough and elastic. It is but slightly soluble
in dilute acids and alkalies, and not at all iu water and alcohol. In
water, however, it swells up from imbibing some of the liquid, but it
shrinks again in bulk when dried.
(b) Tests.—1. If cellulose is treated with dilute sulphuric acid, and
shortly afterward with a weak solution of iodine, it is colored blue.
2. Treated with gchultz’s Solution it assumes a blue color.
(c) In the Mvxomycetes, if the large mass of protoplasm composing a
plant is somewhat dried, it separates itself into smaller masses, which
surround themselves with a cell-wall. Upon applying sulphuric acid
and iodine, the characteristic blue color of cellulose appears, showing
that the wall is a true wall of cellulose. If, however, any such dried
mass of protoplasm is subjected to the proper conditions of moisture
and temperature, the cell-wall is dissolved and absorbed into the proto-
plasmic mass. Tests applied now utterly fail to show the presence of
cellulose. These observations prove the truth of the statement that
cellulose is a secretion, and that it is not contained, as cellulose, in the
protoplasm.22
BOTANY.
24.—After the formation of tlie cell-wall it generally
grows, and increases its surface and thickness. Usually the
surface-growth at first preponderates, afterward that in
thickness. Neither the one nor the other is uniform over
all points of the cell-wall, hence each cell during its growth
may also change its form. As the growth of the cell-wall is
directly dependent upon the protoplasm, it is clear that it
can continue only as long as the protoplasm is in contact
with its inner surface. In the
growth of the cell-wall the new
cellulose secreted by the protoplasm
is deposited between the molecules
of the membrane already formed.
When the new molecules are de-
posited between the previously
formed ones only in the plane of
the cell-wall, surface-growth takes
place ; but when the planes of de-
position of the new molecules lie at
right angles to the plane of the
cell-wall, increase in thickness is
the result; when the molecules are
deposited in both planes, the wall
increases both in surface and thick-
be
Fig. 10.—Diagrams to illustrate
the intercalary growth of CEdoso- neSS.
nium. A, internal ring of cellu-
lose secreted at f; B, showing 25.— Surface-growth may
the wav in which, by the liom n- . . .. J „
tai splitting of ihe ring, the ceil is terminal or intercalary. in the ior-
•elongated ; z, the new portion of ,, 1 ,
the wall formed i>y the splitting mer case the growth is greatest at
^,'^,eth?nso-cai”eVcap?lbrmeVby some point on the surface, decreas-
1^erdi88b^re»i^epiwth.- ing in intensity on all sides. The
Modified from Sachs. growing point thus comes to pro-
ject as a point or knob, or it becomes the end of a cylindri-
cal sac. If several points of growth occur in a cell it may
become star-shaped, and by a continuation of the process
repeatedly branched. The typical form of intercalary
growth takes place in definite belts which surround the cell,
as is seen in (Edogonium (Fig. 10). The growth of the
whole of the side wall of a cylindrical ceil, as in Spirogyra,
is also a form of intercalary growth.THE CELL-WALL.
23
26. —Growth in thickness of the wall produces changes
in the cell of even greater importance than growth in sur-
face. While surface-growth has but little to do with the
■determination of the functions of the cell, the thickening of
its wall generally results in a
change in function, or an entire
suspension of all physiological
activities. Cells with extremely
thin walls are most active; only
■such can take part m growth.
■(See Chap. XI.) Nutrition and
assimilation are confined to cells
whose walls have but slight thick-
ness. Cells with moderately thick
walls may be used as storehouses “S
for food ; starch, for example, is x m~ Atter DucharIre-
frequently found in such cells. But as the walls attain great
thickness the protoplasm loses all activity save that neces-
sary to the secretion of cellulose.
27. —The thickening generally produces certain markings
■or sculpturings in the shape of projecting points, ridges,
bands, etc., which on the one band are on
the outside of the wall, while on the
other they are on the inside. In some
pollen grains and spores we have the best
examples of external markings. Here, in
some cases, certain isolated points in the
cell-wall become strongly thickened, giv-
ing -ise io sPines or prickles (Fig. 11).
bus. The almost spherical jn other cases the thickening is in cer-
substance of the cell-wall . °
is fur' ished with ridge- tain bands, which may rise into high
like thickenings united __ °
into a network. Each of walls, as in Fig. 12. External markings
these bears thickeuiDgs, , , . ■, «
wh / y a toe, older wood-cell-* (tracheides);
being formed by the bottom of t\ t", V", bordered piis, increasing in
,, . ,. age; $t, large pits where c lla of the
the pit, and the inner by the medullary rays lie next 10 the wood-
f , ... J cells. X 3S5.-After Sachs.
opening at its top.
The bordered pits of pines, firs, and other Conifer* may be readily
examined by making a longitudinal radial section. They are nut found
in abundance on the tangential surfaces of the cells.
The real structure of the bordered pitsof theConiferee was not under-
stood until quite recently.* Von Mohl, apparently not noticing the
* Schacht, in 1859 (Botanische Zeitung, pp. 238,239), and in a memoir
in 1860 (“ De Maculis in Plantarum Vasis Cellulisque Lignosis”), gave
the first correct explanation of the structure of bordered pits.26
BOTANY.
tliin partition, thought that the lenticular cavity was formed by the-
separation of the walls of the two contiguous cells at that place, and con-
sequently that they were
intercellular. This in-
terpretation is still given
in some hooks.*
31. — While the
bordered pits of the
Conifer* are never
crowded together, in
the cells of some
plants they are so
numerous as to lie
closely side by side
(Fig. 17). In such
ease the first thick-
ening of the'wall pre-
sents itself as a net-
work of ridges en-
closing elliptical thin
places. As the thick-
ening advances £he
ridges increase in
height, but at first
not in breadth ; later
they increase in
breadth at the top and
overarch the thin
areas, much as in the
Fig. 16.—Bordered pits of Firms sylvestris. A, bordered pits of the
transverse section of mature wood ; m, central layer rinnifaYco Tn
of the common wad; /, a mature pit cut through the ^OniieroB. in iniS
middle ; t\ the same, but in a thicker part of the sec- Vmwpvpv flip
tion, the part of the cavity of tne pit seen in perspec- iiuvvevei, tntJ
tive ; t"y a pit cut through below its openings ; B, rvnprnnrr af thp frm nf
transverse section through the cambium ; c, cambium ; 0Pynill&
h, very young wood-cells; ty t, very young bordered fV»p nit ia ari ploncrnf-
pits, seen in section ; C, diagram of sectional and lat- . P1L dn eiOI18dt
eral views of a young bordered pit; D, diagram of ed slit instead of a
sectional and lateral views of a mature bordered pit; .
Ey section of a mature pit, seen in perspective; F. Circle (Pig* 17, -d,
section of a younger pit seen in perspective. A and , ~ ° , .
b x 800.—After Sachs. and G, c). Ihe thin
plate separating opposite bordered pits of this kind breaks-
* See I.e .Muout and Decaisne’s" Traite Generate de Butanique,” 1868
^English edition, 1872] ; Griffith and Heufrey’s “ Micrographic Die-THICKENINGS OF THE WALL.
27
away as in the previous case, and so free communication
between adjacent cells or vessels is established.
Fig. 18.
Fig. 17.—Bordered pits of the thick root of Dahlia varinMlix. A, front view of a
piece of the wall of a vessel, seen from without; B, transverse section of the same
(horizontal, ana at right angles to the paper); C, longitudinal section of A (vertical,
and at right angles to the paper) ; q, septum ; a, the original thin thickening-ridge ;
b, the expanded part of the rh ckeiung masses, formed later and overarching the pit;
the fissure through which the cavity of the pit communicates with the cell cavity ;
at '), and many modifications and irregularities occur—e.g.,
in the figure at v"’" is the form known as the reticulated.
34.—In all the foregoing cases the marking of the wall
has been general; there are some cases, however, where it
is localized. A good example of this is in the formation of
the pits of sieve-cells (Fig. 20). The horizontal walls, and
also areas upon the longitudinal ones, become thickened
reticulately, leaving rather large thin areas, as shown in
Fig. 20, q, q. After a while the thin areas become absorbed,THICKENINGS OF THE WALL.
29
allowing the protoplasm of contiguous cells to become struc-
turally united. The sieve-like appearance of these modified
portions of tire wall give to the cells their name of sieve-cells.
35.—The collen-
chyma cells which
are frequently found
beneath the epider-
mis of the succulent
parts of h i g h e r
plants afford an-
other instance of
localized thicken-
ing. Here only the
angles of the cells
become thickened,
leaving broad por-
tions of the wall un-
modified (Fig. 21).
(а) Examples of tlie
uniform thickening of
the cell-wall may he
obtained for study by
making thin sections of
the hard parts of many
nuts and seeds (Figs. 58
to 61); in many of these
more or less complex
channels may be found.
Bordered pits are best
studied in longitudinal
sections of the young
wood of the pines, firs, Fig. 20.—Young sieve tujjes of Cucurbita pepo The
and tlio crowded drawing made from specimens whirh, hr having lain a
etc., ana me cro aea jong time m absolute alcohol, have allowed the produc-
pits in the stems of tion of extremely clear sections ; q, transverse view of
, , -p, sieve-like septa; si, sieve plate ou side wall; at, thin-
most other mianero-, ner part8 of the longitudinal wall; l, the same seen in
wer-buds in a dark chamber; when
the flowers expand they will be seen to have their natural colors.
§ II. Starch.
67. —Next to chlorophyll, one of the most important pro-
ducts of the plant-cell is starch, an organic compound closely
related to sugar and cellulose, and represented by the em-
pirical formula C1S Hao O10. It occurs in the form of whitish
or semi-transparent, rounded or slightly angular stratified
grains, and is generally found closely packed in the interior
of certain cells.
68. —The form of starch grains varies greatly in different
plants, and considerably even in the same plants ; neverthe-
less, the general appearance of the grains in each plant is so
characteristic that the different kinds of starch may be quite
easily distinguished. In every case the grains have more or
less clearly defined lines, which are concentrically arranged
about a nucleus * (Figs. 44 and 45). In some cases (excep-
* The nucleus is called the hilurn by some authors, a term which54
BOTANY.
tionally in some plants and uniformly in others) two or more
nuclei occur in each grain; by growth such grains become
compound and may finally separate into as many parts as
there are nuclei.
69.—The molecular structure of the starch grain has been
determined to be similar to that of plant-cellulose. It is re-
garded as composed of molecules, each of which is surrounded
by a watery layer of greater or less thickness. Growth takes
place by the intercalation of new molecules between the pre-
viously formed ones—in other words, by intussusception,
exactly as in the case of
the cell-wall. During the
formation of the grain, in
certain portions of it the
watery layers surrounding
the molecules become
thicker. When seen by
transmitted light such
more watery parts appear
darker than those which
are less watery, and an ex-
amination shows that they
surround the nucleus on
all sides in a concentric
manner. In this way the
starch grain conies to be
made up of alternating
layers of more and less
watery substance. Every watery layer is thus between two
layers which contain less water, and so every less watery one
lies between two more watery ones. As an increase in the
amount of water in any portion of the starch grain de-
creases the density of that portion, the layers just described
may be distinguished as of greater density when having
less water and of less density when having more water.
Tig. 44.- Cell* from the cotyledon of the pea,
ric acid, the thickened angles become greatly swollen.
Fig. 55.—Longitudinal radial section of stem of Echinocijstislobala. ep, epidermis:
eo, collencliyma ; pa, parenchyma; f, a single wood fibre, marked with “ crossed1
{i.e., twisted) pits ; sp, intercellular spaces. X 500. From a drawing by J. C. Arthur.
(c) Upon treatment with Schultz’s Solution the thickened angles are
colored light blue.
{d) Upon slight warming in a solution of potash, and then treating
with a solution of iodine in potassium iodide, the thickened angles be-
come colored dark blue.
101.—Sclerenchyma. In many plants the hard parts are
composed of cells whose walls are thickened, often to a very72
BOTANY.
considerable extent. The cells are usually short, but in some
cases they are greatly elongated ; they are sometimes regular
in outline, but more frequently they are extremely irregular.
They do not contain chlorophyll, but in some cases at least
(e.g., in the scleienchyma-cells in the pith of apple-twigs)
they contain starch.
Sclerenchyma occurs in Bryophytes, Pteridophytes, and
Phanerogams.
(a) Good specimens of sclerenchyma may be obtained for study by
making longitudinal sections of the rhizome of Pteris aquilina, in
Fig. 56.—Twoprlereir hymn cells from the hypodermft of the l'hizome of PterU
aquilina, isolated by Schu.ze’o maceration. A, a very thick-walled cell, with bnmch-
iugpits; B, a cell with walls less thickened—the wall of the opposite side of the
cell is seen to be filled with numerous pits. X 500.—After Sachs.
Fig. 57.—Margin of leaf of Pinus pinaster, transverse section, c, cnticularized layer
of outer wall of epidermis ; i, inner non-cuticularized layer; c\ thickened outer
wall of marginal cell; g, i', hypcderma of elongated s. ierenchyma ; p, chlorophyll-
bearing parenchyma ; pr, contracted protoplasmic contents, x 600.—After Sachs,
■which it occurs as a thick liypodermal mass ; by boiling in potassium
chlorate and nitric acid (Schulze's maceration) the cells may be com-
pletely isolated (Fig. 56, A and B).
(6) The cells of the medullary rays of woody Dicotyledons—c.g.,
Acer, Pirus, Ostrya, Liriodendron, etc.—are generally thick-walled
when old, and in this state must be classed as sclerenchyma.
(c) The hypoderma of the leaves of pines consists of elongated scle-
renchyma-cells, which at first sight might easily be mistaken for bast
fibres (Fig. 57, g, i). The hypoderma of many other plants appears to
be of a similar nature.THE PRINCIPAL TISSUES.
73
(I) The hard tissues of nuts and of stone fruits furnish excellent ex-
amples of short and very thick-walled sclerenchyma-cells. In the
hickory nut (Cary a alba) the cells (Figs. 58 and 59) are not more than
Fig. 58. Fig. 59.
Fig. 58. — Sclerenchyma-cells of the shell (endocarp) of the hickory-nut {Carya
alba), taken parallel to the surface of the nut. X 400.
Fig. 59.—Sclerenchyma-cells of the shell (endocarp) of the hickory-nut {Carya
alba), taken at right-angles to the surface of tne nut. X 400.
two or three times as long as broad, and the thickening is so great as
almost entirely to obliterate their cavities; the thickened walls are
Fig. 60.—Sclerenchyma cells of the seed-coat of Echlnocystis lobata, from a section
at right angles to the surface of the seed ; a, a cell cut directly through its centre,
showing the whole of the cavity—the three dark spots are probably oil ; b, a cell
cut through at one side of the middle ; c, a cell whose cavity was not cut into in
making the section. X 250. From a drawing by J. C. Arthur.
Fig. 61.—Sclerenchyma-cells of the seed-coat of Echinocystis lobata, from a section
parallel to the surface of the seed. X 250. From a drawing by J. C. Arthur.
pierced by many deep pits. The cells are arranged with their longer
axes perpendicular to. the surface of the nut, and are very closely
packed together.74
BOTANY.
(«) The seed-coat of Echinocystis lobata is composed almost entirely
of sclerenchyma (Fig. t>0). The cell-walls are greatly thickened, and
the cells are very closely packed together, so much so that all are
sharply prismatic (Fig. 61).
102.—Fibrous Tissue. This is composed of elongated,
thick-walled, and generally fusiform elements, the fibres
(Figs. 62 and 63), whose walls are usually marked with
simple or sometimes bordered pits. These elements in cross-
section are rarely square or round, hut most generally three
to many-sided. They are found in, or in connection with,
the fibro-vascular bundles of Pteridopbytes and Phanero-
gams,and give strength and hardness to their stems and leaves.
Fig. 62. Fig. 63.
Fig. 62.—Wood fibres of Acer dasycarpvm. isolated by Schulze’s maceration. ay
four fibres, X 95 ; b. a portion of a fibre, X 280, showing the diagonally placed elon-
gated pits ; c, the ends of eleven united film s, X 95.
Fig. 63.—Bast fibres of Acer dasycmpvm, it-olated by Schnlze’s maceration, a, a
fibre, x 95 ; 6, a portion of a fibre, X 2£0, showing the much-thickened wall.
Two varieties of fibrous tissue may be distinguished, viz.,
(1) Bast (Fig. 63), and (2) Wood (Fig. 62). The fibres of
the former are usually thicker walled, more flexible, and of
greater length than those of the latter. In both forms the
fibres are sometimes observed to be partitioned.*
* These partitions have generally been considered as formed subse-
quently to the fibres; but it may well be questioned whether, in someTHE PRINCIPAL TISSUES.
75
To examine fibrous tissue it is only necessary to make thin longitudi-
nal slices < f the stems of woody plants—e.g., Acer, Pirns, etc.—and to
heat for a minute or less in nitric acid and potassium chlorate. The
Pig. 64. Pig. 65.
Fie. 64.—Laticiferous tubes from Euphorbia. A. moderately magnified; 71. more
highly magnified, and showing the hone-shaped or dumb-bell-shaped starch grains.—
After S ichs.
Fig. 65.—Laticiferous vessels of Scorzonera hispardea. A, a transverse section of
the phloem of the root; B. the same more highly magnified.—Alter Sachs.
fibres may now be separated under a dissecting microscope, or tlia
cases at least, the fibres are not cell-derivatives, and the partitions the
persistent walls of the original component cells.76
BOTANY.
specimens may "be transferred to a glass slide and dissected by tapping
gently upon the centre of the cover-glass.
103.—Laticiferous Tissue. In many orders of Phanero-
gams tissues are found whose component elements contain a
milky or colored fluid—the latex. To these, although vary-
ing greatly in structure and position, the general name of
Laticiferous tissues has been given. For the sake of simpli-
city two general forms may
be distinguished: (1) that
composed of simple or branch-
ing elements (Fig. 64), which
are scattered through the
other tissues. As found in
Euphorbiacece, where they oc-
cur in parenchyma, they are
somewhat simply branched,
and have very thick walls
(Fig. 64, B); in other orders
they are thin walled and are
sometimes inclined to anasto-
mose. From their position it
is quite certain that the ele-
ments of this form of laticif-
erous tissue frequently replace
bast fibres. In such cases
they are said to be metamor-
phosed bast fibres ;* in other
cases, however, they appear
not to be of this nature, but
to arise from the parenchyma
by the absorption of the horizontal partition-walls: f
* There is an objection to the word metamorphosed in this connec-
tion, as it does not exactly express the relation between the laticiferous
elements and the bast fibres. It must not be understood that the
former are made by a transformation of the formed bast fibres ; the
relation is rather that they develop from what under other circum-
stances would have developed into bast fibres. We may express the
relation by saying that laticiferous elements and bast fibres are closely
related sister elements.
f " According to Hanstein, it is probable that in some Aroideee vessels
Fig. 06—Laticiferous cells of the onion,
from a longitudinal seciion of a scale of
the bulb, e, epidermi& with cuticle c ; p,
parenchyma ; sg, coagulated contents of
laticiferous cells, contracted so as to show
the porous walls; q, q, transverse wall.—
-After Sachs.THE PRINCIPAL TISSUES.
77
(2.) The other form is that composed of reticulately anas-
tomosing vessels. Here the tissue is the result of the fusion
of great numbers of short cells. The walls are thin and
often irregular in outline. In Ciclioriacece this form of
laticiferous tissue is very perfectly developed as a consti-
tuent part of the phloem portion of the fibro-vascular
bundles (Fig. 65, A and B).
(a) Laticiferous tissue has not yet been shown to contain either pro-
toplasm or nucleus.* * The latex is an emulsion of several substances,
some of which, as caoutchouc (India-rubber), gutta-percha, and opium,
are of great economic importance. In some cases, as in Eup/iorbia,
grains of starch are contained in the latex (Fig. 64, B).
(b) The chemical composition of latex is shown by the following
analyses, as given by De Bary: f
Latex of Hevea Ouianensis, as determined by Faraday :
Water with an organic acid................70.3 per cent.
Caoutchouc ..............................31.7 “ “
Albumen................................... 1.9 “ “
Bitter nitrogenous matter, with wax. ......7.1 “ “
Residue soluble in H., O, butinsoluble in alcohol. 2.9 “
99 9
Latex of Galactodendron utile, as determined by Heintz :
Water......................................57.3 per cent.
Albumen.................................... 0.4 “ “
Wax (C'35 He« Os)...........................5.8 “ “
Resin (C3s HsB 02).........................31.4 “ “
Gum and sugar.............................. 4.7 “ “
Ash........................................ 0.4 “ “
100.
Latex of Euphorbia cyparissias, determined by Weiss and Wiesner:
Water...................................... 72.1 per cent.
Resin .....................................15.7 “ “
Gum......................................... 36 “ “
Sugar and extractive substances.............4.1 “ “
Albumen.................................... 0.1 “ “
Ash........................................ 0.9 “ “
96.5
of the xylem assume the form and function of laticiferous vessels.’’
Sachs’ “ Text-Book of Botany,” English edition, p. 110.
* The latex of some Cichoriacese coagulates much like protoplasm;
possibly further investigation will show it to be present,
f “Anatomie der Vegetationsorgane,” etc., p. 194.78
BOTANY.
(c) Examples of the simpler forms of laticiferous tissue may be ob-
tained for study from Euphorbiaceon, TJrticaceas, Asclepiadacece, Apocy-
nacece. Forms less simple occur in Aracecc, and in the maple ; in the
last-mentioned they appear to replace the sieve-vessels. Related to
these again are the peculiar milk-vessels of the onion (Fig. 66), which
consist of elongated cells separated by thin or perforated septa.
Fig. 67. — Longitudinal
section through the sieve
tissue of Cucurbita Pepo.
q, q, section of transverse
sieve - plates ; si, lateral
sieve-plate ; x, thin placea
in wall ; l, the same seen in
section ; ps, pro1 oplasmic
contents contracted by the
alcohol in which the speci-
mens were soaked ; sp, pro-
toplasm lifted off from the
sieve-plate by contraction;
si, protoplasm still in con-
tact with the sieve-plate ; zf
parenchyma between sieve
tubes. X 550. — After
Sachs.
(d) The more complex or reticulated forms of laticiferous tissue
occur in Cichoriacm, Campanula cm, Lobeliacecc, Convolvulacece, Pa-
paverace<2.
{e) By heating thin sections of any of the foregoing plants in a di-
lute solution of potash the laticiferous tissues may be readily isolated
for study.
O') The walls of the laticiferous elements are always rich in water,
and are composed of cellulose, as may be shown by the blue coloration
which follows treatment with Schultz’s Solution.THE PRINCIPAL TISSUES.
79-
104. —Sieve Tissue. As found in the Angiosperms this
tissue is made up of sieve ducts and the so-called latticed
cells. The former (the sieve ducts) consist of soft, not
lignified, colorless
tubes of rather wide
diameter, having at
long intervals horizon-
tal or obliquely placed
perforated septa. The
lateral walls are also
perforated in restrict-
ed areas, called sieve
discs, and through
these perforations and
those in the horizontal
walls the protoplasmic
contents of the con-
tiguous cells freely
irnite (Figs. 67 and
68). In many plants
the sieve discs close up
in winter by a thick-
ening of their sub-
stance (Fig. 69).
The tissue composed
of these ducts is gene-
rally loose, and more
or less intermingled
with parenchyma; in
some cases even single
ducts run longitudin-
ally through the sub-
stance of other tissues.
In the form described
above it is found only
as one of the compo-
nents of the phloem
portion of the fibro-vascular bundle.
105. — The so-called latticed cells
Fig. 68.—Longitudinal tangential section of the
young bark of the grape (Vitis vinifera), taken in
the beginning of July, s, s, sieve tubes, with sec-
tions of the transverse plates—in the left-hand sieve
tube, at the top of tne figure a lateral plate is
shown; m, m, medullary rays, with crystals in
some of the cells—between the sieve tubes them-
selves, and between them and the medullary rays,
aie masses of parenchyma (phloem parenchyma).
X 145.—After l)e Bary.
arc probably to be80
BOTANY.
regarded as undeveloped sieve ducts, and hence the tissue
they form may be included under sieve tissue. Latticed
cells are thin-walled and elongated ; they differ from true sieve
ducts principally in being of less diameter, and in having
the markings but not the perforations
of sieve discs. Both of these differences
are such as might be looked for in un-
developed sieve tissue.
106.—In the corres-
ponding parts of the vas-
cular bundles of Gymno-
sperms and Pterido-
phytes a sieve tissue is
found which differs
somewhat from that in
Angiosperms. In Gym-
nosperms the sieve discs,
which are of irregular
outline, occur abundant-
ly upon the oblique ends
and radial faces of the
Fig. 69. — Longitudinal broad tubes (Fig. 70).
In Pteridophytes the
Srft^ieVetapiate i" tubes have varying
closed up by the thickening f avmo • i-n ~F]nvi
of its substance. X 400.— > 111 ■nqutbtl-Uin
After DeBary. and Oph ioglossum they
are prismatic, with numerous horizontal but
not vertical sieve discs ; in Pteris and many
other ferns they have pointed extremities,
and are greatly elongated, bearing the sieve
discs upon their sides (Fig. 71). In the viewl'f the'end^of a
larger Lycopodiacm the sieve tubes are pris-
matic and of great length; in the smaller oidmstem^aihe0sieve
species there are tissue elements destitute of plates are placed iat-
* . . erally and are com-
sieve discs, but which arc otherwise, includ- P°se|!of many little
y * punctured areas
ing position in the stem, exactly like the grouped togetherir-
0 -1 * regularly x 375_
sieve ducts of the larger species. After De Bary.
(a) Good specimens of sieve tissue may be obtained for study by
making longitudinal sections of the steins of Cucurbita, Cucumis,THE PRINCIPAL TISSUES.
81
Echinocystis, Ecbalium, Vitis, Bignonia, and Calamus Rotang; also
Abies pectinata, Larix, Juniperus, Sequoia, and Ginkgo; also Pteris,
Osmunda, Equisetum, and Lycopodium.
(b) By making repeated horizontal sections the horizontal sieve discs
may be found and studied.
(c) Alcoholic specimens afford much more satisfactory results than
fresh ones ; especially is this the case with the more succulent plants.
Pig. 71.—Sieve tissue of Pteris aquilina. A, end of a sieve tube isolated by macer-
ation : B. portions of two tubes seen iu vertical section; in s' the sieve plates are
seen in front view ; at c. c. they are seen in section; the tube s2 has sieve plates
on its right and left walls, but none on its further wall, which is in contact with pa-
renchyma-cells ; two of the latter are seen to have nuclei in them, x 375.—Alter De
Bary.
107.—Tracheary Tissue. Under this head are to be
grouped those vessels which, while differing- considerably in
the details, agree in having thickened walls, which are perfo-
rated at the places where similar vessels touch each other. The82
BOTANY.
thickening, and as a consequence the perforations, are of
various kinds, but generally there is a tendency in the former
to the production of spiral bands ; this is more or less evident
■even when the bands form a network. The transverse parti-
tions, which may be horizontal or oblique, are in some cases
perforated with small openings, in others they are almost or
entirely absorbed. The diameter of the vessels is usually
considerably greater than that of the surrounding cells and
elements of other tissues, and this alone in many cases may
serve to distinguish them. When young they of course con-
tain protoplasm, but as they become older this disappears,
and they then contain air.
108.—Tracheary tissue is found only in Pteridophytes
Pig. 72.—Longitudinal section of a portion of the stem of Impatiens Balsamina. v, a
ringed vessel ; v'. a vessel with rings and short spirals ; v", a vessel with two spirals;
D"' and v'"', vessels with branching spirals; n""\ a vessel with irregular thicken-
ings, forming the reticulated vessel.—After Duchartre.
and Phanerogams. The principal varieties of vessels found
in tracheary tissues are the following :
(1.) Spiral Vessels, which are usually long, with fusiform
extremities ; their walls are thickened in a spiral manner
with one or more simple or branched bands or fibres (Fig.
72, v”, v'", v""). This form may be regarded as the typical
form of the vessels of tracheary tissue. In most cases the
direction of the spiral is from right to left.* It is frequent-
ly in one direction in the earlier formed spirals and the op-
* Right to left, in speaking of these spirals, as also in describing the
twining of certain climbing plants, is passing up and around in the di-
rection of the hands of a watch. Left to right is of course up and
around opposite to the hands of a watch.THE PRINCIPAL TISSUES.
83
posite in those formed later; while in interrupted spirals
both directions occur in the same vessel. Ringed and reticu-
lated vessels are opposite modifications of the spiral form;
Fig. 73.—Scalariform vessels of the rhizoma of Pteris aquilina. A, longitudinal sec-
tion of an end (about one third of the whole) of a short vessel: /, the fusiform ex-
tremity, with long pits placed transversely: B, a small portion of A, taken from#,
and much more highly magnified ; C, a longitudinal section of a portion of the side
Avail between two vessels ; D, a similar section through the inclined end wall (A,f);
in rhe upper part of J), at/the wall between the thickening ridges is broken through.
A, X 142 ; the others x 375.—After De Bary.
the first are due to an under-development of the thickening
forces in the young vessels, resulting in the production here
and there of isolated rings (Fig. 72, v) ; reticulated vessels
are due, on the contrary, to an over-development, which84
BOTANY.
gives rise to a complex branching and anastomosing of the
spirals (Fig. 72, v""').
(2.) Scalariform vessels. These are prismatic vessels whose
walls are thickened in such a way as to form transverse
ridges, as described in paragraph 32, page 28. They are wide
in transverse diameter and their extremities are fusiform or
truncate (Fig. 73).
(3.) Pitted Vessels. The walls of
these vessels are thickened in such a
way as to give rise to pits and dots,
as described in paragraph 31, page
26. The vessels are usually of wide
diameter; in some forms they are
crossed at frequent intervals by per-
IW/
Fig. 74.
Fig. 75.
Fig. 74.—Pitted vessels of Aristolochia sipho, from a longitudinal section of the
stem ; the vessel on lhe l ight is seen in section, that on the left from without ; a,a,
rings, which are remnants of the original transverse partitions ; 6, b, sections of the
walls; between the vessels are parenchyma-cells, highly magnified.—After Duchartre.
Fig. 75.—Tracheldes of Cytv-us laburnum, from a longitudinal tangential section
of the stem ; m,»i, a cross-section of a medullary ray ; in lhreeof the cells the pitted
partitions are seen ; the medullary ray is surrounded by tracheldes, which are spi-
rally marked and sparingly pitted ; at o, two tracheldes have fused by the breaking
of the wall ; s, 8, slightly modified cambium-cells, x 875.—After De Bary.
forated horizontal or inclined septa (Fig. 74); in other
forms they have fusiform extremities.
(4.) Tracheldes. These consist for the most part of single
closed cells, or of elements which closely resemble cells;THE PRINCIPAL TISSUES.
35
•otherwise they possess the characters of vessels. In one form,
•as in the so-called wood-cells of Gymnosperms (see paragraph
30, page 25) they resemble on the one hand the pitted ves-
sels, and on the other the fibres of the wood of Angio-
sperms. Every gradation between these tracheides and the
other forms of tracheary tissue occur. In another form, as in
Cytisus and Celtis, the tracheides are shorter than in the
preceding, quite regular in their form, and with tapering
extremities (Fig. 75). Their walls are but slightly thickened,
• and are marked with spirals and pits. When the wall be-
tween two contiguous cells breaks through or becomes ab-
sorbed the close relation of such tracheides to spiral vessels
is readily seen.
Tracheides may be regarded as composing a less different
tiated form of tissue, related on the one hand to true tra-
©heary tissue and on the other to fibrous tissue.
(os) Specimens of spiral vessels with the spirals passing from right
to left may be obtained by making longitudinal sections of the stems
of Malm rotundifolia, Impatiens Balsamina. and many other plants.
If the thin slices are macerated in nitric acid and potassium chlorate
the structure may be studied to.still better advantage. The spirals in
the vessels of Pinus sylvestris pass from left to right; they may be
examined in longitudinal sections of the leaves or young twigs. The
stems of Vitis ninifera, Berberis vulgaris, Bignonia capreolata, and Ar-
temisia abrotanum furnish examples of vessels, the first formed of
which have their spirals running from right to left and the later ones
from left to right. Interrupted spirals showing the two directions may
be found in stems of Cucurbita.
(b) Examples of scalariform vessels may be obtained with the greatest
•ease from the rhizomes of ferns—e.g., of Pteris ; it may also be obtained
from many Dicotyledons—e.g., the stems of Vitis.
(c) Fine specimens of pitted vessels may be studied in longitudinal
sections of many kinds of wood—e.g., Pirus, Quercus, and Liriodendron ;
among herbs, Impatiens and Ricinus furnish good examples.
(d) In order to study the tracheides of the Gymnosperms thin slices
of the wood—of Pinus, for example—should be heated for some time in
nitric acid and potassium chlorate. By this means, after transferring
to a glass slide and covering in the usual way, the tracheides may be
easily isolated by gently tapping upon the cover-glass.
(e) Tracheides of the second form are easily studied in horizontal and
longitudinal sections of the wood of Celtis.85
BOTANY.
§ III. The Primary Meristem.*
109. —Under this name are grouped the unformed and
growing tissues found at the ends of young stems, leaves, and
roots. In these parts the tissues described above (paragraphs
99 to 108) have not yet formed ; they are, on the contrary,
composed entirely of a mass of thin-walled, growing, and
dividing cells containing an abundance of non-granular pro-
toplasm. In the lower plants the meristem-cells do not
change much in their configuration or general structure as
they develop into the ordinary plant-cells; but the higher
the type of plant, the greater are the changes which take
place during the development of meristem into permanent
tissues.
110. —In most of the plants outside of the Phanerogams
the primary meristem is the result of the continually repeated
division of a single mother-cell situated at the apex of the
growing organ. In the simplest forms this apical cell is the
terminal one of a row of cells, as in many algae and fungi.
The apical cell, in such cases, keeps on growing in length,
and at the same time horizontal partitions are forming in its
proximal portion. In this way long lines of cells may
originate.
In the more complicated cases the segments cut off from
the apical cell grow and subdivide in different planes, so as
to give rise to masses of cells. The partitions which succes-
sively divide the apical cell are sometimes perpendicular to
its axis, but more frequently they are oblique to it. In most
mosses, for example (Fig- 76), the apical cell is a triangular,
convex-based pyramid, whose apex is its proximal portion.
The successive segments are cut off from the apical cell by
alternate partitions parallel to its sides, thus giving rise to
three longitudinal rows of cells. Most Pteridophytes have
an apical cell not much different from that of the ma-
jority of mosses. In Equisetum, for example, it is an in-
verted triangular pyramid, having a convex base (Fig. 77 ;
* From tbe Greek ficpo5, part, and Te/iviev, to cut off. This tissue is
sometimes called Proto-meristem.PRIMARY MERISTEM.
8?
A, side view, B, a section). The segments (daughter-cells)
are cut off by alternating partitions parallel to the plane
sides of the pyramid, as in the mosses. In some of the
Bryophytes and Pteridophytes the apical cell is wedge-shaped
—i.e., with only two surfaces—and in such cases two instead
of three rows of meristem-cells are formed.
111.—In the Phanerogams the Primary Meristem is de-
veloped from a group of cells, instead of from a single one ;
they therefore have no apical cell. This group of cells
Fig. 76.—Longitudinal section of apex of stem of a moss (Fontinalis antipyretica).
vt apical cell, forming segments (3 rows), each segment divided into an outer cell,
a, and an inner one—the former develops cortex of the stem and a leaf, the latter
the inner tissue of the stem; z, apical cell 'of lateral leaf-forming shoot, arising
below a leaf ; c, first cell of leaf ; b, cells forming cortex.—After Leitgeb.
occupies approximately the same position in the organs of
Phanerogams as the apical cell does in the Bryophytes and
Pteridophytes ; it is composed of cells which have the power
of indefinite division and subdivision.
112.—The apical cell, and its actively growing daughter-
cells in its immediate vicinity, or in the case of the Phanero-
gams the apical group of cells, with their daughter-cells,
constitute the Growing Point or Vegetative Point (Punctum
vegetationis) of the organ. When this active portion is
conical in shape it is the Vegetative Cone of some authors., 88
BOTANY.
(a) Primary Meristem tissue may be readily obtained for study by
making thin longitudinal sections of the tips of growing shoots of
JSquisetum,, Phaseolus, Hippuris, and the roots of Pteris, Zea, Impa-
tiens, etc., or by carefully dissecting out the youngest rudiments of the
leaves of many Monocotyledons.
The value of the specimen will often be increased by staining it
with carmine.
(b) The apical cell, which may be seen in the best of the above-men.
Fig 77.—The growing point of the stem of Equiaetwm seirpoides. A, seen from
without., showing the apical cell at the top ; the numerals 1, 3, 4, etc., indicate the
order of the formation of the partitions of the apical cell; that marked 1 is the last
formed, 3 the third from the last, etc. ; between 4 and 7 on the right, and 6 and 9 on
the left, are the partitions which form after the primary ones; B, a vertical section of A.
tioned sections of Equisetum and Pteris, should also be studied by
making extremely thin cross-sections of the apical portion of the
Vegetative Cone ; the triangular shape of the apical cell can thus be
made out.
The simple side view of the isolated Vegetative Cone is also instruc-
tive wlien so prepared that it can be rotated under the microscope.CHAPTER VII.
TISSUE SYSTEMS.
§ I.—The Differentiation of Tissues into Systems.
113. —It rarely happens that the tissues which compose
the body of a plant are uniform. In the great majority of
cases the cells of the Primary Meristem become differently
modified, so as to give rise to several kinds of tissues. The
outer cells of the plant become more or less modified into a
boundary tissue, and the degree of modification has relation
to its environment. Certain inner cells, or lines of cells, be-
come modified into sclerenchyma, or some other supporting
tissue (collenchyma, or fibrous tissue), and here again there
is a manifest relation to the environment of the plant. Cer-
tain other inner cells, or rows of cells, become modified into
tubes affording a ready means for conduction, and appear to
have a relation to the physical dissociation of the organs of
the higher plants, in which only they occur. Thus, in phy-
siological terms, there may be a boundary tissue, a support-
ing tissue, and a conducting tissue, lying in the mass of less
differentiated ground tissue.
114. —In different groups of plants the elementary tissues
described in previous paragraphs (99 to 108) are aggregated
in different ways, and are variously modified to form these
bounding, supporting, and conducting parts of the plant.
Several tissues, or varieties of tissue, are regularly united or
aggregated in particular ways in each plant, constituting
what may he called Groups or Systems of Tissues. A Tis-
sue System may then be described as an aggregation of ele-
mentary tissues, forming a definite portion of the internal
structure of the plant. Prom what has already been said, it90
BOTANY.
is clear that systems of tissue do not exist in the lowest
plants, and that they reach their fullest development only
in the highest orders. It is evident also that these systems
have no existence in the youngest parts of plants, but that
they result from a subsequent development.
115.—Many systems of tissue might be enumerated and
described ; hut here again, as with the elementary tissues,
while there are many variations, there are also many grada-
tions, having on the one hand a tendency to give us a long
list of special forms, and on the other to reduce them to one,
or at most to two or three. The three systems proposed
by Sachs are instructive, and will be followed here ; they
are : (1) the Fundamental System, which includes the mass ,
of unmodified or slightly modified tissues found in greater or
loss abundance in all plants (except the lowest); (2) the
Epidermal System, composed mainly of the boundary cells
and their appendages (hairs, scales, stomata, etc.) ; (3) the
Fibro-vascular System, comprising those varying aggrega-
tions of tissues which make up the string-like masses found
in the organs of the higher plants.
§ II.—The Epidermal System of Tissues.
116—This is the simplest tissue system, as it is the ear-
liest to make its appearance, in passing from the lower forms
to the higher. It is also (in general) the first to appear in
the individual development of the plant. It is sometimes
scarcely to be separated from the underlying mass, as in
most higher Thallophytes and Bryophytes ; and here it is
composed of but one tissue—parenchyma—or of two or more
slight variations of it. In Pteridophytes and Phanerogams,
while it may be very simple in some (aquatic) plants, it fre-
quently attains some degree of complexity, and is sharply
separated from the underlying ground tissues.
117.—In the simpler epidermal structures of the Thallo-
phytes the cells are generally darker colored, smaller, and
more closely approximated than they are in the subjacent
mass ; in some higher fungi a boundary tissue may be easily
separated as a thickish sheet, but probably in such case aTHE EPIDERMAL SYSTEM.
01
portion of the underlying mass is also removed. In many
of the Thallophytes there is absolutely no differentiation of
an epidermal portion.
118. —In the Bryophytes there is in general a poor epider-
mal development; it is composed for the most part of one
or more weakly defined layers of smaller cells, which, how-
ever, pass by insensible gradations into the inner tissue
mass. Here, however, the first true epidermal hairs make
their appearance.
119. —In one group of the Liverworts—the Marchantiacece
Fig. 78.—Longitudinal section of erect portion of thallus of Marchanlia polymor-
pha. o, epidermis ; S, walls between air-spaces, the latter filled with ro ws of chloro-
phyll-bearing cells, chi; sp, a stoma; g, a large parenchyma-cell, x 550.—After Sachs.
—there is an epidermal system of a high degree of perfection,
and composed of epidermis proper and stomata (Fig. 78).
The epidermis consists of a single layer of somewhat tabu-
lar cells arching over the air-cavities which occupy the upper
surface of the plants ; it is perforated here and there by sto-
mata or breathing pores, composed of four to eight circular
rows of cells placed one above the other {sp in the figure).
These chimney-like structures originate by the division of a
single cell into four or six radiating daughter-cells ; in the
centre of this group an intercellular pore is formed by the
lateral growth of the cells (Fig. 79) ; and by a subsequent92
BOTANY.
horizontal division the several superimposed circular rows'
of cells are formed.
120. —In true mosses the sporangia possess an epidermal
system which is composed of a layer of strongly cuticular-
ized cells—the epidermis—sometimes provided with stomata.
Other portions of the plant, aside from the sporangia, are-
destitute of a true epidermis or of stomata.
121. —The epidermal systems of Pteridophytes and Phaner-
ogams are so much alike that they may be described together,
although it must be remembered that in the latter group-
they are, in general, somewhat more perfect than in the for-
mer. In these groups the epidermal
structures consist usually of three por-
tions : (1) a layer of more or lesa
modified parenchyma—the epidermis
proper—bearing two other kinds of
structures which develop from it, viz.,
(2) trichomes, and (3) stomata.
122.—Epidermis. The differentia-
tion of parenchyma in the formation
of epidermis, when carried to its ut-
most extent, involves three different
modifications of the cells, viz., (1)
-change of form, (2) thickening of the
walls, (3) disappearance of the proto-
plasmic contents. These three modi-
fications may occur in varying de-
grees of intensity ; they may all be slight, as in many aquatic
plants and in the young roots of ordinary plants ; or the cells
may change their form, while there may be little thickening
of their walls, as in other aquatic plants, and some land plants-
which live in damp and shady places ; or on the other hand,
the change of form of the cells may be but little, while
their walls may have greatly thickened, resulting in a disap-
pearance of their protoplasm, as may be seen in parts of
some land plants which grow slowly and uniformly. When
the differentiation of epidermis is considerable, it can usu-
ally be readily removed as a thin transparent sheet of color-
less cells.
Fig. 79.—Top view of two
Btomata of Marchantiapoly-
morpha. B. young stoma;
si, guard cells ; C, older sto-
ma, in which the pore or
opening, po, is much larger;
81, guard-cells —After Sachs.THE EPIDERMAL SYSTEM.
93
123. —The change in the form of the epidermal cells is
due to the mode of growth of the organ of which they form
a part; the lateral and longitudinal growth of an organ
causes a corresponding extension and consequent flattening
of the cells ; if the growth has been mainly in one direction,
as in the leaves of many Monocotyledons, and the young
shoots of many Dicotyledons, or if the growth in two direc-
tions has been regular and uniform, as in the leaves of some
Dicotyledons, the cells are quite regular in outline ; where,
however, the growth is not uniform the cells become irregu-
lar, often extremely so (Fig. 89, page 100).
124. —The thickening of the walls is greatest in those
plants and parts of plants which are most exposed to the dry-
ing effects of the atmosphei e. It consists of a thickening of
the outer walls, and frequently of the lateral ones also. The
outer portion of the thickened walls is cuticularized, and
this, by a subsequent stratification and lamellation, is separ-
ated as a continuous pellicle, the so-called cuticle.
125. —The cuticle extends uninterruptedly over the cells,
and may be readily distinguished from the other portions
of the outer epidermal walls. It is insoluble in concen-
trated sulphuric acid, but may be dissolved in boiling
caustic potash. Treated with iodine it turns a yellow or
yellowish brown color. A waxy or resinous matter is fre-
quently developed upon the surface of the cuticle, constitut-
ing what is called the bloom of some leaves and fruits. De-
Bary* distinguishes four kinds of waxy coating, as follows :
(1) continuous layers or incrustations of wax—e.g., on the
leaves and stems of purslane, the leaves of Fuchsia, yew, the
stems of the wax palms (Ceroxylon), etc. ; (2) coatings com-
posed of multitudes of minute rods placed vertically side by
side upon the cuticle—e.g., on the stems of sugar cane,
Coix lachryma, and some other grasses; (3) coatings made
up of minute rounded grains in a single layer—e.g., on the
leaves of the cabbage, onion, tulip, clove-pink (Diamthus■
* “ Vergleichende Anatomie der Vegetationsorgane der Plianeroga-
men und Fame,” 1877, p. 87, where figures of several of these kinds
are given.94
BOTANY.
Caryophyllus), etc.; (4) coatings of minute needles or grains
irregularly covering the surface with several layers—e.g., on
the leaves of Eucalyptus globulus, rye, etc.
126. —The protoplasm of the epidermal cells generally
disappears in those cases where there is much thickening of
the walls ; it is always present in young plants and parts of
plants ; it is also frequently present in older portions, which
are not so much exposed to the drying action of the atmos-
phere, as in roots, and the leaves and shoots of aquatic plants,
and of those growing in humid places. In few cases, how-
ever, are granular protoplasmic bodies (e.g., chlorophyll) pres-
ent in epidermal cells. *
127. —While the epidermis always consists at first of but
one layer of cells, it may become split into two or more lay-
ers by subsequent divisions parallel to its surface. These
layers may resemble the outer one and have their walls
thickened, as in the leaves of the Oleander, or they may con-
sist of thin-walled cells with watery contents (constituting
the so-called Aqueous Tissue), as in the leaves of Ficus and
Begonia.
(a) Epidermis may be studied with comparatively little difficulty.
In many cases it may be stripped off in tliin sheets and mounted in
the usual way ; such preparations, with thin cross-sections (which are
readily made by placing a piece of leaf between pieces of elder pith),
are sufficient, in most cases, to give a good knowledge of the structure.
The leaves of many Liliacem (hyacinths, lilies, etc.) and Graminece may
be examined for regular cells, and those of many Dicotyledons, as bal-
sams, primroses, and fuchsias, for irregular ones.
(b) Thickened epidermal walls may be found in leaves of a hard tex-
ture, as those of the pines, holly, oleander, mistletoe, many Composite,
and in the stems of many Cactaceoe. The stratification of the thickened
walls may be brought out in the cross-sections by heating in a solution
of potash.
(c) A series of specimens of the epidermis, taken from leaves of all
ages, from their youngest and smallest rudiments in the bud up to full-
grown ones, is instructive.
* In the leaves of Primula, sinensis, grown in the green-house, the
epidermal cells contain many chlorophyll-bodies ; the leaves of Fuchsias,
under similar conditions, possess a few chlorophyll-bodies in the epider-
mal layer.THE EPIDERMAL SYSTEM.
95
128.—Trichomes. Under this term are to be included the
outgrowths which arise from the epidermis ; they may have
the form of hairs, scales, glands, bristles, prickles, etc., and
may be composed of single cells, or of masses of cells.
They originate mostly from the growth of single epidermal
cells,* and on their first appearance consist of slightly en-
Fig.80.
Fig. 80.—Transverse section of epidermis and underlying tissue of ovary of Cu-
curlnta. a, hair of a row of cells ; b and cl, glandular hairs of different ages; e,f,
c, hairs in the youngest stages of their development. X 100.—After Prantl.
Fig. 81.—A seedling mustard plant with its single root clothed with root-hairs;
the newest (lowermost) portion of the root is not yet provided with root-hairs.
larged and protruding cells (Fig. 80, e, f, c). These may
elongate and form single-celled hairs, which may be simple
or variously branched. The most important of these hairs
are those which clothe no abundantly the young roots of most
of the higher plants, and to which the name of Eoot-hairs
* It is probable that the common statement that trichomes always
develop from single cells must be modified.96
BOTANY.
has been applied (Fig. 81). These are composed of single-
cells, which have very thin and delicate walls (Fig- 82), and
are the active agents in the absorption of nutritive matters
for the plant.
129.—In the development of the hairs on aerial parts of
plants it frequently happens that the terminal cell becomes
changed into a secreting cell, in which gummy, resinous, or
other substances are produced ; sometimes several terminalTHE EPIDERMAL Si Sl um.
97
'Cells are so transformed into a
tion appears as a rounded
pustule, partly surround-
ing the secreting cell
(Pigs. 83 to 87), and
which is removed upon
the slightest touch. Tri-
chomes of this nature are
called glandular hairs;
they are exceedingly vari-
able in form, and are not
infrequently short and
depressed, when they are
known as surface glands,
or glandular scales (Pig.
87).
secreting organ. The secre-
Fig. 83.—Glandular hairs from the petiole of
Primula sinensis, in several stages of develop-
ment. a, the beginning of the secretion iu the
terminal cell; b, hair with a large mass of se-
creted matter ; d, an old hair after the removal
of the secreted matter. X 142.—After De Bary.
(a) Tri ebonies are, in gene-
ral, easy objects of study.
In many cases they may be
simply scraped off and mounted in alcohol, or in a solution of potash
Fig. 86.—The end of the hair d, in Fig. 83, more highly magnified, showing the frag-
ments of the secretion pustule surrounding the terminal cell, which still contains pro-
toplasm. x 375.—After De Bary.
Fig. 87.—Glandular scale from the hop. A, in its young stage; B, the same some
time afterward—the secretion from'the cells has pushed out the cuticle and filled the
spuce between it and the cells (in the specimen from which these were drawn the
secretion was removed by solution in alcohol). X 142.—After De Bary.
. after wetting them with alcohol to free them from entangled and en-
closed air.98
BOTANY.
(b) One-celled simple hairs may be obtained from the vegetative
organs of species of CEnothera and Brassica and many grasses—e.g.,
species of Panicum—and from the seeds of the cotton plant; the last
constitute the ‘ ‘ cotton” of commerce.
(c) Many-celled simple hairs occur on the filaments of Tradescantia,
on leaves of the Primrose, Ageratum, Erigeron Canadense, pumpkin,
and very many others.
(d) Branched one-celled hairs occur in Capsetta, Draha, Sisymbryum,
Alynsum, and many other Gruciferoe.
(e) Branched many-celled hairs may be found on the Mullein and
Ivy.
(/) Clustered or tufted hairs are found on many Malvacece, and the
nearly related scales or peltate hairs on Sfiepherdia.
(g) Root-hairs are best obtained for study by growing seeds of mustard,
radish, wheat, etc., on damp cotton or blotting-paper, and then mak-
ing careful longitudinal sections of the terminal portion of the root at
the place where the hairs are just appearing (usually several millimetres
above the tip of the root). By making preparations in this way all
stages of the development of these hairs may be studied in the same
specimen.
(h) Glandular hairs are found in many groups of plants ; they may
be studied in Petunia, Verbena, Primula, Martynia, and the, tomato.
(i) Apparently related to glandular hairs are the curious hairs fromTEE EPIDERMAL SYSTEM.
99
•which, as pointed out by Professor Beal* are drawn out the long
thread-like lashes which are so abundant on the leaves of some thistles
and other Composites (Pig. 88). These lashes appear to be of the na-
ture of secretions, and they are capable of being drawn out to an aston-
ishing length. These are, in turn, much like the glandular hairs on
the leaves of Dipsacus sylvestris, discovered by Francis Darwin,f
and from which motile protoplasmic filaments protrude. Mr. Darwin
concludes that they have the power of absorbing nitrogenous matter.
130. —Stomata (singular, Stoma). These structures con-
sist, in most cases, of two specially modified chlorophyll-
bearing cells, called the Guard-cells, which have between
them a cleft or slit passing through the epidermis (Figs. 89,
90). These openings are always placed directly over interior
intercellular spaces. Stomata are developed from, and in
their distribution always have a relation to, the epidermal
cells; in an epidermis composed of regular cells there is
more or less regularity in the arrangement of the stomata ;
but when the epidermal cells are irregular the stomata are
also irregularly placed.
They occur on aerial leaves and stems most abundantly,
being sometimes exceedingly numerous, and are exception-
ally found on other parts, as the sepals, petals, and carpels
of the flowers. On submerged or underground stems and
leaves they are found in less numbers, and from true roots
they are always absent. The stomata on leaves are generally
confined to the lower surface, and when present on the up-
per they are usually much fewer in number ; there are, how-
ever, some exceptions to this.
131. —Their development generally takes place in the fol-
lowing way : in a young epidermis-cell a partition forms at
right angles to the plane of the epidermis, cutting off a por-
tion of the cell; this, in one series of cases becomes the
mother-cell of the stoma; in another series of cases, how-
ever, it is divided one or more times by subsequent partitions
before the mother-cell is formed. In either case, wrhen once
* In an article entitled “How Thistles Spin,” in the American Nat-
uralist, 1878, page 643. See also an article by the same writer on
“ Hairs and Glandular Hairs of Plants : their Forms and Uses,” in the
same volume of the journal named, on page 271.
f See his account, with a plate, in Qr. Jour, of Mb, Science, 1877, p. 245.100
BOTANY.
■the mother-cell is formed a median partition-wall forms
m it, and gradually becomes separated into two plates, which
eventually sepa-
rate and form a
pore through
the epidermis.
The two halves of
the mother-cell be-
come symmetrical-
ly rounded off into
semilunar or semi-
circular forms,
and constitute the
guard-cells before
mentioned. The
details of the fore-
going process in
one of its more
complex forms
are illustrated in
Fig. 91, A and B.
The splitting of
the middle partition-wall of the mother-cell is shown in the
successive sections (Fig. 92).
132.—In the light, under certain conditions of moisture
and temperature, the
guard-cells become
curved away from each
other in their central
portions, thus opening
the slit and allowing
free communication
between the external
air and that in the in-
tercellular spaces and
passages of the leaf.
(a) A superficial examination of stomata may be easily made by
stripping off tbe epidermis, and mounting it in water or alcohol. Good
sections of stomata are more difficult to make ; they may be obtained,
Fig. 90.—Double stomata from the under surface
of the leaf of Echinocystis lobata. X 500.—From a
drawing by J. C. Arthur.101
Fig. 91.—The development of the stomata of the leaf of Sedum pur pur ascent. A,
a piece of very young epidermis, showing the early stages of the process. The. nu-
merals indicate the order of formation of the partitions; that marked 1,1, 1, was
formed first, then 2,2, and last 3, 3; the cell enclosed by these three partitions is the
stoma-mother-cell; B, a fully completed stoma; e, e, two original epidermis-cells—
in the right hand one the new partition 1,1,1, first appeared ; this was followed by
2, 2. 2, then by 3, 3, and 4, 4 ; lastly the cell thus formed became divided by a middle
partition, which soon split, and thus formed the opening of the stoma.—After Sachs.
Fig. 92.—Development of the stomata of the leaf of Hyadnthus orientalise seen in
transverse section. A, the division of the mother-cell S; e, e, epidermis-cells ; p p,
parenchyma-cells ; i, small intercellular space ; B and C, the same a little later ; D%
first separation of the two guard-cells by the splitting of the partition between them,
forming the opening t; E, the fully formed stoma. X 800.—Alter Sachs.102
BOTANY.
however, by making a large number of very thin sections of the whole
leaf (by placing it between two pieces of elder pith), when it will be
tound that in some cases stomata have been cut through in the man-
ner shown in Fig. 92.
(.b) Examples may be obtained from any of the higher plants, but
those which are of a firm texture and have a smooth epidermis are
best to begin with—e.^.,the hyacinth, tulip, the lilies, many grasses,
fuchsia, lilac, etc.
(c) Weiss* determined the number of stomata on the epidermis of
both surfaces of 167 leaves of plants ; some of his results are given
below:
In one square millimetre. In one square inch.
Upper 6ide. Under side. Upper 6ide. Under side.
Olea Europea 0 625 0 403,125
Vinca minor 0 477 0 308,665
Juglans nigra 0 461 0 298,345
Ailanthus glandulosa 0 386 0 248,970
Syringa vulgaris 0 330 0 212,850
Helianthus animus 175 325 112,875 209,625
Brassica oleracea 138 302 88,910 194,790
Platanus occidentals 0 278 0 179,310
Populus dilatata 55 270 35,475 174,150
Solanum dulcamara 60 263 38,700 169,635
Euphorbia cyparissias 0 259 0 167,055
Maclura aurantiaca 0 251 0 161,895
Betula alba 0 237 0 152,865
Berberis vulgaris 0 229 0 147,705
Pisum sativum 101 216 65,145 139,320
Buxus sempervirens 0 208 0 134,160
Primus Malialeb 0 204 0 131,580
Asclepias incarnata 67 191 43,215 123,195
Datura stramonium 114 189 73,530 121,905
Vaxus baccata 0 166 0 107,070
/5ea mais 94 158 60,630 101,910
Cheuopodium ambrosioideB.. 184 156 118,680 100,620
Ficus elastica 0 145 0 93,525
Kibes aureum 0 145 0 93,525
•Populus monilifera . 89 131 57,405 84,495
Pinus sylvestris 50 71 32,250 45,895
Anemone nemorosa 0 67 0 43,215
Lilium bulbiferum 0 62 0 39,990
Iris Germanica 65 58 41,925 38,410
A vena sativa 48 27 30,960 17,415
*In a paper on the Number and Size of Stomata, published in
Pringslieim’s “ Jahrbiicher fur Wissenschaftliche Botanik,” 1865.THE EPIDERMAL SYSTEM.
103
(ft) In the plants he examined he found that there were
Ttt species with from 1 to 100 stomata per eq. mm. = 645 to 64,500 per sq. inch
88 “ 100 to 200 “ u “ = 64,500 to 129,000 “
89 “ 200 to 300 tt “ = 129,000 to 193,500 “ “
12 “ “ 300 to 400 “ it “ = 193,500 to 258,000 “ “
9 <( 400 to 500 “ tt “ = 258,000 to 322,500 “ tt
1 tt 500 to 600 “ it “ = 322,500 to 387,000 ' “ tt
3 “ it 600 to 700 “ tt “ = 387,000 to 451,500 “ “
(e) Morren’s measurements* vary somewhat from those given by
Weiss. Tlie following, not given by Weiss, are taken from Morren’s
■table:
In one square millimetre.
In one square inch.
Upper side. Under side. Upper side. Under side.
Trifolium pratense 207 335 133,515 216,075
Humulus Lupulus 0 256 0 165,120
Prunus domestica 0 253 0 163,185
Pirus Malus 0 246 0 158,670
Hedera helix 0 196 0 126,420
Vitis vinifera 0 155 0 99,975
Beta vulgaris 75 115 48,375 74,175
Piru8 communis 0 91 0 58,695
Philadelplius coronarius.... 0 86 0 55,470
Secale cereale 40 42 31,605 27,090
(f) The stomata of the so-called Compass Plant (Silphium lacinia-
turn) are nearly equal in number on the two sides of the vertical leaves;
there are on the true upper surface 82 per sq. mm. (= 52,700 per sq.
inch), and on the under surface, 87 per sq. mm. (= 57,300 per sq.
■inch).f
(g) On moat leaves the stomata are not distributed equally over all
portions of either surface ; they are not found on the veins, but are
restricted to the areas between them. In some plants this restriction
is accompanied by a further modification, as in Geanolhus prostratus,
where the stomata are confined to the bottoms of sunken pits which
occur on the under side of the leaves. In the long harsh leaves of
Stipa spartea the stomata of the upper surface are restricted to the
sides of the deep longitudinal channels which lie between the promi-
nent nerves. (See Figs. 135-6, page 158.)
* Published first in Bulletin de VAcademie royale de Belgique, vol.
16, number 12, 1864, and also in part in Pringsheim’s “ Jalirbiicher,”
etc., 1. c.
f See an article in American Naturalist, 1877, p. 486 : “ Observations
•on Silphium laciniatum, the so-called Compass Plant,” by C. E. Bessey.104
BOTANY.
(7i) Water-pores. De Bary* describes under this name seme curious
Btoma-like structures which occur on many plants. These, instead of
containing air in their cavities, normally contain water. Their guard-
cells, which are, in some cases at least, much like those of ordinary
stomata, are immovable, and as a consequence the pore is incapable of
enlargement or contraction. They are always found over the ends of
small bundles of spiral vessels, which appear to pass into the pore cav-
ities.
One form of these may be readily examined in the leaves of the fucli-
Fig. 93.—Surface view of the water-pore on the extremity of the leaf-tooth of Fuch-
sia globosa. X BOO.—After Arthur.
Fig. 94.—Transverse section of leaf-tooth of Fuchsia globosa; cp. chlorophyll-
bearing parenchyma, within which is the fibro-vascular bundle; ra. raphis-cells. X
135.—After Arthur.
sia, and .the primrose (Primula sinensis). In the fuchsia they are found
in the papillae or small teeth on the margins of the leaves, and in the
primrose, in the papillae terminating the lobes and lobules. In Fuchsia
globosa each leaf-tooth is provided with a single terminal pore (in some
of the dark colored varieties there are several), which resembles an
ordinary stoma (Fig. 93). Beneath the pore is a cavity, commonly filled
with water (Fig. 95, b), which, by evaporation, deposits calcium car-
bonate upon the walls of the lining cells, thereby discoloring them. A
fibro-vascular bundle is continued from the veins of the leaf through
* In •'Vergleichende Anatomie der Vegetationsorgane,” etc., 1877,
on page 54, et seq. References are there given to the literature of the
subject, which is both recent and limited. After Mettenius’ paper in
Filices liorti Lipsiensis, others appeared by other writers in Botanische
Zeitung, 1809, 1870, and 1871.THE EPIDERMAL SYSTEM.
105
the tooth to the water-cavity ; in the tooth it becomes greatly enlarged,
and is there composed of spiral cells (tracheides), which surround a
central mass of narrow elongated parenchymatous cells (Fig. 95, c, g).
The bundle terminates by the free ends of the parenchyma-cells extend-
Fig. 95.—Vertical section of a leaf-tooth of Fuchsia globosa. a. vertical longitudi-
nal section of water-pore ; b, water-cavity; c, tracheides; d. chlorophyll-bearing
parenchyma ; e, large cell containing raphides; /, hair ; g, parenchyma of the fibro-
vascular bundle. The lower part or the figure passes into the leaf-blade. X 125.—
After Arthur.
ing loosely into the water-cavity. Between the bundle and the epider-
mis of the leaf-tooth lie two or three cell layers of ordinary chlorophyll-
bearing parenchyma, in which there are occasionally large cells con-
taining raphides (Fig. 94, cp and to).*
* The foregoing account of the water-pores of Fuchsia globosa, and
the drawings for Figs. 93-4-5, are taken from an unpublished paper
on •• The Water-Pores of Fuchsia globosaby J. C. Arthur.106
BOTANY.
Water-pores nearly like tliose of the fuchsia occur on some species of
Saxifmga, Heuchera, Mitetta, Aconitum, Delphinium, Samlucus, and.
many other plants.
Another form, more closely resembling the ordinary stomata (but of
much larger size), occurs on Tropceolum Lobbianum, Bochea coceinea,
and others.
§ III. The Fibro-vascular System.
133___In most of the higher plants portions of the pri-
mary meristem early become greatly differentiated into-
firm elongated bundles, which traverse the other tissues.
They are composed for the most part of tracheary, sieve,
and fibrous tissues, together with a varying amount of pa-
renchyma. These elementary tissues have, with some con-
siderable variations in the different groups of plants, a gen-
eral similarity of arrangement and aggregation throughout
the Pteridophytes and Phanerogams. In a comparatively
small number of cases laticiferous tissue is associated with
the above-mentioned tissues. To these aggregations of tis-
sues the name of Fibro-vascular Bundles has been given.*
134. —In many plants the fibro-vascular bundles admit of
easy separation from the surrounding tissues; thus in the-
Plantain (Plantago major) they may readily be pulled out
upon breaking the petioles. In the leaves of plants, where
they constitute the framework, they are, by maceration,
readily separated from the other tissues as a delicate net-
work. In the stems of Indian corn the bundles run through
the internodes as separate threads of a considerable thick-
ness. ' ■ '
135. —It is impossible to fix upon a particular form as the
type of the fibro-vascular bundle. It should be understood
at the ‘outset that the similarity between the bundles of
widely separated groups of plants is only a general one, and
that there are great differences in the details of their struc-
ture. It must further be borne in mind that these bundles
are not themselves tissues, but aggregations of dissimilar tis-
* They are also called Vascular Bundles; this term ought, however,
to he retained for those reduced bundles in which only vessels are pres-
ent—e.g., in the veinlets of leaves.THE FIB BO- VASCULAR SYSTEM.
10?
sues, any of which may be wanting in, or separated a little
space from, the bundle. In short, the elementary tissues,
particularly tracheary, sieve, fibrous, and parenchymatous
tissues, are to be considered as the units, and the term Fibro-
vascular Bundle as little more than a convenient expression
of the usual condition of aggregation of these units.*
The general structure of fibro-vascular bundles will be
more readily un-
derstood after
the examination
of a number of
examples. Those
which follow are
not in any sense
typical; they are
only illustrative.
136.—The fi-
bro-vascular bun-
dle of the stem of
Pteris aquilina
is composed of
tracheary and
sieve tissues, par-
enchyma, and a
small amount of
poorly developed
fibrous tissue. In
transverse sec-
tion the bundle
has usually an
elliptical outline.
The great mass
of the bundle is made up of large scalariform vessels,
which occupy its interior (g, g, g, Fig. 96). Enclosed in
the scalariform tissue are masses of parenchyma and a few
I
Fig. 96.—Part of a transverse section of the fibro-vas-
cular bundle of the stem of Pteris aquilina ; s, spiral ves-
sel ; g, g, scalariform vessels ; sp, sieve tissue; b, fibrous
tissue (protophloem of Eussow) ; sg, bundle sheath; pf
starch-bearing parenchyma: K, K, thickened angles of
scalariform vessels.—After Sachs.
* By considering tlie Fibro-vascular Bundle to be one of the struc-
tural units of the higher plants a serious mistake has been made,,
leading to profitless discussions and speculations as to its typical struc-
ture, and diverting attention from the study of its actual structures108
BOTANY.
spiral vessels, tlie latter occurring near the foci of the el-
liptical cross-section of the bundle (s, Fig. 96). Surround-
ing, or partly surrounding, the tracheary portion of the bun-
dle is a layer of sieve tubes (sp, Fig. 96), separated from the
large scalariform vessels by a layer of parenchyma. Outside
of the sieve tissue is a mass of fibrous tissue (&,_ Fig. 96),
which is itself bounded externally by another layer of paren-
chyma. The whole bundle is surrounded by a layer of paren-
Fig. 97.—Transverse section of the fihro-vascular bundle of the rhizome of Polypo-
divm vulgare; sp, sp, narrow spiral vessels in the edge of the mass of scalariform ves-
sels; s, region of the sieve tissue filled with parenchyma and poorly developed sieve
tissue ; u, bundle sheath, outside of which is parenchyma. X 225.—After De Bary.
chyma differing from the other parenchymatous tissues in
not containing starch in its cells ; to this the name of Bun-
dle Sheath has been given.
A noticeable feature in the structure of this fibro-vascular
bundle is that the tissues have a concentric arrangement;
the tracheary tissue is encircled by a layer of parenchyma ;
See, in this connection, an article on “ Some recent views as to the com-
position of tlie Fibro-vascular Bundles of Plants,” by S. H. Vines, in
<2? . Jour. Mic. Science, 1876, p. 388.THE FIBRO-VASGULAR SYSTEM.
109
this by one of sieve tissue ; this again by fibrous tissue, and
so on.
137.—A similar but not identical structure is found in the
Fig. 98.—Part of the cross-section of an old root of Adiantum MoHtzlanum. A, k.
hairs of the root surface; u,u, bundle sheath (endodermis); between h and u, pa-
renchyma ; pc, pericambium ; pr, a plate of tracheary tissue, which is bounded on
each side by sieve tissue. X 225.—After De Bary.
bundle of the rhizome of Polypodium vulgare. Here the
central portion of the stem is made up of scalariform tissue
(Fig. 97, the larger, thicker-walled tissue), and this is sur-
rounded by a tissue which may be regarded as but partly110
BOTANY.
differentiated, being composed of parenchyma and poorly-
developed sieve tubes (s, Fig. 97). The whole bundle is sur-
rounded, as in Pteris aquilinci, by a bundle sheath (u, Fig.
97). In the outer part of the mass of scalariform tissue are
a few narrow spiral vessels (sp, sp, Fig. 97), but they are-
not sufficiently numerous to constitute a ring or layer.
138.—In the root of Adiantum Moritzianum the bundle
consists of a cen-
tral plate of tra-
cheary tissue (pr,
Fig. 98), with a
mass of sieve
tissue on each
side of but not
quite enveloping
it. Next outside
of this is a layer
of active paren-
chyma, the peri-
cambium (pc,
Fig. 98), and sur-
rounding the
whole is a poorly
developed bundle
sheath (n, Fig.
98).
139. — In the
stem of Equise-
Fig. 99.—1Transverse section of a fibro-vascular bundle of , 7 ,
Eqmsetum paluslrt. r, t, ringed vessel** on the border of a tUT)l pCUUStTG 1C
large intercellular canal; #, sieve tissue; gyg. groups of • .
annular and reticulated vessels; uy the so-called general 10 IJUU eci&j cio
bundle sheath, which surrounds all the bundles; i,i, axial ^ -fo-rorminrr
air cands ; x , x, fragments of the ruptured cells. X 145. ILL LXJC AA'At'&UAAA&
-After De Bary. cases to mark the
limits of the bundles, which are arranged in a circle about
the axis.* On the axial side of each bundle there are at.
first a few spiral and annular vessels, most of which,
along with a considerable amount of parenchyma, are
* In Equisetum limosum, however, there is a bundle sheath about,
each bundle, consequently there is in that species no difficulty as to
the limits of the bundle.THE FIB 110- VASCULAR SYSTEM.
Ill
destroyed shortly after their formation, thus forming a
wide canal (Fig. 99; t, spiral, and r, annular vessels
on the border of the canal). Immediately in front of or
outside of the canal is a considerable mass of sieve tissue,
made up of true sieve tubes and the nearly allied cambiform
or latticed cells
(s, Fig. 99).
Right and left of
the sieve tissue
lie a few annular
and reticulated
vessels (q, q, Fig.
99). Exterior to
all the bundles
(in this species)
is a cellular lay-
er, which has re-
ceived the name
of bundle sheath,
but which, prob-
ably, has no rela-
tion to the lay-
er so named that
surrounds each
fibro - vascular
bundle of some
plants.
140. — The
structure of the
bundle in Selagi-
nella incequifolia
bears a consider-
able resemblance
to that of Pteris aquilina.
Pig. 100.—Cross-section of the stem of Selaginella IncequU
foliu, showing three bundles; in each bundle the inner
thicker walled tissue is composed of scalariform vessels,
with a few narrow spiral vessels on each extreme margin;
surrounding the ecalar-form tissue is the thinner walled
sieve tissue, and around this again is a layer of cells which
may be called the bundle sheath ; l, l, intercellular spacea
surrounding the bundles, x 150—After Sachs.
There is in each bundle a
centra] plate of tracheary tissue, consisting of a few narrow
spiral vessels in its two edges and a remaining mass of scala-
riform vessels (Fig. 100). The tracheary portion is sur-
rounded by a tissue of elongated, thin-walled tissue which
is, at least in part, a sieve tissue. In this and allied species112
BOTANY.
the bundles are curiously isolated from the surrounding
ground tissues of the stem.
141.—The bundle of the nearly related Lycopodium com-
planatum is much more complex in its structure (Fig. 101).
Here there are four parallel plates of tracheary tissue, each
having a structure like the single plate of the bundle of
Selaginellci inmquifolia. Between the tracheary plates there
is in each case a row of sieve tubes imbedded in a lignified
tissue composed of elongated cells (sclerenchyma, or fibrous
Fig. 101.—Cross-section of the stem of Lycopodium complanntum. The fibro-vas-
cular bundle is composed of four plates of tracheary tissue (darker in the figure),
between which are masses of lignified tissue composed of elongated cells ; each of
these latter masses encloses a row of sieve tubes (larger and thicker walled in the
figure); the bundle sheath is seen to bound on its inner side a thick mass of very thick
walled fibrous tissue; exterior to this (toward B) is a layer of chlorophyll-bearing
parenchyma, bounded by a well-devt'loped epidermis. The small vessels at the ex-
treme edges of the plates of tracheary tissue are narrow and spirally marked ; the
remainder of each plate is composed of scalariform vessels, x 100.—After Sachs.
tissue?). Around this central fibro-vascular portion there is
a layer of parenchyma, and outside of this a bundle sheath,
which is commonly regarded as marking the boundary of
the bundle ; it is doubtful, however, whether it should be so
considered, as exterior to it lies a thick mass of fibrous tissue
which completely envelops all the previously described
tissues.*
* Sacha (“Text-Book,” p. 418) regards the stem of Lycopodium as
composed of four united bundles and compares them to the separate
bundles of Selaginella. De Bary (“Anatomie,” etc., p. 362), on theTHE FIBRO- VASCULAR SYSTEM.
113
142.—In the fibro-vascular bundle of the stem of Indian
corn (Zea mais) the central portion is composed of tracheary
Fig. 102.—Transverse section of fibro-vascular bundle of Indian corn (Zea mats),
a, side of bundle looking toward the circumference of the stem; i, side of bundle look-
ing toward the centre of the stem ; p, thin-walled parenchyma of the fundamental
tissues of the stem; g,g, large pitted vessels; s, spiral vessel; r, ring of an annular
vessel: l, air-cavity formed Dy the breaking apart of the surrounding cells; v, v,
latticed cells, or soft bast, a form of sieve tissue. X 550.—After Sachs.
tissue, consisting of pitted, spiral, ringed, and reticulated
vessels (Fig. 102, g, g, s, r, and the tissue between v—s, g—-g)
other hand, considers the cylindrical portion in the centre as hut one
bundle, belonging to what he terms the Radial type. Both agree in con.
sidering the fibrous tissue outside of the bundle sheath as not belong-
ing to the bundles ; but certainly if this is one bundle, there is as good
reason for including the fibrous cylinder in it as there is in the case of
the bundle of Indian corn.114
BOTANY.
Lying by the side of the tracheary tissue (on its outer side as
it is placed in the stem) is a mass of sieve tissue, composed of
latticed cells (v, v, Fig. 102). Surrounding the whole is a
thick mass of fibrous tissue composed of elongated, thick-
walled cells (the shaded ones in the figure).
143.—The fibro-vascular bundle of the flowering-stalk of
Acorns calamus bears a close resemblance to that of Indian'
corn. Like that, it has a central tracheary portion (g, Fig.
103), which has lying exterior to it a mass of sieve tissue (w,
plates of tracheary tissue (pp, Fig. 104), which alternate
with thick masses of sieve tissue (ph, Fig. 104). Between
these alternating tissues, and within the circle formed by
them, there is a mass of parenchymatous tissue. The
whole bundle is separated from the large-celled parenchyma
of the root by a well-marked bundle sheath (s, Fig. 104) ;
the latter is bounded interiorly by a layer of active thin-
walled cells — the pericambium — from which new roots
originate. In the older root, the central cell mass (which,
Fig. 103). On the inner
side there is a large in-
tercellular canal, evi-
dently holding the same
relation to the other
tissues that the smaller
canal does in the bundle
of Indian corn. The
exterior of the bundle
is here also made up of
a thick mass of fibrous
tissue.
144. — In the fibro-
vascular bundle of the
adventitious roots of
Acorus calamus the ar-
rangement of the tis-THE FIBRO-VASCULAR SYSTEM.
115
as described above, is in younger specimens composed
of parenchyma) is transformed into sclerenchyma (Pig.
105).
145.—The fibro-vascular bundles of Ricinus communis
have an arrangement in the stem, and a general structure
somewhat similar to those of Equisetum palustre, described
above. The limits of the bundles are so poorly marked that
Fig. 104.—Transverse section of the fibro-vascular bundle of the root of Acorus
calatrms. s. bundle-sheath (also called endodermis), with parenchyma outside and a
single layer of pericambium-cells inside: yrp. plates of radially-plac d tracheary
tissue ; ph, bundles of sieve tissue ; pp. narrow peripheral (and first formed) ves-
sels ; g, large and still young vessel.—After {Sachs.
in places it is impossible to tell whether the tissues belong
to them or to the surrounding ground tissues.
The inner portion of the bundle (g, g, t, t. Fig. 106, and s
to t, Fig. 107) is made up of tracheary tissue of several varieties;
on the inner edge of this tracheary portion lie several spiral ves-
sels (s, s, Fig. 107) ; next to these, on their outer side, are sca-
lariform and pitted vessels (t, t, g, g, Fig. 106, l, t, f, Fig.
107), intermingled with elongated cells, whose walls are pitted116
BOTANY.
(h, h’, h", h"', Mg. 107). The last-named are clearly related
to the vessels which surround them, and from which they
differ only in their less diameter, and in having imperforate
horizontal or oblique septa. They are doubtless properly
classed with the Trache'ides (see p. 84). On the outer side of
the tracheary portion just described lies a mass of narrow,
somewhat elongated, thin-walled cells, which constitute a
true meristem tissue, to which the name of Cambium* has
been given (c, c, Mgs. 106 and 107). Next to the cambium
Fig. 105.—A very thin cross-section of the radial fibro-vascnlar bundle of an old
adventitious root of Acorvs calamus, g, the radial plates of tracheary tissue ; w, the
sieve tissue alternating with the plates of tracheary tissue ; s, the bundle-sheath;
the tissue in the centre of the bundle is sclerenchyma. X 145.—After De Bary.
lie, in order, sieve tissue and parenchyma; these do not occupy
separate zones, but are more or less intermingled, forming
a mass sometimes called the Soft Bast (y, y, y, Fig. 106, and
p, Fig. 107). The sieve tissue includes sieve tubes and
cambiform or latticed cells. In the extreme outer border of
the bundle is a mass of fibrous tissue (b, b, Figs. 106 and 107).
The layer of starch-bearing cells just outside of the last-
named tissue is the so-called bundle sheath.
* Cambium, a low Latin word, meaning a liquid which becomes
glutinous. The term was introduced when the real structure of the
part to which it was applied was not understood.THE FIBRO- VASCULAR SYSTEM.
117
146.—The bundle of the adventitious root of Ranunculus
repens is very different from the one just described. It may
be briefly described as composed of a mass of tracheary tis-
Fig. 106.—Transverse section of hypocotyledonary portion of stem of Ricinus com-
munis. r} ?', parenchyma of the primary cortex ; m, parenchyma of the pith •, br
bast fibres ; y, y, soft bast; c, cambium • g, g, large pitted vessels ; t, t, smaller pit-
ted vessels ; cb, continuation of the cambium into the parenchyma lying between the
bundles—the parenchyma-cells are repeatedly divided by tangential walls. Between
the primary cortex r and the fibrous tissue of the phloem lies a layer, the so-called
bundle-sheath, filled with compound starch grains. Highly magnified.—After Sachs.
sue, which is cross-shaped, as seen in transverse section (g,
r,g, .Fig. 108), and four masses of sieve tissue, which lie in
the angles between the projecting portions of the tracheary
tissue. Around the whole is a layer of pericambium (p,118
BOTANY.
Fig. 108), and exterior to this is the bundle sheath (u, Fig.
108).
147.—In Gym nosperms and Dicotyledons the fibro-vascu-
lar bundles of the stems have a structure essentially like that
of Ricinus communis, described above. In them it is evi-
dent at a glance that the bundle is divided into two some-
what similar portions, an inner and an outer, by the cam-
Fig. 107.—Longitudinal radial section of the flbro-vasnilar bundle of the hypocot-
yledonary stem of Ricinus communis (the transverse section being bhown in Fig.
106). r, parenchyma of the primary cortex ; gs, bundle sheath : rn, parenchyma of
the pith ; &, bast fibres ; p, phloem parenchyma ; c, cambium ; the row of cells be-
tween c and p is afterward developed into a sieve-tube—this and i constitute the
soft hast; ., the first-formed narrow spiral vessel; from s the development of the
xylem portion of the bundle is toward t; s', wide spiral vessel ; IJ scalariform ves/
eel; t, V, wide pitted vessels ; q, the absorbed septum ; /1traCheides (?); h, hr,
forms of cells apparently intermediate between pitted vessels and tracheides. Highly
magnified.—After Sachs.
bium zone. Nageli,* who first pointed out these divisions,
named the inner one the Xylem portion, because from it the
wood of the stem is formed ; the outer he named the Phloem
portion, for the reason that it develops into bark.f In
some cases the similarity between the structure of xylem
* “ Beitriige zur Wissenscliaftlicken Botanik,” 1858.
f Xylem from £v/ioi>, wood ; Pliloem from Greek ^koidc, bark.THE FIBRO- VASCULAR SYSTEM.
119
■and phloem is so marked that they are said to be composed
•of corresponding tissues, (1) Vascular, (2) Fibrous, and (3)
Parenchymatous.* The vascular tissues are, on the one
hand, the tracheary tissue found only in the xylem, and on
the other, the sieve tissue of the phloem. The fibrous tissue
•of the xylem is the variety with the shorter and harder
Fig. 108.—Cross-section of the fibro-vascular bundle of an old adventitious root of
Ranunculus repens, g, a, g, the outer margins of the radial plates of tracheary tissue ;
r. a large central pitted vessel; x , septum in pitted vessel, with its central portion
absorbed ; p, pericambium ; u, bundle sheath; between the four projecting parts of
the tracheary portion of the bundle, and just within the pericambium, lies the sieve
tissue. X 145.—After De Bary.
fibres, known as wood fibres ; that of the phloem is com-
posed of the longer and tougher bast fibres. The paren-
chyma of the two portions is much alike.
* Attention should be called liere to the fact that in a good many
orders of Phanerogams the laticiferous vessels are constituent parts of
the fibro-vascular bundles. Thus in Ciclioriacese, Campanulacese,
Papaveraceae, Asclepiadaceae, Apocynaceae, and Acerineae they occur in
the phloem; in Papayacese and Aroideae they occur in the xylem.120
BOTANY.
148. —Nageli extended this classification of the tissues to
the fibro-vascular bundles of Monocotyledons, and subse-
quently it has been still further extended so as to include all
kinds of fibro-vascular bundles. In every case the tracheary
portion is the essential, or most constant, characteristic of
the xylem, as the sieve tissue is of the phloem.
These terms are valuable when used in reference to the
fibro-vascular bundles of the stems of Phanerogams; they
may also be valuable, if properly used and understood, when
applied to other forms of the fibro-vascular bundle. The
xylem portions of the stem bundles of different plants
among the Phanerogams are homologous parts of the tissue
systems—the bundles ; but when the term xylem is applied
to certain parts of two dissimilar bundles—e.g., of Ricinus
(Fig. 106) and Lycopodium (Fig. 101)—no homology of parts
should be understood. The tissues themselves, in some
cases of dissimilar bundles, may be homologous, but they are
homologous tissues, and not homologous parts of a system
of tissues.* When, therefore, these terms are used in the
present work, it must be borne in mind that they do not
necessarily convey the idea of homology of parts.
149. —De Bary’s f recent structural classification of fibro-
vascular bundles is useful in designating their general plan.
He includes a'll forms under three kinds, viz., (1) the Col-
lateral bundle, which has one mass of xylem by the side of
a single mass of phloem ; this is the form of all bundles of
the stems of Eqtdsetum, and of the stems and leaves of Pha-
nerogams l (Figs. 99, 102,103,106, 107); (2) the Concentric
* This point, which is an important one, may be made clearer by an
illustration from zoology. The nervous tissue of one animal is the
homologue of that found in any other, but the nervous system of one
may or may not be the homologue of the other. The nervous system
of the bee, for example, is not the homologue, but the analogue, of
that of the ox ; it is, however, the homologue of the nervous system
of the lobster. The brain of the ox and the brain of the bee are not
homologues as parts of a system, but they are homologues as tissues.
f " Vergleichende Anatonlie,” etc., p. 331, et seq.
f In the Cucurbitacese and some other orders there is a mass of sieve
tissue on the inner side of the xylem, so that the latter is between twoTHE FIBRO- VASCULAR SYSTEM.
121
bundle, which has its tissues arranged concentrically around
one another; this is the bundle of the stems and leaves of
ferns (with a few exceptions), Selaginellse, and a few excep-
tional cases in Phanerogams (Figs. 96, 97, 98, 100); (3) the
Eadial bundle, which has its tissues arranged radially about
its axis ; such a bundle occurs in the stems of Lycopodium,
and it is the primary bundle of the roots of most Pterido-
phytes and Phanerogams (Figs. 101, 104, 105, 108).
150. —The development of the fibro-vascular bundle takes
place in this wise: in the previously uniform Primary Meris-
tem there arises an elongated mass of cells, constituting the
Procambium of the bundle; as it grows older the cells,
which were at first alike, become changed into the vessels,
fibres, and other elements of the bundle tissues. In the
fibro-vascular bundle of the stems and leaves of Gymno-
sperms and Dicotyledons this change begins on the two sides
of the bundle—i. c., on the outer edge of the phloem and
the inner edge of the xylem ; from these points the change
into permanent tissue advances from both sides toward the
centre of the bundle. In some cases (e.g., in the leaves)
all of the procambium is changed into permanent tissue,
forming what is termed the closed bundle; in other cases
there is left between the phloem and xylem a narrow zone
of the procambium (now called the Cambium), forming
what is known as the open bundle.
151. —In the stem and leaf bundles of Monocotyledons
the development of procambium into permanent tissue is
essentially as in Dicotyledons and Gymnosperms, with this
difference, that here they all become closed. In Pteridophytes
and the roots of Phanerogams the development, while agree-
ing in general with the foregoing, is quite different as to de-
tails; all are closed, unless those in the roots of Dicotyledons
and Gymnosperms should be shown to be exceptions.
152. —The fibro-vascular bundles of leaves and the re-
productive organs are quite generally reduced by the absence
so-called phloem portions. Such bundles are considered by De Bary to
be variations of the collateral form, and he designates them as bi-col-
lateral bundles.122
BOTANY.
of one or more tissues; this reduction may be so great as to
leave but a single tissue, which in many cases is composed of
only a few spiral vessels or tracheides (Fig. 109). In other
cases, instead of spiral vessels the bundle may consist of a few
fibres of hast; or of elongated, thin-walled cells, which are
doubtless to be regarded as meristem-cells which failed to
fully change into one of the or-
dinary permanent tissues; this
last is a very common accom-
paniment of reduced bundles.
(a) In the study of the structure
of fibro-vascular bundles much care
is required in the preparation of the
specimens. The thin transverse sec-
tions are obtained by ordinary pro-
cesses with no great difficulty, but
such is not the case with the lon-
gitudinal sections ; they must not
only be extremely thin, but must run
parallel with the cells and fibres,
and moreover, must be sufficiently
large to show all, or a considerable
part, of the bundle. It is necessary
also to have several longitudinal
sections, and to know the exact posi-
tion of each one when compared
with the transverse section.
(A) The most satisfactory results
can be obtained only by the use of
some mechanical section-cutter.* In
most cases the sections are made
more easily after soaking the stems,
roots or leaves used in alcohol.
(a) In many cases it is profitable
to macerate some of the longitudi-
nal sections in nitric acid and potassi-
um chlorate (Schulze’s maceration),
so as to permit of an isolation of the fibres, cells, and vessels.
(d) Good specimens for study may be obtained from any of the
higher plants, but the examination will be most profitable if the order
Fig. 109.—Terminal ramifications of
the reduced fibro-vascular bundles of
the leaf of Psoralea bituminosa; the
ends x, x, are cut off in making the
preparation, the others are the actual
termini ; the bundles are seen to be
composed of spiral tracheides, and
spiral vessels resulting from their fu-
sion ; around the bundles are seen the
cells of the chlorophyll-hearing paren-
chyma. X 225.—After De Bary.
* For the various contrivances used for cutting sections see the com-
mon books on microscopy, also American Naturalist, 1874, p. 59;
American Quarterly Microscopical Journal, 1879, p. 131, and several
articles in Qr. Jour. Mic. Science, 1870, 1874, 1875, 1877.THE FUNDAMENTAL SYSTEM.
123
in the following list of examples is observed : (1) the rhizomes and
roots of ferns; (2) stems of Selaginella and Lycopodium ; (3) stems of
Monocotyledons ; (4) siems of Equisetum ; (5) young stems of Gymno-
sperms and Dicotyledons ; (6) roots of Phanerogams; (7) reduced
bundles of leaves.
(e) The discussion of the disposition of the bundles in the stem, and
their relation to the leaf bundles, together with the development and
structure of secondary bundles, belongs properly to the special anatomy
of the Phanerogams. (See Chapter XX.)
§ IY. The Fundamental System, or the System of
Ground Tissues.
153. —These terms refer to the mass of various tissues
lying within the epidermis, and not included in the fibro-
vascular bundles, when they are present. In passing down
through the lower plants this inner mass becomes more and
more simple, until it is composed of but one homogeneous
tissue, when the term system can no longer be profitably
applied to it; in passing to the higher plants, on the other
hand, there is in this portion of their structure an increasing
complexity, which comes at last to more than equal that of
either the epidermal or fibro-vascular systems.
154. —In its fullest development, the fundamental system
may contain parenchyma of various forms, collenchyma,
sclerenchyma, laticiferous tissue, and possibly also fibrous
tissue.* Their arrangement, within certain limits, presents
a considerable degree of similarity in nearly related groups
of plants, but this is by no means as marked as in the case of
the fibro-vascular system.
* It is a question whether fibrous tissue occurs in the fundamental
system ; there are some cases (e.g., in Ferns, Lycopodiaceae, etc.)
whicli appear to show that it does, but possibly they admit of other in-
terpretation. It should be mentioned here that many eminent botanists
(notably Schwendener, Russow, Falconberg, and De Bary) hold that all
fibrous tissue belongs to the fundamental system, and as a consequence,
that it in no case is a proper constituent of the fibro-vascular bundle.
This is, however, nothing more than making a typical form of bundle
(composed of tracheary and sieve tissues), and then insisting that all tis-
sues not found in the type are extra-fascicular, a course which cannot
be followed in this book.124
BOTANY.
(1.) Parenchyma is the most constant of the fundamental
tissues ; it makes up the whole of the interior plant-body in
those cases where there has been no differentiation into more
than one tissue, and from here, it is present in varying
amount in nearly all (if not all) cases up to and including
the highest plants. In stems of Monocotyledons it makes up
the mass of tissue lying between the scattered bundles, and
in stems of Gymnosperms and Dicotyledons it constitutes
the pith and portions of the bark.
(2.) Collenchyma, when present, as it frequently is in the
mental tissues will turn out to be sclerenchyma instead.
(4.) Laticiferous tissue may occur, apparently, in any por-
tion of the fundamental system of Phanerogamous plants.
155.—It is thus seen that in general the tissues of the
fundamental system are so disposed that the periphery is
harder and firmer than the usually soft interior, although
there are many exceptions. This general structure has given
rise to the term Hypoderma for those portions of the funda-
mental system which lie immediately beneath, or near to the
epidermis. Hypoderma is not a distinctly limited portion—
in fact, it is often difficult to say how far it does extend;THE FUNDAMENTAL SYSTEM.
125
however, it usually includes several, or even many, layers of
cells, or the whole of each of the tissue-masses (e.g., collen-
chyma, sclerenchyma, etc.) which immediately underlie the
epidermis (Fig. 110, g, i).
The remaining portion of the fundamental system, inside
of the hypoderma, is designated by Sachs as the Intermediate
tissue. The term is of but little value in many of the higher
plants, where more particular names may be applied ; but in
some Monocotyledons, most Pteridophytes, and in Bryo-
phytes it is very
serviceable.
156. —Cork.
Within the zone
which the hypo-
derma includes
there frequently
takes place a pe-
culiar devclop-
ment of the
young parenchy-
ma, giving rise
to layers of dead
cells, whose cav-
ities are filled
with air only.
The walls in
cnmo oncac (o n Fig. 111.—Transverse section of one-year old stem of Ai-
bOine cases ye.g., lanthus glandulosus. e, epidermis ; k, cork-cells ; r, inner
om'V r\ctV\ a vo green cells, the phelloclerma ; between k and r a layer of
tut; t/UiJ^-uctAy cue cejj8 fine(i with protoplasm, called the phellogen or cork
thin and weak, cambium, x 350,-Aftei- Prantl.
while in others (e.g., the beech) they are much thickened,
and in all cases they are nearly impermeable to water. True
cork is destitute of intercellular spaces, its cells being of
regular shape (generally cuboidal) and fitted closely to each
other (Fig. 111).
157. —Cork substance is formed by the repeated subdivis-
ion of the cells of a meristem layer of the fundamental tissue
(Fig. Ill) ; these continue to grow and divide by parti-
tions parallel to the epidermis, forming layers of cork with
its cells disposed in radial rows (Fig. Ill, h). Shortly after126
BOTANY.
their formation the cork-cells lose their protoplasmic con-
tents, while beneath them new cells are constantly being cut
ofE from the cells of the generating layer; in this way the
mass of dead cork tissue is formed and pushed out from its
living base.
158.—The generating tissue is called the Phellogen,* or
Cork-cambium ; it occurs not only in the hypoderma, but in
any other part of the fundamental system, and, as will he
shown hereafter, in the secondary fibro-vascular bundles.
When a living portion of a plant is injured, as by cutting,
the uninjured parenchyma-cells beneath the wound often
change into a layer of phellogen, from which a protecting
mass of cork is then
developed.
159.—Lenticels
are in many cases the-
result of a restricted
corky growth just be-
neath a stoma. Phel-
logen consisting of a
few cells of the hypo-
derma, is formed im-
mediately below a
stoma (Fig. 112, x)
by the growth of cork
from this phellogen the epidermis is pushed out and finally
ruptured, exposing the roundish or elongated mass of corkf
(Fig. 113). Lenticels are of frequent occurrence on the young
branches of birch, beech, cherry, elder, lilac, etc., and may be-
distinguished by the naked eye as slightly elevated roughish
spots, usually of a different color from the epidermis.
Fig. 112 —1Transverse section of a portion of the
intemode of a young twig of Betula alba, c, cuticle,
somewhat separated from the epidermis ; , e, epider-
mis ; a. cavity under the stoma seen in cross-section
above ; at, x. cells which are beginning the process of
multiplication by fission, constituting the phellogen
of the future lenticel. X 375.—After De Bary.
(a) The examination of the tissues of the fundamental system may-
in general be made with considerable ease, by making transverse,tan-
gential and radial sections.
* From the Greek ipeUoc, cork.
f It appears quite certain that not all lenticels develop from the
hypoderma beneath stomata; phellogen forms beneatli the epider-
mis at other points, and gives rise to lenticels in a way essentially as.
in the other cases.THE FUNDAMENTAL SYSTEM.
137
(J) Ordinary herbaceous Dicotyledons furnish the best examples of
fully developed fundamental tissues ; they can be most easily exam-
ined after soaking for some time in alcohol.
(c) Examples of thin-walled cork are, of course, best obtained from
Fig. 113.—Transverse Bection through a lenticel of Betula alba. e. e, epidermis ; s,
old stoma ; under this ie a mass of cork which develops from the phellogen layer
lying next to the ordinary parenchyma (figured darker) ; the great multiplication of
cork-cells has pushed out the epidermis. X 28U.—After De Bary.
the ordinary commercial article ; the thick-walled form may be obtained
from the bark of the beech, willow, prickly ash (Xanthoxylum Amer-
icanum), Viburnum opulus, etc. Its development may be observed by
making successive sections of the shoots at different heights.CHAPTER VIII.
INTERCELLULAR SPACES AND SECRETION RES-
ERVOIRS.
160. —In addition to the cavities and passages which are
formed in the plant from cells and their modifications, there
are many important ones which are intercellular, and which
at no time were composed of cells. In some cases they so
closely resemble the cavities derived from cells that it is with
the greatest difficulty that their real nature can be made out.
In their simplest form they are the small irregular spaces
which appear during the rapid growth of parenchyma-cells
(Fig. 51, p. 67); from these to the large regular canals
which are common in many water plants there are all inter-
mediate gradations.
161. —In leaves, especially in the parenchyma of the under
portion, there are usually many large irregular spaces be-
tween the cells ; they are in communication with the exter-
nal air through the stomata, and contain only air and watery
vapor. The petioles and stems of many aquatic plants con-
tain exceedingly large air-conducting intercellular canals,
which occupy even more space than the surrounding tissues
(Fig. 9, page 20). In the Water-lilies (Nymphceacece) and
Water-plantains (Alismacece) they are so large as to be read-
ily seen by the naked eye, and in the Naiads (Naiadacew)
they are almost equally large (Fig. 114). In the fibro-vascu-
lar bundles of Equisetum, and of many Monocotyledons and
some Dicotyledons, there are intercellular canals, sometimes
of very considerable diameter (Figs. 99, 102, 103). Lastly,
in the medullary parenchyma (pith) of many plants there is
a large central cavity (although formed in part by the rup-
ture of some cell-walls), which must be considered as inter-INTERCELLULAR SPACES.
129
cellular ; of this nature are the cavities in many hollow stems
—e.g., in many UmbelliferEe and Gramineae.
162.—There are in many plants intercellular spaces and
canals, which are made the receptacles for special secretions,
and to which the
name of Secretion
Reservoirs may be
applied. They are
surrounded (at
first, at least) by
secreting cells,
which furnish the
oil, gum, resin, and
other substances
(see p. 62) found in
the reservoirs.
Their structure
and mode of de-
velopment may be
illustrated by the
gum-canals of the
Ivy (Hedera helix).
Each at first con-
sists of a long col-
umn developed in
the phloem, and
composed of four
or five rows of thin-
walled cells arrang-
ed radially about a
common axis. The
cells soon separate
from each other in
the axis of the col-
umn, and thus
form a small canal
Fig. 114.—Part of the transverse section through the
intemode of the stem of Potamoneton pectinatus. show-
ing the large intercellular spaces between the central
fibro-vascalar bundle and the circumference of the stem ;
e, e, epidermis; a, a small bundle, consisting of surround-
ing fibrous tissue and a vnry small central mns« of sieve
tissue; ft, ft, ft, small bundles containing only fibrous tis-
sue; u, bundle sheath of principal bundle in the axis of
the stem, within which is a mass of sieve tissue surround-
ing the intercellular canal, g. X 80.—After De Bary.
(Fig. 115, A), which is afterward increased in diameter by
the formation of radial partitions, and the tangential growth
of the surrounding cells (Fig. 115, E). The surrounding130
BOTANY.
cells secrete a peculiar sap or gum, which passes into and
fills up the canal.
In the Goniferse the turpentine canals have essentially the
same structure. They are found in the bark,wood and pith ;
they occasionally unite with one another, or change their
direction through some of the medullary rays, the cells of
which have apparently become transformed into resin-secret-
ing tissue.
163.—Allied to the foregoing, although formed in a
slightly different way, are the small secretion reservoirs of
many plants, and in which oils, resins, gums, and other
I
Fig. 115.—Transverse sections of young stem of Ivy (Hedera helix). A, young in-
tercellular gum canal, surrounded by four cells ; c. cambium ; wb. soft bast ; E,
fully developed canal, q ; 5, bast; rp, cortical parenchyma. X 800.—After Sachs.
odorous substances are collected. The fragrance of many
fruits—e.g., oranges and lemons—is due to the oils and other
matters contained in such receptacles. In Dictamnus frax-
inella these are developed as follows : two mother-cells (p, p,
Fig. 116) appear in the hypoderma and divide by several
partitions, forming a mass of thin-walled secreting cells
(Fig. 116, B); these, by a degeneration of their walls, fuse
into a common cavity filled with oil and watery matter (Fig.
116, C). It appears that the outer layer of secreting cells
(c, c) is developed from the epidermis (Fig. 116, A, d, c);
hence this is partly an epidermal structure.
Of like nature are the reservoirs in the “ glandular hairs ”
of the same plant; in fact, the two structures are apparentlySECRETION RESER VOIRS.
131
but slightly different developments of the same organ (Fig.
117).
(a) The smaller and more irregular intercellular spaces may be
studied in the fundamental tissue of the stem of Indian corn, in the
parenchyma of most leaves, and the stems of Juncus.
A
Fig. 116,—Internal glands of the leaf of Dictamnus fraxineUa. A and B, early
stages of development; 6\ mature gland ; d, epidermis ; c, p, mother-cells of the se-
creting cells; o, drop of ethereal oil.—After Rauter.
Fig. 117.—Glandular hair of the inflorescence of Dictamnua froodnella ; A and B,
earliest stages, showing the origin to be similar to that of the internal glands ; C, fully
developed hair ; the part h is the true hair, while all below it, including the oil cav-
ity, is to be regarded as an outgrowth of the sub-epidermal cells. X about 220.—After
Rau ter.
(b) Tliin cross-sections of the stems and petioles of Nymplma,
Nuphar, Nelumbium, Sagittaria, Potamogeton, and many other water
plants, afford excellent specimens for the study of intercellular canals.132
BOTANT.
The relation of the intercellular spaces of the leaves to the canals of
the petioles may be studied by carefully made longitudinal sections.
(c) The resin canals of Silphium laciniatum and 5. perfoliatum, and
the turpentine canals of Conifers, furnish excellent examples of the
larger secretion reservoirs, while the smaller ones may be studied in
the cavities in the rind of the orange and lemon, the leaves of Dictam•
nus, Xanthoxvlum, Rue (Buta), Hypericum, and many Labiatse.CHAPTER IX.
THE PLANT-BODY.
§ I. Genekalized Fokhs.
184.—The cells, tissues, and tissue systems described in
the preceding pages are variously arranged in the different
groups of the vegetable kingdom to form the plant-body.
The simplest plants are single cells or undifEerentiated
masses of cells ; in those next higher the cells are aggre-
gated into simple tissues, while still above these the tissues
are grouped into tissue systems. With this internal differ-
entiation there is a corresponding differentiation of the ex-
ternal plant-body. The lower plants are not only simpler as
to their internal structure, but they are so as to their exter-
nal form as well. The higher plants are as much more
complex than the lower ones as to their external parts as
they are in regard to their tissues and tissue systems.
165. —In the .lowest groups of plants the simple plant-
body has no members ; the single-or few-celled alga has no
parts like root, stem, or leaf ; it is a unit as to its external
form. In the higher groups, on the contrary, the plant-
body is composed of several to many less or more distinct
members. In those plants in which they first appear, the
members are not clearly or certainly to be distinguished from
the general plant-body; but in the higher groups they be-
come distinctly set ofE, and are eventually differentiated into
a multitude of structural and functional forms.
166. —As will be seen in the future chapters, every plant,
in its earliest (embryonic) stages, is simple and memberless,
and every member of any of the higher plants is at first indis-
tinguishable from the rest of the plant-body ; it is only in134
BOTANY.
the later growth of any member that it becomes distinct; in
other words, every member is a modification of, and develop-
ment from, the general plant-body. Likewise, where equiva-
lent members have a different particular form or function,
it is only in the later stages of growth that the differences
appear. All equivalent members are alike in their earlier
stages, whether, for example, they eventually become broad
green surfaces (foliage leaves), bracts, scales, floral envelopes,
or the essential organs of the flower.
167. —These facts make it necessary to have some general
terms for the parts of the plant-body, which are applicable
to them in all their forms. We must have, for example, a
term so generalized as to include foliage leaves, bracts, scales,
floral envelopes, and all the other forms of the so-called leaf-
series. So, too, there is need of a term to include stems,
bulbs, bud, and flower axes, root-stocks, corms, tubers, and
the other forms of the so-called stem-series.
168. —By a careful study of the members of the more
perfect plants we find that they may be reduced to four
general forms, viz., (1) Caulome, which includes the stem
and the many other members which are found to be its
equivalent; (3) Phyllome, including the leaf and its equiva-
lents ; (3) Trichome, which includes all outgrowths or ap-
pendages of the surface of the plant, as hairs, bristles, root-
hairs, etc. ; (4) the Root, which includes, besides ordinary
subterranean roots, those of epiphytes, parasites, etc.
169. —As indicated above, in the lower plants the differ-
entiation into members is not so marked as in the higher,
and in passing downward in the vegetable kingdom groups
are reached in which it is inappreciable, and finally in which
it is entirely wanting ; such an undifferentiated plant-body
is called a Thallome, and may properly be regarded as the
original form, or prototype.
170. —Thallome.* The simplest thallome is the single
cell; this, though generally rounded, is, in some cases
(Botrydium, Caulerpa, etc.), irregularly extended into
branch-like or leaf-like portions, which must not be mistaken
* From the Greek ffa/l/Ms, a young shoot, branch, or frond.GENERALIZED FORMS.
135
for members coordinate with those mentioned above, as they
are only parts of a unit, instead of members of a body; they
may be regarded as, to a certain extent, foreshadowings or
anticipations of the members of the higher plants. Plants
composed of rows of cells or cell surfaces frequently show
no indication whatever of a division into members ; but, in
some cases, there is a little differentiation, which, though
not carried far enough to give rise to members, is the same
in kind. In the larger algae there is sometimes so much of
a differentiation that it becomes difficult to say why certain
parts ought not to be called members. Caulome and phyl-
lome, at least, are strongly hinted at in the Fucaceae, and
in this group, although the term thallome is applied to the
plant-body, it must be admitted as not fully applicable.
Structures of this kind are instructive, as showing that the
passage from the thallome plant-body to that in which
members are differentiated is by no means an abrupt or
sudden one.
171. —Mutual Relations of Thallome, Caulome, and
Phyllome. The caulome is the phyllome-bearing axis of the
plant, and phyllomes are the members developed upon the
caulome. The two have a reciprocal relation, and in no
case is the one present without the other. The definition of
the one involves that of the other. Both are derived
directly from the thallome, and that differentiation which
gives rise to one necessarily produces the other. The differ-
entiation of thallome into caulome and phyllome is simply
a lobing and contraction of the marginal portions into sepa-
rable phyllomes, and a rounding and contraction of the
central or axial portion into a caulome.
172. —Caulome.* By this general name we designate
all axial members of the plant. In the more obvious cases
the caulome is the axis which bears leaves (foliage), and in
this form it constitutes (1) the Stem; branches are only stems
which originate laterally upon other stems.
The other caulome forms are :
(2.) Runners, which are bract-bearing, slender, weak, and
trailing.
* From the Greek navMs, stem.136
BOTANY.
(3.) Boot-stocks, which are bract or scale-bearing, usually
weak, and subterranean.
(4.) Tubers, which are bract or scale-bearing, short and
thickened, and subterranean.
(5.) Corms, which are leaf-bearing, short and thickened,
and subterranean.
(6.) Bulb-axes, which are leaf-bearing, short and conical,
and subterranean.
(7.) Flower-axes, which are bract, perianth, stamen, and
pistil-bearing, short, and usually conical and aerial.
(8.) Tendrils, which are degraded, slender, aerial cau-
lomes, nearly destitute of phyllomes.
(9.) Thorns, which are degraded, thick, conical, aerial
caulomes, nearly destitute of phyllomes.
173.—Phyllome.* The phyllome is always a lateral
member upon a caulome. It is usually a flat expansion and
extension of some of the tissues of the caulome. Its most
common form is (1) the Leaf (foliage), which is usually large,
broad, aud mainly made up of chlorophyll-hearing paren-
chyma.
The other phyllome forms are :
(2.) Bracts, which are smaller than leaves, generally green.
(3.) Scales, which are usually smaller than leaves, wanting
in chlorophyll-bearing parenchyma, and with generally a
firm texture.
(4.) Floral envelopes, which are variously modified, but
generally wanting in chlorophyll-bearing parenchyma, and
with generally a more delicate texture.
(5.) Stamens, in which a portion of the parenchyma de-
velops male reproductive cells (pollen).
(6.) Carpels, bearing or enclosing female reproductive
organs (ovules).
(7.) Tendrils and Spines, which are reduced or degraded
forms, composed of the modified fibro-vascular bundles, and
a'very little parenchyma; in the first the structures are weak
and pliable, in the latter stout and rigid.
The altogether special modifications of the phyllome, as in
pitchers and cups, will be noticed hereafter.
* From the Greek (<7) 9-ranked in Lycopodium selago.
((/<.) 11-ranked not rarely in Sedum reflexum and Opuntia vulgaris.
(k.) 13-ranked in Verbascum, Rhus typhina, Tsuga canadensis.
* This list of examples is from Hofmeister's “ Allgemeine Morphol-
ogic der Gewachse,” p. 448 et seq.ARRANGEMENT OF LEA VES.
151
(il.) 21-ranked in the weak branches of Abies pectinata and Picea
•excelsa, and in most cones of these species.
(m.) 34-ranked on strong branches of Abies pectinata and Picea
excelsa, cones of Pinus laricio, and the interfloral
bracts of the inflorescence of Kudbeckia.
(n.) 55-ranked in the uppermost shoots of many
pines and firs, in many Mamillaries, etc.
(o.) 144-ranked in the interfloral bracts of
strong-grown flower-heads of Helianthus annuus.
199.—By an examination of various
leaf-arrangements, the following interest-
ing hut not very important facts may be
noted (Fig. 129) :
(1.) If we draw a line from the inser-
tion of one leaf to the one next above and
nearest to it, and continue this around the
.stem to the next, and so on, a spiral will
be obtained agreeing with the order of
development of the young leaves on the
punctum vegetationis. To this line, so
drawn, the name of Generating Spiral
has been given.
(2.) In most cases the spiral passes more
than once around the stem before inter-
secting leaves of all the. ranks.
(3.) The number of turns of the spiral
about the stem in intersecting leaves of
all the ranks equals the numerator of the
fraction wdiich indicates the angular di-
vergence of the leaves from each other.
(4.) Two sets of secondary spirals {Par-
astichies)* crossing each other at an acute
angle may be observed on the stem when
the leaves are close together, as in Fig.
and bottom in Roman
numerals, I. to VIII; the
geni'ratiog spiral may lie
readily followed from
kaf to leaf, the latter
being numbered from be-
low upward. — After
Prantl.
129 ; the leaves numbered 1, 6, 11, and 16 form one of the
* It is of great importance that the student should not regard these
spirals (generating spirals and parasticliies) as anything more than
convenient means for describing any particular leaf-arrangement. En-
tirely too much attention has been given to working out all kinds of curi-
ous mathematical laws, which are, to say the least, absolutely worthless152
BOTANY.
parastichies passing to the right, while leaves 3, 6, 9, 12,
15, 18 belong to the parastichies which pass to the left.
(5.) Upon counting,
in Fig. 129, it is found
that there are three
parastichies passing to
the left and five to the
right; the smaller
number is the same as'
the numerator of the
fraction expressing the
angular divergence,
while the sum of the
two equals the denomi-
nator ; similar rela-
tions may be shown to
Fig, 130. — Diagram of eight-ranked arrange- ... ,,
ment, vie wed from above. The orthostichies, which 6XlSt 111 OtJier Cases.
200. — If now we
study the several ar-
rangements by projecting the stem upon a flat surface in
such a way that the successive
nodes, in ascending the stem,
are represented by smaller
and smaller concentric circles
(Fig. 130) (as would, in fact,
be the case if we made sections
through the nodes of the
punctum vegetationis), it is
at once evident that each leaf
is so placed as to stand over
the vacant space between the
previously formed ones, and
that as regards the, leaves
formed after it, it is equally
well situated.
Hofmeister formulates this
here appear to be radial lines, are numbered, as in
Fig. 129, from I. to VIII The leaves are number-
ed from 1 to 10.— After Sachs.
Fig. 130a.—Cross-section of a leaf-bud
of the Hemlock Spruce (Tmga Canaden-
sis). Magnified.—After Hofmeister.
to tiie morphologist. So much has this been done, that the study of
Phyllotaxis has in some quarters become little more than a species of
mathematical gymnastics.ARRANGEMENT OF LEA VES.
153
as follows :* “Kew lateral members have their origin above
the centre of the widest gaps which are left at the cir-
cumference of the punctum vegetationis between the in-
sertions of the nearest older members of the same kind
and no doubt this is one of the most important immediate
causes which determine where each new leaf is to arise. If it
be asked why, then, are not all leaves arranged alike, the
answer must be looked for in the differences in structure of
the puncta vegetationes. In cases where there is an apical
cell, the arrangement of the leaves may be directly traced to
its mode of division. In Phanerogams it is often clearly due
Fig. 1305 — Cross-section of the leaf-hud of the chestnut (Castnnea vesca).
the scale-like leaves;/1,/2,./3, etc., the rudimentary leaves; ^-s1. s2-s2, etc., the
stipules belonging to the correspondingly numbered leaves. Magnified. — After
Hofmeister.
to a difference in the size and form of the punctum vegeta-
tionis ; in Conifers and Composites, for example, it is com-
mon for a change in the arrangement to take place in pass-
ing from the foliage leaves to the bracts of the inflorescence
upon the same stem, the number of ranks in such cases
being greater on the larger axes. Doubtless some of the dif-
ferences can be explained only by taking into account, also,
the inherited peculiarities of the plant.
* “Allgem. Morphol.,” p. 482, and quoted in Saclis’ “Text-Book,”
p. 177.154
BOTANY
A study of actual cross-sections of leaf-buds will make the
truth of the previous statements more clearly evident. Hof-
Fig. 130c.—Cross-section of a lateral bud of the Virginia Creeper (Ampelopsis quin-
quefolia)% showing arrangement of parts in a double bud. Magnified.— After Uof-
meister.
meister’s figures,* several of which are here reproduced (Figs.
130, a, to 130, d), show
that in all cases the leaf
rudiments occupy in
the bud the positions in
which they meet with
the least resistance.
This is beautifully
shown in the leaf-bud
of the Hemlock Spruce
(Fig. 130, a). In the
leaf-bud of the chest-
nut (Fig. 130, i), the
Fig. 130*.—Cross-section of the leaf-bud of a larSe StiPuleS fol'm the
young plant nf Indian corn (Zea mats). I, the bud-SCaleS ; but here, US
cotyledon, with its two flbro-vascular bundles, 1, 1'; .
II, III., IV., V, the successive leaves, their mid- m the preceding Case,
ribs marked by a dot. Magnified.—After Hoftneis- .. . ,,
ter. growth appears to iollow
the “lines of least resistance,” the young leaves occupying
the interspaces between the stipules. The double lateral bud
* In “ Allffem. Morpliol.’INTERNAL STRUCTURE OF LEAVES.
155
of the Virginia Creeper (Fig. 130, c) may also be studied with
profit, and it is curious to see how the positions of some of the
leaves are altered by the fact that the bud is a double one.
The bud of the Indian corn (Fig. 130, cl) shows that the same
law holds in the Monocotyledons as in the Dicotyledons.
- j>
g V. The Internal Structure of Leaves.
201. —The internal structure of leaves varies considerably.
In all cases, however, the leaf is composed mainly of thin-
walled, chlorophyll-bearing parenchyma, and this is to be re-
garded as the proper leaf tissue. The fibro-vascular bundles
constitute little more than the framework of the leaf and
its connection with the
stem, while the epider-
mis is here, as elsewhere
in the plant, a covering
tissue. In the related
members of the plant,
such as bracts, scales,
floral envelopes, and
other phyllome struc-
tures, chlorophyll-bear-
ing parenchyma is gen-
erally wanting, but
flOm tine leaves it is Fig. 131.—Vertical section of a portion of the leaf
rtirol v ottov nl-icpnf Tlip of Echinocustis lobala. e. epidermis of the upper
rai eiy evei aosent. ± ne surface. ^ epidermis of the lower >urface; p, the
shape of the leaf, its parenchyma constituting the “palisade” tissue;
-V 7 p', the loose and irregular parenchyma of the lower
size, position, and re- part Of the leaf. In a part of the section the chlo-
. r 7 rophyll granules are shown. X 250.—From a
lation to other mem- drawing by J. C. Arthur.
hers, all have somewhat to do with securing the best disposi-
tion of the essential leaf tissue.
202. —In leaves composed of one layer of cells, as in many
mosses and some ferns, obviously there is no need of any
special arrangement of the cells in order to secure their best
exposure to light, heat, gases, etc. In thick leaves, however,
the internal cells are clearly not so well situated as the
external ones are, hence we find such leaves possessing some
peculiarities in their structure which obviate this difficulty.
Instead of being composed of solid tissues, their cells are156
BOTANY.
Pig. 132.—Section of tne “ pali-
eade” tissue of the leaf of Echi-
generally loosely arranged, with large intercellular spaces be-
tween them (Figs. 131 and 133), and these are in free com-
munication with the external air by means of the stomata.
It most frequently happens that this loose tissue is in the
under part of the leaf, while the
upper portion is composed of one or
more layers of closely placed cells ;
and this agrees with the general
distribution of the stomata, there
being usually many more on the
under than the upper surface.
203.—The upper denser tissue,
termed palisade tissue, is composed
of elongated cells, which stand at
right angles to the surface of the
leaf (Fig. 131). In cross-section the
t^i‘atm?f«ietakrtewtfjhe palisade-cells are cylindrical, with
chiOToph^n granfali1 “xm- Small intercellular spaces between
Hfrom a drawing by j.c. Arthur, them (Fig. 132), or in some cases
they are more or less compressed and angular.
In general, palisade tissue is confined to the upper surface
of the leaf, the lower being occu-
pied by the loose tissue previously
mentioned ; but there are some cu-
rious exceptions to this rule. The
most notable of these is found in
the leaf of Silphium laciniatum—
the so-called Compass Plant*-—of
the Mississippi Valley ; its chloro-
phyll-bearing parenchyma is almost
entirely arranged as palisade tissue,
so that the upper and lower por-
tions are almost exactly identical
in structure (Fig. 134). The ver-
tical leaves of the Manzanita of
the Pacific Coast (Arctostaphylospungens, var. platypliylla)
have a similar structure.
Fig. 133.—Section of the loose
parenchyma of the leaf of Echino-
cystis lobata, taken parallel to the
leaf Furface. Several of the cells
are drawn showing their chloro-
phyll granules. X 250.—From a
drawing by J. C. Arthur.
* For descriptions of this curious plant, whose leaves have a marked
tendency to stand with one edge to the north and the other to theINTERNAL STRUCTURE OF LEAVES.
15
204.—Another curious leaf structure is to be seen in
Stipa spartea, the Porcupine Grass of the interior; each long
harsh leaf is longi-
tudinally channel-
led on its upper
surface, which, by
the twisting of the
basal portion of
the leaf, becomes
apparently the low-
er, and the chlo-
rophyll-bearing pa-
renchyma is con-
fined to the sides of
the channels (Pigs.
135 and 136). At
the bottom of each
channel the epider-
mal cells are pe-
culiarly developed
into a hygroscopic
tissue, which, by
contracting, closes
the channels and
rolls the leaf to-
gether, as always
takes place in dry
air.
(a) Many Monocoty-
ledons—as, for exam-
ple, Iris and Indian
rnr„__afford o-ond sne FiS- 134.—Transverse section of the leaf of Sllphivm
corn anora gooa spe- iaciniatvm. e< epidermis of the ui.per surface ; e', ept-
cimens of very young dermis of the lower surface ; p, palisade tissue of the
loaves Tlv earefnllv ?ppe,r Polti<>“ of the leaf; p\ palisade tissue of the
reaves, rry eareiuuy lower part of the leaf ; s, a stoma seen in transverse
removing the outer section. X 235.— From n drawing by the anthor.
leaves in succession all stages of leaf-development may he obtained.
south—i.c., with the leaf-planes parallel to the plane of the meridian-
see articles in the American Naturalist: 1870, p. 495 ; 1871, p. 1;
1877, p. 489.158
BOTANY.
In this way often much light will be thrown upon the morphology'
of leaf parts.*
(p) Among Dicotyledons it is generally best to select those whose
young leaves are least downy or hairy,
otherwise the difficulties of the examina-
tion are greatly increased. The lilac iB
one of the best for this purpose. Longi-
tudinal sections, prepared as in the ex-
amination of young stems, should be
made.
(c) The young leaves in the winter buds
of the hickory are instructive, as showing
how compound leaves are formed.
chlorophyll-bearing parenchyma (d) The study of the arrangement of
(figured dark in the cut), x 18. ieaves \3 most interesting in the twigs
and cones of the Conifers, and the stems and heads of the Composites.
The student should, however, before spending much time in tha
Fig. 135.—A part of a trans-
verse section of the leaf of Stipa
spartea in the position it as-
sumes— i.e., with what is really
the upper surface turned toward
the earth. /,/, ribs, each con-
taining a fibro-vascular bundle ;
between these are the masses of
Fig. 136.—Transverse section of one of the ribs of the leaf of Stipa spartea. tp,
chlorophyll-bearing parenchyma ; $, s, portions of the epidermis containing stomata ;
he, he, hygroscopic cells, which contract when the leaf rolls up. The blank space on
the left shows the extent of the cavity occupied by chlorophyll-bearing parenchyma.
X 125—From a drawing by the author.
examination of the more difficult forms, study the twenty-sixth section
of Sachs’ '* Text-Book of Botany,” and the whole subject of the
* In illustration of this, the Iris itself may be cited. Its leaf is
usually spoken of as made by the folding of its upper surface uponTEE ROOTS OF PLANTS.
159
arrangement of lateral members as given in Hofmeister’s “ General
Morphology.” * *
* (e) The internal structure of the leaf may be easily studied. The-
most important sections are those made at right angles to the surface ;
but some should be made also parallel to it, so as to show the form of
the palisade cells and the dispositions of the cells in the loose tissue of
the under surface. The leaves of the lilac, apple, cherry, Impatiens,
SiTpMum, sunflower, etc., are very good for this study. The more
difficult sections can be more easily made after soaking the leaves for
some time in strong alcohol, thus hardening them.
§ YI. Of the Eoots of Plants.
205. —The root differs from all other members of the
plant in being tipped with a peculiar mass of cells—the Root-
cap (pileorhiza f)—and in originating endogenously ; from
stems it differs in never producing leaves or other phyllome
structures. There is some doubt as to whether the Primary
Root—i. e,, the first root of the embryo—is not in many cases
formed otherwise than endogenously ; \ but all common roots
certainly are developed from beneath the surface of other
parts of the plant.
206. —Roots may develop from any part of a plant which
contains fibro-vascular bundles, so that it is no uncommon
thing for them to issue from stems (particularly their nodes)
and leaves, as well as from other roots. Whatever their
origin, they are essentially alike, the differences, as before
intimated, being of minor importance. They all agree in hav-
itself, so that the two sides exposed to the air and light are said to be
in reality the under surface. A study of the very young leaf of the
Iris, along with that of Ilemerocallis, shows them to be alike ; both are
composed of an upper laterally flattened portion and a lower channelled
one; in the Iris the upper portion grows fully as much as the lower,
while in Hemerocallis the growth is almost entirely confined to the lower
portion, the upper extending but little aDd forming the small extremity
of the leaf. The small tip of the leaf in the latter case is clearly the
homologue of the whole of the so-called ensiform leaf of the former.
* “ Allgemeine Morphologie der Gewachse,” von Wilhelm Hofmeis-
ter; Leipsig. 1868.
\ From the Greek m'/leoS, a cap, and f>%a, a root.
\ The mode of formation of the Primary Root will be taken up for each
group of plants in Part II.160
BOTANY.
ing less perfectly developed tissues and tissue systems. Their
epidermal system is more feebly developed, and they bear vervTHE ROOTS OF PLANTS.
161
simple tricliomes—the root-hairs. The fibro-vascular bun-
clj.es are, especially in the higher plants, of a much lower
type than those in the stems and leaves. The fundamental
system is also poorly developed, and has not that variety of
tissues found in other portions of the plant.
207. —Another remarkable peculiarity of roots is that they
differ much less from one another in structure than do their
stems. The young roots of Monocotyledons have very nearly
the same structure that those of Dicotyledons have, and those
of Pteridophytes do not differ much from either. The older
roots of Monocotyledons and Dicotyledons differ considerably,
on account of changes in their structure which take place
later, and then each root bears a closer resemblance to the
stem from which it grows, or to which it belongs.
208. —The general structure of the root-cap may be easily
understood from the accompanying figure (Fig. 137). It is
a cap-like mass of parenchymatous cells which surrounds
the end of the root; its outer cells are loose, and in some
cases are more or less changed into a mucilaginous mass;
in any event they gradually lose their protoplasm and become
detached and destroyed. The inner layers (i, s, Fig. 137) are
constantly developing from a deep-lying tissue, the Dermato-
gen* (not shown in the figure), so that as the cap is destroyed
on the outside it is renewed from the interior. By its lat-
eral growth it in some cases ensheatlies the terminal part of
the root for a considerable distance.
209. —Back of the root-cap lies the primary meristem of
the root, composed, in Phanerogams, of a mass of small and
actively dividing cells. In this meristem there is as yet no
differentiation, but as it is prolonged by rapid cell-multipli-
cation the cells become modified in its posterior portion.
There is thus a constantly advancing formation of meristem,
followed at a little distance by as constant a modification
into other tissues. The usual course of this differentiation
is first into a central cylindrical mass, the Pleromef (Fig.
* From the Greek Stppa, depfiarot, skin, and yevvuo, to bring forth or
generate.
| So named by Hanstein (“ Scheitelzellegruppe im Vegetationspunkt
der Phanerogame^” 1868), from the Greek jrXfjpupa, a filling up.162
BOTANY.
137, m, f, g), which is ensheathed by the Periblem,* which
■soon becomes transformed into the cortical portion of the
root (x, r, Fig. 137). The epidermis is developed from the
region from which the root-cap grows, and, in fact, as will
be shown below, it is a continuation and modification of the
generating tissue of the root-cap.
210.—In Fig. 138 the relation of the parts is even better
shown than it .he previous figure. The central plerome
•column is surrounded by a layer of active cells, the pericam-
Fig. 138.—Median longitudinal section of the apex of the root of the buckwheat
Fagopyrum esculentum). pc, pericambium, constituting the boundary of the plerome
column ; e, dermatogen ; between e and^?c, periblem ; 7i, root-cap.—Alter De Bary.
bium (pc); outside of the latter lies the periblem, or young
cortical portion, and still outside of this the dermatogen
(e), which further back on the root becomes the epidermis.
The root-cap (h) lies entirely outside of, and is quite distinct
from, the back portions of the dermatogen, but near the
apex of the root there is a tract in which dermatogen and
root-cap apparently fuse into one. At this point the layers
* Another of Hanstein’s terms, from the Greek izepiSXrifia. a cloak.TILE ROOTS OF PLANTS.
163
of the root-cap originate by the successive divisions of the
dermatogen cells by partitions parallel to the curved surface
of the root-tip. As the dermatogen is continuous with the
epidermis, we may regard the root-cap as morphologically
•a greatly thickened and somewhat modified epidermis.
Fig. 139.—Mode of formation of the lateral roots in a mother-root of Trapa natans.
A, a portion of the pericambium n, bounded externally by the innermost layer of cor-
tical cells, r; d, dermatogen ; n, the inner layer of the pericambium after splitting :
B, the same advanced somewhat, the inner layer is beginning to divide; C, young
root enclosed in the tissue of the mother-root; R. r, cortex of mother-root; tt, pen-
cambium of mother-root, from which the new root has been formed ; h, first layer of
the root-cap of the new root, formed by the splitting of its dermatogen b ; i, n, mass
of cell* resulting from the division of the layer n m A ; D, new root further devel-
oped (the thick cortical tissues of the mother-root are not shown ; r, inner layer of
conical tissue of mother-root); p, p, periblem of new root; m, m, the tissue which
connects the new root with the tissues of the mother-ioot. Magnified.—After
Reinke.
The plerome column is a mass of nascent fibro-vascular
elements, and in it, somewhat further back from the root-tip,
a differentiation into the bundle takes place.164
BOTANY.
211. —The formation and development of a new root is
interesting and suggestive. It usually takes place at some
distance from the primary meristem, in the cambium or peri-
cambium. In the root of Trapa natans it takes place as fol-
lows : The cells of a restricted portion of the pericambium
divide by tangential walls into an outer layer, which becomes
the dermatogen of the new root (d, Fig. 139), and an inner
layer, from which develops its primary meristem (n, Fig.
139). The inner cells multiply by divisions in several direc-
tions, and as their mass increases they push out the young
dermatogen (B, C, and D, Fig. 139). From the dermato-
gen the first layer of the root-cap is formed by the tangen-
tial division of its cells (C, h, Fig. 139). These growing
tissues push out the overlying portions of the mother-root,
and finally break through them. The root is thus seen to
be a strictly endogenous formation ; there is no connection
between its tissues and the epidermal and cortical portions
of the mother-root, the sole connection being with the deep-
lying tissues in, or in connection with, the fibro-vascular
bundles. Herein roots present a marked contrast to stems
and leaves, which, as a rule, develop from the exterior of
the plant-body, or, in other words, are exogenous in their
origin.
212. —Roots are rarely arranged in as regular an order as
are stems. In general they arise in acropetal order upon the
mother-roots of Pteridophytes and the primary roots of Pha-
nerogams, but this order is subject to many more disturbing
influences than in the case of the origin of stems. As to
position, they may arise in rows or ranks, or in particular
spots, dependent upon the disposition of the fibro-vascular
bundles, or the generating tissues in the root or stem. Thus
it may happen that on a root or stem there may be as many
rows of roots as there are fibro-vascular bundles. Roots
which develop from stems are generally much more affected
by external influences than those which grow from othei
roots. The degree of moisture of the different parts of the
stem appears to have much to do in determining the point
of the appearance of roots ; this is seen in stems which touch
the ground, as in the tomato, and in climbing plants, as theTHE ROOTS OF PLANTS.
105
Ivy (Hedera), Poison Ivy (Rhus), tlie Virginia Creeper (Am-
pelopsis), etc.
213.—In form roots are generally fibrous, and this is
manifestly their best form, in so far as they are organs for
obtaining dissolved matters from the soil. In perennials,
however, as the stems become larger the roots increase cor-
respondingly to support the additional weight; they thus
become hold-fasts or mechanical supports. In other cases
they are made the recipients of assimilated matters, as starch,
sugar, etc., arid thus become thickened storehouses.
In many cases the latter are capable of forming buds and
of sending out new stems from the ineristem tissue in, or in
the vicinity of, the fibro-vascular bundles, as is notably the
case in the tuberous root of the sweet potato.
(a) The root-cap may be studied with the least difficulty in roots
which are grown in water. Those of Lemua may be easily obtained,
and are excellent.
(b) Roots of Indian corn, Hyacinth, Impatiens, etc., also furnish
easily made and good specimens.
(c) In preparing specimens for examination thin longitudinal sections
should be made, and these should be supplemented by transverse sec-
tions taken at various heights on a root-tip.
(d) By the use of staining fluids, as carmine, magenta, etc., some
points in the structure will be made more evident. Iodine should also
be used ; by treatment with it, the starch which is present in the root-
tip in many, if not all, cases may be seen.
(e) For studying the formation and development of new roois suc-
culent plants should be chosen, as the sections of their tissues are more
transparent than those of other plants. On this account many water
plants are to be preferred. Among land plants, Impatiens is one of
the best; it always has a large number of forming roots on its stem
near or at the surface of the ground.
(/) Vertical sections of the papillae, showing the point of appearance
of new roots, should be made. If many longitudinal slices of the
lower part of the stem of Impatiens are made in a section-cutter, it will
almost certainly happen that some good specimens will be found.CHAPTER X.
THE CONSTITUENTS OF PLANTS,
g I. The Water in the Plant.
214. —Amount of Water in Plants. All living parts of
plants are abundantly supplied with water. It is always
.present in living protoplasm, and the greater its activity the
more -watery is its composition. The cell-walls of living
tissues also contain large quantities of wafer; and in plants
composed of many cells (as the larger flowering plants) even
those cells and tissues which have lost their activity generally
have their walls saturated with water. In ordinary herbace-
ous land plants the amount of water is not far from 75 per
cent of their whole weight; thus in growing rye it is about
73 per cent; in meadow grass, before blossoming, 75—after
blossoming, 69 ; in lucerne, when young, 81—in blossom, 74 ;
in white clover, 80; in red clover, before blossoming, 83—
after blossoming, 78 ; in oats, in blossom, 81; in Indian
corn, in blossom, 84. In certain parts of plants the per-
centage is still higher ; for example, in the leaves of the field
beet it is 90 ; in tubers of the potato, 75 ; in the thickened
root of the parsnip, 88 ; in the similar root of the turnip,
92. In aquatic plants the percentage is much higher, often
■exceeding 95; it is so abundant in many of the simpler
forms that upon drying nothing but an exceedingly thin and
delicate film is left.
215. —Water in the Protoplasm. As explained in parar
graphs 4 and 5 (page 5), living protoplasm has the power
of imbibing water, and thereby of increasing its fluidity.
Even after it has imbibed all the water which it can retain
it continues the process, and separates the surplus in dropsTHE WATER IN THE PLANT.
167
in its interior, the so-called vacuoles. Now an examination
of the cells of rapidly growing tissues shows that their pro-
toplasm is much more watery than that of living, but dor-
mant tissues—e.g., those of seeds—and one of the first signs
of activity in the latter is the imbibition of water.
This avidity of protoplasm for water plays an important
part in the general economy of the plant. By it all the cells
which contain protoplasm are kept turgid, and by the ten-
sion thus created the soft parts of plants are made rigid.
It plays no small part also in keeping up the supply of
moisture in living tissues when wasted by evaporation. (See
paragraph 220 et seq.)
210.—Water in the Cell-walls. In the cell-walls, accord-
ing to Nageli’s theory, the water forms thinner or thicker
layers surrounding the crystalline molecules of cellulose. (See
paragraph 37, p. 32.) The wall of the cell is thus not a
membrane which separates the water of one cell cavity from
that in the next, but rather a pervious stratum, composed of
solid particles which are not in contact, and between which
the water freely passes. In a living tissue the water is con-
tinuous from cell to cell, and constantly tends to be in equi-
librium—i.e., the turgidity of the cells is approximately
equal throughout the tissue, and likewise the wateriness of
both cell-walls and cell-contents.
In the simpler aquatic plants the water of the cells and
their walls is continuous with that in which they grow.
Likewise the water in the tissues of roots or other absorbing
organs of the higher aquatic plants is continuous with that
which surrounds them; and even in ordinary terrestrial plants
there is a perfect continuity of the water in the root tissues
with the moisture of the soil.
217.—Water in Intercellular Spaces. In some cases the
intercellular spaces and passages, and even the vessels of the
more succulent plants, are filled with water, thus increasing
its amount in the whole plant very considerably. More
commonly, however, these cavities are filled with air and
gases, the vessels having early lost the inotoplasm which
they contained at first. It is probable, moreover, that the168
BOTANY.
water which is occasionally found in their cavities has little
or no physiological relation.
218. —The Equilibrium of the Water in the Plant. The
water in the tissues of every plant tends constantly to become
in equilibrium, and this state would soon be reached were it
not for certain disturbing causes which are almost as con-
stantly in action. In any cell an equilibrium may soon be
reached between the two forces which reside respectively in
the cell-wall and the protoplasm, viz., (1) the attraction of
the surfaces of the molecules for the water, and (2) the
“ imbibition power ” of protoplasm. This equilibrium onoe
attained, all motion of the water must cease, and it must
remain at rest until disturbed by some other force or forces.
This condition, or one approximating very closely to it, is
reached by many of the perennial plants during the winter
or period of rest.
219. —Disturbance of Equilibrium. During the growing
stages of plants the equilibrium of the water is constantly
disturbed in one or more ways, viz., (1) by the chemical
processes within the cells ; (2) by the “ imbibition power” of
the protoplasm and walls of newly formed cells ; (3) by the
evaporation of a portion of the water.
The chemical processes within the cell include : (1) the
actual use of water by breaking it up into hydrogen and
oxygen ; every molecule which is so broken up leaves a
vacancy which, sooner or later, must be replaced; (2) the
formation of substances which are more soluble than those
from which they were formed ; (3) the formation of sub-
stances which are less soluble than those from which they
were formed. These processes take place in all cells, even
those of the simplest plants.
In plants composed of tissues, wherever new cells are
forming and developing, the new protoplasm and cell-walls
require considerable quantities of water to satisfy their
molecular attraction (paragraphs 215 and 216 above) ; this
supply is always made in part or entirely at the .expense
of the adjacent cells. In many aquatic plants there can
be little doubt that the needed water in meristem tissues
is obtained partly by direct absorption from the surround-THE WATER IN THE PLANT.
1G9
ing water, but tins can only be the case with the external
cells ; the deep-lying ones must obtain their supply from the
cells which surround them. In aerial parts of plants the
newly formed cells obtain all their water from the adjacent
cells.
220.—Evaporation of Water. In the aerial parts of plants
the evaporation of water from their surfaces is a far more
powerful disturbing cause than either of the two preceding.
Whenever a cell is exposed to dry air at ordinary tempera-
tures a portion of its water passes otf by evaporation ; this
immediately disturbs the equilibrium of water throughout
the tissue, and the more rapid or the longer continued the
evaporation, the greater the disturbance.
Evaporation (called also transpiration and exhalation)
from living cells or tissues is dependent upon a number of
conditions, some of which are entirely exterior, while others
are connected with the structure of the plant itself. Among
the former, the most important is the condition of the air as
to the amount of moisture which it contains. In air satu-
rated with moisture no evaporation can take place ;* but
whenever the amount of moisture falls below the point of
saturation, if the other conditions are favorable, evaporation
takes place. The temperature of the air (and, as a conse-
quence, that of the plant also) has some effect upon the
rapidity of evaporation. It appears that there is an increase
in the amount of water given off as the temperature rises;
this may be due, however, to the fact that with such increase
of the temperature of the air there is generally a considerable
decrease in its moisture. The direct influence of light upon
evaporation is also somewhat doubtful. While there can be
no doubt that plants generally lose more water in the light
than in darkness, it may be questioned whether this is not
* Many experiments, at first Bight, seem to show that plants evapo-
rate water in air saturated with moisture ; but Knop has found
(“ Versiiclis-Stationen,” Vol. VI., p. 255) that, under similar conditions,
moist pieces of paper or wood also evaporate water, thus showing that
the air, instead of being saturated, lacked somewhat of being so.iro
BOTANY.
mainly due to the increased heat and dryness which axe
common accompaniments of the increase of light.*
221. —In enumerating the internal conditions one general
one must not be forgotten, which is, that the water in plant-
cells contains many substances in solution, and consequently
evaporates less rapidly than pure water, in accordance with
well-known physical laws. Moreover, the attraction of the
molecules of the cell-walls for the water layers counteracts,
to a considerable extent, the tendency to evaporation ; and
in the same manner, even to a greater extent, the water is
prevented from passing off by the “imbibition power” of
protoplasm. It is, in fact, impossible to deprive cellulose
and protoplasm of their intermolecular water in dry air at
ordinary temperatures.
In all the aerial parts of higher plants the epidermis
offers more or less resistance to the escape of the water of the
underlying tissues. This is mainly accomplished by the
thick and cuticularized outer wall of the epidermal layer ; in
many cases, especially in plants growing naturally in very
dry regions, the epidermis consists of several layers of cells,
which offer still more resistance to evaporation by being
themselves filled with moist air only. Among the lower
pilants, the single reproductive cells (spores) are guarded
against the loss of water by having their walls greatly thick-
ened and cuticularized. Even in the lowest plants, the Slime
Moulds (Myxomycetes), the naked masses of protoplasm,
when placed in dry air, will contract into rounded masses,
which then become covered with a somewhat impervious
envelope (paragraph 23, c : page 21).
222. —The stomata of the green and succulent parts of
higher plants control to a great extent the amount and
rapidity of their exhalation. In leaves, for example, where,
on account of its cuticularization, there can be but little
evaporation through the epidermis, it is dependent upon the
* I am aware that some experiments made with plants in saturated
and in dry air appear to show that in direct sunlight there is a rapid,
evaporation. I cannot, however, regard these experiments as con*
elusive.THE WATER IN THE PLANT.
171
number, size, and condition (i.e., whether open or closed)
of the stomata. As previously described (paragraph 130, p.
99), the stomata are placed over intercellular spaces, which
are in communication with the intercellular passages of the
plant. These spaces and passages are filled with moist air
and gases, which, when the stomata are open, expand and
contract with every change of temperature or atmospheric
pressure, and thus permit the escape of considerable amounts
of water ; when, on the other hand, the stomata are closed,
little or no escape of moisture is possible. The opening and
closing of the stomata appear to depend upon the amount of
light; they open more widely the greater the amount of
light, and close almost completely in darkness. The amount
of moisture on the surface of the epidermis appears also to
aifect somewhat the opening and closing of the stomata ;
when the epidermis is very dry the stomata are generally
closed, and vice versa.
223.—The Amount of Evaporation. The conditions con-
trolling evaporation are thus seen to be many and various.
They never, or but very rarely, act singly, two or more of
them usually acting together with varying intensity, so that
the problem of the amount of evaporation taking place at
any particular time is a complex and difficult one. All the
observations yet made, and which have necessarily been upon
a very small scale, indicate that the rate of evaporation is
actually very slow. Thus Hales long ago found that the
amount of water evaporated from a vine in twelve hours of
daylight equalled a film only .13 mm. (.005 in.) thick, and
having an extent as great as that of the evaporating surface ;
the amount from a cabbage in the same time equalled a film
.31 mm. (.012 in.) thick ; from an apple tree, .25 mm. (.01
in.) thick ; from a sunflower in a day and a night, equal to
a film .15 mm. (.006 in.) thick.* M tiller found the rate of
evaporation from the leaves of Hcemanthus puniceus to be
only one seventeenth as rapid as that from an equal area of
water during the same time. Sachs found the evaporation
* “ Statical Essays : Vegetable Statics,” by Stephen Hales. 1727.
Fourth edition. 1769. p. 21.172
BOTANY.
from the leaves of the White Poplar to be about one third as
rapid as from water. Unger places the evaporation from
most leaves at about one third that from equal areas of
water; in some cases, however, running as low as one fifth
and one sixth.*
224. —Pfaff calculated the amount of water evaporated
from an isolated oak tree during the growing season. The
tree selected was a close-topped one 6f metres (20 ft.) high,
bearing about 700,000 leaves. The results were as follows :
May (14 davs).......... 883 kilograms = ( 1,944 lbs.)
June......!............26,023 “ =(57,250 “
July....................28,757 “ = (63,265 “
August..................21,745 “ =(47,839 “
September...............17,674 “ = (38,882 “
October.................17,023 “ = (37,450 “
The evaporation from each leaf was for the season of five
and a half months (one hundred and sixty-seven days) .16
kilograms (.35 lbs.); allowing forty-eight square centimetres
of surface to each leaf, this amounted to a layer of water
3.33 centimetres (1.31 in.) deep over the whole evaporating
surface, f
225.—The Movement of Water in the Plant. It is clear,
from what has been said, that in polycellular plants there
must be a considerable movement of water in some parts, to
supply the loss by evaporation. Thus in trees there must be
a movement of water through the roots, stems, and branches
to the leaves, to replace the loss in the latter. This is so
evident that it scarcely needs demonstration ; it can, how-
ever, be shown by cutting off a leafy shoot at a time when
* The three last statements and the following are given on the
authority of Duchartre (“ Elements de Botanique,” second edition, 1877,
pp. 844 and 846).
f Pfaff found that the water evaporated during the season, when con-
sidered with reference to the area of ground covered by the tree top,
was equal to a layer 5.39 metres high (212 incites). Observation had
shown the annual rain-fall to be .65 metres (25.6 inches); so that the
water evaporated from the tree was eight times the amount which fell
upon the earth under it. The evaporation is very much less in dense
forests than in isolated trees, but with every allowance it is sufficient
in dry, hot seasons to quickly exhaust the moiBture of the soil.THE WATER IN THE PLANT.
173
evaporation is rapid ; in a short time the leaves wither and
become dried up, unless the cut portion of the shoot be
placed in a vessel of water; in the latter case the water will
pass rapidly into the shoot, and the leaves will retain their
normal condition. If in such an experiment a colored watery
solution (as of the juice of Poke berries) be used instead of
pure water, it will be seen that the liquid has passed more
abundantly through certain tracts than through others, in-
dicating that the tissues are not equally good as conductors
of watery solutions. As would readily be surmised, the
tissues in ordinary plants which appear to be the best con-
ductors are those composed of elongated wood-cells, and it is
doubtless through them that the greater part of the water
passes. Furthermore, it is probable that the movement of
the water is through the substance of the cell-walls, and not,
at least to any great extent, through the cell cavities. Ac-
cording to this view, the force which raises the water, in
some cases to the height of a hundred metres or more, is the
attraction of the surfaces of the crystal molecules for the
layers of water which surround them.
226.—The rapidity of the upward movement of water evi-
dently varies directly as the rapidity of evaporation, and in-
versely as the area of the conducting tissue in transverse sec-
tion. As both these factors are variable, it is impossible to
give an average rate of movement. Sachs estimated the
rate of ascent in a branch of the Silver Poplar, from which
there was strong evaporation, at 23 cm. (9 in.) per hour.
McNab, by Watering plants with a solution of lithium citrate
and then examining the ashes at successive points, found the
rate in a Cherry Laurel to be 101 cm. (40 in.) per hour. Pfit-
zer obtained the astonishing result of 22 metres (72 ft.) per
hour in the Sunflower ; there is but little doubt, however,
that this is entirely too high.
(a) In addition to the movements of the water described above, that
which has been called root, pressure requires a brief mention. If the
root of a vigorously growing plant be cut off near the surface of the
ground and a glass tube attached to its upper end, the water of the root
will be forced out, often to a considerable height. Hales* noted a pressure
* Statical Essays, p. 114.174
BOTANY.
upon a mercurial gauge equal to 11 metres (3G.5 ft.) of water when at-
tached to the root of a vine ( Vitis). Clark,* in a similar manner, found
the pressure from a root of the birch (Betubi lutea) to be equal to 25.8-
metres (84.7 ft.) of water. This root pressure appears to be greatest
when the evaporation from the leaves is least ; in fact, if the experi-
ment is made while transpiration is very active, there is always for a.
while a considerable absorption of water by the cut end of the root,
due probably to the fact that the cell-walls had been to a certain ex-
tent robbed of their water by the evaporation from above. Root pres-
sure is probably a purely physical phenomenon, due to a kind of en-
dosmotic action taking place in the root-cells.
(b) The flow of water (sap) from the stems and branches of certain
trees, notably from the Sugar Maple, appears to be due to the quick
alternate expansion and contraction of the air and other gases in the
tissues from the quick changes of temperature. The water is forced out
of openings in the stem when the temperature suddenly rises ; when
the temperature suddenly falls, as at nighl, there is a suction of water
or air into the stem. When the temperature is nearly uniform, whether
in winter or summer, there is no flow of sap.
§ II. As to Solutions.
227____The water in the plant holds in solution several
substances, so that it is not water alone, but in reality a
complex solution. Some of the substances in solution are-
solids, as the inorganic salts taken up from the soil or water,
while others are gaseous, as the air and carbon dioxide taken
up in the water by the roots, or absorbed by the leaves and
there entering into solution in the water. The final use of
these solutions will be spoken of further on ; here it is only
necessary to point out some of the more important general
facts as to solution and diffusion :
1st. When a substance has entered into solution it still
exists as that substance, and the water in which it is dis-
solved is in one sense pure. This is readily shown by driving-
off the water by heat, when the dissolved substance is again
obtained in its original solid state.
2d. As soon as solution begins the process of diffusion
* In 1873, recorded in the Twenty-first Report of the Secretary of
the Massachusetts State Board of Agriculture, See also further re-
sults by the same observer in the Twenty-second Report.PLANT FOOD,
175
necessarily commences also ; this is the passage of the mole-
cules of the dissolved substance through the water without a
movement of the latter. Thus in perfectly quiescent water
a substance may diffuse itself between the molecules of the
latter to considerable distances, and this may take place in
any direction, even when the substance is heavier than water ;
thus common salt placed in the bottom of a tall vessel of
water will dissolve and gradually diffuse throughout the
whole.
3d. The rapidity of diffusion varies for different sub-
stances ; thus the diffusion.rate of sugar is more than three
times that of common salt (exactly as 365 to 110).
4th. Two or more diffusions may take place at the same
time in the same fluid, and they may move in the same or in
opposite directions.
5th. Diffusion continues until all parts of the solution
contain equal quantities of the dissolved substance.
6th. If at any point in a solution the dissolved substance
be removed in some way, as, for example, by the formation
of a new salt by chemical reaction, there will be, as a conse-
quence, a continued diffusion toward that point; and if the
new salt be a soluble one it must diffuse in every direction
from the point of its formation. Thus the molecular move-
ments may become quite complex.
§ III. Plant Food.
228.—The most important elements which are used in
the nutrition of plants, or which, in other words, enter into
their food, are Carbon, Hydrogen, Oxygen, Nitrogen, Sul-
phur, Iron, and Potassium. These all appear to be necessary
to the life and growth of the plant, and if any of them are
wanting in the water, soil, or air from which the plant de-
rives its nourishment, death from starvation will soon follow.
There are other elements which are made use of by plants,
but as life may be prolonged without them, they are regarded
as of secondary importance. In this list are Phosphorus,
Calcium, Sodium, Magnesium, Chlorine, and Silicon.176
BOTANY.
229.—The Compounds Used. With the single exception
of oxygen, the elementary constituents named above do
not enter into the food of plants in an uncombined state ;
on the contrary, they are always absorbed in the condition
of compounds, as water, carbon dioxide, and the
Nitrates )
Sulphates
Carbonates !
Phosphates
Silicates, or
Chlorides
' Ammonia.
Potash.
Lime.
Iron.
Soda, or
Magnesia.
In addition to these, many organic compounds are- ab-
sorbed in particular cases, as in those plants which live in
decaying animal or vegetable matter (saprophytes), as well
as those which absorb the juices from living plants (para-
sites).
230.—How the Food is Obtained.—In the case of aquatic
plants, these compounds are taken into the plant-body by a
process of diffusion from the surrounding water; in terres-
trial plants the gaseous compounds, as carbon dioxide and
carbonate of ammonia, are absorbed—at least in part—by the
leaves directly from the surrounding air, while the solutions
of these and the other compounds in the water in the soil
find their way into the plant by diffusion.
230a.—How the Food is Transported in the Plant.
Once within the plant-body, the food materials diffuse to all
watery parts, in the case of the larger terrestrial plants ris-
ing through the stem to the leaves. By diffusion, there is a
constant tendency toward an equal distribution throughout
the plant of the solutions which enter it, and if there were
no disturbing chemical reactions taking place, such a condi-
tion would in most plants be soon reached. It is quite
probable, indeed, that this actually happens for certain sub-
stances which are found in solution in the soil or water, and
which, entering plants, diffuse through them to all parts,
but not being used they soon reach a state of equal diffusion,
which is only slightly disturbed by the extension of the
plant-body by growth. Doubtless the rapid diffusion of
food materials throughout terrestrial plants is aided by thePLANT FOOD.
177
evaporation of water from the leaves, thus causing a strong
upward movement of the water which contains the various
solutions of food matter. Moreover, there can be no doubt
that the movement of the water in terrestrial plants, caused
by the swaying and bending of the stems and branches,
facilitates and hastens the diffusion of food materials.CHAPTER XI.
CHEMICAL PROCESSES IN THE PLANT.
§ I. Assimilation.
231. —In many plants the food materials which are taken
into the plant-body are of such a nature that they can be
directly used by the protoplasm ; thus in the saprophytes
the solutions of organic compounds derived from the decay
of animal or vegetable tissues are imbibed by the protoplasm
and used by it as true food ; and in the parasites the proto-
plasm and the juices of living tissues are directly used in a
similar way. It is, furthermore, probable that in some of
the lowest forms of vegetation, as in the Myxomycetes and
Schizomycetes, the protoplasm is capable of making, to a
limited extent, a direct use of some of the inorganic sub-
stances absorbed by them. For the most part, however, the
principal food materials taken in by plants are such as can-
not be directly used by protoplasm in either its vegetative
or reproductive activity; thus neither water nor carbon
dioxide is directly used as food by the protoplasm of ordi-
nary green plants, but in all cases they undergo certain
chemical changes, bv which they are made suitable for use
by protoplasm. To these preparatory changes, which fit the
crude food materials for protoplasmic food, the general name
of Assimilation has been given.
232. —It is impossible as yet to give a complete statement
of all the processes in assimilation ; the principal facts now
made out appear to be as follows : In the chlorophyll-
bearing portions of plants, carbon dioxide and water are de-
composed, and from their component elements carbohydrates
are at once formed. This decomposition and subsequent
combination take place only in the granules or masses ofMETASTASIS.
179
chlorophyll, and only in sunlight. Those parts of ordinary
plants which are destitute of chlorophyll are entirely want-
ing in the power of assimilation, and likewise the chloro-
phyll-bearing portions are unable to assimilate in darkness.
Carbon dioxide is probably decomjjosed into carbon oxide
and free oxygen : C02 = C0 + 0. At the same time water
is decomposed into hydrogen and oxygen : H2 0 = 2 II +
0. The free oxygen atoms are exhaled, and by the union
of carbon oxide and hydrogen, starch is in most cases
formed; this appears as minute granules imbedded in the
chlorophyll-bodies (Fig. 43, p. 52). In some plants no
starch is formed in the chlorophyll, but oily or sugary mat-
ters which have nearly the same chemical significance.
Assimilation is thus a deoxidizing process. Both water and
carbon dioxide contain large quantities of oxygen, while in
starch it is much less ; consequently, in the formation of the
latter from the former, there must be a surplus of oxygen.
This may be shown as follows :
13 co* = ...........................
If - = 24 O set free.
,0 = 11^"’
12 Hj
( 21H .
starch
= C12H20O10 + 2H2O
Here twelve molecules of carbon dioxide and twelve mole-
cules of water produce one molecule of starch and two mole-
cules of water (water of organization), while twenty-four
atoms of oxygen are set free and permitted to escape from
the cells into the surrounding air or water.
§ II. Metastasis.
233.—Its General Nature. The chemical changes just
described, which constitute assimilation, take place only in
chlorophyll-bearing plants, or parts of plants, and in these
only in the sunlight. In cells which are destitute of chloro-
phyll, and in the chlorophyll-bearing ones in the absence of
light, other chemical changes take place ; these, while differ-
ing much among themselves, agree in always being processes
of oxidation, and changes of one organic compound into an-
other. To these chemical changes, in order to distinguish180
BOTANY.
them from those of assimilation, the term Metastasis* has
been applied.
It is even more difficult to give anything like a complete
account of the processes of metastasis than of those of assim-
ilation ; all that can be done is to indicate the general nature
of the chemical changes which are best known.
234. —Transformation of Starch. In darkness the starch
which had previously formed in the chlorophyll-bodies at
once undergoes changes which render it soluble, allowing it
to diffuse to other parts of the plant with great freedom.
The nature of these changes appears to vary somewhat in
different plants, but they consist essentially in the transform-
ation of the insoluble starch into a chemically similar but
soluble substance. Glucose (C12 H2] 013), inulin (Cia II20 O10),
and cane sugar (C]3 IIS2 On) are the more common of the
soluble substances so formed, and one or other of these may
frequently be detected in the adjacent cells after the disap-
pearance of the starch from the chlorophyll.
235. —The Nutrition of Protoplasm. These diffusing as-
similated matters are imbibed by the protoplasm of the living
tissues, and constitute its most important food. In connec-
tion with the nitrates and sulphates, also imbibed, they
furnish the materials for the increase of protoplasmic sub-
stance in growing cells. The exact changes which take
place in the formation of protoplasm are unknown, but it is
probable that a portion of the soluble assimilated matter
(glucose, inuline, etc.) is broken up by the action of oxygen
into carbon dioxide and one of the organic acids (e.g.. oxalic
acid); and the latter, by replacing the acids in the sulphates
and nitrates, may set free the sulphur and nitrogen necessary
to the formation of protoplasm. The occurrence of crystals
of calcium oxalate in the tissues of many plants rather indi-
cates the probability of this or a similar series of reactions.
* Literally “to place in another way," from the Greek fieri! beyond,
or over, and loruvai, to place. We owe the present application of the
word to Professors Bennett and Dyer, who used it as the equivalent
of the German “ Stoffwechsel ” in their English translation of Sacha’
■ Lelirbnch.”METASTASIS.
181
236. —The Storing of Reserve Material. In many plants
the surplus of assimilated matter is stored up in one or more
organs as reserve material; thus in the potato the starch
formed in the leaves in sunlight is, in darkness, transformed
into glucose, or a substance very nearly like it, and in this
soluble form it is diffused throughout the plant, and in the
underground stems (tubers) is again transformed into starch.
So in the case of many seeds a mass of reserve material is
stored up, generally in the form of starch (e.g., the cereal
grains), and sometimes in the form of oily matters {e.g., the
seeds of Cruciferse, Flax, Castor Bean, Cucurbitacese, etc.).
In the storing of starch a notable feature of the changes which
take place is the apparent addition and subtraction of one
or two molecules of water; it is probable, however, that in
the transformation of starch to glucose oxygen combines
with some of the carbon, forming free carbon dioxide, as
follows:
6 (Cl2H20O10) + 24 0 = 5 (C15H34013) + 12C03.
The transformation of glucose to starch may be a simple
process of breaking up of a molecule of the former into starch
and two molecules of water, as follows :
C„ H21 0„ = C13 HJ0 0... + 2H, 0.
In the storing of oily matters it is probable that these are
formed at the expense of the starch, and that they are the
results of subsequent deoxidation.
237. —The Use of Reserve Material. In the use of re-
serve material, as in the germination of a starchy seed, the
starch appears to undergo a change exactly like that in its
disappearance from chlorophyll. Here it is certain that oxy-
gen is absorbed, and that carbon dioxide is evolved, while
the starch is transformed into glucose (see the reaction above)
Similar ■ transformations doubtless take place in the use of
the starch stored up in buds, twigs, stems, bulbs, etc. In
the germination of oily seeds, after the absorption of oxy-
gen, starch is (in many cases, at least) first produced, and
from this the soluble sugar is formed. In any case, after the
solution is attained the subsequent metastatic changes are182
BOTANY.
similar to those which follow the transformation of the
starch of the chlorophyll.
238. —The Nutrition of Parasites and Saprophytes is
similar to that of embryos, buds, bulbs, etc. Here assimi-
lated materials are drawn from some other organism, and
subsequently undergo metastatic changes. In some cases the
parasitism is only partial, as in the mistletoe, where a part
of the assimilated matter is formed in the parasite (which,
therefore, contains chlorophyll), while a portion seems to be
taken along with the mineral salts from the host plant. So,
too, there are plants which are partially saprophytic in habit,
deriving a part of their nourishment as saprophytes, while
the remainder is elaborated by their chlorophyll. Many cul-
tivated plants, as we grow them, are partially saprophytic,
deriving a portion of their nourishment from decaying or-
ganic matter in the soil. The so-called Carnivorous plants,
as Drosera, Dionaea, Sarracenia, Darlingtonia, Nepenthes,
TJtricularia, etc., are in reality partially saprophytic, obtain-
ing a considerable part of their food materials from de-
caying animal matter.
239. —The Formation of Alkaloids. Among the most
obscure of the metastatic changes are those which give rise
to the alkaloids. These are compounds of carbon, hydro-
gen, nitrogen, and generally oxygen, in which the first two
elements have approximately an equal number of atoms,
while the last two have also a nearly equal but much smaller
number.
The more important ones are the following :
Conia (Ce HiSN,) from Conium.
Nicotine (Ci0 H14N2) from Tobacco.
Cinclionia (Cn Hu N20) from Peruvian Bark.
Morphia (C,7 H19 N 03 + H2 0) from the Opium Poppy.
Strychnia (C21 H22 N2 02) from the seeds of Strychnos.
Caffeine (Ca H„ N, 02 ■+■ H2 0) from Coffee and Tea.
These and many others occur in plants in combination
with organic acids, such as : malic acid (C, 110 06) ; tartaric
acid (C4 H„ 06); citric acid (C0 H8 0,) ; oxalic acid (C, H
0,); tannic acid (0„ 0„) ; quinic acid (C, H12 Oa);
meconic acid (C, II, 0.). These acids are probably formedMETASTASIS.
183
"by the oxidation of some of the saccharine or amylaceous
substances in the plant, while the alkaloids with which they
are combined appear to have some relation to the nitrogenous
■constituents of the protoplasm, and are possibly derived from
them. From the fact that the alkaloids are formed more
abundantly in those tissues which have passed the period of
their greatest activity, it may be surmised that they are
either compounds of a lower grade which are formed instead
of the ordinary albuminoids, or the first results of the incip-
ient decay of the cells.
240.—Results of Metastasis. In the preceding para-
graphs it is seen that chlorophyll-bearing plants absorb
■carbon dioxide and exhale free oxygen, the former being de-
composed in the chlorophyll granules in sunlight and the
oxygen being set free as a consequence. In other words, the
absorption of carbon dioxide and the exhalation of oxygen
are connected with the process of assimilation. It is further
seen that oxygen is absorbed and carbon dioxide evolved, as
results of certain metastatic processes which take place in
any tissues, whether possessing chlorophyll or not, and inde-
pendently of the piresence or absence of sunlight. In the
sunlight the absorption of carbon dioxide to supply assimila-
tion is so greatly in excess of its exhalation as a result of
metastatic action, that the latter is unnoticed. In dark-
ness, however, when assimilation is stopped, the exhalation
of carbon dioxide becomes quite evident. So, too, with
oxygen ; in the sunlight the excess of its evolution is so
great over its absorption that the latter was long unknown ;
but in the absence of light its absorption becomes manifest.
Parasites and saprophytes, as well as those parts of ordinary
plants which are wanting in chlorophyll, as flowers and many
fruits, deport themselves in this regard exactly as chloro-
phyll-bearing organs do in darkness.CHAPTER XII.
THE RELATIONS OF PLANTS TO EXTERNAL
AGENTS.
§ I. Temperature.
241. —General Relations. The functions of plants are
possible only between certain limits of temperature of the
' air, water, or soil, varying considerably for each species. In
every plant there is a certain minimum temperature, below
which all functional activity ceases ; thus in most instances
plants become inactive when the temperature approaches
0° Cent. (32° Fahr.). On the other hand, there is a maxi-
mum beyond which activity ceases ; this ranges in different
plants from about 35° to 50° Cent. (95° to 122° Fahr.). Be-
tween these two extremes is the temperature at which the
greatest activity takes place ; this has been termed the opti-
mum.
In any particular plant, the maxima, optima, and minima
are not exactly alike for all functions, some being performed
at temperatures considerably above or below those at which
others cease. It is furthermore to be observed that, in gen-
eral, there is a simple suspension of activity at temperatures
a few degrees below the minimum, whereas above the max-
imum the death of the organ ensues ; in the former a resto-
ration of the normal temperature is soon followed by a re-
sumption of activity; in the latter the activity cannot be
restored, even under the most favorable conditions.
242. —Absorption of Water as Affected by Temperature.
The absorption of water and watery solutions is greatly
affected by changes in the temperature of the absorbing
■ organs, as the roots of the higher plants. Thus Sachs
found “that the roots of the tobacco-plant and gourd noTEMPERATURE.
185
longer absorb sufficient water to replace a small loss by evap-
oration in a moist soil, having a temperature of from 3° to
•5° Cent. (37° to 41° Falir.); the heating of the soil to a tem-
perature of from 12° to 18° Cent. (53° to 64° Fahr.) sufficed
to raise their activity to the needful extent.”* According
to the same investigator, the roots of the turnip and cabbage
continue to absorb water, even when the temperature of the
soil is reduced very nearly to 0° Cent. (33° Fahr.). In the
winter and early spring, when the temperature of the soil is
low, the roots of trees and other perennials cannot absorb
moisture unless they extend deep enough to reach the
warmer strata beneath ; under such circumstances, it not in-
frequently happens that if the air temperature rise high
enough to allow evaporation, evergreen trees and shrubs are
tilled by too great loss of moisture.
243. —Evaporation or Transpiration. In aerial plants,
when the temperature of the air is low, but little evaporation
takes place from the leaves or other living organs, while an
increase of temperature is followed by an increase in the
rapidity of evaporation. It is probable that this is due (1st)
to the closing of the stomata in the lower, and their opening
in the higher temperature, and (2d) to the fact that in all
ordinary cases, as the temperature of the air is lowered its
degree of saturation is increased, and as its temperature is
raised its degree of saturation is decreased. As transpiration
appears to be a purely .physical phenomenon, we scarcely
need expect it to be as definitely or certainly affected by
changes of temperature as are the proper functions of the
plant.
244. —Assimilation. The lower limit of the temperature
in which assimilation is possible varies much in different
plants. The “Red-snow Plant” (Protococcus, sp.) of the
Arctic regions grows rapidly upon the surface of the snow in
a temperature which must be little, if any, above 0° Cent.
(32° Fahr.) ; in the larch, assimilation takes place at from
0.5° to 2.5° Cent. (33° to 36° Fahr.), and in meadow-grasses
at from 1.5° to 3.5° Cent. (35° to 38° Fahr.). In water-
* “ Lehrbuch,” English edition, p. 652.186
BOTANY.
plants the lower temperature limit is apparently somewhat
higher than in aerial ones ; thus in Hottonia palustris it is
2.7° Cent. (37° Fahr.); in Vallisneria, 6° Cent., or more (42°
Fahr.) ; in Potamogeton from 10° to 15° Cent. (50° to 59°
Fahr.).
Neither the maximum nor the optimum temperature has
been determined for ordinary land plants ; in Hottonia
palustris, an aquatic plant, the maximum temperature for
assimilation is, according to Sachs, between 50° and 56°
Cent. (122° and 132° Fahr.).
245.—Metastasis. But little is accurately known as to.
the effect of an increase or decrease of temperature, within
moderate ranges, upon those metastatic changes which take
place in the ordinary growth of plants or the storing of reserve
material. It is well known, however, that some plants live
wholly in low temperatures, performing all their functions
in air or water little, if any, above the freezing point.
Thus in the “ Red-snow Plant,” above cited, the metas-
tatic changes must take place very near 0° Cent.
In the polar waters, where the temperature is from 3° to
5° Cent. (37° to 41° Fahr.), or even less, myriads of diatoms
flourish, and in seas but little warmer many of the higher
sea-weeds (Fucacete and Florideae) abound. In all these
cases the metastatic changes (as well as all others) must take
place at these low temperatures. In ordinary land-plants it
is to be observed that whereas assimilation takes place only
during the light part of the day, when it is warmer, metasta-
sis takes place not only in daylight, but even more rapidly in
darkness, when the temperature is considerably lower.*
Sachs measured the length of plumule developed upon
different plants of the same species subjected to different
temperatures, and in this way found the approximate optima
for several species, as follows :f
* It must not be forgotten, however, that assimilation is dependent
upon light, while metastasis is somewhat checked by it, and this is
doubtless by far i he most important relation ; and still it is a significant
fact that in ordinary land-plants metastasis continues when assimi-
lation has stopped.
f In “ Physiologische Untersuchungen fiber die Abhfingigkeit derTEMPERATURE.
18?
Pea 26° Cent. (78.8° Fahr.).
Wheat (winter var.) 34° “ (927° “
Indian corn 34° “ (92.7° “
Scarlet Bean 34° “ (92.7°
In Sachs’ and others’ observations upon the growth of
roots, it was found that the most rapid growth took place
for different plants at the following temperatures :
Scarlet Bean.......................26° Cent. (78.8° Fahr.).
Pea................................26.6° “ (79.9° “
Flax...............................27.4° “ (81.3° “
Wheat (winter var.)....... ........28.5° “ (83.3° “
Barley (summer var.)...............28.5° “ (83.3° “
Indian corn........................34° “ (92.7° “
In the deposit of reserve material there can be no doubt
that metastasis often takes place at lower temperatures than
assimilation ; thus the storing of starch in the potato tubers,
and in many other subterranean stems and roots, takes place
in the soil which, at the time, is much cooler than the air.
In the growth of many plants in early spring, at the ex-
pense of reserve material in the roots or stems, the metas-
tatic changes often take place at quite low temperatures.
Thus perennial and biennial rooted plants, as many grasses,
thistles, parsnips, etc., begin to grow almost as soon as the
snow has disappeared, and the flower buds of many perenni-
als develop equally early—e.g., the hazel, elm, maple, liver-
leaf (Hepatica), Mayflower, etc.
As regards the metastatic changes which take place in the
germination of seeds, we have much more definite informa-
tion. Sachs has determined the minimum, optimum, and
maximum temperatures for the germination of the seeds of
the following plants :*
Minimum. Optimum. Maximum.
Ind. corn. Scar. B’n.. Pumpkin. Wheat... Barley... 9.4° C.= (48.8° F.). 9.4° C.= (48.8° F.). 14° C.= (56.7° F.). 5° C.=r (41° F.). 5° C. = (41° F.). 34° C. = (92.7° F.). 34° C. = (92.7° F.). 34° C. = (92.7° F.). 29° C. = (83.7° F.). 29° C. = (83.7° F.). 46° C. = (115.2° F). 46° C. - (115.2° F.). 46° C. = (115.2° F.) 42° C. = (108.5° F.). 37° C. = ( 99.5° F.).
Keimung von der Temperature,” in “ Pringslieim’8 Jahrbiicher fur
Wissenschaftliclie Botanik,” Vol. II., 1860, p. 354.
* “ Physiologische Untersuchungen,” etc., op. cit., p. 365.188
BOTANY.
According to several observers, the minima and optima 1
for the germination of the seeds of the following plants are :
Minimum. Optimum.
Lepidium sativum.... 1.8° C. = (35° Fahr.). 1.8° C. = (35° “ 0.0° = (32° “ 6.7° C. = (43° “ 27.4° C. = (81° Fahr.). 27.4° C. = (81° “ 27.4° C. = (81° “ 26.6° C. = (80° “ 31.5° i . = (88.7° “ 31.5° C = (88.7° “ 31.5° C. = (88.7° “ 37.5° C. r= (99.5° »
White Mustard
246.—Death Caused by High Temperature. When the
temperature rises above a certain point the death of the
plant takes place. Those plants, or parts of plants, which
contain the least water are capable of enduring higher tem-
peratures than those which are more watery. Thus at from
65° to 80° Cent. (149° to 177° Fahr.) many dry spores and
seeds are uninjured, while in water they are generally killed
when the temperature exceeds 50° or 55° Cent. (122° or 131°
Fahr.). For ordinary growing parts of plants the, tempera-
ture must be, as a rule, considerably lower than those given
above. Few aquatic plants can endure a prolonged tempera-
ture much, if any, above 40° Cent. (104° Fahr.), and at 50°
Cent. (122° Fahr.) most terrestrial plants are soon killed.
It appears, also, that at temperatures much lower than these
some plants arc killed ; thus, according to Hofmeister,* the
organization of the protoplasm of the plasmodium of Didy-
mium serpula (one of the Slime Moulds) is destroyed by
heating it, in air, to 35° Cent. (95° Fahr.), and in the nearly
related Fuligo varians the same destruction follows at 39°
Cent. (102° Fahr.).
The immediate cause of death appears to be the coagula-
tion of the albuminoids of the protoplasm. The protoplasm
thus loses its power of imbibing water, and the cells conse-
quently lose their turgidity. In watery tissues chemical
changes at once begin, resulting in the rapid disintegration
* “ Die Lehre von der Pflanzenzelle,” 1867, p. 27.TEMPERATURE.
Ib9
' of the substances in the cells, accompanied by an evolution
of carbon dioxide.
247.—Death Caused by Low Temperature. In many
respects the results of too great a reduction of temperature
are similar to those produced by too great an elevation.
There is observed the same coagulation of the albuminoids,
resulting in the destruction of the power of the protoplasm
to imbibe water, and, as a consequence, in the loss of the tur-
gidity of the cells. Moreover, as in the case of injury from
high temperature, those cells which are the most watery are
the ones which, other things being equal, are injured most
quickly by a reduction of temperature. Embryo plants in
seeds, when dry, are able to endure almost any degree of low
temperature ; but after they have germinated, and the cells
have become watery, they are generally killed by a reduction
to, or a few degrees below, 0° Cent. (32° Fahr.). So, too,
the comparatively dry tissues of the winter buds and ripened
stems of the native trees and shrubs in cold countries are
rarely injured even in the severest winters, while the young
leaves and shoots in the spring are often killed by slight
frosts.
Death from low temperature is always accompanied by the
formation of ice-crystals in the succulent tissues ; these are
formed from the water of the plant, which is abstracted from
it in the process of congelation. Much of the water thus
frozen is that which fills the cavities (vacuoles) of the cells,
while some of it is that which moistens the protoplasm and
cell-walls. Now it is evident that the water in the large
vacuoles is much more easily congealed than that in the pro-
toplasm and cell-walls ; for in the latter the force of adhesion
between the molecules of protoplasm or cellulose and the
imbibed water offers a considerable resistance to the separa-
tion of the water in ice-crystals, and this resistance is greater
as the contained water is less. As the liquid in the vacuoles
is not pure water, but a mixture of several solutions, it freezes
at a lower temperature than water, and then, according to a
well-known law of physics, separates into pure ice-crvstals
and a denser unfrozen solution. By a greater reduction of
temperature more ice-crystals may be separated out, and the190
BOTANY.
remaining solution made denser still. These adhesive forces,
tend to retard the formation of ice-crystals, and it is jrrob-
able that it is only in extremely low temjjeratures, if at all,
that the liquids in the plant are completely solidified.
248.—A plant which has been frozen may survive in many
instances if thawed slowly, whereas if thawed quickly its
vitality is generally destroyed. Thus many herbaceous
plants will endure quite severe freezing if they are afterward
covered so as to secure a slow rise of the temperature, and
many bulbs, tubers, and roots will survive the severest win-
ters if covered deeply enough to prevent sudden thawing.
Likewise turgid tissues, which are not living, as those of'
many succulent fruits, are injured or not by freezing, accord-
ing as the thawing has been rapid or slow. From these facts
it may be inferred that the injury in freezing is primarily of
a physical instead of a chemical nature, and that it is mainly
the withdrawal of water from its physical union with the
solids of the cell. According to this view, the difference be-
tween slow and rapid thawing is that in the former the
slowly liquefying water is reabsorbed by the same solids from
which it had been abstracted, while in the latter the large
amount of water set free is imperfectly absorbed, forming
solutions which are unstable and subject to subsequent fer-
mentive changes. It is probable that to these fermentive
changes is doe the coagulation of the albuminoids and
the rapid disorganization of the protoplasm which accom-
pany injury from freezing.
While the sketch given above is doubtless true in a large
number of cases, it appears that in many other cases death
follows freezing whether the thawing be rapid or not ; and
this indicates that besides the immediate causes of death al-
ready indicated, there are others which are as yet unknown
to us.
§ II. Light.
249.—General Relations. Directly or indirectly plant-
life, as indeed all life, whether vegetable or animal, is de-
pendent upon light. Parasites and saprophytes may growLIGHT.
191
in complete darkness, but they do so at the expense of ma-
terial which has been elaborated in light. So, too, some
parts of many ordinary plants grow in total darkness, as
roots, tubers, bulbs, etc., but these depend for their carbo-
hydrates upon the aerial, chlorophyll-bearing parts which
are in the light. As will be shown in the sequel, this depen-
dence of all life upon light is due to its relation to chloro-
phyll in the processes of assimilation ; and while other func-
tions than that of assimilation and othef orgars than those
which contain chlorophyll are somewhat affected by the
presence or absence of light, or its greater or less intensity,
yet these latter are of comparatively little moment when com-
pared with the former.
The absorption of water by the plant appears to be entirely
independent of light, and in most plants it takes place in its
entire absence. Likewise it is probable that light itself does
not directly affect the rate of evaporation of water from the
leaves of higher plants. As, however, the stomata are gen-
erally opened more widely in light than in darkness, evapo-
ration may be promoted by it in some cases.
250. —Light and Assimilation. It is first of all to be
observed that chlorophyll itself is dependent upon light.
Those parts of plants (with rare exceptions) which grow in
darkness are destitute of chlorophyll, and even parts which
contain chlorophyll lose it when placed for some time in com-
plete darkness. When such a colorless plant is brought into
the light it soon becomes green from the formation of chlo-
rophyll in its protoplasm.
The decomposition of carbon dioxide, and the consequent
evolution of oxygen, only take place in the light. As the
light decreases in intensity from a certain point the amount
of assimilation decreases ; on the other hand, there is a de-
crease in assimilation as the intensity increases unduly, and
beyond certain points in either direction assimilation ceases.
Thus there are here, as in the case of temperature, a mini-
mum, optimum, and maximum ; but we cannot define their
limits as readily, for want of a proper instrument.
251. —Experiments have often been made upon plants
when placed in rays of different refrangibility, and it has192
BOTANY.
been shown (1) that the assimilation is greater in the whole
beam (white light) than in any one of its constituent rays,
and (2) that the amount of assimilation varies greatly in the
different rays.* When plants are grown in the different
rays of the spectrum, and properly protected, so that each
receives but one kind of light, the amount of assimilation in
each case is about as follows, that for white light being 100 :
Red, Orange, Yellow, Green, Blue, Indigo, Violet,
9.5 23.5 37.3 14. 8.2 5, 2.5
The less refrangible rays are thus seen to be far more effica-
cious than the more refrangible ones, and in the yellow and
orange rays, which are the brightest to the eye, the greatest
amount of assimilation takes place. From these rays there
is a decrease toward each end of the visible spectrum, and in
the so-called heat rays and chemical rays, found respectively
beyond the red on the one hand and the violet on the other,
there is no assimilation whatever.
252.—Light and Metastasis. Many of the metastatic
changes in the plant take place in complete darkness, such
as those connected with the growth of roots and other sub-
terranean organs. In trees and thick-barked shrubs the metas-
tatic changes which occur in the stems are in total darkness,
and even in many herbs the thick cortical tissues must cut
off the greater part of the light from the active interior cells.
On the other hand, in a great number of aquatic plants their
translucency is so great that every internal change must be
in bright light, and in a few terrestrial plants—as, for ex-
ample, in Impatient Balsamina—the cortical tissues permit
most of the light to penetrate to the inner active cells. These
facts indicate a marked indifference of the metastatic changes
to light, as compared with those of assimilation.
This indifference is further illustrated in the growth of
flowers in the dark, where, with few exceptions, they develop
as perfectly as in the light. So the colorless parasites—e.g.,
Monotropa, Apliyllon, Corallorhiza, etc.—and all the fungi
* The earliest experiments of much value were those of Charles
Daubeny, “ On the Action of Light upon Plants, and of Plants upon
the Atmosphere,” pub. in Phil. Trans., 1836.HELIOTROPISM.
193
grow either in light or darkness. It must not be inferred,
however, that there is a complete indifference to the presence
or absence of light, for careful experiments show that light
favors some metastatic changes, while in many cases it actu-
ally exerts a retarding influence. Thus if all other condi-
tions, as temperature, moisture, etc., are made constant, the
rapidity of growth of most aerial stems is considerably greater
in darkness than in light; while under similar conditions
the growth of the leaves of most plants is less. Experiments
show that the retardation of growth is due to the rays of
high refrangibility, blue, indigo, violet, and ultra violet, and
that, so far as the metastatic changes under consideration
are concerned, the less refrangible rays are equivalent to
darkness.
§ III. Heliotropism.
253. —The retarding influence of light upon the growth
of stems gives rise to a curvature when the illumination is
stronger upon one side than upon the other. Thus, as is
well known, most plants, when grown in windows, bend
strongly toward the light, and if their position be afterward
reversed they soon bend again toward the side of greatest
illumination. To this phenomenon, which is an exceedingly
common one throughout the vegetable kingdom, the name
Heliotropism* has been given. The explanation which is
commonly given is that the light retards the growth on the
illuminated side, while the shaded side elongates, resulting
in a tension which necessarily produces a curvature.
254. —Evidently allied in some way to heliotropism is the
bending of certain organs away from the light. Thus the
leafless stems (runners) of Saxifraga sarmentosa, when grown
in a window so that they are illuminated upon one side more
strongly than upon the other, curve toward the darker side.
This opposite bending has been called Negative Heliotro-
pism, and is supposed to be caused by light in some way not
yet understood. The tendrils of the Vine and Virginia
* From the Greek rj\ioS, the sun, and rpinciv. to turn.194
BOTANY.
Creeper (Avipelopsis) are negatively heliotropic, and they
are thus enabled to reach and attach themselves to the sur-
faces—e.g., walls, tree-trunks, etc.—which give them sup-
port. The same organ may be positively heliotropic in one
stage of its growth and negatively so in another ; thus the
younger internodes of the ivy (Hedera) bend toward the
light, and the older ones away from it; and the runners of
Saxifraga sarmentosa, mentioned above, are positively he-
liotropic as soon as they develop tufts of leaves upon their
free extremities.
The rays of light which cause the curvature are those
having the greatest refrangibility. Sachs’ experiment shows
this conclusively ; he grew plants in light which had passed,
on the one hand, through a solution of potassium bichro-
mate, and, on the other, through one of ammoniacal copper
oxide; in the light passed through the first solution (red,
orange, and yellow rays, and a portion of the green) there
was no curvature whatever, while in the blue, indigo, and
violet rays passed through the second solution the heliotro-
pic curvature was strongly shown.
§ IV. Geotropism.
255.—Nearly all organs of plants have a definite, normal
direction of growth, which is in general terms, either toward
or away from the earth. Thus the plasmodium of Fuligo
varians creeps upward ; the conidia-bearing hyphte of moulds
grow upward, while the root-like liyphse grow downward ; the
stems of many mosses grow upward, and their rhizoids down-
ward ; in the higher plants the stems, as a rule, grow upward,
some root-stocks and other stems growing downward, how-
ever, while the roots, as a rule, grow downward. To these
phenomena of growth the name Geotropism* has been
given ; when the direction of growth is downward, the organ
is said to be positively geotropic, when upward, negatively
geotropic.
Knight long ago proved gravitation to be the cause of
* From the Greek yrj, yea, the earth, and rpeireiv, to turn.GEOTROPISM.
195
geotropism.* He placed germinating seeds upon wheels,
which were made to rotate rapidly, in one series of experi-
ments in a vertical, and in the other in a horizontal direction.
In the first case he found that the roots grew directly away
from the centre of the wheel, and the stems toward it—that
is, having in his experiment substituted centrifugal force for
gravitation, leaving all other conditions unchanged, he found
that the root grew in the direction of that force, and the
■stem opposite to it. In the second series of experiments, in
which gravitation and centrifugal force were made to act at
right angles to each other upon the growing plantlets, the
■direction of growth coincided with that of the diagonal of
the two forces, the roots growing diagonally outward and
■downward, the stems inward and upward. Dutrochet after-
ward showed, by similar experiments, that many leaves are
geotropic, turning their under surfaces toward the circum-
ference, and their upper toward the centre of the wheel, f
256.—If positively and negatively geotropic organs are
placed in what may he termed their normal positions, they
grow on the one hand downward and on the other upward,
without any curvature, and in such case the cells in all parts
of any section of either the ascending or descending portions
show a symmetrical development. But if such symmetrically
developed positively and negatively geotropic organs are af-
terward placed in a reversed or horizontal position, they
will become considerably curved in order to assume their
normal positions. Thus the first roots of most young plants,
if placed horizontally, soon become curved downward near
their tips ; this takes place even when there is considerable
resistance to the curvature, as is shown by the penetration
of roots into mercury. A similar curvature in an upward
direction, however, takes place in most stems when placed
horizontally ; in grasses the curvature is almost entirely con-
fined to the nodes. In such curved parts of roots and stems
the cells are more elongated upon the convex than upon
* “On the Direction of the Radicle and Plumule during the Vegeta-
"tion of Seeds.” Philosophical Transactions, 1806.
■)■ “ Memoires.” Pari9,1837.1&6
BOTANY.
the concave side, and it is evident that this is the immediate
cause of the bending. We do not, however, know how grav-
itation causes this inequality in the growth of the cells,
and the problem is the more difficult from the fact that the
more rapid elongation of the cells is in one case upon the
upper and in the other upon the under side of the organ.
Moreover, in “ weeping trees ” the branches are positively, in-
stead of negatively, geotropic, although we know of no struc-
tural difference between these and the branches of ordinary
trees.
§ V. Certain Movements of Plants.
257. —Under this head are to be considered a few only of
the more important movements in plants. It must be remem-
bered that living protoplasm has everywhere, under proper
conditions, the power of spontaneous movement. In the
lower forms of vegetation this results in visible movements,
which are of common occurrence ; but in the greater part
of the vegetable kingdom, while the protoplasm is doubt-
less as active, the cell-walls which enclose it are so rigid that
its physical activity is incapable of producing external move-
ment. Thus most parts of ordinary plants do not perform
movements which are the direct results of the physical activ-
ity of the protoplasm ; but this is not because of a want of
activity in the protoplasm, but mainly from the rigidity of
the walls surrounding it. In a comparatively small number
of instances, however, the structure of the organs of even
the higher plants is such that movements directly due to pro-
toplasmic activity are performed. Such are the so-called
spontaneous movements of the leaves of some plants, and
those dependent upon external stimuli, as light, heat, me-
chanical irritation, etc., which have been called paratonic
movements.
258. —Spontaneous Movements. The most remarkable
case of movements apparently not dependent upon external
agents is that of the leaves of Desmoclium gyrans, an Indian
plant. The small lateral leaflets of the trifoliate leaf bend
upon their slender stalks (petiolules) in such a way that theilMOVEMENTS OF PLANTS.
.37
apices describe nearly a circle. A revolution occupies from
two to five minutes if the temperature is above 22° Cent.
(72° Fahr.). This continues, when the conditions are other-
wise favorable, in darkness as well as in the light. Other less
noticeable movements of this nature occur in many plants—
e.g., Clover, Mimosa, Oxalis—but they are often hidden by the
more marked movements due to other causes. The active
portion of the moving organ (in the cases cited above, a por-
tion of the leaf-stalk) consists of a tissue composed of thin-
walled cells, forming, in many cases, a thickened “ pulvinus.”
The cells are turgid and the tissues are in a state of tension.
When movements occur, it appears that the protoplasm in
certain layers of cells permits the escape into the intercellu-
lar spaces of a portion of the water of the vacuoles; it is,
however, quickly absorbed again and the cells rendered
thereby turgid, while the escape of water takes place in
contiguous layers, to be quickly absorbed again, and so on
regularly around the axis of the contracting organ.
259.—Movements Dependent upon External Stimuli.
These are exhibited by many parts of the higher plants—e.g.,
leaves in Mimosa (the Sensitive Plant), Cassia, Clover,
Oxalis, Dionaea, etc., stameus of many Compositse, of Bar-
berry, Portulaca, etc., stigmas of Martynia, Mimulus, etc.
In the Sensitive Plant, the leaves, when touched roughly ox
jarred, close up quickly by the secondary leaflets moving
upward and forward, so that the upper surfaces of the
pairs are approximated to each other; next, the primary
leaflets bend downward, and at the same time approach each
other, and finally the whole leaf bends downward. The
movements are in all cases at the bases of the organs, where
tissues are developed similar to those in the spontaneously
moving organs (paragraph 258). In the other cases essen-
tially the same movements and mechanism are found. When
the movements occur, there is an escape of the water of the
vacuoles from the cells in one side of the organ, and this
side is, as a consequence, shortened and made concave.
After a time the -water is reabsorbed and the organ resumes
its normal position. In addition to the mechanical stimuli
of jarring, concussion, etc., greater or less amounts of light,198
BOTANY.
increase or decrease of temperature, and electrical discharges,
may cause movements. Those movements which are brought
about by changes in the amount of light constitute what are
known as the “ sleep” and “ waking” of plants. Thus the
leaves of the Sensitive Plant close up in darkness exactly as
from a concussion, but they remain closed until the reap-
pearance of the light.
260.—The power of movement, whether spontaneous or
paratonic, may be temporarily suspended by certain external
conditions. Thus, according to Sachs, transitory rigidity
or immobility takes place under the following conditions :
1. Low Temperature. In Mimosa pudica rigidity com-
mences at about 15° Cent. (59° Fahr.), in Desmodium gyrans
at about 22° Cent. (72° Fahr.).
2. High Temperature. Mimosa slowly becomes rigid at
40° Cent. (104° Fahr.), and very cpiickly at 50° Cent. (122°
Fahr.).
3. Darkness. Long exposure to darkness (twenty-four
hours or more) produces a rigidity which is only removed by
a long exposure to light.
4. Insufficient Moisture. When the supply of water to
the roots of the Sensitive Plant is too little, a partial, and
sometimes almost complete, immobility is produced, which is
soon removed, however, by copious watering.
5. Insufficient Supply of Oxygen. In a vacuum, or in an
.atmosphere of nitrogen, hydrogen, ammoniacal gas, etc.,
motile organs become immobile. On the other hand, in
pure oxygen rigidity takes place also.
6. Anaesthetics. In the vapor of ether or chloroform the
leaves of the Sensitive Plant become immobile, but in the
air they soon regain their motility.
Mr. Darwin’s experiments* upon the leaves of Drosera and
Dionaea are confirmatory of the foregoing statements. The
sensitive tentacles of the former and leaf-blades of the lat-
ter were rendered insensible to the peculiar stimulus of con-
tact with soluble nitrogenous bodies when subjected to most
of the above-mentioned conditions.
* “ Insectivorous Plants.” London, 1875. Chap. IV.,IX., and XIII.MOVEMENTS OF PLANTS.
199
These facts indicate the correctness of the view that the
movements are the results of the motility of the protoplasm.
261.—Movements of Nutation. In the organs of many
plants an inequality of growth is often noticeable, one side
growing for a time more rapidly than the other. If this is
followed by a more rapid growth upon the other side, and this
again by a more rapid growth upon the first side, and so on,
alternating from side to side, simple movements of nutation
will take place, the apex of the organ swaying or oscillating
from side to side in one plane. If the tracts of unequal
growth pass slowly and regularly around the organ, its apex
will describe a circle iu its nutation.
Of simple nutation in one plane many leaves afford good
■examples ; thus in the bud the growth is greatest upon the
outer or under side of each leaf, which, as a consequence, is
bent upward, but in the opening of the bud the greater growth
takes place upon the upper side. The greater growth of the
upper side of an organ has been termed epinasty ; that of the
lower side, hyponasty. Many floral leaves exhibit first
hyponasty and afterward epinasty, the first in the bud and
the second in anthesis (i.e., the opening of the flower).
Many stamens and styles exhibit nutations of this nature;
thus in Claytonia both sets of organs are at first erect, but
afterward they become divergent by epinasty.
In many cases, particularly in leaves and the parts of
flowers, these movements of nutation are controlled by vari-
ous external agents, among which light and heat are the
most important. To these are to be referred the successive
opening and closing of many flowers, and the diurnal and
nocturnal positions of the leaves of many plants.
262.—Of the second class of nutations, the leaves of the
onion, and the ends of the stems and the tendrils of climb-
ing plants, furnish good examples. These rotate through
circles or spirals, in the case of the hop and honeysuckle to
the left, and in the bean and morning-glory to the right.*
* To the right, or from left to right, is opposite to the direction of
the hands of a watch ; to the left, or from right to left, is in the direc-
tion of the hands of a watch.200
BOTANY.
"When such rotating stems come in contact with an up-
right object they continue their rotation, and in this way
come to twine around it. The plants mentioned above af-
ford common examples of twining. In the case of tendrils
nutations also occur ; but after coming in contact with any
object there is a very unequal growth of the two sides, that
in contact with the object growing very slowly, as compared
with the rapidity of growth of the outer side. Thus De
Vries found that in the tendrils of the pumpkin twined
around an object 1.2 mm. in diameter the ratio of the
growth of the inner side to that of the outer was as 1 to 14.
This inequality of growth is due to a retardation of growth
upon the inner side and an acceleration upon the outer. In
some cases there appears to be an actual contraction of the
inner side.
263.—Movements of Torsion. In many cases in the
higher plants the stems or other organs become twisted upon
their axes. Even in the lower plants this is not uncommon—
e.g., in Nitella, the pedicels of mosses, etc. This twisting
appears in many cases to be due to a peculiar inequality in
the growth of the tissues. Thus if the outer layers of cells
grow in length more rapidly than the inner ones, the stem
will become twisted upon its axis, and the greater the ine-
quality in growth of the inner and outer layers, the greater
the torsion. In some cases torsion arises in a much simpler
way, by the twisting due to the unequal distribution of the
weight of certain organs, as in some prostrate plants, where
the weight of the leaves and the advancing and obliquely
ascending growing extremity of the stem produce torsions
which become permanent by the hardening of the tissues.
Likewise torsions may arise on account of the heliotropism or
geotropism of an organ itself, or of organs connected with it.
It may be in place here to direct attention to the fact that inequali-
ties in the growth of the tissues of plants are of common occurrence.
They are, however, for the most part of such a nature as to prevent
torsions of the stem, giving it, on the contrary, a rigidity which en-
ables it to stand erect. If the pith of a growing stem of a Dicotyledon
be isolated from the surrounding tissues, the former elongates, while
the latter contracts, showing that the pith has grown more rapidly inMOVEMENTS OF PLANTS.
201
length than the other tissues. Thus in a young internode of the Moun-
tain Ash, 60 mm. long, the pith, when isolated, elongated 3 mm., while
the surrounding parts shortened 1 mm. Close examination of the tissues
surrounding the pith shows iliat they also have developed unequal-
ly. Sachs expresses this inequality by the formula, E < C < X < P,
which indicates that the epidermis is shorter than the cortex, the
cortex shorter than the xylem, and the xylem shorter than the pith. It
is at once evident that in such a condition of things the epidermis is
elongated by the other tissues; the cortex is shortened, on the one
hand, by the epidermis, and elongated on the other by the xylem and
pith ; the xylem is shortened by the cortex and epidermis, and elon-
gated by the pith ; while the pith is shortened by the three surround-
ing tissues. There is thus a considerable tension in the several tissues,
and upon this condition it may be remarked :
1st. That it produces a rigidity of the stems or other organs in which
it occurs.
2d. That it tends to prevent ordinary torsion ; for the twisting of
such a stem must elongate still more the already elongated tissues,
while contracting the shortened ones ; on the other hand, there is some
tendency to an internal torsion.
3d. That the exact length of a stem is dependent upon a balancing
of the tensions of its tissues.
There are in many cases tensions whose directions lie at right angles
lo the foregoing. Thus in the trees of the colder climates the growth
of new tissues from the cambium layer produces an outward pressure
upon the bark, and an equal inward pressure upon the wood. Even in
herbaceous plants similar tensions are often to be observed, the epider-
mis being laterally distended by the enclosed tissues. Tensions in this
direction have been denominated transverse tensions, to distinguish
them from the others, which may be called longitudinal tensions.*
* For a full discussion of tensions the student is referred to larger
works, such as Sachs’ “Lehrbuch,” and his “ Experimental-Physi-
ologie.”
The whole subject of the movements of plants, including heliotro-
pism and geotropism, is fully treated by Mr. Darwin in Ris recent
work “ The Power of Movement in Plants,” New York, 1881.PART II.
SPECIAL ANATOMY AND PHYSIOLOGY OF PLANTS,
AND OUTLINES OF THEIR CLASSIFICATION.
CHAPTER XIII.
CLASSIFICATION.
264. —In order to obtain a definite knowledge of the com-
parative structure of plants, it is necessary here to take up
in order the different groups, and to study with some care
the more important modifications and differences noticeable
in the plant-body. This study, so taken up, is intimately
connected with the classification of plants ; the differences
and modifications of structure which we study in order to
gain a better knowledge of plants as a whole, are the very
ones which serve to separate the vegetable kingdom into
larger or smaller groups. This part (Part II.) of this trea-
tise will, therefore, include the outlines of the Classification
of Plants, as well as a discussion of Special Morphology.
265. —(1.) In the classification of living objects they “are
arranged according to the totality of their morphological re-
semblances, and the features which are taken as the marks
of groups are those which have been ascertained by observa-
tion to be the indications of many likenesses or unlikenesses. ”*
Such an arrangement is “ a statement of the marks of sim-
ilarity of organization, and of the kinds of structure which,
as a matter of experience, are universally found associated
together.”
* T. H. Huxley in the article “Biology,” in “ Encyclopaedia Britan-
nica,” ninth edition, Vol. Ill , p. 683.CLASSIFICA TION.
203
266. —(2.) Every natural classification takes into consider-
ation not only the adult characters, but also those of the
embryonic life of its objects. It is not enough to know the
differences and resemblances between two plants in their
adult state ; we must also know whether they difEered or not
in their modes of reaching that state. In other words, in
order to determine the degree of relationship existing be-
tween two or more plants, all the characters of each plant,
as presented in its whole life, must be taken into the ac-
count. By ignoring this important law great confusion has
arisen, especially in the lower grou^is of plants.
267. —(3.) There is still another factor which should
enter into classification. Every classification should show
real relationship, not similarity alone; it should bring to-
gether not those which simply show present coincidences,
but those in which similarity of form indicates similarity
of origin ; in addition to structural relationship, it should
show genetic relationship. This can be accomplished only
by a study of the genealogy of plants, a subject surrounded
by many difficulties. In but few cases can we trace an
ancestral line, and yet it is desirable that we should use the
facts we have, as by so doing we shall be the more likely to
discover others.
(a) It is a mistaken notion tliat living tilings can be grouped natu-
rally by taking into consideration only one, or even two or three char-
acters. Botany and zoology are full of the debris of attempts at classi-
fications upon single characters, and in every case sucli classifications
have proved a hindrance to knowledge. The division of the vegetable
kingdom into Flowering and Flowerless Plants, by Ray,* in 1703, is an
illustration of one based upon a single character. The influence of
this classification, which is even yet much followed, has been injurious.
It has kept alive the notion that the so-called Flowerless plants are
quite different as to their reproductive organs from the Flowering ones;
it fixed an imaginary gulf between groups of plants, some at least of
which are in nature placed side by side. Endlicher’sf two great
groups, Cormophyta and Thallophyta,are likewise based upon a single'
character, and are, as a consequence, misleading. The Thallophytes are
* John Ray : “ Metliodus Plantarum emendata et aucta.”
f Stephen Endlicher: “ Genera Plantarum secundum Ordines Natu-
rales disposita.” 1836-40.204
BOTANY.
not all tliallus plants, nor are all the thallus plants found in the Thal-
lophyta ; on the other hand, the Cormophytes are not all plants with
trunks or stems.
(b) We often, however, retain in our present classification some of
the groups founded originally in this erroneous way, and even some-
times retain their old names. For example, the group Phanerogamia
includes now the same plants it did when its exceedingly inapplicable
name (Phanerogamia, from ijtavcpdi, open to sight, and yapoS, marriage)
was applied to it ; but it now rests upon a more scientific basis. The
name is now unmeaning, and refers to no character or set of characters
now used to designate the group ; and, more than this, its etymological
signification is actually directly opposite, to the facts as now known.
The term Cryptogamia (/cpaa-rof, hidden, and yapoq, marriage) no longer
exists in a scientific sense, as it is no longer the name of a group of
plants ; not only has the term now no' meaning (for the plants it refers
to have a fertilization which is far less “ hidden ” than in the so-called
Phanerogams), but the plants it formerly designated by a negative
character are now known by positive characters to belong to several
groups. We may still use the word Cryptogam in speaking of the
members of certain groups of plants, just as in zoology we frequently
make use of the word Invertebrate ; hut in neither case are the terms
flie names of natural groups, or of natural assemblages of groups. It
is convenient to retain them as popular names of certain artificial as •
semblages of groups.
(c) The term Tballophyta is to be placed in thqsame category. It is
still used to designate a great assemblage of the lower plants, hut the
original meaning of the term is lost, aud the limits of the group to
which it was applied have been somewhat changed, while the plants
composing it have undergone an entirely new distribution into new
groups. Nevertheless, it is convenient to retain the term, although in
this, aB in the previous cases, care must be taken not to suppose that
when used it designates more than an artificial assemblage of natural
groups of plants.
(d) The importance of the study of the individual development of
plants can hardly be overestimated. What Embryology has done for
zoological, it doubtless can do for botanical classification. It is already
bearing fruit ; the recent advances in the classification of the algse and
fungi are due to a study of the whole life of the individual. In the
fungi the long list of spurious families and genera, and the yet longer
one of spurious species, bear witness against the system of classification
under which they came into existence.
(ie) There is another reason for studying closely the life-history of the
individual, which is that it throws some light upon the difficult ques-
tions relating to the ancestry of plants. The life-history of the indi-
vidual appears to bear much resemblance to the life-history of the
species ; and while no doubt it would be unsafe in any particular caseCLASSIFICA TION.
205
to assume that the specific development had followed lines parallel to
those of the individual, yet the latter may always serve to point out the
probable course of the former.
268.—Applying the preceding principles, so far as possi-
ble, we find that the vegetable kingdom may be quite readily
separated into six principal Divisions, which, although by no
means distinct, are capable of being quite clearly character-
ized. To these must be added a seventh, composed mainly
of unclassified and poorly understood forms. These seven
Divisions, beginning with the lowest, are, (1) Protophyta,
(2) Zygophyta, (3) Oophyta, (4) C'arpophyta, (5) Bryophy-
ta, (6) Pteridophyta, (7) Phanerogamia.
Their relation to the old groups Cryptogamia, Thallophy-
ta, etc., may be seen from the following tabular comparison :
I.
Kay, 1703; Linnrcus, 1735.
Flowerless (Ray),
Cryptogamia (Lin-
naeus).
Flowering (Ray),
Phauerogamia(Linn.)
II. III. IV.
De Candolle, Endlicher,
1813. 1836-40.
Cellular
Plants.
Vascular
Plants.
Thallophyta.
Cormophyta.
f 1. Protophyta.
I 2. Zygophyta.
"j 3. Oophyta.
14. Carpophyta.
15. Bryopliyta.
0. Pteridophyta.
7. Phanerogamia.
The arrangement in the fourth column, which will be fol-
lowed in this book, is essentially that of Sachs, with some
modifications, which will be pointed out hereafter.
It is only necessary in tliis place to say tliat the classification here
given does not recognize the old groups Algae, and Fungi. The terms
are, however, quite useful, if properly used and understood, and con-
sequently they will be retained when general reference is made to the
chloropliyll-bearing and the chlorophyll-free Thallopliytes. By the
term alga must be understood a Thallophyte which contains chloro-
phyll ; and by fungus one which is saprophytic or parasitic in habit,
and which is, as a consequence, destitute of chlorophyll. The terms
have thus, as here used, a physiological meaning only, and not a class-
ificatory one.CHAPTER XIV.
THE PKOTOPHYTA.
269. —The Protophytes are the lowest and simplest plants.
In many cases they are exceedingly minute, requiring the
highest powers of the microscope for their study. For the
most part the cells are poorly developed; the protoplasm
is frequently destitute of granular contents ; the nucleus is
wanting in many cases, and not infrequently there is either
no cell-wall, or only a poorly developed one. The cells in
all cases have little or no coherence, and even when they are
united into loose masses, each cell retains nearly as much
independence as in the unicellular forms. The differentia-
tion of cell-form is very slight, even in those cases where
there is the greatest coherence of cells, and yet in some or-
ders certain cells of the filaments are uniformly larger than
the others, as the “heterocysts” of Nostoc, and the “ basal
cells ” of the filaments of Rivul'aria.
270. —No sexual organs are known, and whether the sex-
ual act occurs or not is somewhat doubtful. As, however,
we must not expect to find well-developed organs or as
distinct a sexual act in these simple organisms as in more
complex ones, it is possible that both exist in the group,
but have hitherto been overlooked or misunderstood.
Their most common mode of reproduction is by fission,
and in only a few cases by internal cell-division.
271. —The lowest Protophytes are destitute of chlorophyll,
or any other coloring-matter, and in those orders in which
chlorophyll occurs it is usually associated with a blue or red
pigment.
Many Protophytes exist in masses of a considerable size,
composed of large numbers of individuals imbedded in aMYXOMYCETES.
207'
gelatinous matter, which appears to be formed by a partial
degradation of the walls of the cells. They are mostly
aquatic ; and the species which are terrestrial live in damp,
and generally shaded places.
§ I. Class Myxomycetes. The Slime Moulds.
272. —In this class is included a large group of remark-
able organisms, which differ in many respects from all other
vegetable structures. In many of their characters, as in
having no cell-wall during the period of their active growth,
in being destitute of a nucleus, in their mode of nutrition,
and in the motility of their naked protoplasm, they resemble
certain Monera among the Protozoa; * while, on the other
hand, they have a close external resemblance to certain
higher fungi (puff-balls and their allies).
273. —It is difficult to give the Myxomycetes a satisfac-
tory place in a system of classification. They have no struc-
tural affinities with plants higher than they are, nor with
any lower ; they stand alone, and appear to belong to a dif-
ferent genetic line. So, although taken up here, they must
not be regarded as on that account the lowest or the first of
the Protophytes.
274. —All members of this class agree in being composed
during the vegetative portion of their existence of naked
masses of protoplasm (Fig. 140), which are yellow, brown,
purple, etc., but never green. These plasmodia, as they are
called, are, during the period of their active growth, endowed
* There are fewer reasons now than formerly against regarding these
as near relatives of the Monera. We no longer imagine an absolute
line of separation between the lower portions of the great domain of
life, and hence may now admit relationships which formerly were in-
admissible. It is by no means an improbable hypothesis that in the
Myxomycetea we have the terrestrial phase and in the Monera the
aquatic phase of a common group of organisms. The Myxomycetes are
not Monera, but they are Moneran in their structure, and probably also
in their affinities. All the differences between the Myxomycetes and a
Moner like Protomyxa, for example, are probably referable to the
terrestrial habit of the former as contrasted with the aquatic habit of
the latter.208
BO TANT.
with a remarkable motility, enabling them not only to
change their form,, hut their place also. When the proto-
plasm passes into a condition of rest, it forms itself into
small rounded masses, each of which secretes a covering of
cellulose about itself. This resting condition may be brought
about in two ways : first, through unfavorable conditions,
as the absence of the requisite amount of moisture ; in such
Fig. 140.—Plasmodium of PJvysamm leucopus (Didymium leucopus of Link).
the more granular central part of the threads. X 350.—After Sachs.
case the masses formed are larger, and irregular in size, and
constitute the so-called sclerotium stage; upon the return of
the proper conditions the sclerotia return to the soft and
motile condition of the original plasmodium ; the second
mode of formation of the resting stage takes place only
when the plasmodium has apparently concluded its period
of vegetation ; the protoplasm becomes heaped up in a com-
pact or even elevated mass, which then separates internallyMYXOMTCETES.
209
into a large number of minute rounded bodies, the spores,
each of which is provided with a cell-wall. This latter is
called the spore-bearing stage, or simply the fructification of
the organisms.
275—When placed under proper conditions of moisture
72V
Fig. 141.—Fuligo variant (JEthalivm septicum of Fr.). a spore; b, c, spore-cas©
rupturing and permitting the protoplasmic contents to escape; grounded mass of
naked protoplasm escaped from the spore-case; e, /, ciliated swarm-spore or
zoospore stage; gy h, i, k, l, amoeba stage; m, young plasmodium.—After Prantl.
and temperature, the spores burst their walls, and the im-
prisoned protoplasm in each escapes and soon becomes a
motile, nucleated mass, provided with
a cilium, or having an amoeboid form ;
in this stage (called the swarm-spore)
it repeatedly divides by simple fission
(Fig. 142). After a day or two, the
swarm-spores, now destitute of cilia,
begin the reverse jtrocess of coales-
cing, two or more of them fusing into
a common mass; the process may unde^oins"Sonf
continue until a new plasmodium is x 390.—After De Bary.
formed, differing from the first one mentioned only in size
(Fig. 141, a to m, and Fig. 143). (See Note on page 49.)
276.—-The classification of the Myxomycetes is mainly
based upon the fructification, which usually consists of a•210
BOTANY.
sporangium, which may be distinct (Fig. 144, B), or it may
be a flattish, cake-like mass, the so-called wthulium, directly
derived from the plasmodium. In most cases the spore-
bearing masses contain internally, besides the spores, a
structure called the Capillitium, consist-
ing of thin-walled, spirally thickened, or
■ otherwise marked tubes variously disposed
(Fig. 144, C, cp). In some cases, where
there is a distinct sporangium, the pedi-
cel of the latter is continued into it as a
central column ; this is known as the Col-
umella ; it may send out branches which
support the walls of the sporangium.
. Swarm-
spores of Chondrioder-
rna diffoeme (Didy-
mimn LiberHanum of
Be Bary) coalescing or
conjugating. X 390.—
After Cienkowski.
(a) The latest classification of the Myxomycetes
is by Rostafinski.* He distinguishes seven or-
ders, as follows :
Order I. Protodermese. Sporangia simple, of regular shape, not
possessed of a capillitium, with violet spores,
Order II. Calcarese. Sporangia simple or compound, often pro-
vided with a columella, spores violet or violet brown ; whole fructifica-
tion, with more or less de-
posits of carbonate of lime.
This includes many com-
mon species, under the
genera Physarum, Fuligo,
Didymium, Spumaria, etc.
Order III. Amauro-
chsetese. Single sporan-
gium or asthalium, with-
out lime; spores, capilli-
tium, and columella almost
always uniformly black, or
brownish-violet colored.
In this order the genus
Stemonitis furnishes the
most common species.
Order IV. Anemese.
Sporangium or sethalium
without capillitium or lime; columella not evident, wall of sporan-
Fig. 144.—Fructification of Arcyria incarnata
(A. adnata of Rtfki.). B, young sporangium; C,
mature sporangium ruptured ; op, capillitium ;
p, wall of sporangium. X 20.—After Sachs.
* “ Monografia Sluzowce.’’ Dr. Joseph Rostafinski, 1875. An Eng-
lish translation of so much as pertains to British species may be found
in 11 The Myxomycetes of Great Britain,” by M. C. Cooke, 1877. In aSCHIZOMTCETES.
211
gium without net-like thickenings, now and then symmetrically per.
forated.
Licea and Tubulina are genera of this order of which we have
species.
Order V. Heterodermese. Sporangia without capillitium, colu-
mella, or lime ; wall of sporangium delicate, when mature at least partly
cracked, exposing the net-like flat thickenings of the inner side of wall ;
spores and thickenings of the inner wall in one and the same sporan-
gium usually of uniform color.
Dictj/dium and Gribraiia are our common genera.
Order VI. Columelliferse. Spores, capillitium, and columella
uniformly bright-colored, without lime ; capillitium of very thin-sided
tubes, without thickenings, combined into a thickly intricate but loose-
hanging net.
Represented by the genus Reticularia.
Order VII. Calonemese. Walls of sporangia, spores, and capillitium
usually uniformly colored in the same sporangium. ^ Color variable
from yellow to brownish or chestnut; more rarely olive green or gray-
ish white ; capillitium usually strongly developed ; threads simple, or
combined into a net, either entirely free or grown to certain places of
the wall of the sporangium ; walls of the threads very rarely smooth,
usually provided externally with protruding thickenings, either spiral-
shaped or under the form of numerous spines, warts, or transverse
rings; without fixed columella; exceptionally containing lime, exclu-
sively on the walls of the sporangia; now and then aethalia covered
with a stout double cortex of colored cells,
Arcyria and Tricliia are our common genera.
(b) Specimens of the Slime Moulds may be obtained for study by ex-
amining the surfaces of decayed logs, and the bark-covered ground in
tan-yards. They may frequently be found on decaying leaves, and
occasionally on the grass and mosses near decaying vegetable matter.
§ II. Class Schizomyoetes.
277.—These are minute unicellular Protophytes. which
reproduce mainly by transverse fission. The cells are gener-
ally somewhat elongated, often much so, although in one
family they are spherical ; they are sometimes provided with
cilia, by means of which they move rapidly through the
paper entitled “ The Myxomycetes of the United States,” published in
the Annals of the Lyceum of Natural History of New York, Vol. XI.,
1877, the same author enumerates our species according to Rostafinski’s
arrangement, and gives a copious list of synonyms.212
BOTANY.
water. They occur in solutions of organic matter in im-
mense numbers, and are said even to appear in solutions of
inorganic salts under proper conditions.*
278.—Order Bacteriacese. This includes the organisms
known as Bacteria, and which are present in.fermenting and
putrefying matter; they also occur in the blood and the air-
passages of diseased animals, and the tissues of some dis-
eased plants, where they have been shown to be the cause of
many kinds of disease. Cohnf defined Bacteria as “ chlor-
ophyll-less cells of spherical, oblong, or cylindrical form,
sometimes twisted or bent, which multiply themselves ex-
clusively by transverse division, and occur either isolated or
in cell-families.” Many forms have since been shown to
produce spores, and these are most important agents in their
multiplication and reproduction. In the unicellular Bac-
teria the cells resulting from division separate at once, while
in the filamentous forms they remain in connection, forming
elongated strings or threads. Bacteria sometimes form a
jelly-like mass by the swelling up of their cell membranes;
this is the Zooglcea stage. When they have exhausted the
nutriment from the liquid, they form a pulverulent precipi-
tate, which may be regarded as a resting state. “ Most
Bacteria present a motile and a motionless condition; the
former is connected with the presence of oxygen.”
It is now known that many Bacteria pass through various
stages, e.g., Coccus, Bacillus, Vibrio, etc., which were for a
time supposed to be generic forms, under which species were
described, as was done by Cohn. The real limits of genera
and species cannot in the present state of our knowledge of
these organisms be determined. We may, for the present,
make use of Cohn’s system, remembering that it is merely
a classification of observed forms.
* See Bastian’s “ Beginnings of Life,” Vol. II., Appendix,
f "Researches on Bacteria" (Untersncli. iiberBacterien)in“BeitrSge
zur Biologie der Pflanzen,” Breslau, 1872. See a resume of this paper
in Quarterly Journal of Microscopical Science, 1873, p. 156. See also
English accounts of further researches by Cohn, 1875, 1876; in the
journal just cited, 1876, p. 259. and 1877, p. 81. Consult “ The Bac-
teria,” by Dr. A. Magnin ; translated by Dr. Sternberg. Boston, 1880.SCHIZ0M70ETES.
213
(a) Cohn separated Bacteria into four tribes, as follows :
(1) Splicer obacteria, with spherical cells. The only genus is Micrococ-
cus. The species M. crepusculum, M. candidus, and M. urece produce
certain kinds of fermentation ; the color-producing species are M. pro-
digiosus (a, Fig. 145), which causes the blood-like patches on bread,
flour, paste, etc., M. luteus, M. aurantiacus, M. chlorinus, M. cyaneus,
and M. violaceus ; those producing or accompanying diseases are M.
vaccinas, M. diphthericus, M. septicus, and M. bombycis. This latter
group is of great importance, but it is one the investigation of which
presents unusual difficulties. Oth-
er species than those named are
supposed to exist.
(2) Microbacteria, with very
small cylindrical cells. The only
genus is Bacterium. The species
are, B. Termo (b, Fig. 145), the
common agent of putrefaction;
B. lineola (c, Fig. 145), a larger
species found in brooks and
ponds ; B. xantliinum and B. syn-
cyanum, which are color-produc-
ing ; and B. ceruginosum, which
is found in blue-green pus.
(3) Desmobacteria, with filiform
cells. There are two genera, Ba-
cillus, with the filament straight,
and Vibrio, with the filament curv-
ed or undulated. Of the first there
are three species, viz.: B. subtilis,
which is the butyric ferment; B.
ulna (d, Fig. 145), much like the
preceding, but larger; and B.
anthracis, which is the cause or
accompaniment of the diseases
known as anthrax and “ma-
lignant pustule.” Vibrio has two
species, viz. : V. Bugula (e, Fig. 145), whose cells are thick and rather
short ; and V. serpens, whose cells are of smaller diameter, but of
greater length than the preceding.
(4) Spirobacteria, with spirally twisted cells. There are two genera,
Spirochcete, with a much twisted spiral ; and Spirillum, with a less
twisted spiral. Of the first the single species is Sp. plicatilis (/, Fig.
145), and of the second, Sp. tenue, Sp. andula and Sp. volutans (g,
Fig 145), the latter a gigantic species, with a flagellum at each end
of the spiral.
(b) Bacteria may be readily procured for study by infusing a pinch
Fig. 145. a, Micrococcus prodigioms,
(Monas prodigiosus of Ehrenberg): b,
Bacterium Termo, zooglcea i-tage ; c, Bac-
terium lineola ; d. Bacillus ulna; e, Vi-
brio Bugula; f, Spirochcete plicatilis ; g.
Spirillum volutans. X 550.—After Cohn.214
BOTANY.
of cut hay or any other similar vegetable substance in warm water for
an hour, and then filtering; the filtrate will, if kept at the ordinary
temperature of a room (20° C.), and allowed free access of air, become
turbid with Bacteria in the course of one or two days.
(c) By adding a drop of the hay infusion to Pasteur’s solution,* made
without sugar, the previously clear liquid is soon made turbid by the
rapid increase of Bacteria.)
279.—Allied to the Scliizomycetes are the species of Sac-
charomyces which produce fermentation in sugar solutions.
The type of the genus is Saccharomyces cerevism, the yeast
plant (Pig. 14G). It presents two conditions : in the first it
is in the form of transparent round or oval cells, averaging
.008 mm. (.0003 inch) in diameter; these reproduce by bud-
ding (a modification of fission), a small daughter-cell being
formed by the side of the
mother-cell, and sooner or later
separating from it (Fig. 146, a,
l). The other form consists of
larger cells, which, by a division
of their protoplasm, form four
new cells within the parent-cell
(Fig. 146, c, d). This is probably
no more than the ordinary pro-
cess of internal cell-division,
although it has been thought
to be of greater importance.^
This formation of new cells by
internal cell-division appears to occur only when the supply
■of nourishment is less abundant, as when the yeast is grown
on cut slices of potato or carrot.
Fig. 146.—The Yeast Plant, Saccha-
ro?nyc,es rerevisice. a. rounded cells
from “ bottom yeast,” 50 hours after
eowing in beer-wort; bs row of oval
cells from “top yeast;” c, “bottom
yeast” alter cultivation on a piece of
carrot, four cells forming in the inte-
rior of the parent cell; d, the four
daughter-cells, a and & X 400, c and d
X 750.—After Reess.
* Made as follows : Potassium phosphate, 20 parts ; calcium phos-
phate, 2 parts ; magnesium sulphate, 2 parts ; ammonium tartrate,
100 parts ; cane sugar, 1500 parts ; water, 8376 parts. The sugar is
to be omitted in some cases.
f The student may profitably refer to Huxley and Martin’s “Ele-
mentary Biology,” Chap. IV., for directions in making his observations.
% Reess, in his “Botanisclie Untersucliungen iiber die Alcoliolgiili-
Tungspilze,” 1870, calls this process the formation of ascospores, the
mother-cell he calls an ascus, and the daughter-cells true ascospores.
Accordingly he considers these plants to be very simple Ascomycetes !GY AN UP 11 YClijE.
215
280. —It was formerly held that the yeast plant was only
the immature condition of a mould ;* but Brefeld’s re-
searches,! which were undertaken to determine whether
true yeast ever develops into a filamentous form, appear to be
decisive against that view. He found that under different
conditions, as with free access of air, or growth in a thin
stratum of a neutral solution, the results were always nega-
tive, and no filamentous forms appeared.
(а) Examinations of the yeast plant are easily made by placing a
very small drop of active yeast upon a glass slide, and, after covering
it in the usual way, keeping it in a warm and moist chamber for some
hours, at the end of which time the “budding” will have become
quite well marked. A slide so prepared may be examined immedi-
ately, but with less satisfactory results.
(б) Yeast may be grown in abundance by placing a few drops in a
quantity of Pasteur's solution, in which it grows with great rapidity
in a temperature of 30“ to 35° C. (about 90° Fahr.).
(c) The state in which daughter-cells are formed may be developed
by growing the yeast-cells (those called bottom yeast are the most sat-
isfactory) upon fresh-cut slices of potato, kohl-rabi, carrot, or, better
still, upon small slabs of plaster of Paris. The preparations must be
kept moist by covering with a bell-jar ; with proper care the formation
of daughter-cells will be seen in a week or ten days from the begin-
ning of the experiment.
(id) In order that the study of these organisms may be at all satisfac-
tory the student should be provided with high powers of the micro-
scope, say from 600 to 800 diameters.
§ III. Class Cyanophyce.®.
281. —These are blue-green, verdigris-green, brownish
green, or rarely purple or red Protophytes, which, in addi-
tion to chlorophyll, contain a soluble coloring-matter—
* “Yeast is, in fact, nothing more than a peculiar condition of a
species of Penicillium, which is capable of almost endless propagation
without ever bearing perfect fruit.” Berkeley’s “ Introduction to Cryp-
togamic Botany,” 1857, p. 299.
f In Flora, 1873.
t The Btudent is again referred to Huxley and Martin’s “ Elemen-
tary Biologyin Chap. I. will be found a valuable account of the
yeast plant, with directions for making examinations.216
BOTANY.
pliycocyanine—and a less soluble one—pliycoxanthine.*
Structurally the members of this class differ but little from
the Schizomycetes, although they are of a much larger size.
The cells generally show a little more coherence than in the
last class.
They live in fresh or stagnant water, or upon damp
ground, rocks, or decaying wood. Unlike the Schizomycetes,
they do not normally inhabit putrid solutions.
282. —Order Chroococcaeese. This is made up of uni-
cellular plants. The cells, which are spherical, oblong, cylin-
drical, or angular, are either single, or more commonly united
by a common jelly into families. Cell-division (in reality
internal cell-division) takes place in
either one, two, or three planes (Fig.
147).
Thirteen genera are known in the United
States. (1) Chroococcus, with globose, oval,
or angular (from pressure) cells, which are
solitary or in free families; our four species
grow on wet rocks or in springs; (2)
Olceocapsa (Fig. 147), with spherical cells,
which are solitary or in enclosed families;
our eleven species form a firm grumous or
gelatinous coatiDg of a light brown color
on wet rocks; (3) Clccosplioerium, with very
small cells,forming a tliallus-like mass; we
have one species, forming a light-colored
scum on stagnant water ; (4) Merismopedia,
with globose, oval, or oblong cells, which occur in tabular families of
four, eight, sixteen, etc.; our two species inhabit streams and fresh
ponds. Clathrocystis, Anacystis, etc., are common.
283. —Order Nostocaceac. The plants of this order are
* Pliycocyanine, the blue coloring-matter, is extracted from the
crushed plants by cold water ; the solution is blue by transmitted and
blood-red by reflected light. After the extraction of pliycocyanine,
treatment of the crushed plants with strong alcohol produces a green
solution which contains chlorophyll, and a yellow coloring-matter,
phycoxanthine; the latter maybe separated by shaking up with the
green solution a large quantity of benziue, which takes up the chloro-
phyll, and when at rest rises and forms a green upper layer containing
chlorophyll, below which is the yellow alcoholic solution of phycoxan-
thine.
A
Fig. 147.—Glceocapsa in dif-
ferent stages of growth, show-
ing mode of cell-multiplica-
tion. The daughter cells are
surrounded by the gelatinous
walls of the mother-cells. A,
youngest; E. oldest stage.
X 300.—After Sachs.CJTANOPUYCEsE.
217
composed of rounded cells loosely united into a filament and
generally imbedded in jelly (Fig. 148, A) ; they frequently
form large masses, united by the glutinous jelly. At inter-
vals in the filaments there are larger clear cells—the hetero-
cysts—which appear from analogy to be reproductive bodies,
although nothing is positively known as to their function.
The usual mode of reproduction is by the simple fission of
the cells. New masses or colonies are formed by the break-
ing up of the old filaments into pieces composed of a few
cells, which then become endowed with a power of motion
which consists of a slow bending from side to side with a
forward movement at the same time. Each moving fila-
ment, when it comes to rest, may become the centre of a
new colony, which arises from it by fission.
Six genera and thirty or more species are known in the United
States. The principal genus
is JYostoc (Fig. 148, A); its ^
species form jelly-like masses
from the size of a pin-head to -
several inches in diameter in gk jj
ponds and streams, adhering
to sticks and twigs, and on wet pig. 14$.—a, a filament of a Xostoc, with a
rocks or wet ground : they '“1,8® heterocyst; B, end of filament of Os-
. ’ , cillatoria. x 300.—After Prantl.
■even grow inside of other
plants—e.g.,Anthnceros Iwvis—and, according to the present view, con-
stitute the so-called gonidia of certain lichens.
284. —Order Oscillatoriaceae. The filaments in this or-
der are composed of more closely cohering cells than in the
previous one ; the cells unite by broad surfaces to form a
rigid, cylindrical, straight or slightly curved filament (Fig.
148, B). They form dark-green, loose, or felted masses in
water or on wet earth, and are remarkable for the peculiar
oscillating movements of their filaments. No other method
of reproduction than by* fission is known.
The principal genus is Oscttlaria, of which we have about thirty
species.
285. —Order Rivulariacese. The filaments in this order
present a greater differentiation than in any of the preced-
ing ; they are usually arranged in a radiating manner, and
imbedded in a common jelly, so as to form small rounded218
BOTANY.
masses. Each filament has a basal cell (which is spherical'
and thick walled), and sometimes interstitial ones; the prin-
cipal cells of the filaments are usually cylindrical and often
much elongated ; at the outer end they become attenuated
into long slender hyaline hairs. Special reproductive bod-
ies, called resting spores, are formed before the close of the
growing season ; these appear just above the basal cells, one
on each filament, and are much larger and thicker walled
than the remaining cells. Upon the death of the mass of
filaments the resting spores remain, and from these upon the-
advent of favorable conditions new filaments are developed.
Five genera are known in the United States, the principal ones-
being JUvularia, Calothrix, and Mastigonema ; their species are found,
in water or wet places everywhere; they also constitute the so-called,
gonidia of lichens.
287.—Closely related to the foregoing orders, but not
falling within the class Cyanophycete, is the doubtful order
Pcdmellacece. The cells are single or in colonies, and im-
bedded in a gelatinous matter, much as in the Chroococcaceae ;
but the cells are destitute of phycocyanine or phycoxanthine,
containing only chlorophyll. This, however, is hardly a
sufficient character for separating them. It is, moreover,
not certainly known whether the forms included in this
order are autonomous species ; it seems probable that at
least a portion of them are only early stages of other plants.
We have five genera, the principal one of which is Scytonema,
which contains nineteen species. Some of these are the “gonidia”
of lichens.
286.—Order Scytonemacese. In this order the differen-
tiation becomes so great that the filaments may be said to-
attain a distinct individuality ; they branch here and there,
and are furnished with thick-walled heterocysts, which are
basal or interstitial. In this order there is also a well-de-
veloped sheath surrounding each filament, which may be
compared with the poorly defined one of the preceding-
orders. The filaments form little masses or mats, growing
in the water or on wet ground, or even on the moist bark of
trees.C YANOPH YCBJZ,
219
288.—The genera Protococcus, Chlorococcum, and one or
two others, are probably to be placed near the Palmellaceee,
although their autonomy is doubtful also. They are all
unicellular in the strictest sense of the term, and reproduce
mainly by fission. In their resting stage they are spheroidal;
in their motile stage they are provided with two cilia. The
latter form is said to arise from the former by internal cell-
division, which results in the production of “gonidia” of
two sizes, the larger being termed macrogonidia, and the
smaller microgonidia.
These organisms are common in shallow pools, in the gut-
ters of roofs, and on the wet earth.
(a) On account of tlieir ready perishability, Protophytes are scarcely
found in a fossil state. Schimper records a species of Nostoo from the
Tertiary.
(b) The relationship of the classes of the Protophytes may be indi-
cated by the following diagram :
(c) For an account of the structure of Protococcus, with directions
as to methods of study, see Arthur, Barnes and Coulter’s “Hand-
book of Plant Dissection,” p. 22.
(d) In the study of the Cyanophycese, and of other “ fresh-water
algae,” the student will find Rev. Francis Wolle’s “Fresh-water
Algae of the United States” (1887) of great value.
Arrangement of the Classes of Protophyta.
Cyanophyce®
Myxomycetes.
Scliizomycetes.CHAPTER XV.
ZYGOPHYTA.
289. —This is an assemblage of quite simple plants, none
of its members attaining any great degree of complexity.
For the most part the plant-body consists of an elongated
filament composed of united cells; sometimes, however,
they form surfaces, and in other cases the plants are unicell-
ular, or aggregated into communities. In these plants we
find the first examples of undoubted sexuality, and through-
out the group, the organs and methods of fertilization are
nearly enough uniform to enable us to use them as distin-
guishing characters. The sexual organs all have this in com-
mon, that between the male and the female there is no ap-
preciable difference as to form, size (with a few exceptions),
color, origin, etc. In the sexual processes, likewise, there is
this in common, that the result of the union of the two
sexual cells is the production of a new cell, the zygospore,
possessing very different characteristics from either. While
the sexual cells have only ordinary walls, or none at all, the
zygospores are covered with thick, firm ■walls.
290. —The zygospore is frequently called the “resting
spore,” because under certain circumstances it remains quies-
cent, while retaining its vitality, often for long periods of
time. Thus at the close of the growing season, as upon
the advent of the summer drought, or of winter, the zygo-
spores fall to the bottom of the pools (in the aquatic forms),
and in the dried or frozen mud remain uninjured until the
return of favorable conditions, when they germinate and give
rise to a new generation of plants.
291. —Nearly all the plants of this group contain chloro-
phyll, only one order being destitute of it. The green forms
are all aquatic, and inhabit either fresh or salt water. TheyZOOSPOREJE.
221
include the greater part of the green algae of our ponds
and streams. Those which have no chlorophyll are sapro-
phytes, and live upon dead organic matter. They are doubt-
less to be regarded as modified forms of some of the types
of the chlorophyll-bearing portion of the group.
§ I. Class Zoospores.
292. —This class is a somewhat doubtful one ; it is com-
posed of plants which, while differing in many other re-
spects, agree in having locomotive sexual cells (zoospores).
In this they agree, however, with the Volvocinece, and bear
a close resemblance to Protococcus and its allies. It is prob-
able that a fuller knowledge of some of the plants of this
class will result in their being distributed elsewhere.
The general structure of the plants referred to this class
may be understood from the examples which follow. No at-
tempt will be made here to indicate the orders to which
they belong.
293. —Pandorina is a unicellular alga, which is united into
colonies (called coenobia), which swim about freely in the
water (A, Fig. 149). Each colony consists of sixteen rounded
or pointed cells (called zoogonidia), each provided with two
cilia, and united into a spherical mass by a gelatinous enve-
lope, through which the cilia project. Each zoogonidium
breaks itself up into sixteen new zoogonidia, forming sixteen
small and new colonies (B, Fig. 149), which are soon set free
by the absorption of the common envelope of the colonies.
The process of colony-formation just described is repeated
again and again, thus giving rise, asexually, to a large num-
ber of colonies.
294. —The sexual process begins in the same way ; but the
zoogonidia of the new colony separate by the softening of
the colony-envelope (G and D, Fig. 149), becoming zoospores,
which are naked protoplasm-masses, which swim about by
means of their cilia. After a time two zoospores meet, their
points coming in contact, and their bodies soon fusing into
one common body (E, F, G, Fig. 149). The result of this
union, which is regarded as a very simple kind of sexual222
BOTANY.
act, is that within a short time a thick coat of cellulose is
formed over the new cell, thus producing a zygospore (II,
Fig. 149). After a long period of rest, these zygospores
Fig. 149 —Pandorina Moi'um. A, non-sexual colony (or ccenobiiim) of 16 zoogoni-
dia ; a, red spot; 6, transparent anterior end of zoogonidium, to which the two
cilia are attached.
B, sixteen young sexual colonies about to leave the gelatinous wall.
Cand D. colonies of sexual zoospores escaping.
E, F, Os conjugating zoospores
H, zygospore in resting stage (red).
J, K, germinating zygospore, the contents escaping as a large red ciliated swarm-
epore.
L. new colony formed by the division of E. very young stage.
Ms the same colony as Z, in a further stage of development.—After CErsted.
germinate by the bursting of the coat (exospore), when the-
protoplasmic contents escape as a ciliated swarm-spore (E,
Fig. 149). After swimming about for some time, the swarm-Z008P0REJE.
225
spores absorb their cilia, and surround themselves with a
gelatinous envelope, when each breaks up into sixteen cells
(zoogonidia) and gives rise to a new colony (L and M, Fig.
149).
Pandorina is nearly related to Yolvox (see p. 243), from
which it seems a violence to separate it. It occurs in pools
of fresh water (in Europe) as minute green spherical coenobia,
3 mm. (.012 inch) in diameter.
295.—Hydrodictyon, the Water Net, is a common plant
in ponds and sluggish streams. It is, when full grown, a
tubular net, composed of a multitude of elongated cells,
which are attached only at their ends ; the net sometimes
attains a length of 25 to 30 centimetres (10 to 12 inches),
• and the cells which compose the meshes are in such speci-
mens 7 to 8 mm. (£ inch) long. The
reproduction is as follows : The pro-
toplasmic contents of certain cells
break up into a large number of
daughter - cells (macrozoogonidia),
there being often as many as 7000 to
20,000 ; these soon arrange them-
selves within the mother-cell so as
to form a miniature net (Fig. 150),
which is freed by the absorption of
the walls of the mother-cell. Under favorable conditions,
the young net attains full size within a month. A second
mode of reproduction is known, or partly known. In cer-
tain cells, in the division of their protoplasmic contents, in-
stead of giving rise to the comparatively large macrozoogo-
nidia, they produce an extremely large number (30,000 to
100,000) of very small ciliated swarm-spores (zoospores, or
the chronizoospores of Pringsheim), which, after swimming
about for a time, acquire thick walls, and fall to the bottom
of the water, where they remain in a resting state. Upon
their germination they pass through a number of curious
stages, and finally give rise to small nets. Suppanetz is said
to have witnessed the conjugation of the swarm-spores within
the mother-cell, or immediately after their emission.*
Fig. 350.—Part of a cell of
Hydrodictyon utriculatum, ii\
which the macrozoogonidia
are beginningto arrange them-
nelves so as to form a minia-
ture net within the mother-
cell.—After (Ersted.
* Qr. Jour. M.c. Science, 187o, p. 399.224
BOTANY.
296.—Closely related to Hydrodictyon is Pediastrum (Fig.
151),which consists of a number of cells arranged into a
.flat, thallus-like mass. The cells at a certain stage produce, by
Fig. 151.—A, a colony of cells constituting a Bo-called individual of Pediastrum
■graimlatum ; t, cells with their contents remaining ; the white cells are empty, their
contents having escaped by the slits sp: g, contents of a cell (macrozoogonidia)
escaping. B, macrozoogonidia (7, in the motile state, enclosed in the membrane b. C,
the macrozoogonidia arranging themselves in a colony, still enclosed by the mem-
brane b. X 400.—After Braun.
internal cell-division, a large number of daughter-cells, which
are of two sizes. The function of the smaller ones is un-
o known ; the larger ones
(macrozoogonidia) escape
by a slit in the wall of the
mother-cell, surrounded by
a thin membrane, in which
they swim freely for a time
(Fig. 151 B). After a
while they lose their pow-
er of motion and arrange
themselves symmetrically,
as in C, Fig. 151. They
soon grow together, and
thus form a colony like
the parent one.
297. — In Cladopliora
(one of the common Confervacese) the cells of the branching
filaments break up into ciliated zoospores which directly
Fig. 152.—Portion of the thallus of TJlva. a,
cells filled with zoospores (zoogonidia); b,
opening in cell-wall, by which the zoospores
escape from the cells; c, zoospores (zoogo-
nidia).—After CErsted.DESMIDIA CEJE.
225
reproduce new filaments. Smaller bodies—swarm-spores—
are also produced, and these are said to conjugate.*
298. —In Viva the plant-body is flat, and composed o f a
single layer of polyhedral cells, in which are found zoospores,
which are asexual (Fig. 152, c), and smaller swarm-spores,
which are said to conjugate, f [See foot-note on p. 242.]
§ II. Class Conjugate.
299. —In this class the sexual process is a distinct conju-
gation, and it always takes place in the mature plant.
Swarm-spores are wanting. The orders of this class are well
marked.
300. —Order Desmidiacose. The Desmids are minute uni-
cellular algse ; the cells are of "very various forms, mostly
more or less constricted in the middle, and divided into two
symmetrical half-cells ; they are free, or united into loose
families, sometimes involved in a jelly. The cell-wall is
more or less firm, but not silicious.
301. —The reproduction of Desmids takes place asexually
and sexually. In the first the neck uniting the two halves
of the cell elongates and becomes divided by a transverse
partition, so that instead of the original symmetrical cell
there are now two exceedingly unsymmetrical ones; these
grow by the rapid enlargement of the new and small halves;
eventually the two cells become symmetrical, by which time
they have separated. This process, which is essentially fis-
sion, may be repeated again and again.
The sexual process takes place in this way: each of
two cells which are near one another sends out from its
centre a conjugating tube, which meets the corresponding
one from the other (cl, Fig. 153). At the jtoint of meeting
the two tubes swell up hemispherically, and finally, by the
disappearance of the separating wall, tire contents unite and
form a rounded zygospore (e, Fig. 153), which soon becomes
* and \. Aresclioug, in “ Observationes Phycoiogicae,” 1874, records
Having seen the conjugation in Clalophora and JJ'oa.226
BOTANY.
coated with a thick wall (/, Fig. 153). This zygospore is a
resting spore, and may retain its vitality for an indefinite
period.
302.—In the germination of the zygospore the first notice-
able change is the partial separation of the contents into two
portions, and the escape of the whole, surrounded by a deli-
cate wall, through a rent in the exospore (, h, Fig. 153);
the separation of the protoplasm now becomes complete
(i, Fig. 153), and each portion becomes again partly divided
by lateral constrictions, which, however, do not quite reach
the centre ; in this way, within the mass which escaped from
the zygospore there are formed two constricted cells, which
Fig. 153.—Conjugation of Cosmarium Menenghinii. a, front; &, end ; c, side
yiew of the adult plants; d, two cells conjugating; e, young zygospore formed ; /,
ripe zygospore, with spiny \yall—the four halves of the parent cells are empty ; g,
the zygospore germinating after a period of rest; h, the young cell escaped from
zygospore ; i, young cell dividing, showing two new plants similar to a, placed
crosswise in the interior of the cell. X 475.—After (Ersted.
are, in fact, new individuals resembling the original ones
which conjugated («, b, c, Fig. 153).
The descriptions above given are of the processes as they
take place in the bilobed Desmids ; in those which are not
lobed it takes place in essentially the same way, with differ-
ences only in the minor details.
303.—Desmids have the power of slow locomotion, and
they may often be seen moving across the field of the micro-
scope, or in a jar or bottle they may frequently be seen to
congregate in particular places. The mechanism of the
movement is unknown, but it appears to be certain that it is
not ciliary.
Desmids are exclusively inhabitants of fresh water (not
salt), and in almost all cases they appear to prefer pure andDIA TO MAC EM.
227
clear water to that which is stagnant, although they are to be
found in the latter also.
The principal genera are Cosmarium (Fig. 153), Muaslrum and
Mierasterias, which are constricted in the middle ; and Closterium, in
which the individuals are cylindrical or fusiform.*
304. —Ord9r Diatomaceae.f The Diatoms are micro-
scopic unicellular algae, resembling in many particulars the
Desmids, but differing from them in having walls which are
silicified, and in the chlorophyll being hidden by the pres-
ence of phycoxanthine. The endochrome, as the colored
contents are called, is always symmetrically arranged. Each
cell (technically called a frustule) is usually composed of two
similar and approximately parallel portions, called the valves.
Each valve may be described as a disc whose edge is turned
down all around, so as to stand at right angles to the remainder
of the surface, making the valve have the general plan of a pill-
box cover. The two valves are generally slightly different
in size, so that one slips within the other (A, Fig. 154), thus
forming a box with double sides. In other cases—as, for ex-
ample, in Diatoma and Fragilaria—the valves are simply
opposed, and do not overlap. In figures and descriptions of
Diatoms, the parts corresponding to the top and bottom of a
box are referred to as the valves, or as the side view (C, Fig.
154), and that which in the box would be called the side, is
in the Diatom called the front.
305. —The individuals may exist singly, or in loose fami-
lies ; they are free, or attached to other objects by little
stipes, and they are frequently imbedded in a mucous secre-
tion. The free forms are locomotive, and may be seen in
constant motion under the microscope. As in the Desmids,
the mechanism of this movement is not certainly known;
* The student is referred to Rev. Francis Wolfe's “Desmids of
ihe United States,” 1884, for an account of our species.
f Most of our species are figured and described in Henri Yan
lieurck’s “ Synopsis des Diatomees de Belgique,” 1880-5.328
BO TANT.
the most probable explanation is that it is due to protrusions
of the protoplasm through orifices in the rigid wall.
306.—Diatoms bear a close resemblance to the Desmids
in their modes of reproduction ; the differences that exist
are easily referable to the differences in the wall. The
asexual reproduction is a true fission, although at first sight
it might not be recognized as such. The protoplasmic con-
tents of the cells divide in a plane parallel to the valves;
each portion then forms a
new valve in the plane of the
division. As during this pro-
cess the two original valves are
pushed apart, the new valves
are fitted, the one into the
larger and the other into the
smaller one- (B, Fig. 154). By
a slight subsequent increase
of their contents, the two
daughter-cells are pushed out
so as to be free from each
other ; in many cases they sep-
arate, while in others they re-
main in contact, although
really free. This process re-
quires from three to four days
for its completion. It will
readily be seen that the con-
tinued formation of individu-
als in this way must result, in all species whose valves are of
a slightly unequal size, in producing smaller and smaller
cells. This reduction of size does not, however, take place
in those species whose valves are simply opposed, as in Dia-
toma. The reduction of size is corrected by the formation
of what are termed auxospores ; * these are large individu-
als, which form either by an asexual or a sexual process.
The asexual formation of auxospores takes place by the
Pj
Fig. 154.—Navicula viriclis. A, front
view of a frusiule ; B, front view of a
frustule undergoing fission; C. side view
of a frustule, showing the central line,
called the raphe, the central and termi-
nal nodules, and the surface markings.
—After (Ersted.
* From the Greek av^avu, to increase.D1A TOMA CEJE.
229
protoplasm of one of the small Diatoms leaving its silicious
shell (the latter falling apart), and then increasing by growth
until it reaches the normal size, when it forms a new coat
about itself. This is not unlike what has been called the
Rejuvenescence of the cell. (See p. 42.)
307. —The second mode of the formation of auxospores is
a sexual one, and is, in fact, the sexual mode of reproduc-
tion above referred to.* Two individuals come near each
other ; their valves separate, and the two protoplasm-masses
unite with each other into one mass, or in many cases two
masses (A, Fig. 155). These new masses* develop directly
into auxospores, the whole process
requiring from ten to fourteen
days (B, Fig. 155).
308. —Diatoms are exceedingly
abundant; they occur in both
salt and fresh water, usually
forming a yellowish layer at the
bottom of the water, or they are
attached to the submerged parts of
other plants, and to sticks, stones,
and other objects ; they have been
dredged from the ocean at great
depths, and appear to exist there
in enormous quantities. They are
also found among mosses and other
plants on moist ground; great
numbers occur as fossils, forming
in many instances vast beds composed of their empty
frustules. The varied and frequently very beautiful mark-
ings of their valves have long made Diatoms objects of
much interest to the microscopist. The great regularity
and the extreme fineness of the lines and points upon some,
have caused them to be used as microscopic tests. The
B
Fig:. 155.—Navicula saxonica,
showing conjugation and forma-
tion of auxospores. .4, conjuga-
tion of two frustules.; jB, two aux-
ospores, with the four valves of
the two parent frustules.—After
(Ersted.
* This process takes place at certain seasons of the year for each
species ; according to Professor H. L. Smith, in Gomphonema olivaceum
it occurs in February and March.330
BOTANY.
fineness of some of these markings is astonishing, as will
he seen from the following list:
*Pleurosigma Balticum.............0006 mm. (.000026 inch).
Pleurosigma angulatum.............0005 “ (.000019 “
Navicularhomboid.es...............0004 “ (.000015 “
Amphipleura pellucida.............0002 “ (.000008 “
(a) The classification of Diatoms is as yet largely artificial. That
proposed by Professor H. L. Smith f is one of the most satisfactory ; it
is based upon the structure of the f'rustule. He divides the order into
three tribes, each containing several families, as follows :
Tribe I. Raphidie,®.
Frustules mostly bacillar (t.e., longerthan broad); always with a dis-
tinct raphe or median line on one or both valves, and with central and
terminal nodules ; without teeth, spines, awns, or processes.
Family 1. Cymbelleas. Raphe mostly curved ; valves alike, more
or less arcuate, cymbiform (i.e., lunate).
Illustrative genera, Amphora, Cymbeila.
Family 2. Naviculeas. Valves symmetrically divided by the
raphe ; frustules not cuneate or cymbiform.
Namcula (Figs. 154 and 155), Stauroneis, Pleurosigma, Amphi-
pleura.
Family 3. Gomphonemese. Valves cuneate ; central nodule un-
equally distant from the ends.
Oomphonema, Rhoicosphenia.
Family 4. Achnantheae. Frustules genuflexed ; nodule or stau-
ros on one valve ; mostly stipitate.
Achnantlies, Achnanthidium.
Family 5. Cocconidese. Frustules (generally parasitic) with valves
unlike ; valves broadly oval.
Cocconeis, Anortheis.
Tribe II. Pseudo-Raphidie/e.
Frustules generally bacillar {i.e., longer than broad) ; valves with-
* These measurements are those given in Carpenter’s work on “ The
Microscope,” fifth edition, p. 212. Those given by Professor Morley, in
Am. Naturalist, 1875, p. 429, are a trifle less in each case.
f “ Conspectus of the Families and Genera of the Diatom ace*,” by
H. h. Smith, published in The Lens, 1872-3, and republished in Le
Microscope, sa construction, etc., by Henri Van Heurck, 1878.
The brief sketch of this system of classification here given is fur-
nished by Professor Smith.DIATOM ACE'M.
231
out a true raphe ; without central and marginal nodules; without
teeth, processes, or spines.
Family 6. Fragilarieae. Frustules adherent, forming a ribbon-
like, fan-like, or zigzag filament, or attached by a gelatinous cushion
or stipe ; sometimes arcuate in front, or side view.
Epithemia, Eunotia, Fragilaria, Synedra, Diatoma.
Family 7. Tabellarieae. Frustules with internal plates, or imper-
fect septa, often forming a filament.
Glimacosphenia, Qrammatophora, Rhabdonema, Tdbettaria, Stria-
tetta.
Family 8. Surirelleee. Frustules alate, or carinate; frequently
•cuneate in front view and side view.
Nilzschia, Sarirtlla, Cyrnatopleura.
Tribe III. Crypto-Rapiiidie.r.
Frustules cylindrical or angular ; frequently with processes, spines,
teeth, or awns ; and often coherent, forming a filament.
Family 9. Chsetocerese. Frustules mostly hyaline and armed
with bristles or awns, and generally coherent.
Rhizosolenia, Ghcetoceros.
Family 10. Melosireae. Frustules cylindrical, adhering and form-
ing a stout filament; valves cylindrical, sometimes armed with spines.
Melosira, Stephanopyxis.
Family 11. Biddulphieee. Frustules adherent, forming generally
a zigzag filament, attached by one or two processes.
Isthmia, Terpdnoe, BiddulpMa, Hemiaulus. ■
Family 12. Eupodiscese. Frustules not forming a filament;
-valves cylindrical, with ocelli ; often with radial ribs or furrows.
Auliseus, Aulacodiscus, Eupoditcus.
Family 13. Heliopeltese. Valves divided into compartments al-
ternately light and dark, often with marginal spines or teeth.
Actinoptychus, Heliopelta, Ralionyx.
Family 14. Asterolamprese. Valves circular (rarely angular) and
mostly hyaline, with linear, often bifurcating, rays.
Actinodiscus, Mastogonia, Asterolampra.
Family 15. Coscinodiscese. Valves circular, generally with radi-
ating cellules, granules, or punctae ; sometimes with marginal or intra-
marginal spines or distinct ribs ; without distinct processes.
Gyclotella, Actinocydu*, Stephanodiseus, Araclmoidiscus, Coscino-
■discus.
(b) Diatoms are very easily obtained for study ; it is only necessary,
to scrape off a little of the slippery covering of submerged stones or
sticks to procure numerous specimens. They may be obtained also
from ordinary drinkiug water, allowing it to flow from a liydrant
through a filter of “ Canton flannel” for an hour or so. Often appar-232
BOTANY.
ently pure water placed for a few weeks in a clean bottle and exposed
to the light will yield an abundant crop, generally of one species.
309. —Order Zygnemacese. The plants of this order are
elongated unbranched filaments, composed of cylindrical
cells arranged in single rows. The cells are all alike, and
each one appears to be independent, or nearly so, of its asso-
ciates. The filament is thus, in one sense, rather a com-
posite body than an individual. Each cell has usually a
centrally placed nucleus, with radiating extensions of the
protoplasm passing from it to the layer lining the inner sur-
face of the wall. The chlorophyll is generally arranged in
bands or plates, but under certain conditions it exists in
shapeless masses.
310. —The vegetative increase of the number of cells takes
place by the fission of the previously formed cells. The
protoplasm in a cell divides, and a plate of cellulose forms in
the plane of division. This is repeated again and again, and.
by it the filament becomes greatly elongated. It is interest-
ing to note that this increase of cells, which here constitutes
the growth of the plant-body, is that which in simpler plants
is called the asexual mode of reproduction. In the plants
under consideration there is barely enough coherence of the
cells to enable them to constitute a.plant-body, and one can
readily see that the same fission of the cells which now takes
place, and which here increases the size of the plant, would,
if the cells cohered less, simply increase the number of indi-
viduals. i
As might be expected, the filaments occasionally separate
spontaneously into several parts of a considerable length,
and the parts floating away give rise to new filaments. The
separation takes place by the cells first rounding off slightly
at the ends, so that their union is weakened at their cor-
ners ; finally only the centres of the rounded ends are left
in slight contact, which soon breaks.
311. —The sexual reproduction is well illustrated in Spi-
rogyra, one of the principal genera. At the close of their
growth in the spring, the cells push out little processes from
their sides, which extend until they come in contact withZYGNEMACEM.
233
similar processes from parallel filaments (a, l, Fig. 156).
Upon meeting, the ends of the processes flatten upon each
other, the walls fuse together, and soon afterward become
absorbed, thus making a channel leading from one cell
to the other (Fig. 157). Through this channel the proto-
Fig. 156.
Fig. 156.—Beginning of the process of conjugation in Spirogyra longata. a,
beginning of the formation of lateral tubes ; b, c, the tubes in contact, x 550.
—After Sachs.
Fig. 157.—Conjugation of Spirogyra longata. A, the protoplasm passing from
one cell to the oiher at a ; b, the mass of protoplasm formed by the union of the
protoplasmic contents of the two cells.
£, two young zygospores (e), each with a cell-wall. They contain numerous oil
drops, and are still enclosed by the walls of the parent cell, x 550.—After Sachs.
plasm of one cell passes into the other, and the two fuse into
one mass, which becomes rounded, and in a short time secretes
a wall of cellulose around itself (Fig. 157, A and B). The
zygospore thus formed is set free by the decay of the dead234
BOTANT.
coil-walls of the old filament surrounding it; it then falls to-
the bottom of the water and there remains until the proper
conditions for its growth appear.
312. —The conjugation described is the one best known
it prevails in a large part of the genus mentioned. There
are some curious modifications of the process. In what is
called genuflexous conjugation the opposing cells of parallel
filaments become strongly bent back so as to form an angle
at their central points ; then the angles approach each other
and fuse, allowing the cell-contents to pass over, as in the
other case.
Lateral conjugation takes place between the cells of the
same filament. At the contiguous ends of two cells tubular
processes are pushed out, which,'meeting, form a curved
channel from one cell to the other. Occasionally there ap-
pears to be only a slight enlargement of the contiguous ends
of the cells, and this is followed by the breaking away of a
portion of the separating wall. These cases of lateral con-
jugation show that the cells are, to a great extent, to be re-
garded as independent organisms, and that the conjugation,
is primarily the union of two cells, instead of two filaments.
313. —The germination of the zygospore is a simple pro-
cess. The inner mass enlarges and bursts the outer hard
coat; it then extends into a columnar or club-shaped mass,
gradually enlarging upward from its point of beginning;
after a while a transverse partition forms in it, and this,
is followed by another -and another, until an extended fila-
ment is formed.
(a) The principal genera are Spimgyra, in wliich the chlorophyll
bands are spirally arranged in the cells, and Zygnema, in which the
chlorophyll is usually arranged in a stellate manner. Thirty-nine
species of Spirogyra are recorded as occurring within the United
States, and of these Sp. longala and Sp. quinina are the most common.
Of Zygnema six species are recorded in the United States, several of
which are common.
(b) These plants may be found at any time in ditches and streams,
where they often form extensive masses of green felt; but it is only
from the middle to rear the end of spring that they can be found in
conjugation. For the Northern States the time varies from April to
the first of June ; in the South it is of course much earlier, being inMUCORINI.
235
Florida as early as February. In searching for conjugating specimens
only the yellow and brown masses of filaments need be examined, as
the process never takes place in the bright green ones.
314. —In the genera Mesocarpus and Pleurocarpus the
conjugation is slightly different from that described above.
The conjugating tube, which is much longer, becomes di-
lated midway between the two filaments, and in this the
contents of the two cells unite and form a zygospore. This
difference has been considered by some botanists to be of
sufficient importance to set off these genera in a group allied
to, but distinct from, the Zygnemacea?. When they are so
set off they constitute the Mesocarpece ; but it is altogether
probable that they are to be considered rather as a subdivi-
sion of the Zygnemaceae than as a distinct order.
Mesocarpus scalaris is our most common species. In general appear
ance it resembles tbe previously mentioned species, but its chlorophyll
is not so regularly arranged.
315. —Order Mueorini. The Moulds are saprophytic and
sometimes parasitic plants; they are composed of long
branching filaments (hyphce), which always form a more or
less felted mass, the mycelium ; when first formed the hyphse
are continuous, but afterward septa are formed in them at
irregular intervals. The protoplasmic contents of the hy-
phee are more or less granular, but they never develop chlo-
rophyll. The cell-walls are colorless, except in the fruiting
hyphse, which are usually dark colored or smoky (fuliginous).
The mycelium sometimes develops exclusively in the inte-
rior of the nutrient medium ; in other cases it develops
partly in the medium and partly in the air. In some species
the mycelium may occasionally attach itself to the hyphse
of other plants of the same order, and even to nearly related
species, and derive nourishment parasitically from them. It
is doubtful, however, whether any Moulds are entirely para-
sitic, and so far as parasitism occurs it appears to be con-
fined to narrow limits ; none, so far as known, are parasitic
upon higher plants.
316. —The reproduction of Moulds is asexual and sexual.
In the asexual reproduction the mycelium sends up erect236
BOTANY.
hyphas, which produce few or many separable reproductive
cells—the spores (Fig. 158). The method of formation of
the spores in Mucor Mucedo is as follows : the vertical hy-
phse, which are filled with protoplasm, become enlarged at
the top, and in each
a transverse partition
forms (A, a, Fig. 159),
the portion above the
partition (5, Fig. 159)
becomes larger, and,
at the same time, the
transverse partition
arches up (B, a, Fig.
159), finally appearing
like an extension of
the hypha, then called
Fig. 158.—Diagram showing the mode of growth the Columella ( 0, «,
«of Mucor Mucedo. m, the mycelium; single 159) The DfO-
sporangium, borne on an aerial erect hypha.—After o' \ *
Aanti. toplasm in the en-
larged terminal cell (5) divides into a large number of
minute masses, each of which surrounds itself with a cell-
wall ; these little cells are the spores, and the large mother-
cell is now a sporangium.
In the other Moulds the process is essentially like that
B
in Mucor Mucedo. In
many cases there are sev-
eral sporangia formed at
the top of the vertical
hyphse; in such cases the
latter are branched before
the formation of sporan-
gia. Another variation
from the method as de-
scribed above is that in
some species but one spore
.is formed in each sporan-
gium ; the hyphae then appear to bear naked spores.
317.—The spores are set free in different ways ; in some
cases the wall of the sporangium is entirely absorbed by the
time the spores are mature ; in other cases only portions of
Fig. 159.—Diagrams showing mode of
growth of lhe sporangium of Mucor Mucedo.
A, very young s?-tage; B. somewhat later ; C,
sporangium with ripe spores, a in all the fig-
ures represents the partition wall between the
last cell of the filament and the sporangium b.MTJCORINI.
237
the sporangium-wall are absorbed, producing fissures of va-
rious kinds—e.g., at the base in Pilobolus ; about the middle
in Circinella ; irregular in Mucor, etc. The spores germi-
nate readily when on or in a substance capable of nourishing
them (but not in pure water) ; they send out one or two hy-
phse (sometimes one from each end), which soon branch and
give rise to a mycelium. Spores may, if kept dry, retain
their vitality for months.
318.—A second kind of asexual formation of spores takes
place in some, if not all, the genera of the Mucorini. The
Fig. 160. —Conjugation of Mucor stolonifer. a, two hyphse near each other, and
sending out short lateral processes or branches, which come in contact; b, the
branches grown larger ; c, the formation of a partition near the end of each branch ;
d, absorption of the wall between the two branches, and the consequent union of
the protoplasm of the end cells; e, zygospore fully formed, e X 90; the others
nearly the same.—After De Bary.
protoplasm in certain parts of the hyphse condenses and be-
comes transformed into single reproductive bodies, known as
chlamydospores. Occasionally they form at the ends of
hyphse, and are then apt to be mistaken for the “fruiting”
of other fungi.
319.—Sexual reproduction takes place after the produc-
tion of asexual spores ; the mycelium produces at particular
points, in the air or within the nutritive medium, two simi-
lar branches, which come in contact with each other, and by
fusing their contents give rise to a zygospore (Fig. 160).238
BOTANY.
The steps in the process in Mucor stolonifer are briefly as
follows : two hyphse come near each other, and send out
small branches, which come in contact with each other (a,
Fig. 160) ; these elongate and become club-shaped, and at
the same time they become more closely united to each other
at their larger extremities (b, Fig. 160); a little later a trans-
verse partition forms in each at a little distance from their
place of union (c, Fig. 160) ; the wall separating the new
terminal cells is now absorbed, and their protoplasmic con-
tents unite into one common mass (cl. Fig. 160); the last
stage of the process is the secretion of a thick wall around
the new mass, thus forming a zygospore (e, Fig. 160, and z,
Fig. 161).
It is interesting and instructive to note here the close simi-
larity between the zygospore of Mucor stolonifer and that of
Mesocarpus, briefly described above (par. 314). In both the
zygospore is formed in the lateral
branches of the ordinary filaments.
320.—In Piptocephalis the for-
mation of the zygospore is essen-
tially like that in Mucor, with
some minor differences. The
uniting hypha-branches are large
and curved, and are smaller at
their points of union ; the zygo-
spore is formed at first in the
small neck formed by the union of
the tips of the branches, but it soon grows so much as to
appear to be external (Z, Fig. 162). In this, as in all other
cases, however, the zygospore is strictly an endogenous for-
mation.
“ The zygospore does not germinate until it has under-
gone desiccation, and has experienced a certain period of
rest,”* when, if placed in a moist atmosphere, it sends out
hyphse which bear sporangia. The zygospores appear never
* “ Researches on the Mucorini,” by Pli. Van Tieghem and G. Le
Monnier (translated in Quarterly Journal of Microscopical Science,
1874, p. 49), upon wliioh most of what is here said about the Moulds is
based.MUCORINI.
239
to form a mycelium; that is always the result of the
growth of spores from the sporangia.
(a) In the study of the Moulds it is almost always necessary to make
use of alcohol for freeing the specimens of air ; afterward they usually
Fig. 162.—Piptocephalis Fresenicina, parasitic upon the hyphse, J/, M, M, of Mucor
Mucedo. m,m, parasitic hyphse, attached to their host by the haustoria, h; c,conid-
ial spores; s,s, the two branches which conjugate and form the zygospore, Z. Highly
magnified.—After Brefeld.
require to be treated with a dilute alkali, as a weak solution of am-
monia or potassic hydrate, which causes tlie hyphse to swell up to their
original proportions before drying ; care must be taken that the hyphae
and spores are not unduly swollen, or serious mistakes may be made.
(6) In the careful study of the Moulds it is necessary to resort to arti-
ficial cultures of the different species, in order to be able to follow them240
BOTANY.
through all their changes. The spore of a particular species must be
sown, and the development of hyphae, mycelium, sporangia, etc., care-
fully followed ; and the greatest care must be taken to guard against
error from the accidental presence of other species.
(c) “ Pan culture,” which consists in sowing the spores upon or in the
nutritive medium in pans or deep plates covered by bell-jars, must always
be resorted to, even if more accurate cultures are also made. By placing
a quantity of horse-dung in a pan under a bell-jar, there will soon be
obtained a good supply of vigorous Moulds ; sometimes several species
may be obtained from a single pan. By care a few sporangia of each
species may be obtained from this first culture, with little probability
of contamination with other species. These are to be used for more
careful cultures.
(id) If now moistened pieces of fresh bread are placed under a bell-
jar, and a few of the spores of a particular species are sown on them,
the growth and successive stages of development may be easily fol-.
lowed. Instead of bread, other materials may be used, as stewed
prunes and other fruits, pieces of oranges or lemons, etc., and for cer-
tain species the half-cleaned bones of beef from the kitchen.
(e) Where still greater care is desirable, the nutritive media may be
prepared by boiling and filtering, after which they are placed in thor-
oughly cleaned pans or plates, and covered by clean bell-jars ; in these
are placed pieces of hardened plaster of Paris or earthenware (porous),
which have previously been heated so as to destroy all spores, and upon
them are sown the selected spores. The sources of error are in this
way very much reduced, but it must be borne in mind that they are by
no means all eliminated ; hence the student must be constantly on the
lookout for other species than the one under culture.
(f ) The media recommended by Van Tiegbem and Le Moimier are,
(lpt) boiled and filtered orange juice, which, being acid and saccharine,
is not so liable to be invaded by other common Moulds ; (2d) a decoc-
tion of horse-dung, boiled and filtered ; this is neutral and alkaline, and
serves as a medium for many species; but it is open to the objection
that it is liable to the invasion of intruding species ; (3d) a saline solu-
tion of the following composition :
Calcium nitrate............................... 4 parts.
Potassium phosphate........................... 1 “
Magnesium sulphate............................ 1 “
Potassium nitrate............................. 1 “
Distilled water..............................700 “
[Sugar...................................... 7 parts, j
In some cases the sugar may be omitted.
(p) The most accurate and satisfactory, but at the same time most
difficult cultures, are cell-cultures. These are made as follows: glass,
tin. or India-rubber rings four to five millimetres high are fastened toMUCOlilNl.
241
ordinary glass slides ; a very little water is placed in the bottom of the
cell so formed, to keep the air in it always moist; a small drop of the
nutrient liquid, free from spores of any kind, is placed in the middle of
a cover-glass of the proper dimensions, and in this a single spore of
some particular Mould is placed ; the cover-glass is now inverted over
the cell, and held in place by a minute quantity of oil on the edge of
tlie cell. The preparation must be placed in a warm and saturated
atmosphere. An ordinary bell-jar set over a plate of water, or better
still, of wet sand, will furnish a very good moist chamber. Tlie appa-
ratus used by Van Tiegliem and Le Monnier is, however, in many re-
spects the best that has yet been devised (Fig. 163).
By means of such cultures as this, the student may follow all the de-
tails of the germination, and after-development of any particular
spore, as all that is necessary to do is to remove the slide from tlie
growing box, and, without disturbing the cell, to place it under the
microscope ; the same specimen may thus be examined any number
of times, with the least possible liability of error.
(h) The most common Moulds are species of the genus Mucor. M.
Fig. 163.—Section of apparatus for cell cultures. The shaded portion represents a
section of a tin or zinc box; a, a, the supporting ledges ; b, 6, the glass slips ; c, c,
glass or metal rings fastened to the glass slips, seen in section, and covered with a
Siece of thin glass ; g, plate of glass, covering the box. The dotted line shows the
eight of the moist sand with which the bottom of the box is covered.
Mucedo and M. st loni’’ir(if distinct) are common on many decaying
substances. M. Syzygites occurs on decaying Agarics and Polypori.
Pilobulus cryst'illinus, Piptoc-pfialis Present in', and Ghcetoclndium,
Jonesii occur on animal excremeut. Phycomyccs nitens grows on oily or
greasy substances, as old bones, oil casks, etc.
(zj The Moulds are evidently related to the Mesocarpese in their
sexual reproduction, which is the most important, as it is the most con-
stant. The conidia of Moulds are clearly homologous with the zoospores,
of the Zoosporeae, being nothing more than aerial modifications of them.
The non-septated condition of the filaments of tlie Moulds does not con-
stitute so great a difference between them and the filaments of tlie green
Conjugate as might at first be imagined; in the germination of the
zygospore of Spirogyra it will be remembered that the filament elon-
gates quite a good deal before a septum forms in it; between this and
the very late formation of septa, as in the Moulds, the difference is
only one of degree. The Moulds may then be looked upon as Meso-
carpous Conjugate which have lost their chlorophyll through their
saprophytic habits, and which have otiierwise undergone slight modifi-
cations mainly correlated with their aerial habits.242
BOTANY.
Fossil Zygophytes.—In the Silurian period species of Lamin-
•ariUs, Harlania, etc., probably represented the Ph®ospore®, which
order was also abundantly represented in the Devonian. Confervites
occurs in the Jurassic, and in the Tertiary. Fossil diatoms of many
species have been found in the Tertiary; at Richmond, Va., they
form a vast bed nearly ten metres thick, and one at Monterey is
sixteen metres in thickness.
The PmEospoREiE, containing the kelp and its allies, are marine
plants of an olive-brown color, varying greatly in size and structure,
from minute filamentous forms to the gigantic kelp with stems and
leaves, often a hundred metres or more in length. In previous
editions they were regarded as more nearly related to the Fucace®
[p. 264], but their reproduction by the conjugation of similar zoo-
spores indicates their relationship to the zygophytic zoospore®. They
include the highest plants of the class.
Twelve families, viz., Scytosiphone®, Punctarie®, Desmarestie®,
Dictyosiphone®, Ectocarpe®, Sphacelarie®, Leathesie®, Chordarie®,
Asperococce®, Ralfsie®, Sporochne®, Lamiuarie®, are represented
on the New England coast by twenty-six genera and forty-eight
species, while many more occur on the Pacific coast, where the
great bladder kelp (Macrocystispyrifera) sometimes attains a length
of two hundred metres or even more.
Arrangement of the Classes and Orders of Zygophyta.
Conjugate. Zoospores.CHAPTER XVI.
OOPHYTA.
321—The distinguishing feature of the plants belonging
to this division is that they develop a large cell (the oogo-
nium), differing from those about it in size and general ap-
pearance, which contains one or more rounded masses of
protoplasm (the oospheres), which are subsequently fertilized
by the contents of a second kind of special cell of much
smaller size (the antheridiurri). The oogonium is the fe-
male reproductive organ, and the antheridium the male.
The protoplasm of the latter is in some cases transferred by
direct contact to the oosphere ; in other cases it is first broken
up into motile bodies, the spermatozoids, which then come
to and become fused with the oosphere. The oosphere itself
is never motile, and in most cases it remains within the
parent plant until long after it is fertilized. The result of
fertilization is the production of an oospore, which differs
from the oosphere structurally in having a hard and gener-
ally colored coating, and physiologically in having the power
of germination and growth after a period of rest of greater
or less duration.
322.—The plants of this division vary greatly as to the
development of the plant-body. In some cases it is a feebly
united colony (Volvox and its allies), while in its highest
forms it is a well-developed thallus, with even the beginning
of a differentiation into Caulome, Phyllome, and Eoot
(Fucacece).
§ I. Volvox and its Allies.
323.—In the classification of the plants of this division
the lowest place must be assigned to Volvox and Eudorina,
which, as previously stated, are, with doubtful propriety,244
BOTANY.
separated from Panclorina. If the two genera are to be
separated from Panclorina there can be but little doubt that
their position must be in the very lowest part of the Oophy-
ta. Such a position would indicate what is probable on
other grounds also, that the divisions Zygophyta and Oophy-
ta lie side by side as two divergent systems, and that in
their lowest members they almost, if not entirely, coalesce.*
324.— Volvox globator is a hollow spherical colony of uni-
cellular algae, having a diameter of .5 to .8 mm (.02 to .03
inch). Each individual of the colony is a flask-shaped cell
of green-colored protoplasm, bearing two cilia upon its
pointed extremity, and surrounded by a hyaline gelatinous
envelope. These individuals are arranged so as to form a
spherical surface, their hyaline envelopes being in contact
with one another, and so placed as to bring the pointed ends
Fig. i64.— roimox giobatov. a, eperma- cilia give to the sphere a ro-
tozoid, X 800. b. oogonium, with sper- , ,. . n
matozoids surrounding the oosphere, X tary motion^ WlllCh. IS USUEily
400.—After Cohn. one pr0gress;0n als0.
325.—The sexual reproduction of Volvox takes place in
this way : some of the cells in a colony undergo conversion
into spermatozoids, which are elongated club-shaped, and
provided with two cilia {a, Fig. 164) ; other cells of the same
colony, or of different colonies, become greatly enlarged into
oogonia, consisting of an outer hyaline coat enclosing an
inner rounded mass of dense and granular protoplasm (b, Fig.
164). Upon the escape of the spermatozoids they penetrate
the cavity of the colony (into which the oogonia have now
pushed), and there coming in contact with the oogonia, they
<
of the green masses, with their
cilia, to the surface. The
sphere is thus made up of
closely approximated individ-
uals, which dot its surface,
and whose cilia give to the
whole colony a hairy appear-
ance. The movements of the
* It will not do violence to any laws of classification, based upon
the general theory of evolution, to propose that Voloox, Eudorina,VOLVOX AND ITS ALLIES.
245
Thus we have in
bury themselves in the hyaline envelope, and finally pene-
trate and become fused into the oosphere (b, Fig. 164). A
thick wall now forms upon the fertilized oosphere, and it
becomes transformed into an oospore
these plants the transformation of an
individual of the colony into an oogo-
nium and oosphere, and the subse-
quent fertilization of the latter by
spermatozoids, which are themselves
fractional parts of other members of
the colony.
326.—The relationship of the low-
er Oophytes with the lower Zygo-
phytes, as indicated by Volvox and
Pandorina, is further shown by the
position of Sphceroplea, an undoubted
relative of the Confervacece (Clado-
phora, etc.). Sphceroplea is a free,
unbranched, filamentous alga, com-
posed of long cells joined end to end
(A, Fig. 165). It produces oospheres
in some of its filaments, each cell
producing several (B, Fig. 165).
While these are forming in one set of
filaments, in another the protoplasm
becomes broken up into a multitude
of elongated, bi-ciliate spermatozoids
(O and G, Fig. 165); these escape
through lateral openings in the cells, A an oospore
which are formed by the absorption
of a part of the wall, and then swim-
ming through the water they find
their way to corresponding openings in the walls of the
Fig. 165.—5
lina. A, ordinary filament ;
r, chlorophyll masses. B, fila-
ment consisting of oogonia,
the contents breaking up into
oospheres ; 0, o, openings for
entrance of spermatozoids ;
s, s, spermatozoids entering the
oogonia ; m and k, oospheres
at the instant of fertilization ;
n, fertilized oosptmres, now
enclosed in a thin cell-wall, C,
filament consisting of anther-
with its thick coats of cellu-
lose. E, zoospore (vegetative
zoogonidium). F, oosphere in
the act of being fertilized by a
spermatozoid, a. O, spermato-
zoids.—After (Ersted.
and their allies in the Oophyta, and Pandorina and its allies in the
Zygospores, be placed in a common class Zygophyta. This class
would thus have two branches, one in the division Zygophyta, and
the other in the Oophyta. Such an arrangement would indicate the
evident relationship of the plants under consideration better than
any yet proposed.246
BOTANY.
cells, which contain the oospheres ; upon coming in contact
with an oosphere they bury themselves in its substance, after
which the oosphere secretes a thick wall, and thus becomes
an oospore (Z>, Fig. 165). In germination (which takes place
after a period of rest) the protoplasmic contents of the
oospore become broken up into a large number of bi-ciliated
zoospores having nearly the shape and general appearance
of the spermatozoids ; these, after swimming about for a
time, become gradually elongated into narrowly fusiform
filaments, which are the young Sphwroplea individuals ; by
growth these take on the form and size of the adult indi-
viduals.
§ II. Class (Edogonie^:.
327. —The plants constituting this well-marked class are
composed of articulated, simple, or branched filaments,
which are attached to sticks, stones, earth, or other objects
by root-like projections of the basal cells. The chlorophyll
ill the cells is always dense and uniform. They inhabit
ponds and slow streams, and form green masses, which fringe
the sticks and other objects in the water.
328. —The (Edogonicie are interesting for the well-marked
examples they afford of the intercalary growth of cells. It
is commonly the case that in any filament at one or two
points there may be seen near one end of a cell a number
of transverse parallel lines, which in profile have the appear-
ance of as many caps slipped into one another (C., Fig. 10,
page 22) ; these are the results of several extensions of the
filaments by intercalary growth. The process is as follows :
in a cell, a little below its upper wall, a growtn inward from
the surface of the wall takes place in such a way as to form
a cylindrical ring (A,f, Fig. 10); after a time the cell-wall
splits circularly from the outside to the centre of the circu-
lar cylinder (/), and the two parts of the cell then retreat
from each other, united only by the straightened out cylin-
der (B, z, Fig. 10); this new part elongates and the process
is repeated, finally giving rise to the series of caps first men-
tioned (Gc, Fig. 10), and, in conjunction with cell-division,
resulting in a considerable elongation of the filaments.(ED 0 G ONIEJE.
247
329.—The asexual reproduction of (Edogonieas is as curi
ous as the growth of its cells, just described. During the
early and active growth of the
plants the protoplasmic contents of
certain cells in a filament become
detached from their walls, and upon
the splitting of the latter the now
rounded protoplasm escapes as a
large zoospore (Fig. 166, A and
B); it is oval in shape, and provid-
ed with a crown of cilia about its
smaller hyaline end, by means of
which it swims rapidly hither and
thither in the water (Fig. 166, G).
After a time it comes to rest,
clothes itself with a cell-wall, and
sends out from its smaller end root-
like prolongations (Fig. 166, D),
which attach it to some object; it
now elongates, and at length forms
partitions, taking on eventually the
form of the adult filament. It
sometimes happens that before the
new plant resulting from the
growth of a zoospore has formed its
first partition, the protoplasm sep-
arates from its wall and again aban-
dons it, to be for a time a zoospore
(Fig. 166, E). This method of
formation of zoospores is what
Braun called Rejuvenescence. (See
p. 42.)
330.—The sexual reproduction
of the plants of this class is in
many respects closely allied to that
of Sphceroplea. The female organs
are in all cases developed in essen-
tially the same way, but the male
organs present a considerable diversity,
Fig, 166. — Asexual reproduc-
tion of (Edogonium. A, fracture
of a filament and escape of the
protoplasm of the broken cell;
the protoplasm in the whole cell
below is seen to be somewhat
withdrawn from the cell-wall,
preparatory 10 escaping. E, es-
cape of protoplasm and formation
of a zoospore; the hyaline por-
tion of the latter is seen to be lat-
eral. G, a ciliated and swimming
zoospore, the hyaline portion now
terminal. Dy zoospore at rest,
and sending out root-like pro-
longations from the hyaline end.
E, a young plant composed of
only one cell, with its protoplasm
escaping. X 350.—After Prings-
heim.
The female organ248
BOTANY.
consists of a rounded oosphere situated within a cavity—the
oogonium; it is developed from one of the cells (sometimes
two) of the filament
by a condensing
and rounding off
of the protoplas-
mic contents; when
the oosphere is ful-
ly formed, an open-
ing is formed in
the oogonium-wall
for the ingress of
the spermatozoids
(A and B, Fig.
167). One or more
spermatozoids are
produced in each of
certain small cells
which are formed
from the large ones
by a process of
simple fission; in
shape they resem-
ble the zoospores
mentioned above—
that is, they are
oval and provided
with a crown of
vibratile cilia on
their smaller ex-
tremity (D, z, z,
Fig. 167). Upon
escaping into the
water, which is ren-
dered possible by
a splitting of the
wall of the mother-
Fig. 167 —A, middle part of a sexual filament of (Edo-
gonium ciliatum (.Androgynia of Wood), with male cells
above at m; og, oogonia (fertilized) ; in, dwarf male
plants attached to the side of the oogonia, the sperma-
tozoids already discharged. X 250. B, oogonium, og,
at the moment of fertilization / o. the oosphere ; z, the
spermatozoid forcing its way into the oosphere ; m, the
dwarf male plant. 0, ripe oospore. D, (Edogonium
gemellipamm (Pringsheimia of Wood), part of the male
filament, with Bpermarozoids, z, issuing from the cells.
E, part of a branch of Bulbochcete intermedia, with oogo-
nia, the uppermost containing an oospore, the middle
one with an oospore escaping, the lower empty. F, four
zoospores resulting from an oospore of Bulooc/icete. O,
zoospore come to test and germinating.—After Prings-
heim.
cell, they swim about vigorously, and eventually make their
way through the opening in the oogonium, and then buryCEB 0 O ONIEJE.
249
themselves in the substance of the oosphere (B, z. Fig. 167).
After fertilization the oosphere becomes covered with a thick
and colored (brown or red) coat, and it then becomes an
oospore (C, Fig. 167).
331. —In certain cases the cells which produce the sper-
matozoids occur on the same filaments which produce
oogonia also ; this is the monoecious type. In other cases one
of the ordinary cells of the filament which bears oogonia be-
comes divided by simple fission into two or more cells ; the
protoplasm in each of these new cells condenses into an
ovate mass, which by a rupture of the cell-wall is set free as
a motile body resembling a small zoospore, and, like it, pro-
vided with a crown of vibrating cilia; this is the androspore.
After swimming about for some time, it comes to rest upon,
or near to, an oogonium, and attaches itself by root-like pro-
jections, exactly as in the case of the growth of true zoo-
spores ; the result of the growth of the androspore is the pro-
duction of a miniature plant composed of three or four cells
(A, m, in, and B, m, Fig. 167). The upper cells of these
little plants develop spermatozoids, and hence the plants are
called dwarf males. This is the so-called gynandrous type
(A and B, Fig. 167). In a third class of cases, the ordinary
plant filaments are of two kinds, the one producing sperma-
tozoids only, and the other only oogonia ; this is the dioecious
type (D, Fig. 167).
332. —After a period of rest the oospore germinates by
rupturing its thick coat, and permitting the escape of the
contents, enclosed in a thin envelope ; by this time the pro-
toplasm has divided into four portions, which take on an
oval form, and develop a crown of cilia (F, Fig. 167). They
soon escape from the investing membrane, and after a brief
period of activity grow into an ordinary filament in exactly
the same manner’ as the zoospores.
(«) It will be unnecessary in this place to fully discuss the arrange-
ment of the genera belonging to this class ; they probably may be all
brought within the limits of one order coextensive with the class.
Wood has separated* two sub-families (= sub-orders), which differ in
* “ A Contribution to the History of the Fresh-water Algae of the
United States,” by H. C. Wood, 1872./
250 BOTANY.
the filaments in the one case (Bulhochatte) being branched and terminated
with setae, while in the other case ((Edogonium and its allies) the fila-
ments are not branched, and are destitute of true setae.
(b) The old genus CEdogonium is divided by Wood into three new
genera, as follows :
Monoecious : antheridia and oogonia upon the same individual—
(Edogonium.
Dioecious : antheridia and oogonia arising upon distinct individuals
—Pringsheimia.
Gynandrous: antheridia upon dwarf plants, growing attached to
the female plant—Androgynia.
Wolle records thirteen species of the first, thirteen of the second,
and twenty-six of the third of the foregoing divisions in the United
States. He does not, however, consider these divisions as having
generic rank. (“Fresh-water Algse of the United States,” Vol. I.
p. 66.)
(c) The genus Bulboehoete includes, gynandrous species, of which
there are sixteen in the United States.
§ III. Class Cceloblastete.
333. —In the plants of this class the protoplasm is con-
tinuous throughout the vegetative organs of the plant, and
is not divided into cells. Only the reproductive organs are-
separated by partitions. They may hence be spoken of as
unicellular, although they often attain a considerable length
and are frequently much branched.
The other characters of the group will be best understood
from a study of some of the plants included in it. Many of
them are chlorophyll-bearing plants, living in brooks and
streams, while others are destitute of chlorophyll, and are
saprophytes, living upon decaying animal or vegetable matter,
or are parasites, living upon the living tissues of the higher
plants.
334. —The genus Vaucheria may be taken as a represen-
tative of the chlorophyll-bearing members of this class. It
is a filamentous alga growing in water or on damp earth, and
forming dark green tufts. Each plant consists of long,
branching, thick-walled tubes, which have a rather large
diameter ; they are attached to the earth, or to sticks orCCELOBLASTEjE.
251
other objects, by root-like processes (w, Fig. 168). The
protoplasmic contents of the tubes, which are destitute of a
nucleus, consist of a thick green layer upon the inner sur-
face of the wall, leaving the centre of the tubes open for the
more watery portions.
335.—The asexual reproduction of Vaucheria presents
some considerable variations; it consists essentially of a
spontaneous separation of a portion of the protoplasm of the
parent plant. In some species this takes place by the sepa-
Fig. 168.— Vaucheria sessilis. A, end of a branch, with escape of a zoospore, sp. Bf
zoospore in its resting stage, after the disappearance of its cilia. C, the same, germi-
nating. D, the same, further advanced. E\ much later stage of germination ; sp, the
zoospore: w the root-like processes (rhizoids). F, fertile plant; og, og, oogonia fer-
tilized ; A, an old antheridium. X 30 —After Sachs.
ration of swollen lateral branches, which then send out fila-
ments ; in other species the protoplasm in the swollen lateral
branch becomes separated from that in the general cavity of
the plant by a septum, and it afterward condenses into a
rounded mass and acquires a wall of its own ; it is set free
by the decomposition of the old surrounding wall, and it
germinates by sending out one or two tubes, which grow252
BOTANY.
■directly into new plants. In still other species the spore
forms as in the last case, but there is a dehiscence of the sur-
Tounding wall which permits the spore to slip out; it begins
to germinate soon. In some species, instead of forming a
spore, the naked protoplasm in the swollen branches, after
condensing somewhat, escapes into the water through a
fissure in the cell-wall, and becomes a zoospore (A, Fig.
168); it is covered throughout its whole surface with delicate
vibratile cilia, by means of which it moves through the
water (Fig. 169). After a short period of activity the zoo-
spores come to rest, their cilia disappear, and a wall of cellu-
lose is formed (B, Fig. 168); in this condi-
tion (the zoogonidium) they remain for some
hours, when they begin to germinate by
sending out one or two tubes (C, I), Fig.
168); the root-like organs grow either direct-
ly from the zoogonidium (F, Fig. 168), or
from one of the tubes (E, Fig. 168).
336.—Sexual reproduction takes place in
lateral branches also. Both antheridia and
oogonia develop as lateral protuberances upon
atFrfgh\6\n|ieC9ti0to the main stem (off, og, h, Fig. 168). They
osporefo? Fa«cl°-" 01'iginate as diverticula of the principal cavity
p1aam*bearin' “the °ff’ Fig- 1^0) > these develop on the one
cilia; s,endoplasm, hand into male organs, and on the other
preparation, alter into female organs. The male organ is long
Str&aburger. ■» -i -1 -•
and rather narrow, and soon much curved
(B, a, Fig. 170) ; its upper portion becomes cut off by a
partition, and in it very small bi-ciliate spermatozoids (Z),
Fig. 170) are developed in great numbers. The female or-
gan is short and ovoid in outline, and usually stands near
the male organs. In it a partition forms near its point of
union with the main stem ; the upper portion becomes an
oogonium, and its protoplasm condenses into a rounded
body, the oosphere (C and E, Fig. 170) ; at this time the
wall of the oogonium opens, and permits the entrance of the
spermatozoids which were set free by the rupture of the
antheridium-wall. Upon coming into contact with the
oosphere the spermatozoids mingle with it and disappear ; theor
CWLOB LASTED.
253
oosphere immediately begins to secrete a wall of cellulose
about itself, and it thus becomes an oospore (F, Fig. 170).
According to Pringsheim, the oospore remains for three
months in a resting state before germinating; in the latter
process the out&r coat of the spore splits, and through the
opening a tube grows out which eventually assumes the form
and dimensions of the full-grown plant.
Fig. 170.—Sexual organa of Vaucheria sessilis. A, beginning of the formation of
the oogonium (oa) and antherirlinm (h) upon the branch b. B, later stage of the
same, the antheridium (a) now separated from the main branch (b) by a transverse par-
tition. C. an open oogonium expelling a drop of mucilage, si. D, spermatozoids. A,
spermatozoids collected at the mouth of the oogonium. F, the antheridium, a, col-
lapsed after the escape of the spermatozoids ; osp, the oospore. X about 100, except
D, which is much more.—C, D, after Pringsheim, the others after Sachs.
(a) The formation of zoospores begins in the night, they escape in
the morning, and the night following they germinate.
(&) The formation of sexual organs begins in the evening, and is
completed the next morning ; fertilization takes place during the day
(from 10 a.m. to 4 P.M.).
(e) Good specimens of Vaucheria may be found clothing the boggy
ground about many springs. The bright green mats may be trans-
ferred to the aquarium for the study of zoospores; but for the sexual
organs the dingy and dirty looking specimens must be collected.254
BOTANY.
(d) The genus Vauclieria may be taken as the type of a group, the
VaucherincecB, but whether it is entitled to rank as an order instead
of a family cannot be decided in this place. Allied to Vaucheria are
Caulerpa, Halimeda, etc., but their exact position is as yet problematical.
(e) Thirteen species of Vaucheria occur in the fresh waters of the
United States, one of the most common being V. sessilis, which
occurs everywhere in brooks and springs.
(/) Gaulerpites cacUides is the oldest known fossil species of this
elass. It occurs in the Silurian : other species have been detected in
the Devonian and Tertiary. Caulerpa extends from the Tertiary to
the present.
337. —Order Saprolegniacese. The plants of this order
are saprophytes or parasites, more frequently the latter ; they
are colorless, and generally are to be found in the water or in
connection with moist tissues. The plant-body is greatly
elongated and branched, and all its vegetative portion is
continuous—i.e., unicellular; the reproductive portions only
are separated from the rest of the plant-body by partitions.
338. —The reproduction is very much the same as in
Vaucheria, and, as in that genus, is of two kinds—asexual
and sexual. The asexual reproduction may be briefly de-
scribed as follows: the protoplasm in the end of a branch
becomes somewhat condensed, a septum forms, cutting off
this portion from the remainder of the filament, and the
whole of its contents becomes converted by internal cell-
division into zoospores provided with one or two cilia
(Fig. 171, 1). These soon escape from a fissure in the wall
and are active for a few minutes (3-4), after which they
come to rest and their cilia disappear (2 and 3, Fig. 171).
In one or two hours they germinate by sending out a filament
(4, Fig. 171), from which a new plant is quickly produced.*
339. —The sexual organs bear a close resemblance to those
of Vaucheria. The oogonia are spherical, or nearly so (in
most of the species), and contain from two to many oospheres,
which are fertilized by means of antheridia, which usually
develop as lateral branches just below the oogonia. In
* The student- is referred to an article, “Observations on Several
Forms of Saprolegnieae,” byF. B. Hine, in American Quarterly Micro-
scopical Journal, 1878, p. 18, from which some of the above facts are
taken, and the accompanying figures adapted.SAPOLEONIA (JEJE.
255
some species the antheridia and oogonia are upon the same
plants, and in such cases the fertilization takes place by the
Pig. 171.—1, end of filament of Saprolegnia, with zoospores (swarm-spores) escape
ing; 2, zoospores of the same at rest; 3, the same more enlarged; 4. the same,
germinating; 5, a portion of a filament of Achlya, bearing sexual organs, X 120 ; 6,
first Btage in the development of sexual organs of Achlya; 7, 8, 9, succeeding stages ;
10, sexual organs of 5, more enlarged, showing the antheridia, and the nearly ripe
oogonium, with its contained oospores.—Adapted from Hine.
direct contact of the antheridium and the passage of its
contents into the oogonium by means of a tubular process256
BOTANT.
from the former ; in other species the plants are dioecious,
and in them the antheridia produce motile spermatozoids, bj
means of which the fertilization is effected. After fertilization
each oosphere becomes covered with a wall of cellulose and
is thus transformed into an oospore.
340. -—The development of the sexual organs of Adilya,
one of the genera of this order, is shown in Fig. 171, 6 to
10 ; at first there is a small pullulation upon the side of a
filament, as at 6 ; this soon extends into a bag-like projec-
tion (7), which is readily seen to be a young oogonium;
it continues to enlarge, while its protoplasm becomes more
dense, and at its narrower
part a second pullulation
forms (frequently two), as
shown at 8 ; when the larger
part has enlarged somewhat
more and become rounded, a
partition separates it from
the remainder of the filament,
and from the young anther-
idium, as shown at 9; the
protoplasm in the oogonium
forms several round masses—
the oospheres—and by this
time the terminal portion of
the antheridium is cut off by
a partition. In the monoe-
cious species a tube is formed by the closely applied anther-
idium, which penetrates into the oogonium through open-
ings in it formed by the absorption of portions of its wall
and comes in contact with one of the oospheres (Fig. 172).
341. —In some cases, instead of the oogonia developing
in the way described above, they are formed in the terminal
part of a filament by one or more partitions arising in it;
such oogonia are cylindrical or barrel-shaped, and sometimes
several of them stand upon one another. The antheridia in
the species which have such oogonia are developed from
below the partition which cuts off the oogonium, and when
there are several superimposed oogonia it actually happens
Fig. 172.—Fertilization of the oospheres
in .Achlyo, racemosa. Each oogonium
contains two oospheres. Magnified.—
After Cornu.SAP JR OLEQNIA CEJE.
257
that the antheridia which fertilize one oogonium grow out
of the oogonium lying immediately beneath.* In this case
it appears that the terminal oogonium is formed first, and
that the antheridia, in each case, grow out from what is yet
a part of the whole filament, and that it is only subsequently
to the formation of antheridia that an oogonium is formed
out of that part of the filament out of which they grew. In
the accompanying diagram (Fig. 173) the
oogonium a is fertilized by antheridia
which grew out of that portion of the
filament which subsequently became cut
off as oogonium b, which in turn is fer-
tilized by antheridia from below it, and so
on to d, which receives its antheridia
from what still remains as part of the fil-
ament. Each oogonium is seen to be
younger than the one above it—in other
words, the oogonia are developed from
the top of the filament downward.
The oospores of Saprolegniacese possess,
when mature, a thick integument, which
is double—that is, formed of an outer
thicker coat (epispore) and an inner thin-
ner one (endospore). After a considerable
period of repose the oospores germinate
by sending out a tube, f
The Saprolegniaceae have been but little stud-
ied in this country, although they may he read-
ily obtained. They grow quickly upon dead
fishes, crayfishes, dies, etc., when placed in tanks
of water, and may often be seen attached para-
sitically to young living fishes in aquaria. They
are often so abundant in the breeding-houses of
fishes as to cause great losses. In some of the rivers in England dur-
Fig. 173.— Diagram il-
lustrating the formation
of the sexual organs
and the fertilization of
Saproleania androqyna.
a, the oldest oogonium,
which is fertilized by
the antheridia grown
from below; b, the next
oldest oogonium; o.
younger oogonium, with
the oospheres not yet
fully formed ; d, young-
est oogonium; the lat-
ter will be fertilized by
the antheridia which
grow out from the upper
end of the filament be-
low.
* The student should consult an article ou “ Two New Species of
Saprolegniese,” etc., in Qr. Jour. Mic. Science, 1867, p 121, in which
figures and a description of such a form as that above referred to are
given.
f See De Bary’s" Morphologie und PhysiologiederPilze," etc., 1866,
p. 155, for an account of the sexual reproduction of Saprolegniaceae,258
BOTANY.
ing the year 1878, and for a year or two previous to that date, large
numbers of salmon and other kinds of fish were destroyed by one of the
•common species, Sapvolegnia ferax* *
342.—Order Peronosporeee. The plants of this order
live parasitically in the interior of higher plants. They are
■composed of long branching tubes, whose cavities are con-
tinuous throughout. They grow between the cells of their
hosts, and draw nourishment from them by means of pecu-
Fig. 174.
Fig. 175.
Fig. 174.—A vegetative hypha, m, m, of Peronospora calotkeca from the tissue of
Asperula sativa. The two cells between z z are filled with the long branching haus-
toria from the hypha m, m. X 390.—After De Bary.
Fig. 175.—Conidia-bearing hyphas of Peronospora infestans. a, formation of the
first conidia upon the ends of slender pedicels ; b, the formation of the second and
third conidia ; the pedicel is proliferous from the base of each conidium after it is
formed, and thus the conidia, which are actually terminal, come to appear lateral.
X 200.—After De Bary.
liarly formed lateral branches (haustoria), which thrust
themselves through their walls (Fig. 174, and Fig. 176, A, li).
The vegetative growth is entirely within the host, and also
and a translation in “ Grevillea,” Vol. I., p. 117. See also Prings-
heim’s “ Jahrbucher fur Wissenschaftliche Botanik,” Vol. IX., p. 289,
and Max Cornu, in “ Annales des Sciences Naturelles,” 5e ser., tom.
XV.
* See a description by W. G. Smith in “ Grevillea,” Vol. VI., 1878,
p. 152.PEliONOSP OIIEE
259
the sexual organs; the asexual reproductive organs, on the
contrary, are on the surface of the host.
343.—The asexual reproduction takes place in the. genus
Fig. 176.—Cystopus candidus. A, branch of mycelium,/, growing at the apex, t,
and giving off haustoria, h, into the cells of the pith of Lepidium sativum. B, co-
nidia-bearing portions of the mycelium, with conidia in rows. C, a conidium with
its protoplasm divided. D, contents of conidia escaping as swarm-spores (zoospores).
E, swarm-spores (zoospores), with cilia. F, germinating swarm-spores. G, two swarm-
spores, so, germinating on a stoma and penetrating it. If, a swarm-spore, sp, of the
potato disease (Peronospora ivfestans) penetrating the epidermis of the potato stem;
e, i, epidermis cells. X 400.— !AJter De Bary.
Peronospora by the mycelium inside the host producing
branches, which protrude through the stomata into the air ;
here their tips become enlarged, and finally separated by par-
titions from the remaining parts of the hyphse, thus forming260
BOTANY.
the conidia (Fig. 175). In the different species there are
considerable variations in the.size and shape of the conidia,
and the mode of branching of the conidial hyphae, and upon
these many specific characters are based.
344.—In the genus Cystopus the formation of conidia is
slightly different. The conidial hyphae multiply greatly at
certain points beneath the epidermis of the host, and there
produce conidia by successive constrictions (B, Fig. 176).
The conidia remain in loose connection, and form moniliform
rows, in which the uppermost conidium is the oldest; some-
times six or more conidia may be seen attached to each other
in this way, but generally the upper ones soon fall away.
When the epidermis of the host ruptures, the conidia appear
as a powdery mass,
which may be blown
away by the feeblest
movement of the air.
345.—The germina-
tion of conidia presents
two modes: in some
species of the genus
Peronospora the con-
tents of the conidium,
swarm-spores (zoospores) ; c, "swarm-spores, with wi „ ,1T,r]pr thp
cilia ; d, swarm-spores after coming to rest, m va- "Ucu jjiatcu uiiutri tut;
rious stages of germination. X 390.—After DeBary. pr0per conditions of
moisture and temperature, become transformed into many
bi-ciliate swarm-spores (a, b, and c, Fig. 177). These are
active for a time, after which they come to rest, their cilia
disappear, and a germinating tube is sent out from each
(d, Fig. 177), which, if properly situated, enters a stoma,
and in the interior of its host gives rise to a system of vege-
tating hyphae ; in other cases it perforates the epidermis cell-
walls and thus passes into the interior of its host (H, Fig.
176). In other species of Peronospora the conidium does not
break up into swarm-spores, but gives rise directly to a ger-
minating filament. In all the species of the genus Cystopus,
the conidia first give rise to swarm-spores (C, D, E, F, G,
Fig. 176), in the manner described above for Peronospora.
Fig. 177.—Germination of the conidia of Perom
spora infestans. a, conidium after lying for sc
time in water, the contents divided ; o, the rupt
of the conidium and the escape of the partsPERONOSPOREM.
261
346____In the sexual reproduction,* which, as above stated,
always takes place in the intercellular spaces of the host,
lateral branches of two kinds arise upon the hyphfe; those
of the one kind, the young oogonia, become greatly thickened
Fig. 178.—The sexual organs and fertilization of Perono8po?'a Alsinearum. a,
youngest stage ; o, young oogonium ; n, young antheridium ; b, the name somewhat
later ; the antheridium is beginning to thrust its beak-like process (fertilizing tube)
into the oogouium ; c, the same at a still later stage—the fertilizing tube has reached
the oospheie. X 350.—Alter De Bary.
in diameter, and finally assume a globular shape; their
highly granular protoplasm becomes condensed, and finally
separated from that of the remainder of the filament by a
transverse septum at the base of each oogonium (a, Fig. 178).
The other branches, the young anthe-
ridia, which arise upon the same fila-
ments as the oogonia and near to
them, or upon other filaments which
are in proximity to the oogonia-bear-
ing ones, become elongated and club-
shaped ; their protoplasm (also gran-
ular) becomes condensed in their up-
per portions, which are soon separated
from the rest of the filament by a
transverse partition in each case (a,
Fig. 178). At this stage the an-
theridia become applied to the oogonia, and in each of
the latter the protoplasm has still further condensed and
Fig 179.—Oogonium of Pe-
rono'pora, with its contained
ooSphere; at the left is the
antheridium, which has pene-
trated the oogonium and
brought its fertilizing tube
into contact with the oo-
sphere. Much magnified.—
After De Bary.
* Consult De Bary’s “ Morpliolooie und Physiologic der Pilze,” etc.,
pp. 158-159, u, translation of which appeared in “ Grevillea,” 1873, p.
150.262
BOTANY.
rounded into an oospliere. Each antlieridium now devel-
ops a tubular beak-like process, which penetrates the oogo-
nium (b, Fig. 178), and finally reaches the oospore (c, Fig.
178, and Fig. 179). It appears that the contents of the an-
Fig. 180.—Cystopvs candidus. A, mycelium, with yonng oogonia, og. B, oogoni-
um, og; os, oospore; on, antheridium. C, mature oogonium, og, with oospore, os;
at the left is the remnant of the antheridium. D, mature oospore seen in section. E,
beginning of germination of oospore, the endospore i with its contents escaping
through a rent in the epispore (or exospore). F, the endospore i filled with swarm-
spores (zoospores) resting on the empty epispore. (?, swarm-spores (zoospores), each
with two cilia. X 400.—After De Bary.
theridium pass into the oosphere, as- in a short time the
former is found to be empty, while the latter becomes envel-
oped in a cell-wall, and thus becomes an oospore. In the
process of fertilization there are no spermatozoids, and thePER ONOSP OREJE.
263
process is comparable to that which takes place among the
moncecious Saprolegniace®. The wall of the oospore be-
comes differentiated into two or more layers (as, in fact, is
usual in resting spores), the outer of which (the epispore) is
thick, hard, rough, and dark colored, while the inner (the
endospore) is thin and transparent (C, D, E, F, Fig. 180).
347. —In their sexual reproduction the species of the genus
Cxjstopus agree with those of Peronospora above described.
The various stages are shown in Fig. 180.
348. —The germination of the oospores takes place in some
species of the genus Peronospora by the formation of a ger-
minating tube, which soon gives rise to a mycelium. In
Cystopus, however, the oospore swells, and by the bursting
of the epispore the endospore escapes as a loose bladder sur-
rounding the protoplasm, which has by this time become di-
vided into a large number of naked masses of protoplasm
(E, F, Fig. 180); by the bursting of the surrounding mem-
brane, these bodies are set free as bi-ciliate swarm-spores (G,
Fig. 180), which, after a short period of activity, come to
rest, and germinate in exactly the same way as those derived
from the conidia. In some species of Peronospora it appears
that swarm-spores are developed as in Cystopus, and it ap-
pears from the observations of W. G. Smith, that in the potato
fungus (Peronospora infestans) some of the oospores pro-,
duce swarm-spores, while others send out a germinating
tube.*
349. —But little is known regarding the time, as well as
the mode of germination of the oospores, but from those ob-
served it is probable that it takes place after a period of rest
extending from autumn to spring. This is known to be the
case in some species of Cystopus, in which the oospores pass
the winter in the rotting tissues of its hosts.
* See a paper “ On the Germination of the Resting Spores of Perono-
spora Infestans,” by Worthington G. Smith, in Gardeners’ Chronicle,
July, 1876, and reprinted in “ Grevillea,” 1876, p. 18. He found that the
oospores which germinated first produced swarm-spores like those of
Cystopus, while the later ones “ protruded a thick and generally jointed
thread.” In his account figures of both modes are given.2G4
BOTANY.
(а) The plants of this order are easily obtained, and so far as their
structure is concerned, are easily studied. Their development is, how-
ever, much more difficult to follow, and in some species it has thus far
baffled the most skilled botanists. 'The two genera Peronospora and
Cystopus are distinguished by their conidia, which in the first are ter-
minal and single upon branches of the aerial liypliae (Fig. 175), while
in the second they are in moniliform rows upon byplise which burst
through the epidermis of the host (B, Fig. 176).
(б) Several species of Peronospora are very easily obtained. P. viti-
cola, the American grape mildew, is common on the leaves and young
shoots of the grape ; from it may be obtained in midsummer an abun-
dance of conidia and conidial hyphae, and in autumn (October) the
oospores may be found in abundance in the dried and shrivelled parts of
the affecied leaves.* P. parasitica is common in spring and early sum-
mer, on Oruciferse, especially on Lepidium, Capsella, Draba, etc., fre-
quently clothing the leaves with a white, frost-like down. P. infestans,
the potato fungus, is common in many parts of the country on the
leaves and stems of the potato, sometimes causii g great injury by de-
stroying the leaves, stems, and even the tubers. Other species occur
on Eupatorium, Bidens, Ambrosia, Impatiens, Potenlilla, Anemone,
etc.
(c) The species of Cystopus which are most common are C. candidus,
which may he found in the spring and summer as white, blister-like
blotches on the leaves of Capsella and other Oruciferse ; and C. Bliti com-
mon on Portulaca oleracea and species of Amarantus in summer and
autumn ; the latter is an excellent species to study, as its oospores are
very easily found, especially in the stems of Portulaca.
(d) In preparing specimens for the study of the sexual organs, small
portions of the tissues containing them should be boiled for a minute
or so in a solution ot potash, and then, while the preparation is hot, a
considerable quantity of acetic acid should be added ; the effervescence
which follows separates the softened tissues so that hut little difficulty
is experienced in isolating large portions of the mycelium with oogonia
and antheridia. It frequently happens that the parts are rendered
more distinct by the addition of iodine to the specimen after mounting
§ IV. Class Fucace,®.
350.—The plants of this class, composed of marine spe-
cies, present, in most cases, a development of the plant-body
which is unusually perfect for the Thallophytes. In many
* For the best account of this fungus see a paper “ On the American
Grape-vine Mildew,” by Professor W. G. Farlow, in Bulletin of the
Bussey Institution, Vol. I., p. 415. Several other species are also briefly
described.FUG ACE JR.
2G3
cases there is a differentiation of the thallus into parts which
have a considerable resemblance to roots, stems, and leaves ;
and in size they approach, and, in some cases, equal or exceed
the larger Phanerogams. Their tissues, too, show a much
higher degree of differentiation than is common in Thallo-
phvtes ; the cells are arranged in cell-masses, and these are
differentiated into several varieties of parenchyma, approach-
ing, in some instances, to the condition which prevails in
the Bryophytes ; the outer tissues are composed of small and
closely crowded cells, which form a dense, and, in some cases,
a hard mass ; the interior tissues are generally looser, and
are for the most part composed of elongated cells so joined
as to leave large intercellular spaces.
351. —With the foregoing there is found in the higher
genera a marked differentiation of portions of the plant-
body into general reproductive organs, analogous to the
floral branches of higher plants. The sexual organs are
found upon modified branches, which differ more or less in
shape and appearance from the ordinary ones. This differ-
entiation into vegetative and reproductive parts is an impor-
tant and significant feature in the plant-body, indicating a
decided advance over all the previous groups of Thallo-
phytes.
In their greater duration many of the Fucacese are in
marked contrast to other Thallophytes, which are generally
short-lived. They are, for the most part, of considerable
size, rivalling, in some cases, even the larger Phanerogams.
They grow principally between and a little beyond the tide-
marks, and furnish the great bulk of the shore vegetation.
352. —The reproduction of the higher Fucaeca; is sexual
only; but in some algse which appear to be nearly allied
(Phseosporere) asexual zoospores are known. In Fucus
the sexual organs are found in the thickened ends of the
lateral branches of the thallus (A, Fig. 181). They occur
on the walls of hollows termed conceptacles, which are
spherical, with a small opening at the top (B, Fig. 181).
The conceptacles are at first portions of the general surface,
which afterward become depressions which are walled in
and overgrown by the surrounding tissues ; they are thus to266
BOTANY.
be still regarded as portions of the general surface, and the
cells which form the inner surface of the conceptacles con-
stitute a continuation of the epidermal tissue of the thallus.
353.—The walls of the conceptacles are clothed with
pointed hairs, which in some species project through the
Fig. 181.—Fucvaplatycarj)u8. A, end of a portion of thallus ; /,/, conceptacles in
fertile branchlet.s. B, vertical section through a conceptacle ; a, hairs projecting
from the mouth ; b, cavity of concentacle nearly filled with hairs ; c, oogonia ; e, an-
theridia; cf, epidermal tissue of thallus.—After Thuret.
opening, and among these are found the sexual organs,
which are themselves, as Sachs has pointed out, modified
hairs. Some of the species are monoecious, while others are
dioecious. In the monoecious species the antheridia and
oogonia occupy the same conceptacle (B, Fig. 181) ; the
antheridia are produced as lateral branches of modified hairsFUG A GBFE.
26?
(A, Fig. 182); each antheridium is a thin-walled cell, whose
protoplasm breaks up into a large number of bi-ciliate sper-
matozoids, which escape by the rupture of the surrounding wall
(B, Fig. 182). Before rupturing, however, the antheridia
detach themselves and float in the water with their contained
spermatozoids.
354.—The oogonia are globular or ovoid short-stalked
bodies, which develop from papillae on the wall of the con-
ceptacle. As each papilla elongates, it becomes divided into
Fig. 182.—Fucus vesiculosus. A, branched hair bearing antheridia, a. B, sperma-
tozoids. 7., og, oogonium, with contents divided into eight parts ; p, paraphyses, or
surrounding hairs. 77., commencement of the escape of the oospheres—the outer
wall, a, of the oogonium has burst, the inner, i, is ready to open. III., oosphere es
caped, and surrounded by spermatozoids ; IV., F, germination of the oospore. B
X 330, ail the rest 100.— After Thuret.
a basal and an apical portion by a transverse partition ; the
apical part enlarges, and (in the genus under consideration)
its protoplasm divides into eight portions (/, Fig. 182),
which eventually become spherical; it is thus an oogonium
containing eight oospheres. The oospheres escape from the
oogonium surrounded by an investing membrane, which floats
out through the opening of the conceptacle, where it finally
ruptures and sets the oospheres free (II, Fig. 182). The
spermatozoids and oospheres ar& liberated at about the same268
BOTANY.
time, and the former gather around the inactive oospheres
in great numbers, and by the vigor of their movements
sometimes actually give them a rotatory motion {III, Fig.
182). The result of the coming together of the spermato-
zoids and the oospheres is the fertilization of the latter, and
their transformation into oospores by the secretion of a wall
of cellulose on each one. There is thus seen to be a close
similarity between the fertilization of Fucus and of other
Oosporese ; particularly does it call to mind the sexual pro-
cess in Volvox and its allies. When, however, the sexual
organs proper, and their accessory organs, the conceptacles,
are taken into the account, the relationship of Fucus to Volvox
is seen to be much less than it appears to be at first sight.
355.—The development of the oospore takes place at
■once; it lengthens and undergoes division into numerous
cells, and at the same time it elongates below into root-like
processes, which serve to hold fast the new plant (V, IV,
Fig. 182). There is a gap in our knowledge of the life-
history of these plants, extending from the young thallus to
the fertile plant; probably when that is filled some plants
now supposed to be distinct will be found to be forms or
stages of these.
(a) The principal genera of Fucacece are Fucus and Sargassum. Of
the first, F. nodosus, F. furcatus, and F. vesiculosus are the most
common species on our Eastern coast, the latter also occurs on the
Pacific coast; both are known as Rock-weeds. Sargassum vulgare is
common on the Atlantic coast; 8. baccifcrum, the Gulf-weed, is
found in the warmer parts of the several oceans, and in mid-Atlantic
covers an immense tract known as the Sargasso Sea.
(b) The species of Fucus and Sargassum are washed ashore in great
quantities during violent storms, constituting the bulk of the
■ wrack " of the coasts. They furnish valuable manure for enrich-
ing the soil, and are largely used for this purpose. From their ashes
alkalies and iodine are obtained. From the hardened stems of a
species of Laminaria walking-sticks, whips, knife-handles, etc., are
manufactured.
< c) In the Silurian period Fucoides antiquus represented the order
Fucace®, In the Devonian period the order was abundantly repre-
sented. Fucus, Sargassum, and other genera were already in exist-
ence during Tertiary times.Zoospores? CEdohonie^:. V Cceloblaste.®. Fttcack®.
—Volvox, etc.
-Bulbochaetaceae.
---(Edogoniaceae.
-------Peronosporeae.
<---------Saprolegniaceae.
— -j-----------Vaucheriaeeae.
Fucaceas.
FUCACEJE. 269CHAPTER XVII.
CARPOPHYTA.
356.—The distinguishing characteristic of the plants
which constitute this vast division is the formation of a
sporocarp, as a result of the fertilization of the female organ.
The sporocarp consists, except in the simplest cases, of two
parts essentially different from each other, viz., (1) a fer-
tile part, which either directly or indirectly produces spores,
sometimes a few, or even one, or, on the other hand, a very
great number; (2) a sterile part, consisting of cells or tis-
sues developed from the cells adjacent to the fertile part,
and so formed as to envelop it. This group includes plants
with chlorophyll, and a large number of species which are
parasitic or saprophytic, and which, as a consequence, are
destitute of chlorophyll. In the former, the sporocarp is
small in proportion to the size of the vegetative parts of the
plant; but in the latter, where the vegetative parts are great-
ly reduced, the sporocarp is proportionately large. In this
the parasites and saprophytes of the Carpophyta are like
those of the Phanerogams, in which the vegetative or assimi-
lative organs are smaller than in those which contain chlo-
rophyll ; thus the very large sporocarp of many of the Asco-
mycetes and the Basidiomycetes, and their relatively small
mycelium, may be compared to the large reproductive organs
and the reduced stems and leaves of the Rajflesiacece.*
* This comparison must not he misunderstood. It does not imply
homology of the parts compared, but it is intended to compare the
vegetative and reproductive organs of the one group of plants, func-
tionally considered, with those of the other. There can be no doubt
that functionally the giant flower of Iiafflesia is the equivalent of the
sporocarp of a Peziza, while structurally they are not equivalent; in.
other words, they are analogues, but not homologues.COLEOCIlJETE.
271
357. —The female organ is in this division called a car-
pogonium, which consists of a single cell (e.g., Coleoclicete,
some Ascomycetes, and the Gharacem), or of several cells {e.g.,
Floridece and most Ascomycetes). In some cases a projec-
tion, called the trichogyne, is attached to the carpogonium ;
its function apjnears to be the conveyance to the carpogonium
of the fertilizing influence received from the antlieridium.
358. —The antlieridium is here, as elsewhere throughout
the Cryptogams, much more variable in structure than the
female organ. In some cases it is applied to the carpogo-
nium in fertilization, while in others it produces sperm ato-
zoids ; in either case contact with the carpogonium is either
direct (Poclosplmra, Characece), or indirect, through a tri-
chogyne {e.g., Coleoclicete, Floridece., Peziza).
359. —The plant-body shows in general a more perfect
development in the Carpophyta than in the preceding di-
visions. While it is but little developed in the parasitic and
saprophytic species, it is well developed in many of the Flo-
ridece and the Characece. In these classes there is often a
considerable amount of differentiation of the plant-body
into caulome and phyllome.
§ I. CoLEOCHjETE.
360. —The genus Coleoclicete maybe taken to represent the
simplest form of sexual reproduction in this division. The
species are all small green fresh-water plants, composed of
dichotomously branching filaments, which are arranged ra-
dially upon a central disc (or sometimes arranged upon irreg-
ularly branched threads) ; the diameter of each cushion-
like mass is from 1 to 2 mm. (.04 to .08 in.).
361. —Reproduction takes place both sexually and asexu-
ally. The latter is by means of zoospores which arise in the
vegetative cells, by the protoplasmic contents becoming, in
each case, converted into a single spherical bi-ciliated zoo-
spore, which escapes through a round hole in the cell-wall
{D, Fig. 183).
362. —The sexual organs and process bear some resem-
blance to those of CEdogoniaceas. The female organ, theBOTANY.
2n
carpogonium, is a single cell, wide below, and tapering above
into a long slender canal, the trichogyne, which is open at
its apex (A, og, Fig. 183). The carpogonium is the terminal
cell of a branch, which in its development swells up, while
at the same time elongating into a tube. In the swollen basal
portion there is a considerable mass of protoplasm, which is
the essential part to be fertilized.
The male organs, the antheridia, are formed as flask-shaped
protuberances which grow out of adjoining cells ; they be-
Fig. 183.—Coleochcete jmlvivata. A, portion of fertile plant; an, antheridia; Off,
carpogonia—each with a trichogyne ; z, z, epermarozoids ; h, hairs, with sheathing
bases. B, fertilized carpogonium surrounded by covering, r (“ pericarp”), the whole
constituting the sporocarp. C, sporocarps burst open, snowing the interior tissue,
8ch ; r. cortical cover (“ pericarp”). D. zoospore- (swarm-spores) from C. X 350.—
After Priugsheim.
come cut off from the cells from which they grow, by trans-
verse partitions. In each antheridium a single oval bi-
ciliate spermatozoid is formed (A, z, z, Fig. 183).
363.—Fertilization is doubtless effected by these sperma-
tozoids coming in contact with the protoplasm of the carpo-
gonium, but the actual entrance of the former has not yet
been seen. After fertilization the protoplasmic mass in the
carpogonium increases considerably in size, and becomes
surrounded by a cellulose coat of its own. The cells whichFLOlilDEh®.
273
support the carpogonium send out lateral branches, which
grow np and closely invest it, and by their growth finally
cover it entirely (excepting the trichogyne) with a cellular
“pericarp” (B, r, Fig. 183). The whole mass, including
the fertilized carpogonium and its investing “pericarp,”
constitutes the simplest form of sporocarp.
364. —The germination of the sporocarp takes place (the
next spring) by the swelling of the protoplasmic contents,
and the consequent rupture of the “ pericarp the inner
portion becomes changed into a many-celled mass (C, Fig.
183), which gives rise to bi-eiliate zoospores closely resembling
those developed from the vegetative cells. From each zoo-
spore a new plant eventually arises.
(a) These little plants occur in fresh-water pools as little green
masses adhering to leaves, sticks, etc. According to "Wolle, we have
five species.
(ft) The sexual process and the development of the sexual organs oc-
cur in May, June, and July.
(c) Nothing can be attempted in this place to determine the grouping
of Goleo^kcete with other Carposporese. Its evident relationship to the
Perisporiacete in the Ascomycetes suggests that possibly the latter
class may have to be broken up, and the first two orders united with
Cnleochatte to form a new class. Certainly the relationship between
Coleochcete, Perisporiaceae, and Tuberacese is much closer than between
the two last named and the other orders of Ascomycetes. There
can be but little doubt that the Ascomycetes are held together by char-
acters which are now of but secondary value, drawn as they are from
the asexual fruiting, while characters which are of far greater value,
derived from the sexual organs, are disregarded.
§ II. Class Floridly.
365. —In the Fieri deae the reproduction is generally
asexual as well as sexual. The former is by means of cells
which originate from a division of a mother-cell into four
parts; on account of their number they have received the
name of tetraspores (A, B, t, t, Fig. 184). These appear
to replace the swarm-spores of other algae, and may also he
compared to the conidia of certain fungi; they are destitute
of cilia, and are, as a consequence, not locomotive. They
develop from the terminal cells of lateral branches, or from
the cells of ordinary thick tissues, sometimes deeply imbedded.274
BOTANY.
366.—The sexual organs consist, as in Coleoclmte, of
carpogonia and antheridia. The latter are composed of one
or more mother-cells, situated singly or in groups on the
ends of branches (A and B, a, a, Fig. 185). The sperma-
tozoids are small, round bodies, which are destitute of cilia,
and, as a consequence, incapable of independent movement
(A, x, Fig. 185) ; they are carried about by currents of
water, and in this way brought to
the carpogonia.
367.—The carpogonia are some-
what variable as to their complex-
ity, being much more simple in
the lower orders than in the high-
er. In the genus Nemalion the car-
pogonium consists of a single cell
(B, b, Fig. 185), resembling Coleo-
chcete closely in this respect. It
is thickened below, and elongated
above into the trichogyne, which
differs from that in Coleochcete in
notbeing°Penatthet0P- When
t. tetmuporce.-After Sachs b, of the spermatozoids are set free from
Corullina offkinalix; t, tetraspores , , .
in a cup-shaped extremity of a the antheridia they attach them-
hranch.—After Berkeley. . .
selves to the trichogyne, as shown
in Fig. 185 ; the result of this contact of the spermatozoids
with the trichogyne is the fertilization of the carpogonium,
which immediately enlarges, and at the same time undergoes
division into many colls, which grow into short, crowded
branches, bearing a spore at the end of each (D and E,
Fig. 185). To this growth, which includes the spores and
the short branches which bear them, and which resulted from
the fertilization of the carpogonium, the name of sporocarp is
applied. In the genus under consideration the sporocarp is
a comparatively simple growth, as compared with the degree
of complexity it reaches in some other orders of this class.
368.—In the genus Lejolisia, the carpogonium, before
fertilization, consists of several cells (A, b, Fig. 185); the'
trichogyne is in connection with certain of the exterior cells
of the carpogonium, but not directly with its central cell.FLORID E^E.
21b
Upon fertilization taking place, which is as in Nemalion,
the peripheral cells of the carpogonium (excepting those con-
stituting the tricliophore—i.e., the trichogyne-bearer) undergo
division, and become developed into articulated branches,
which lie side by side, and form a more or less spherical
Fig. 185.—A,Lejolisia mediterranea. r, root-like processes (rhizoids); antherid-
ium ; x, spermatozoids ; b, carpogonium, with trichogyue, to the apex of which two
epermat zoids ar • attached; section of ripe sporocarp ; t, ripe spore escaping. B,
Nemalion multifidum. a, branch with antheridia and spermatozoids ; b, carpogo-
nium, with tricuogyne, the latter with spermatozoids attached to its apex. D and E,
development of the sporocarp of Nemalion. x 150.—After Bornet.
organ, the so-called “pericarp.” In the meantime the cen-
tral cell of the carpogonium develops processes or outgrowths
which eventually become spores, occupying the cavity of the
“pericarp” (A, s, Fig. 185). An interesting fact in this
connection is that neither the trichogyne nor trichophore
take part in the development subsequent to fertilization ; in
other words, the cells which directly receive the influence of
the spermatozoids do not themselves undergo a subsequent
development, but adjoining ones do develop, on the one
hand, into the spores, and on the other into the filaments
of the pericarp. The sporocarp in this genus is thus seen
to be somewhat more complex than in Nemalion, including276
BOTANY.
the pericarp, in addition to the parts found in the latter
genus.
369.—In the genus Dudresnaya there is a curious and
complicated sexual process. After the fertilization of the
trichogyne, a long “ connecting tube” (ct, Fig. 186) grows out
from beneath the trichophore, and comes in contact with the
fertile branches (/, f,
Fig. 186), to the ter-
minal cells of which it
becomes closely applied.
These fertile branches,
which grow as lateral
branches on the same
plant as the trichogyne,
are the true female or-
gans, and fertilization
is consummated only
when the connecting
tube comes in contact
and coalesces with
them. The result of
this curious process is
the production of a spo-
rocarp on each fertile
filament.
(a) This class is a large
and interesting one, but un-
fortunately it cannot be
and even then, from the
Fig. 186.—Dudresnaya purpnrifera. tv. tricho-
gyne, with epermatozoids attached; ct, connecting-
tube which grows out from below the base of the
trichogyne, and comes in contact with the fertile
branches, /, f; ct'. young connecting-tube.—After
Thurct and Bornet.
studied readily except near the seaside,
fact that the species mostly inhabit the deeper waters, it presents many
difficulties. The plants are mostly red or violet in color, although this
is not due to the absence of chlorophyll. The red color is due to the
presence of a pigment (phycoerythrine), which is soluble in cold fresh
water ; its solution is carmine-red in transmitted light and reddish yel-
low in reflected light. Upon extraction of the phycoerythrine the
plants are found to be green from the presence of the chlorophyll
which had been masked by the brighter pigment.
(6) There are many orders in this class, the following of which are
represented in the United StateB.*
* The sequence of the' orders is that given by Dr. Farlow in his
“ List of the Marine Algae of the United States,” 1876, published in theFLORIDEJK.
277
Order Rhodomelece, of wliicli Basya and Polysiphonia are common
■genera.
Order Chylocladiece, represented by only two Californian species.
Order Sphoerococcoidea, represented abundantly by species Belesseria.
Order Corallines, containing plants which are remarkable for the
•large amount of calcium carbonate they contain. Corullina is abundant.
Order Celidies, represented by Gelidium.
Order Hypnes, including only a few species of one genus Hypnea.
Order Rhodymeniece, of which Rhodymenia and Lomentaria are com-
mon genera. Rhodymenia palmata, the “ Dulse ’’ of our coasts, is used
as human food.
Order Spongiocarp ce, with one species of Polyidea.
Order Squamarieoe, with one species of Peyssonnelia.
Order Batrachospermes, to which Nemalwn (Fig. 185, B) belongs.
Order Wrangelies, with two species of Wrangelia.
Order Oigartines, of which Chondrus crispus, the Irish moss so
largely used for food, for making blanc mange, etc., is the best-known
of the many species on our coasts.
Order Cryptonemiece, represented mainly on our Southern and Pacific
coasts. Bchizynemia edulis, of Europe and our Western coasts, is
used as human food.
Order Bamon iem, to which Halosaccion of our Eastern coast belongs.
Order Spyridies, represented by Spyridia of our Eastern coast.
Order Ceramics. This order contains algre “ which are either strictly
monosiphonous (i.e., composed of a single tube) and filiform, or which
are more simple in their structure than others, approaching in this re-
spect the Confervaceas. It abounds in species which display the most
exquisite combination of ramification and coloring.” A large portion
of our marine flora is composed of individuals of this order, as “ they
•abound on our coasts in every little rocky pool, onevery piece of wood-
work exposed to the waves, on rocks and stones, and, above all, on the
•stems of the larger or firmer algae, or even on marine Phanerogams,
which they fringe in the most exquisite way with every shade of red,
from a bright rose to purple.’'f
Lejolisia (-4, Fig. 185) and Budresnaya (Fig. 186) are genera of this
order. Callithamnion is represented by many species on both our At-
Report of the U. S. Fish Commissioner for 1875. It is modified from
Thuret’s arrangement. The arrangement of the orders and the group-
ing of genera into orders are not based upon sexual characters, and con-
sequently must be regarded as to a considerable extent artificial. The
first-named orders in the list are higher than those that follow.
f “ Introduction to Cryptogamic Botany,” by M. J. Berkeley, 1857, p.
178. The student is also referred to Harvey’s “ Nereis Boreali-Ameri-
•cana,” « “ Contribution to a History of the Marine Algae of North
.America,” published by the Smithsonian Institution, 1852 to 1858-278
BOTANY.
lantic and Pacific coasts. Geramium rubrum, is a very common spe
cies.
(c) The order Coralline* was represented in the Silurian by a spe-
cies of Corattin.a. Others occur in the Secondary (Jurassic) aud Ter-
tiary. Chondrites represented the order Gigartine* from the Permian
to the Tertiary (Miocene). The order Sphserococcoide* was represented
in the Secondary by Jurassic species of Splimrococcites, and in the Ter-
tiary by Delesseria. In the order Rliodomele* a species of Polysi-
phonides occurs as a fossil iu the Tertiary.
§ III. Class Ascomycetes.
370. — This large class includes chlorophyll-less plants
which differ much in size and appearance, but which agree
with one another, and differ from all other Carposporese in
producing their spores (ascospores) in sacs (asci). The sex-
ual reproductive organs, consisting of carpogonia and anthe-
ridia, are produced upon the mycelium, and, after fertiliza-
tion, a sporocarp, which includes the asci and ascospores, is
developed. The asci are, at first, single cells at the ends of
branches which result from fertilization of the carpogonium ;
in these, ascospores arise by internal cell-formation. The
most common number of ascospores is eight in each ascus,
but it sometimes exceeds, and frequently falls short, of this
number, there being often no more than one or two. The
asci are in many cases arranged side by side in a compact
mass, forming a spore-bearing surface, the hymenium. In
addition to the ascospores there are generally one or several
other kinds of spores, which are developed on the same my-
celium as the sexual organs, or on another, the latter case
being one of an alternation of generations.
371. —The Ascomycetes are readily separated into a num-
ber of well-marked groups, which may not all turn out to be
coordinates. For the present they may be treated as orders.
372. —Order Perisporiacese (or Erysiphacese). In this
order the plants, which are mainly parasitic, are composed
of branching articulated filaments, which form a white web-
like film upon the surface of the leaves and stems of their
hosts. There are both sexual and asexual spores, and of
the latter there are in most cases two or three different kinds,
which are produced earlier than those that result from a fer-P E1USP OBI A CEJE.
279
tilization. The sexual organs and the sporocarp resulting
from the act of fertilization bear a striking, resemblance to
those of Coleochcste, the difference being such as may be ac-
counted for by considering the aquatic habits of the one, and
the aerial and parasitic or saprophytic habits of the other.
373. —In the parasitic Perisporiacece the jointed filaments
of the mycelium closely invest and cover the leaves and
other tender parts of their hosts, and draw nourishment
from them by means of haustoria, which project as irregular
pullulations from the side of a
the hyphte next to the epider-
mis (Fig. 187) ; these haustoria
apply themselves closely to the
epidermis cells, and, in some
cases at least, appear to penetrate
them.* The crossing and rami-
fying hyphse soon send up many
vertical branches, in which parti-
tions form at regular intervals;
the cells thus formed are at first
oblong and cylindrical, with flat-
tened ends ; but the topmost one
soon becomes rounded at its ex-
tremities, and the others follow
in quick succession, thus giving
rise to a moniliform row of loose-
ly attached elliptical or rounded
cells, the conidia (I, Fig. 188).
These fall off and germinate at
once by pushing out a germinatin.
to a new mycelium.
374. —The sexual process, which in most species takes
Fig. 187. — Erysipfie (Oidium)
Tuckei'i. a, apiece of a vegetative
hypha, m, m, upon a fragment of the
epidermis of the leaf of the vine, and
to which it is fastened by the haus-
toria. h; 6, an isolated piece of a
vegetative hypha, with the hausto-
rium, h, seen in side view. X 370.—
After Von Mohl.
tube, which gives rise
* De Bary (“ Morphologie und Physiologie der Pilze,” etc., 1865, p.
19) pays that the haustoria of the investigated species do not. penetrate
into the epidermis cells ; while Sachs (“ Lehrbucli, 4te Auflage,” 1874,
p. 312) says that haustoria are sent into the epidermis cells. A myce-
lium on Poa pratensis (probably of Erysiphe communis) examined in
1877 appeared to have sent its haustoria through the outer walls of
the epidermis cells.280
BOTANY.
place late in the season, is as follows : where two filaments
cross each other or come into close contact they swell
slightly and send out from each a short branch ; one of these
thickens and assumes an oval form, becoming at the same
time separated from the filament by a partition ; this is the
carpogonium {111, c, Fig. 188, and c, Fig. 189). From the
swollen part of the other filament a corresponding branch is
given off, which grows up in contact with the carpogonium ;
near its extremity it forms a partition, which thus cuts
Fig. 188.—conidia-bearing hypha of Spharotheca pannofia. IT.. the ripe eporo-
-carp of the Fame ; a, thp single ascue escaping from the peritbecinm. h; only a few
•of the hypha-like appendages of the perithecium are shown. III., sexual organs of the
same: c, carpogonium : p, antheridium. IV., 1 he formation of the perithecium by
the growth of the enveloping cells, h; c, carpogonium ; p. antheridium. F, section
of the young sporocarp of Sphcerotheca Castagvei; c, carpogonium : a. the young
■ascus; h, h, cells of the perithecium-. I. and II. after Tulasne ; III.- V. after De
Bary.
off a small rounded terminal cell, the antheridium {III., p,
Fig. 188, and b, Fig. 189). Immediately after the forma-
tion of the antheridium the effect of fertilization show's itself
in the growth from below the base of the carpogonium of eight
or ten branches, which join themselves to its sides and to one
another, finally completely investing it {IV., Fig. 188, and d,
Fig. 189). Each of these joined enveloping branches be-
comes transversely divided several times, thus giving to the
covering layer a distinctly cellular structure. The enclosedPEJtlSP ORIA (JEM.
281
carpogonium becomes divided in such a way that from one
portion of it an inner layer of cells is formed in contact with
the outer envelope described above. From the remaining
central part of the carpogonium one ascus (in Sphcerotheca
and Podosphcera), and in the other genera two or more, are
developed. In each
ascus from two to d \\
eight ascospores arise 6'
by internal cell-for-
mation (II, a, Fig.
188). The sporocarp
(technically called
the peritheeium) be- Plg m__The 8esual procesB in srymphe ciciwH-
COmeS dark and hard, acearum. a, threads of mycelium ; &, anthoridium;
_ . . * c, carpogonium ; d, young sporocarp ; e, older sporo-
and Irom Its outer carp. Highly magnified.— After (Ersted.
cells there grow out long filaments (technically known as
appendages), which are usually septate, and of a particular
shape in each genus ; thus in Podosphcera and Microsphcera
they are dichotomously branched ; in Phyllactinia they are
straight and needle-shaped; in Uncinula they are curved
regularly at their tips (Fig. 190), while in the other genera
they are tortuous, and simple or irregu-
larly branched. The perithecia remain
during the winter upon the fallen and
decaying leaves, aud finally, by rupturing,
permit their asci, with their contained
ascospores, to escape.
375.—There are usually present some
carpSo^ncSnda S(Fdun °^ier organs, which bear small spore-like
cn; the appendages of bodies, but whose function is not certain
the peritheeium are
curved in a circinate known. These organs, which are
manner at their free ex* , . ,. . . .
tremities.—After Cooke, known as pycmdia, are clavate, ovate, or
nearly spherical in shape ; the bodies they contain (the so-
called pycnidio-spores) in their cavities are usually oblong
or elliptical.
376.—In the genus Eurotium (composed of saprophytes)
the conidia are produced in a slightly different way. The
mycelium, which is common on articles of food, as bread,
pastry, preserved fruit, etc., and on poorly dried specimens in282
BOTANY.
the herbarium, sends up vertical hyplise, which swell up at
the top, and bear a large number of small protuberances or
branches, the sterigmata (A. c, st, Fig. 191). Each sterigma
produces gradually a long chain of conidia, so that each
Fig. 191.—Eurotium repens. A, a portion of the mycelium, with erect bypha, c,
bearing at its top a radiating cluster of sterigmata, st, from which the conidia have
fallen ; as, young carpogonium—below it a younger branch is be ginning to coil spi-
rally to form another carpogonium. B, the carpogoniuip, as, and the antneridium, p.
0, the same beginning to be surrounded by the enveloping branches which grow out
from its base. D, sporocarp. E, F, sections of unripe sporocarps ; w, outer wall;
/. inner cells of sterile tissue ; as, developing carpogonium, giving rise to branches
from which asci are produced. G, an ascus containing eight ascospores. H, ripe as-
cospore. Highly magnified.—After De Bary.
vertical hypha is terminated by a round mass, made up of
these radiating strings of conidia. The sexual organs appear
a little later than the conidia. The end of a branch of the
mycelium becomes coiled into a hollow spiral (A, as, Fig.PERISPORIA CEJU.
*83
191), which constitutes the carpogonium, and which is soon
divided by cross-partitions into several cells. From below
the spiral there pushes out a branch (the antheridium), which
grows upward, and brings its apex in contact with the upper
cells of the carpogonium (B, Fig. 191). After this pro-
cess, which constitutes fertilization, other branches grow up
around the carpogonium, and linally completely enclose it,
as in the parasitic genera described above (C, D, E, and F,
Fig. 191). By the subsequent growth and division of the
enveloping branches, the carpogonium becomes imbedded in
a thick parenchymatous mass. In the meantime, from the
cells of the carpogonium branches bud out and penetrate the
surrounding parenchyma (F, Fig. 191), and finally produce
eight-spored asci on their extremities (G, Fig. 191) ; after a
time the asci are dissolved, and the sporocarp, now of a sul-
phur-yellow color, contains only loose ascospores, intermingled
with the debris of the broken-up asci and parenchyma.*
The plants of this order are abundant and easily studied. The
following partial list will enable the student to intelligently begin Ms
investigations:
Parasitic Plants.
A. Peritliecium containing a single ascus.
Appendages floccose..................Genus, Sphmrotheca.
Appendages dichotomous............... “ Podosphcera.
B. Peritliecium containing many asci.
Appendages needle-shaped, rigid.......Genus, Phyllactinia.
Appendages hooked....................... “ Uncinula.
Appendages dichotomous.................. “ Microsphtvra.
Appendages floccose..................... “ Mrysiphe.
Bplicerotlieca pannosa occurs on wild gooseberries, on whose stems,
leaves, and fruits it forms brown felted masses. In its conidial stage
it is frequently so abuudant on the leaves of roses as to entirely destroy
them.
8. Gastagnei sometimes occurs upon the hop in such abundance as to
destroy the crop.
* The student is referred to De Bary’s “ Morpliologie und Physiolo-
gie der Pilze,” etc., 1805, p. 162. A translation of the part relating to
the Erysiplici appeared in “ Grevillea,” Vol. I., p. 152.284
BOTANY.
Podosphcera Kunzei may be found on tbe leaves of the cherry and
apple, which it injures greatly in some cases ; the conidia may be ob-
served in midsummer, and the sexual process and formation of perithecia
in autumn.
Phyttuctinia guttata may be obtained in great abundance in autumn
upon tbe leaves of tbe hazel and iron wood.
TJncinula adunca is frequently abundant on willow leaves in the
autumn (Fig. 190).
U. spiralis is tbe species to whose conidial stage the name Oidium
Tuckeri has hitherto been applied in this country. It occurs on the
grape, and does great injury. According to Dr. Farlow, it is not cer-
tain that the so-called Oidium Tuckeri of this country is identical with
what is so named in Europe, and which is even more injurious to
grapes in that country than in this.
U. circinata occurs on the leaves of the red and silver maples in the
autumn.
Microsphwra Eriesii is one of tbe most common species. It may be
found in the conidial stage at any time during the summer on the
leaves of the lilac, and late in summer or in autumn the perithecia are
usually abundant.
■ M. extensa is a nearly related species, often very common on oak
leaves.
Erysiphe lamprocarpa, which may be found on Compositse (especially
on Helianthus), and also on wild verbenas, is readily distinguished by
its two-spored asci. The commonness of tills species makes it a valua-
ble one for study.
E. tortilis may be frequently obtained on the leaves of the Virgin’s-
Bower.
E. Martii occurs in great abundance upon cultivated peas, greatly
to their injury. In summer it covers the leaves and fruits with a
white mould-like growth, which is the conidial stage of the parasite ;
as autumn approaches the mycelium becomes darker, and finally large-
numbers of perithecia may be found.
E. communis appears in early cummer on grass leaves, where the
vegetation is rank. In autumn the perithecia may be found in abun-
dance on Ranunculaceae (especially on Anemone) growing in grass.
Saprophytic Plants.
Eurotium lierbariorum may be readily obtained for study by placing
a few green specimens of Phanerogams in an ordinary plant-press and
permitting them to remain until they become mouldy. The conidial
stage, which first appears, is what has long been described as a distinct
fungus under the name of Aspergillus glaucus; somewhat later the
bright yellow perithecia will be found in abundance.TUBERACEJE.
285
377. —Order Tuberaeese. In this order the sporocarp is
a rounded underground mass, composed of pseudo-paren-
chyma and the asci with their contained
ascospores. In the Truffle (Tuber) the
sporocarp is large, and dark colored and
warty on the exterior. Internally it con-
tains narrow tortuous chambers, on whose
walls are the asci, containing two to eight
usually areolate or echinulate ascospores
(Fig. 192, A and £). The sexual organs,
as well as the early stages of the Truffles,
are unknown.
378. —The common blue mould, found
on all sorts of decaying bodies, and known
as Penicillium glaucum (or P. crustci-
ceum), has recently been found by Brefeld
to be a member of this order. Its life-his-
tory is now pretty well known, and it in-
dicates what the early
stage of the Truffle
must in all probability
turn out to be. In
Penicillium the my-
celium sends up a large
number of vertical
hyphae, which branch
at the top, and produce chains of conidia
(Fig. 193). It appears, from Brefeld’s
researches, that this stage is the only
one which the plant passes through
under ordinary circumstances ; by care-
ful culture, however, he succeeded in
making it pass into its sexual stage.
He found the sexual organs to be in all
essentials similar to those of Eurotium
\11
Fig. 192.—Tuber me-
lanospoj'um. A, a por-
tion of a transverse sec-
tion, showing the asci,
with contained asco-
spores ; i?, an ascua
with ripe ascospores.
Both much magnified.—
After Tulasne.
Fig. 193. — Penicillium
charturum, showing co-
nidia-bearing hypha; at
the side is shown an iso-
lated chain of conidia.
Magnified.—After Cooke.
(Fig. 191); like it, the carpogonium is a spirally twisted end
of a hypha, and the antlieridium a branch growing out from
below it. The subsequent development is also much as in
Eurotium; a thick covering forms over the fertilized carp-286
BOTANY.
ogonium by the growth of many basal enveloping branches,
and inside of this the carpogonium increases in size, and
sends out branches, which finally produce eight-spored asci.
The little tuber-like mass thus formed is yellowish, and of
the size and appearance of a coarse sand grain.
(a) Aside from Penicillium, we have in this country very few repre-
sentatives of this order. Two or three species of Tuber have been
tion ; /i, A, the hyphsB from which the re- . e. , ? ,,
ceptucle is developed.—After Tulasne. ends 01 Certain. hypilSB Swell
up into ovoid vesicles, the carpogonia (Figs. 194 and 195),
each of which is provided with a more or less bent and
curved appendage, the tricliogyne (Fig. 195, and /,/, Fig.
194). From below the carpogonium a branch grows out,
and, curving around, becomes closely applied by its tip to
the extremity of the trichogyne (Figs. 194 and 195). The
* See Bulletin of the Torrey Botanical Club, November, 1878, for the
species of Tuber discovered in North America.
recorded, and two of Elaphomy-
ces*
(ib) In Europe, where they grow
abundantly, Tuber cestivum, T.
melanosporum, and T. inaguatum
A are gathered for food. They are
nJ found by the aid of dogs and pigs,
D which are trained to search for
them.
379.—Order Helvellacese
(or Discomycetes). These
are for the most part disc-like
or cup-like saprophytes,
which frequently attain large
dimensions. The liymenium
is spread over the upper and
generally exposed surface of
the full-grown plant, which
In Peziza, one of the prm-
jci iH1Z.UUUU , u, eat uui , j , u muu- _ -
gjyne ; anth* ridiura. B, after fertiliza- oil 01’ in the ground l the
t.ion : li. h.. the hvnhfrc from whirh t.he re- 0 _IIEL YELL ACE JR.
ZS7
immediate result of this process of fertilization is the bud-
ding out and upward growth of a large number of hyphse from
beneath the carpogonium
(B, Fig. 194); these form
a dense felted mass, from
which, eventually, there
rise vertical, closely
crowded hyphse, which
form the hymenium (A,
Ji, Fig. 190). In the ter-
minal portions of certain
of the vertical hyphse
the protoplasm condenses
around certain points, and
thus gives rise to asco-
spores (B, a to /, Fig.
196). In this genus (Pe-
ziza), as well as most
others of this order, the
ascospores are always eight
in each ascus. At matur-
Fig. 195.
Fig. 196.
Fig. 195.—Sexual organs of Peziza omphalodes. The two spherical carpogonia have
each a crooked trichogyne, and to each trichogyne is applied the swollen end of the
curved antheridium. Much magnified —Afier Tulasne.
Fig. 196.—Peziza conveanila. ' A, vertical section of the whole plant; h, hymen-
ium ; s, sterile tissue forming a margin, 47, and giving off below fine hyplue which
pass into the soil, x 20. By vertical section of a portion of the hymenium ; a to f,
asci, with ascospores in various stages of development, intermixed with slender
paraphyses ; 8/1, sub-hymenial hyphte. X 550.—After Sachs.
ity the ascospores escape by the rupture of the walls of the
asci, this generally taking place at the upper or free end.^88
BOTANY.
380. —In Ascobolus the carpogonium consists of a row of
cells ; it develops from the end of a branch of the mycelium,
which becomes curved and divided by several partitions (c,
Fig. 197). On account of its peculiar shape it is frequently
spoken of as the “ vermiform body,” or scolecite. From
another portion of the mycelium an elongated and branched
antheridium rises, and comes in contact with the free end of
the carpogonium (l, Fig.
197); after this pro-
cess numerous filaments
branch from the mid-
dle cell of the carpogo-
nium and pass upward,
eventually producing
asci (s and a, Fig. 197).
At the same time an
abundant growth of hy-
phffi takes place from the
mycelium below the car-
pogonium, and from this
the greater part of the
mass of the fruiting
plant is produced; it
also invests the hyme-
nium, forming the so-
called pericarp which
encloses it (r, Fig. 197).
Vertical branches of the sterile tissue also pass into the
hymenial layer and constitute the paraphyses.
381. —The asexual reproductive bodies are but little
known, but enough is known to indicate that there is at
least a conidia-beaving stage for these Ascomycetes, as for all
others. De Bary has shown that the early stage of the little
plant known as Peziza Fuckeliana is mould-like in appear-
ance, in fact having been described as a mould under the
name of Polyactis cinerea. In this stage it grows upon dead
grape leaves, sending its mycelium through the dead tissues.
Its vertical hyphag produce clusters of oval conidia, which
are much like those produced in the corresponding stage of
Fig. 197.—Diagrammatic vertical section of
the eporocarp ot Ascobolns furfuracevs. m, m,
mycelium- c, carpogonium; l, antheridium; s,
branches bearing tne asci, a. a; /), pseudo-
parenchymatous sterile tissue ; r, r, cortical
portion of sterile tissue— above it forms the so-
called pericarp, which surrounds and encloses
the hymenium, h.— After Janczewsky.P YltENOMl CETES.
28P
Eurotium and Penicillium. In another species, Peziza
fusarioides, the conidial stage has been pretty certainly de-
termined to be the growth which was formerly supposed to
be a species of Dacrymyces; it consists of little tubercles
which contain slender linear bodies on branched threads.
Bulgaria sarcoides is known to bear conidia in an earlier
stage, which was formerly referred to the genus Tremella
(Hymenomycetes).*
(a) Tlie principal genus of this order is Peziza, which contains many
species ; they are common on the ground in forests. Ascobolus fuefu-
raceus is common on cow dung. Morchclla esculenta, the Morel, grows
on the ground in forests. It attains a height of from 10 to 15 centim-
etres (4 to 6 inches), and bears its hymenium in shallow depressions
of its convex surface.
(ft) The Morel is edible, and is much used for food in some places.
According to Dr. M. A. Curtis, some species of Helvetia, also, are edible.
(c) Peziza sylvatica, P. Candida, and Genangium Piri occur as fossils
in the Tertiary.
382. —Order Pyrenomycetes. The plants of this order
are parasitic or sajiropbytic in habit; their tissues are usually
hard and somewhat coriaceous, differing in this respect from
the Helvellacew, which are generally fleshy ; they differ also
from the plants of the last-named order in having the hyme-
nium imbedded in deep cavities {■peritliecia) with narrow
openings. In other respects the Pyrenomycetes present a
close similarity to the Helvellacem, to which they are doubt-
less closely related.
383. —Their general structure may be illustrated by a
couple of examples. In Claviceps purpurea, the fungus
which produces ergot on rye and other grasses, the first
stage consists of a profuse growth of the mycelium in the
tissues and upon the surface of the young ovary (s, A, and
B, Fig. 198). In this stage, which is called the Sphacelia
stage, it produces a multitude of conidia on the ends of
hyphse which grow out at right angles to the surface of the
mycelial mass (0, Fig. 198, b and p) ; these conidia fall off
very easily, and quickly germinate (D, Fig. 198), giving
rise under favorable circumstances to new sphacelia, which
in turn may produce conidia, and these, new sphacelia, and
* See further, De Bary, op. cit., p. 200.290
BOTANY.
so on. The contact of an infected head of rye with an unin-
fected one is sufficient to communicate the fungus to the
latter, and doubtless the conidia are also freely carried by the
winds, and, to a certain extent, by insects. It appears that,
in some cases at least,
the germinating co-
nidia produce, first,
short hyphfe, which
bear a few small
spores (sporidia, D,
Fig. 198, x), which
themselves germi-
nate, and then pro-
duce the sphacelia; it
is doubtful, however,
whether this always
takes place.
384. — After the
conidial stage, the
mycelium at the base
of the ovary becomes
greatly increased, and
assumes a hard and
compact form; it
grows with a consider-
able rapidity, and car-
ries up on its summit
the old sphacelia and
the remains of the
now-destroyed ovary
(A and B, Fig. 198).
The compact, horn-
shaped, and dark-col-
ored body which re-
'•A o
Fig. 198,—Clavtcepg purpurea,.
sclero-
tium, c, with crtd. sphacelia, s ; p, the apex o^the dead
ovary of rye. B, upper part of A, in longitudinal sec-
tion, showing sphacelia, 8. C, transverse section
through the sphacelia more highly magnified ; m, the
mycelium, surrounded with the hyphte b, bearing co-
nidia ; p, conidia fallen off ; io, the wall of the ovary.
Dy germinating conidia, forming sporidia, x. A and
B moderately, C and D highly magnified.—After
Sachs.
suits is called the sclerotium ; that which is produced upon
rye is from one to three centimetres long (.4 to 1.2 in.) and
from two to six millimetres in diameter (.08 to .25 in.) ; on
other grasses it is usually of less size. The sclerotium occu-
pies the position of the displaced ovary, and in the autumnP YRENOM T CETES.
291
falls to the ground, where it usually remains till the follow-
ing spring, when its hyphse begin a new growth. As a re-
sult of this new growth several little branches shoot up, and
each forms a globular head (the receptacle) at its summit
(A, Fig. 199). Large numbers of flask-shaped perithecia
fox-m in the cortical region of the receptacles (B, Fig. 199, cp);
each contains many elongated asci, which rise from the hot-
Fig. 199.—Olovicepspurpurea. A. a sclerotium (ergot), c, forming the receptacles
(sporocarps ?), cl. B. longitudinal section of a receptacle, showing the perithecia, cp.
O, a perithecium, with the surrounding tissue ; cp. its orifice; /iy, hyphae of the re-
ceptacle ; sh, outer layer of the receptacle. D, a single ascus, ruptured, permitting
the elongated narrow ascospores, sp, to escape. A and B moderately, U and D high-
ly magnified.—After Tulasne.
tom of the cavity (0, Fig. 199), and themselves contain
several greatly attenuated ascospores (Z>, Fig. 199, sp).
The ascospores germinate under proper conditions, and pro-
duce sphacelia, thus completing the round of life.
385.—Thus far no sexual organs have been found, hut
from the general similarity of these fungi to the Pezizce and
other Helvellaeese, it may be, surmised that sexual organs and292
BOTANY.
;a sexual process precede the formation of each receptacle
■which springs from the sclerotium. It may be, however,
that each perithecium is the result of a sexual act; in the
latter case the single perithecium would be the homologue of
the Peziza cup, while in the former the whole receptacle of
Claviceps would be homologous to the receptacle of Peziza.
386. —As a second illustration of the plants of this order,
the Black Knot (Sphceria morbosa) which attacks the plum
and cherry may be taken.* In the spring the liyplne, which
the previous year penetrated the young bark, multiply
greatly, and finally break through the bark, and “form a
dense pseudo-parenchymatous tissue.” The knot-like mass
grows rapidly, and when full sized is usually from two or
three to ten or fifteen centimetres long ( 8 or 1.2 to 4. or 6.
in.), and from one to three centimetres in thickness (.4 to
1.2 in.); it is solid and but slightly yielding, and is composed
of hyphse intermingled with an abnormal development of the
phloem parenchyma of the host plant; bast fibres and modi-
fied vessels of the wood also occur. Externally the knot is
at this stage of a “ very dark brownish-green color,” and has
a velvety appearance, which is due to the fact that its surface
is covered with myriads of short, jointed, vertical hyphae,
each of which bears one, two, or more ovate pointed conidia
(Fig. 2Q0, 1). The conidia fall off readily, and doubtless are
important agents in multiplying the number of these para-
sitic growths ; they are produced until the latter part of
summer, when the hypha branches which bear them shrivel
up and disappear.
387. —During the latter part of summer peritliecia are
produced ; but the asci require the greater part of winter to
come to perfection. In February the ascospores are fully
ripe. The perithecia at this time are nearly globular in
shape, and are situated in minute papillae (3, Fig. 200); the
asci loosely cover the walls of the perithecial cavity, and are
intermingled with slender parapbyses (4, Fig. 200). Each
* What follows is condensed from a paper on “ The Black Knot,” by
Professor W. G. Farlow, in the Bulletin of the Bussey Institution, Vol.
X, p. 440 (1876). Three excellent plates accompany the paper.P YRENOM YCETES.
293
ascus contains eight ovate ascospores, which are two-parted,
as is the case in many other members of this order (5,
Fig. 200). The ascospores escape through a pore in the top
of the ascus, and in from three to five days begin to ger-
minate by sending out a tube or small hypha ; sometimes
two or more hyphee start out from a single ascospore (0,
Fig. 200).
388.—Besides the perithecia, there are other cavities
found which much resemble them, but which contain other
supposed reproductive bodies. In one kind are found the
stylospores, which are qnadrilocular oval bodies, borne on
long stalks (2, Fig. 200) ; they occur generally in definite
Fig. 200.—Reproductive organs of Spkoeria morbosa. 1, conidia-bearing hyphse
from a section of the knot on the cherry, made in May ; 2, stylospores ; 3, outline of
a vertical section of a perithecium, made in winter; 4,two asci. with the contained
ascospores, enlarged from 3 ; p, paraphyses ; 5, a ripe ascospore ; 6, two ascospores
in process of germination. All much magnified.—Alter Farlow.
patches on the walls of the globular cavities above men-
tioned. Their function is unknown ; but in all probability
they are asexual reproductive bodies. In other perithecium-
like cavities slender filaments are produced ; these are the sper-
matia, and the cavities in which they occur are the sperma-
gonia. Still other cavities, much like the preceding, “ are
lined -with short delicate filaments, which end in a minute
oval hyaline body; ” these small bodies are produced in
immense numbers ; when they are discharged from the cavi-
ties in which they grow, they ooze out in long jelly-like
masses. The cavities are called pycnidia, and the small294
BOTANY.
bodies pycnidio-spores. Neither the spermatia nor the
pycnidio-spores have been known to germinate ; but from
the resemblance of the former to those of Cucurbit-aria,
Valsa, and other genera of this order, which have been seen
to germinate,* it is quite certain that they, at least, are
reproductive, and that “ they are the agents for the dissem-
ination of the species to a great distance,” for which they are
fitted by their extreme minuteness. In all probability the
pycnidio-spores have also a similar function.
389. —No sexual organs have as yet been observed.
Doubtless they exist in the dense tissues of the knot, and
fertilization probably occurs in the spring or early summer,
while the conidia are being produced on the surface of the
young knot.
390. —The hyplne of each year’s knot generally penetrate
downward some centimetres into the uninjured bark, and
remain dormant there until the following spring, when they
begin the growth which results in the production of a knot,
as described in paragraph 386.
(a) Tlie Pyrenomyeetes include a large number of exceedingly in-
jurious fungi ; they often attack and destroy not only plants, but also
insects, upon which their ravages are in many cases very great.
(b) The classification is as yet in great confusion.f The principal
genus is Sphce ia, which contains many species. Valsa, Diatrype, and
Hypoxylon are other important genera.
(c) Good specimens of Claviceps purpurea may be obtained from
almost any rye-field, and more certainly from the isolated bunches of
rye growing here and there in many fields. By making repeated ex-
aminations soon after the flowering of the rye the conidia may be
obtained ; and by gathering the sclerotia and burying them in moist
sand under a bell-jar, the receptacles may be grown.
(d) Specimens of Sphcpria morbosa for study should be gathered at
different times in the season—from early spring to the latter part of
the winter following. The first gathered will be necessary to the
* Dr. Max Cornu, in “ Annales des Sciences Naturelles,” Sixth Series,
Vol. III., gives the details of his experiments upon germinating the
spermatia of many Pyrenomyeetes. A translation appeared in “ Gre-
villea,” 1877 and 1878, Nos. 36 to 39.
■j The student may profitably consult, in studying this difficult order,
the finely prepared sets of “ North American Fungi,” by J. B. Ellis,
begun in 1878, and still continuing.LICHENES.
295
study of the young and forming knot, while the succeeding ones will
show firat the conidia, and then the forming perithecia and developing
asci and ascospores. The last gathered specimens in February will
show the fully formed ascospores.
(e) Ergot, which occurs on rye and many of the forage grasses, is
poisonous, producing gangrenous sores when eaten in considerable
quantities. It is used somewhat in medicine.
(/) Xylomties in the Jurassic, and Sphceria, Phacidium, Bhytisma
and other genera, in the
Eocene and Miocene, are )f
the fossil representatives 0
of this order.
391. —Order Lich.-
enes. Lichens agree,
in all the essentials of
their structure, with
the two preceding or-
ders, Helvellaccce and
Pyrenomycetes, and
there can no
be shown any
reasons for not class-
ing them with the
latter, under the As-
comycetes.
392. —The tissues
of lichens consist of
various aggregations
of colorless, jointed
hyphte; in general
the hyphffi in the cor-
tical portion of the
thallus are compact-
longer
good
_ 201.—Transverse section of the thallus of
Sticta fuliginosa. o, cortical layer of rlie upper sur-
face ; v. cortical layer of lower surface; ?\ rhizoids
or attaching fibres ; m, medullary layer, composed of
distinct liyphse, many of which are cut transversely;
<7, layer of green gonidia. Each gonidia group is sur-
rounded by a gelatinous envelope. x 550.—After
Sachs.
ed and developed into a pseudo-parenchyma (o and u, Fig. 201,
and cc, B, Fig. 202), while in the medullary portion they are
distinct (to, Fig. 201, and cm, B, Fig. 202). In all lichens
there occur numerous green, blue-green, or brown-green cells,
the gonidia, which are either scattered through the interior
(homoomerous), or disposed in one or more distinct layers
(heteromerous) ; of the former, Collema and Leptogium are296
BOTANY.
examples, while of the latter Usnea, Parmelia (Fig- 202),
and Sticta (Pig. 201) may be taken as illustrations.
3
Fig. 202.—Parmelia aipolia. A, a portion of a thallus with two apothecia, ap,
and several spermagonia, s, s. B, transverse section of thallus through an apothe-
cium ; cc, cortical layer of pseudo-parenchyma ; g, g', gonidial layers ; cm, medul-
lary layer ; h. h, hypothecium ; ty t, t, t, the hymenium ; th, asci (thecae), with
ascospores. (7, section through three spermagonia, s.s,s; rh. rh, rhizoids. D,
stcrigmata from the interior of a spermagoniuin, bearing spermatia, s', s'.—After
Tulasne.LICHENES.
29?
393. —In their modes of reproduction, also, lichens agree
with the before-mentioned orders of the Ascomycetes. Like
them, they produce asci, containing ascospores, spermago-
nia, with their contained spermatia, and one or more other
organs whose functions are supposed to be reproductive.
394. —The asci are always developed from the hyphse, and
have no connection whatever with the gonidia. They arise
in most (but not all) cases from the hyphae of the interior of
the lichen. It appears that the particular hyphae which
produce asci differ from those which are found elsewhere in
the lichen in being of greater diameter and richer in proto-
Fig. 203.—Vertical section through the young apothecinm of Lecanora subfusca
(partly diagrammatic); ,h, h, hymeniura, composed of (1) paraphyses, which de-
veloped from the ordinary hyphae, and (2) the young asci in various stages of de-
velopment; shy Mscophorous hyphas, from which the asci develop; e, excipulum—i.e.,
the layer of hyphae upon which, or above which the ascophorous hyphae are borne ;
r, r, cortical layer of thallus ; m, medullary portion of thallus ; p, the gonidia. X 190.
—After De Bary.
plasm. The asci are developed from vertical, club-shaped
branches, which penetrate between narrow, vertical branches
(paraphyses) of the ordinary hyphae (Fig- 203). In many
cases they are collected in a disc-like surface, forming an ex-
posed hymenium (gymnocarpous lichens), while in other cases
they are in the interior of cavities (perithecia), whose walls
they line (angiocarpous lichens). The ascigerous fructifica-
tion is in either case technically called an apotheoium.
395.—The spores arise in the asci exactly as in the case of
Peziza and other Ascomycetes previously described ; that is,
they are formed simultaneously by the condensation of the
protoplasm about certain points in the interior of the young298
BOTANY.
ascus (the so-called free cell formation). Usually there is a
considerable quantity of the unused protoplasm left over
after the ascospores are fully formed (Fig. 204, a, i, c). The
usual number of ascospores is eight (Figs. 202, 203, 204),
although in exceptional genera they range from one or two
( Umbilicaria) to a hundred or more (Bactrospora, and other
genera). They are frequently septate, sometimes being di-
vided into two portions—e.g., Parmelia (Fig. 202)—or
many, as in Collema Urceolaria, etc. In the gymnocarpous
lichens the ascospores escape directly into the air. and this
they generally accomplish with such force as to be projected
some millimetres ; in the angio-
carpous genera they first escape
into the cavity of the perithe-
cium, from which they pass out
through an opening in its apex.
396.—In germination the as-
cospore commonly sends out a
germinating tube, which is a
growth from the endospore; it
develops directly into a bypha,
and becomes branched and sep-
tate. Bi- or multilocular asco-
spores usually send out a germi-
nating tube from each cell. In
ra?-Aft£ the Senera with ™ry large asco-
DeBary- spores—e.g., Megalospora, Per-
tusaria, etc.—the germination takes place in a way somewhat
different from that just described. In the endospore a
great number of cavities or canals form (g, Fig. 205), from
each of which there grows out a germinating tube (d, Fig.
205) ; these many tubes elongate into hyphse, and become
septate and branched (/, Fig. 205).
397.—In addition to the apothecia, with their contained
ascospores, there are other organs which contain bodies
which are probably reproductive in their nature. The
best known of these are the spermagonia (Fig. 202, A, s,
and Fig. 206), which are small cavities, usually found upon
the same thallus as the apothecia ; they contain branched
Fig. 204.—Asci and ascospores of
Sph&rophorus globiferus. a, young
asci in various stages; b, the oldest
ascus in a, more magnified ; c, an as-LIOHENES.
299
threads (sterigmata), which line the inside of the wall (Fig.
202, D) ; upon the sterigmata are borne large numbers of
minute cells (the spermatia), which fall off and are per-
mitted to escape through the small opening at the apex of
the spermagonium. It is unknown whether these germinate
or not ; some botanists have supposed them to be sexual in
their nature—hence their name, spermatia; the recent in-
vestigations of Stahl, to be referred to below, seem to indi-
Fig. 205.—Germination of the spores of lichens, a, ripe ascospore of Megal-
ospora affitiis; £and c, 6ticcesfdve stages of germination, seen in optical section;
d, still later statre of germination, seen in perspective, e, beginning of germination
of ascospore of Ochrolechia pallescens; f, the same at a much later stage, show-
ing the many young hyphte, much less magnified, g, half of an ascospore of Per-
tusaria ceutivocaipa? seen in optical section, showing the pores in the endospore
through which the hyphie p iss out. The exospore is shaded in the figure. / X
190, the others X 390.—After De Bary.
cate the truth of the theory that they are the male sexual
elements ; on the other hand, their analogies to the similar
organs of HelvellacecB and Pyrenomycetes point rather to
their conidial nature.
Still other cavities (pycnidia) occur, in which spore-like
bodies are found, differing in size and other chax-acters from
the spermatia.300
BOTANY.
398.—Until Stahl’s researches* showed the existence of
sexual organs in Collema, they were entirely unknown among
lichens. He discovered, deeply
imbedded in the tissue of the
\p pjan^ an organ composed of a
spirally coiled hypha-branch, and
a vertical septate portion, which
rises to, and projects above, the
surface; the spirally coiled por-
tion he called the ascogonium,
and the vertical portion the tri-
chogyne. The whole he regarded
Fig. 206.—Vertical action or a as a species of carpogonium (Fig.,
small portion of the thallus of Col- onry a n onrl r7\ TT« nPeprvprl
lema Jacobcefolium, showing the ^ h c, ana a). ne ooservea
colorless branching and jointed hy- gpermatia adhering to the pros
phse, the Nostoc-like gomdia, and a r ^
spei-magonium, from which sperma- iecting portion 01 the tl’icho-
tia are escaping. Magnified.—After 0 o ± .. , .,
Tuiasne. gyne ; some ot these united them-
selves to the trichogyne by means of a tube (0, Fig. 207).
The result of this coalescence was the withering and disap-
pearance of the
cells of the tricho-
gyne, and the
growth and devel- j
opment of the as-
cogoninm. The
latter process takes
place as follows :
“ The cells of the
ascogonium first of
all increase in size,
and then undergo
,. . . ° Fig. 207.—Scxnal organs of Collema microphyllvm. A,
division y as a re- section of thallus; a, a, hyphse; b, b, the Nostoc-like
» ,, . gor.idia ; c. ascogonium ; d, the exserted trichogyne. B,
Slllt OI tlllS, tlie the spermatia, b, surrounding the exserted trichogyne, a.
r,A • i C, coalescence of a spermatium, b, with trichogyne. a.
spiial anangement All the figures magnified, B and (7 much more than A.—
of the cells be- AflerStail1-
comes less and less conspicuous, for the cells gradually sepa-
* “ Ueber die Oesclileclitliche Fortpflanzung der Collemaceen,” 1877
(On tbe Sexual Organs of the Collemaceae). A brief synopsis of Stahl’s
results appeared in the Qr. Jour, of Mic. Science, October, 1878.LICHEN EH.
301
rate from one another. Whilst these changes have been
taking place in the ascogonium, it has become invested by a
dense felt-work of hyphee, formed by the active growth of
the liyphaa of the thallus. From this investing layer hyphse
grow inward between the separating coils of the ascogo-
nium, and bear paraphyses, which form the rudimentary
hymenium. At the same time outgrowths have been
formed from the cells of the ascogonium, which either are
asci, or grow into hyphal filaments, which bear asci as
lateral branches. The asci, whether derived directly or in-
directly from the cells of the ascogonium, come to lie in the
hymenium among the paraphyses.” Thus the apothecium
is partly developed from the carpogonium, and partly from
the hyphse of the thallus, agreeing in this with what is now
known to be the mode of formation of the corresponding
parts of some, at least, of the Helvellacece.
Whether there are similar sexual organs in other lichens,,
is at present unknown ; probably, when discovered, they will
be found to bear some resemblance to those of Collema, just
described ; but it is altogether likely that, instead of fertili-
zation taking place lay means of free male elements (sper-
matia), it will be shown to be more nearly like that now
known in Peziza or Ascobolus.
399.—The Gonidia. The gonidia of lichens are of so
much importance that they demand a somewhat extended
notice. As above stated (paragraph 392), they are green or
greenish cells, or rows of cells, which occur either distributed
irregularly through the tissue of the lichen-thallus (the ho-
moomerous lichens), or in different layers or regions (the
heteromerous lichens). These green bodies are of different
forms in different groups of lichens, while in nearly related
species they are often exactly alike. They may consist of
isolated cells, or groups of cells, as in most fruticose or folia-
ceous lichens (e.g., Parmelia, Fig. 202, Sticta, Fig. 201,
Sphcerophorus and Usnea, Fig. 208), while, on the other
hand, they may be made up of rows or chains of cells
{e.g., Lecanactis and Graphis, Fig. 209, Mallotium, Fig.
210, and Collema, Figs. 206 and 207). They are known to
reproduce by the division (fission) of their cells, and, inBOTANY.
302
some cases at least, when free from the lichen-thallus, by
the production of zoospores.
Their connection with the hyphfe is sometimes by the
prolongation of a short branch from the latter, which passes
to each gonidial cell (Fig. 208); in other cases the connec-
tion is with one cell of a row, as in Plectospora,* where the
connection may be with the terminal cell of the row, or with
any of the intermediate ones; in either case, the cell to
which the hypha-branch is attached is considerably larger
than the others in the row. Schwendener describes! a con-
Fig. 208.—Gonidia of different lichens, a to et of Parmelia tiliacea, showing a, 6,
and e, the attached hyphae, X 390; /, of Usnea barbata, with attached hypna, X
700 ; g, of Sphcerophorus globifervs, with attached hypha, x 390.—After De Bary and
Schwendener.
Fig. 209.—Gonidia. a, a, of Lecanactis illecebrosa; b, b, of Graptiis scripia.—
After De Bary.
nection which he has seen in certain gelatinous lichens, in
which two and three short branches pass off from the same
hypha, and unite with the cells of one gonidial chain.
TrcubJ confirms Schwendener’s statement, saying that he
* See De Bary’s “ Morpliologie und Pkysiologie der Pilze, Flecliten,”
etc., p. 264.
f “Die Flecliten als Parasiten der Algen,” 1873.
\ Dr. MelcUior Treub, “ Onderzoekingen over de Natuur der Liclie-
nen,” 1873.L1CHENES.
303
has “succeeded many times”in finding gonidia so connected
to the hyphse by more than one branch.
400.—With regard to the origin of gonidia, Fries asserts
that the hypha-branches swell up at their ends, become glob-
ular, and, after a while, filled with green contents.* * * § He,
however, does not speak of any observations of his own upon
which he bases his statement. Berkeley! likewise regards
them as developed from the mycelium, but made no observa-
tions which can be considered conclusive. Speerschneider’s
observations,! in 1853 to 1857, along with those of Bayr-
Fig. 210.—MalloHum (or L"p'ngium) Hildenbrandii. a, vertical section through the
thallus, u, the under side, x 100 ; b, portion of a very thin section near the under
side, showing three gonidia chains, two hyphse, a portion of the lower limitary tissue,
and two large and several small hairs, which are organs of attachment, x 390.—After
De Bary.
hoffer,§ some years earlier, appear to be, in reality, the ones
upon which the view that gonidia develop from the hyphae
depends ; their statements appear to have been accepted and
repeated by lichenologists without sufficient inquiry. The
other errors of observation and interpretation made by these
observers render their testimony upon the question of the
origin of the gonidia of doubtful value. Schwendener, :n
* “Liclienograpliia Scandinavica,” 1871.
f “ Introduction to Cryptogamic Botany,” 1857.
j In Botanuche Zeituny, 1853, 1854, 1855, 1857.
§ “ Einiges fiber die Lichenen und deren Befruclitung,” 1851.804
BOTANT.
reviewing the subject, affirms that the actual development of
a gonidium from tire end cell of a hypha has not been ob-
served. Nylander even goes so far as to declare that in no
case do the filaments themselves give birth to gonidia, but
that they “have their origin in the parenchymatous cortical
cells which are observed on the prothallian filaments of ger-
mination.”*
401.—The recent observations of Dr. Minks, f if con-
firmed, will put to rest the question as to the origin of go-
nidia. He studied the small green cells sometimes called mi-
crogonidia, and makes the announcement that they originate
in the interior of the cells of every portion of the lichen-
thallus, viz., the cortical and medullary cells, the paraphy-
Fig. 211.— Soredia of Usvea barbata. A, sore- by Cell-Walls, and after-
that intermediate forms of all degrees are to be met with be-
tween microgonidia and gonidia. Dr. Muller,in making simi-
lar observations, arrived at the same conclusion^; as to the
origin of the microgonidia.
The third view as to the origin of gonidia is so intimately
connected with the question of the real nature of the gonid-
ium and its functional relation to the hypliai, that it can
only be explained by taking these into consideration.
* In Flora, 1877, p. 256, as quoted in Bevue Mycologique, p. 4,1879,
and in " Grevillea,” 1879, p. 91.
f For accounts of these observations see Flora, 1878, Benue Mycolo-
gique, 1879, and American Journal of Science and Arts, 1879, p. 254.
X Flora. 1878.
ses and young asci, and
crogonidia. He assertsLICHENES.
305
402.—The gonidia sometimes escape from the thallus of
the lichen surrounded with a few hyphse (Fig. 211) ; these
are called soredia. Under favorable circumstances they may
give rise to new lichens, and hence have been looked upon
by some as asexual organs of reproduction. Soredia are,
however, rather of the nature of buds or gemma?, which,
xmder certain circumstances, become detached. Their pro-
duction is, to a certain extent, accidental.
(a) 1. The Nature of Gonidia. Until recently, tlie gonidia of
lichens have been generally regarded as accessory reproductive bodies.
De Bary,* * * § however, in studying the Collemace®, and noting the remark-
able resemblance between their gonidia and certain algae, came to the
following conclusion : “ Either the lichens in question are the perfectly
developed states of plants whose imperfectly developed forms have
hitherto stood among the algae as the Nostocace® and Cliroococcaceae ,
or the Nostocace® and Cliroococcaceae are typical algae which assume the
form of Collema, Epliebe, etc., through certain parasitic Ascomycetes
penetrating into them, spreading their mycelium into the continuously
growing thallus. and becoming attached to their phycoclirome-contain-
ing cells.” Scliwendener,f Reess.f and Borneig have taken up the
second theory in the above alternative, and extended it to all lichens.
Scliwendener, who first made the definite statement of the theory, holds
that every lichen is a colony composed of a parasitic fungus on the one
hand, and a number of low alg® on the other ; the former, which pro-
duces the asci, spermatia, and other reproductive bodies, is nourished
by the latter, which constitute the gonidia of the lichen.
A lichen, according to this view, is not an individual plant, but rather
a community made up of two kinds of individuals ; and the gonidia are
only the temporarily imprisoned alga;, which furnish nutriment to the
parasitic fungus. The fungus parasite does not differ in any essential
character from those of the two higher orders of the Ascomycetes.
Leville, in speaking of lichens and the ascomycetous fungi, said,||
“ I find the distinctions to be so trifling, that I have always regretted
that these vegetables should not be placed under one head. The para-
physes, tliec® (asci), and spores are identical.”
* “ Morphologie und Physiologie der Pilze, Flechten, und Myxomy
ceten,”1865, p. 291.
f Dr. S. Schwendener : “ Untersuchungen fiber den Fleclitentliallus,”
1868, and “ Die Algentypen der Flechtengonidien,” 1869.
J Professor Max Reess : “ Ueher die Entsteliung der Fleclite Collema
glaucescens,” etc, 1871.
§ Dr. E. Bornet: “ Recherches sur les Gonidies des Lichens,” 1873.
II A letter to Decaisne, as given in Le Maout and Decaisne’s ‘‘ Traite
-Generale de Botanique,” 1868306
BOTANT.
2. Scliwendener has shown* that the gonidia may be referred to well-
known groups of alga;, some of which belong to the Zygophyta, while
others belong to the Protophyta. Thus the gonidia of Collema, Lepto-
gium (including Mallotium), Peltigera and some other genera, are iden-
tical with Nostocace® ; those of Omphalaiia and others, with Cliroo-
coccace® ; those of Oraphis, Vetrucaria, etc., with Chroolepide® (re-
lated to Conferva and Cladophora) ; those of Usnea, Cladonia, Physcia,
Parmelia, and most higher lichens with Palmellace®. _ The gonidia of
some other lichen genera are referred to still other alga groups.
3. When gonidia are dissected out from the lichen-thallus they are
capable of independent existence ; and there can be no doubt that (as
De Bary intimated) many of the forms regarded as algae are identical
with gonidia.f With these facts before us, it can scarcely be doubted
that the mode of origin described by Speerschneider and Bayrhoffer is
incorrect. There cannot now be shown any good evidence that the go-
nidia develop from the hypli® with which they are seen to be in contact.
The connection between hypli® and gonidia is doubtless one which takes
place after the origin of the latter. The two remaining views—
Scliwendener’s and Minks’—agree upon this point, and in both the idea
of a genetic connection between gonidium and the hypba-filament in
contact with it is rejected. These two theories, however, differ radi-
cally in this, that while on the one hand the gonidia are regarded as
true lichen-cells, ou the other they are held to be algae belonging to en-
tirely different thallophytic groups.
4. It must at once be evident to any one that the actual relation of
the liyphal portiou of the lichen to the gonidia is the same whether the
origin of the latter be, as asserted by MinkB, within the liyphae, or en-
tirely independent of them, as maintained by Schwendener. Any con.
nection which subsists between these two can be, under the circum-
stances, of only one kind, namely, that of a greater or less degree of
parasitism. It makes no difference to show that the gonidia are derived
from the hypli® themselves, for they are (it is Baid) Bet free after their
formation in the mother-cell ; now any subsequent connection of these
green cells with the hypli® cannot possibly have any other meaning
than that, the latter derive nourishment from them. The only differ-
ence between the two theories may be expressed in this way : according
to the one, the imprisoned slaves which furnish nourishment for the
liyphal master are members of entirely different groups of the vegetable
kingdom ; while according to the other, the slaves are the offspring of
the liyphal master which imprisons them. In the first the gonidia are
* “ Die Algentypen der Flechtengonidien,” 1869.
f This was long since shown by Itzigsohn—Botanische Zeitung, 1854,
by Hicks—Qr. Jour, of Mic. Science, 1861, and by Famintzin and Baranet-
sky—Botanische Zeitung, 1867 ; Nylander also arrived at the same con-
clusion with regard to the gonidia of Collema—Flora, 1868.LICHENEH.
30?
slaves not at all related to the hyphae ; in the other they are produced
by them, and after a brief period of freedom are fastened upon, and
compelled to do service for the hyphae which produced them.
It is impossible to decide between these two theories until further in-
vestigations shall determine the truth or falsity of Dr. Minks’ state-
ment as to the origin of microgonidia. It must, however, be said, that
the view which appears to he most in accord with what we, now know
of plants, is that taken by Schwendener.
(b) 1. Cultures of lichens have been made by many observers,
especially by Bornet, Reess, and Treub. The latter made an extended
series, from which the following details of methods are condensed.
Spores may be secured for germination by placing freshly gathered
lichens upon plates covered with well-moistened glass slips, and keep-
ing them under a bell-jar for from twelve to twenty-four hours, at the
end of which time a number of spores will be found on the slides.
2. The spores may be left upon the slides and allowed to remain in a
moist atmosphere, as in a bell-jar. Others may be placed upon very
thin pieces of the bark upon which the lichens naturally grow. Still
others may be made to grow in the presence of a small quantity of the
ash of the same species of lichen.
3. A too copious supply of moisture is unfavorable to the successful
germination of the spores. If the conditions are favorab e germination
will begin in from two to eight days. In about a month after sow-
ing, the protoplasm of the spore becomes in great part used up in the
formation and elongation of the germinating filaments. It always hap-
pens that the growth of the hyphae from the spores ceases soon alter the
exhaustion of the protoplasm, unless the hyphae come in contact with
algae of the proper kind, or witli gonidia.
4. An interesting culture may be made by repeating Bornet’s exper-
iment, as follows: He placed on fragments of bark, previously boiled
to kill all other germs, and also on pieces of limestone freshly broken,
a layer of Protococcus viridis scraped off of a damp wall, and to this
added the spores of Theloschistes parielinus. In about a fortnight the
hyphae were seen to be large and ramified ; wherever they came in
contact with cells of the Protococcus they adhered either directly or by
means of lateral branches. Bornet made at the same time parallel cul-
tures, without, however, bringing the germinating spores into proximity
to Protococcus; the growth was much less, and in no case did he get
any evidence that the hyphae themselves formed gonidia.
5. Treub modified Bornet’s culture by using, in some of his experi-
ments, the artificially isolated gonidia of one species of lichen—for ex-
ample, of some species of Ramalina—and the spores of a different one. as
Theloschistes parielinus. He also used glass slides for his cultures,
whether with gonidia or free algae, taking the precaution, however, to
allow the drop of water in which the spores and gonidia were placed308
BOTANY.
to completely evaporate before placing in the moist chamber. By tak-
ing precautions to keep out moulds, by supplying the moist chamber with
air passed through one or two plugs of cotton-wool, lie succeeded in
continuing the growth of the liyphae for three months, at the end of
which time the algae were surrounded by a good number of branches
Fig. ‘ZVl.—Usrwabarbata, nat. size, a, a, apothecia ; /, diBk by which it is attached
to the bark of a tree.—After Sachs.
Fig. 213 —Siicta pulmonacea, nat. size, a, a, apothecia.—After Sachs.
of the hyplise, many of which had firmly attached themselves to the
cells of the algte.
(c) The classification of lichens is by no means settled.
The arrangement which is followed in this country is that of Profes-
sor Tuckerman.* He divides the order into five tribes, as follows:
Tbibe I. Pabmeliacei.
Apothecia rounded, open, scutelliform, contained in a thalline exciple.
Family 1. Usneei. Roccella, Ramalina, Dactylina, Cetraria. flver-
nia. Umea (Fig. 212), Alec'oria. Roccella nnctoria and other species of
the genus furniBh the dye known as orchil, and chemical test “litmus.”
Cetraria islandica, the Iceland moss, is used both as a food and a medi-
* Edw. Tuckerman : “Genera Lichenum; An Arrangement of North
American Lichens,” 1872, and “ Synopsis of N. A. Lichens,” 1882.LICHENES.
309
Fig. 214.— Collema pulposum,
slightly magnified, showing the
apothecia.—After Sachs.
cine. Species of Evernia are sometimes used for furnishing yellow
dyes.
Family 2. Parmeliei. Speei schneidera, Theloschistes, Parmelia
(Fig. 203), Physcia, Pyxine. From Parmelia parietina fine dyes have
been obtained.
Family 3. Umbilicariei. Umbilica-
ria.
Family 4. Peltigerei. Sticta (Fig.
213), Nephroma, Peltigera, Solorina. Stic-
ta pulmonacea was formerly used in medi-
cine, but it lias fallen into disuse, except-
ing with quacks.
Family 5. Pannariei. Heppia, Pan-
naria.
Family 6. Collemei. Ephebe, Licli-
ina, Synalissa, Omphalaria, Collema (Fig. 214), Leptogium, Hydro-
thyria.
Family 7. Lecanorei: Placodium, Lecanora, Rinodina, Perlusa-
ria (Fig. 215, C), Conotrema, Dvrina, Oyalecta, Urceolaria, Thelotrema,
C-yrostomum. Lecanora tarta-
rea lurnislms a dye, and L.
esculenta, of Asia Minor, sup-
plies a valuable food; it is
sometimes “ carried up by
whirlwinds and deposited after
traversing the air for many
miles, giving rise to stories of
the miraculous descent of food.
A few years since, in a time of
great scarcity at Erzerouin, a
shower of these lichens fell
most opportunely, to the great
relief of the inhabitants.”*
Tribe II. Lecideacei.
Apothecia rounded, open, pa-
telliform, contained in a proper
exciple.
Family 1. Cladoniei. Ste-
reocaulon, Pilophovus, Cladonia.
Cladonia rangiferina is the
“ Reindeer moss " of the Arctic
it furnishes a valuable food to the reindeer.
Fig. 215 —A, Graphis elegant; on a piece of
a twig of the holly ; B, Ihe same slightly mag-
nified ; C, Pertusaria Wulfeni, slightly mag-
nified, on a piece of old wood.—After Sachs.
regions
* Berkeley: “ Introduction to Cryptogamic Botany,” p. 383.310
BOTANY.
Family 2. Coenogoniei. Cmnogonium.
Family 3. Lecideei. Bceomyces, Biatora, Ileterothecium, Lecidea,
Buellia.
Tribe III. Graphidacei.
Apotliecia of various forms, frequently lirelliform, in a proper ex-
ciple. 'Phallus crustaceous.
Family 1. Lecanactidei. Lecanactis, Platygrapha, Melaspilea.
Family 2. Opegraphei. Opegrapha, Xylographa, Oraphis (Fig.
213, A).
Family 3. Glyphidei. Chiodecton, Olyphis.
Family 4. Arthoniei. Arthonia, Mycoporum.
Tribe IV. Caliciacei.
Apothecia turbinate-lentiform or globose, frequently stipitate, mar-
gined by a proper exciple, the disk breaking up into naked spores,
which form a compact mass.
Family 1. Sphaerophorei. Sphwropliorus, Acroscyphus.
Family 2. Caliciei. Acolium, Calicium, Coniocybe.
Tribe V. Verrucariacei.
Apothecia globose, in a proper exciple, becoming pertuse with a pore.
Family 1. Endocarpei. Endocarpon, Normandina.
Family 2. Verrucariei. Seges'rin, Staurothele, Trypethelium, 8a-
geaia, Verrucaria, Pyrenula, Pyrenastrum, Strigula.
(d) Fossil lichens are extremely rare, only a few Tertiary species of
modern genera being recorded.
403. —Order Uredinege.—The Uredineae are related to the
foregoing orders of the Ascomycetes, and probably should be
grouped with them. They are all parasitic in habit, and the
vegetative portions of the plant-body are greatly reduced,
leaving but little more than the organs of reproduction.
Their life-history is but imperfectly known, and nothing is
yet known as to their sexual organs. They are generally
polymorphic—that is, they assume, in their production of
various kinds of spores, such apparently distinct forms, that
these have frequently been mistaken for distinct plants.
404. —So far as made out, the life-history of the Uredinege
appears to be about as follows : In the spring there appear in
the tissues of the leaves of various plants dense masses ofUREDINEJE.
311
hyphae, which penetrate between the cells, causing the leaves
to become usually much thickened and distorted in those
parts which are infested with the parasitic growths. Oc-
Fig. 216—Several stages of Puccinia graminis. A, part of a vertical section of a
leaf of the Barberry (Berberis vulgaris), with a young unopened aecidium fruit; w,
epidermis. section of a Barberry leaf, natural thickness at X, greatly thickened
from h toward y; u, epidermis of the under surface; o, of the upper surface; »,
unopened tecidium fruit; a, a, a, opened aecidium fruits ; sp, sp, spermagonia. IT.,
a mass of teleutospores on a leaf of Couch-grass (Triticum repens); e, the ruptured
epidermis ; b, sub-epidermal fibres of the grass leaf. Ill, three uredospores, ur,
with one teleutospore, t; sh, sub-hymenial hyphse. All highly mugnified.— A and I.
after Sachs ; II. and III after De Bary.
casionally these hyphse are found in other parenchymatous
parts besides the leaves, as the petioles, young stems, and
■even the flowers and fruits. After a short time there form312
BOTANY.
globular masses, which lie in the parenchyma just beneath
the epidermis ; these are composed at the bottom of an hyme-
nium-like layer of sterigmata (shown in Fig. 216, A and I, as
a layer of elongated cells). Each sterigma produces a chain
of cells, which are at first many-sided from mutual pressure,'
but afterward spherical. By their growth these globular
masses finally burst through the epidermis (Fig. 216, I., pi),
and soon afterward, by the rupture of the thin investing
layer of cells (peridium), they become opened and cup-
shaped (Fig. 216, I., a, a, a). The now rounded cells are set
free as large yellow conidia (or secidiospores). At one time
this stage was supposed to constitute a distinct plant, and it
received the generic name of AEcidium, hence it is still
known as the Eecidium stage.
In many (if not all) cases there is a second kind of repro-
ductive organ present, resembling in some respects the Eecid-
ium fruits just described. These are smaller flask-shaped
cavities, which are filled with slender hair-like filaments (Fig.
216, I, sp, sp); these are the spermagonia, and they pro-
duce, by the breaking up of the filaments, numerous ex-
ceedingly small oblong bodies, the spermatia. The function
of these is not known ; at one time it was supposed that they
were the male reproductive bodies, but it is very doubtful
whether they are of this nature.
405. —The conidia (secidiospores), when they fall upon the
leaves of the proper host plant, germinate, and penetrate
the stomata, thus reaching the leaf parenchyma, where a dense
mycelium is formed. Upon this are formed, within a short
time, stalked spores (uredospores, Fig. 216, III., ur) ; these
finally burst through the epidermis, and form orange-colored
spots upon the leaves. The uredospores fall off very easily,
and germinate quickly, giving rise immediately to another
mycelium (Fig. 217, D), which produces uredospores, which
may, in turn, give rise to new mycelium, and so on indefi-
nitely. The function of the uredospores is clearly the quick
reproduction of the fungus.
406. —After the production of uredospores has continued
for some time, the same mycelium gives rise to stalked, thick-UREDINE'JE.
313
walled bodies (teleutospores,* or pseudo-spores), which are
one, two, three, or many-celled (Fig. 210, III., t). Like
the uredospores, the teleutospores are produced beneath the
Fig. 217.—Puccinia graminis. A, germinating telentospore, t, with promyceliura
forming the sporidia. sp. B. similar protnycelium, with sporidia. C, a sporidium,
sp, germinating on a piece of the under side of a leaf of the Barberry, the mycelium,
i, penetrating the epidermis. D, a terminating uredospore, u, fourteen hours after
being placed on the leaf of a grass, forming a branched mycelium. Highly magnified.
—After Be Bary.
epidermis of their hosts, which in their growth they burst
through, and appear as small rounded clusters (sori), or more
* From tlie Greek TtAevTrj, end ; so named because it is generally the
last reproductive body of these fungi produced in the season.314
BOTANY.
or less elongated lines. In color they are almost invariably
brown or nearly black,in marked contrast to the reddish yellow
(orange) uredospores. In some cases they are produced early
in the season, but in the greater number of cases they appear
in the autumn, and then remain through the winter upon
the dead stems of their host plants. The following spring
the teleutospores germinate by sending out a jointed filament
(the jpromycelium) from eacli cell; this grows to several times
the length of the teleutospore, and then sends out a few lateral
branches, each of whicli bears a small terminal cell, a sporid-
ium (Fig. 217, A and B, and Fig. 218). The sporidia are
extremely minute, and, as a
consequence, are carried about
from place to place in the wind
with great ease. When they
fall upon the proper plant, each
sporidium sends out a minute
filament, which perforates the
epidermis-cells, and from these
passes into the leaf parenchy-
ma, where it develops into a
mycelium (Fig. 217, C). From
this last mycelium the secidium
fruits first described develop.
Fig. 218.—Germinating teleutospore ,
of Puccinia Molinia, showing promy- (a) The life-cycle, as above given,
celium and sporidia.—After Tulasne. jg apparently abridged ill some of
the Uredinese. The secidium and uredo stages are merged into one, or
either the first or second is entirely wanting. This appears to be the
case in Phragmidium, Gymnosporangium, Melampsora, etc.
(&) With most of the species it happens that the aecidiospores (conidia)
develop upon one host, and the uredospores and teleutospores upon an-
other. This alternation, which is termed by De Bary hetercecism, has
added very much to the difficulty of the study of these fungi, and pos-
sibly the apparent abridgement of the life-cycle above mentioned may
in some instances be only an obscure lieteroecism.
(c) Thus far the sexual organs have not been discovered ; Sachs*
argues that they must precede the aecidiospores, and that the aecidium
fruit is in all probability the result of a sexual act. He bases his argu-
ment upon the law that the reproductive organs of most complex struc-
* ‘ Lehrbuch der Botanik,” 4te Auflage, 1874, p. 331.o RKD IN K-H.
315
ture follow or proceed from a sexual act; and maintains that the secid-
ium fruit is more complex in structure than any of the others. He
further says, “ Theaecidium fruit corresponds, then, to the perithecium of
the Ascomycetes, the aecidiospores to the ascospores ; and the uredo-
spores and teleutospores are evidently differ-
ent forms of conidia.” It is very doubtful,
however, whether future investigations will
prove the correctness of Sachs’ surmise. It is
much more probable that the teleutospores re-
sult from a sexual act, and that they are to
be compared to the asci of the Ascouiycetea.
The teleutospores are possibly reduced asci,
containing one or more large ascospores; in
some cases—e.g., in Puccinia Helianthi—an
outer investing membrane can be distinguish-
ed after treatment with potassic hydrate,
while in Puccinia (Uropyxis) Amorphm there
is “ a deciduous outer coat,”* which contains
the double spore, and (when moistened) a mass of jelly. In both these
cases the membranous covering closely resembles an ascus which fits
closely over its contained double spore. In the genus Phragmidium
(Fig. 220), especially in young teleutospores, the resemblance to asci
and ascospores is still more striking; the so-
called “ cells” of the teleutospore originate as so
many separate masses in the interior of a large
ascus-like membrane (Fig 219); in their further
development the cells become large, and at last
fill up the whole cavity, and then have the ap-
pearance of Fig. 220.
The resemblance of the teleutospores to re-
duced asci is close enough to make it probable
that sexual organs resembling those of Asco-
mycetes will lie found to precede them. This
is rendered the more probable from the resem
hlance of secidiospores, spermatia, and uredo-
spores to the conidia, spermatia, and stylospores
of var'ous Ascomycetous fungi.f
(d) The principal genera in this order are
Uromyces and Melampsora with one-celled te-
fied*^After CoolufmagQl" leutospores, Puccinia and Gymnosporangium,
with two cells, and Phragmidium (Fig. 220) with
many cells. Many species are known, there being in the genus Puo-
* So described by Berkeley : “ Introduction to Cryptogamic Botany,’
1857, p. 325.
f Some of these resemblances were pointed out many years ago by
Fig. 219.—Yonna teleuto-
spores of Phragmidium mu-
ci-onatum, showing the an-
gular masses which eventu-
ally develop into the cells
of the mature teleutospore.
Highly magnified.316
BOTANY.
einia alone from forty to fifty species in the United States. They at-
tack many species of Phanerogams, hut are scarcely known as para
sites upon Cryptogams. The first stage was long known as the genus
JEadiwm, and under this many supposed species were described, and
this is still the case in all English systematic works ; in the same way
the second stage gave rise to the supposed genera, TJredo, Tnchobam,
etc., and even these are, to a great extent, retained in the ordinary
books, although their autonomy was long since disproved.
(e) One of the best known species of this order is that which appears
upon wheat, oats, and some oilier cultivated grasses, producing, or
rather being, the disease known as Bust (Puccinia. graminis). It ap-
pears in the spring upon the leaves of the Barberry, developing there
the aeeidiospores (conidia), and constituting what for a long time has
been known as the Barberry Cluster-Cups, or Barberry Rust (Fig. 216,
A and I). Later in the season, and usually after the Cluster-Cups
have entirely disappeared from the Barberry, the uredo stage begins
to make its appearance, first, upon the leaves, and then upon the stems
of tlie wheat, oats, etc.; at first it may be detected by the pale yellow-
ish or whitish spots on the leaves ; these mark the places where the
uredosj ores are l> ginning to form beneath the epidermis. Witliiu a
few days the uredospores (Fig. 216, TIL., ur) break through the epider-
mis and expose long lines of the orange-red spores. By the quick ger-
mination of the uredospores, first produced, the fungus is greatly
ir creased, bo that frequently the host plant is destroyed before reach-
ing its maturity. This stage is known popularly as the Red Rust of
wheat, oats, barley, and other similar grasses. Still later in the season,
and usually after the ripening of the host plants, the dark-colored
teleutospores (Fig. 216, II.) appear in long black lines, sometimes upon
the leaves, but more frequently upon the stems, and in ordinary
cases upon the uncut part of the stem, viz., the “ stubble.” This.stage
is known as the Black Rust. The teleutospores remain upon the dead
stems through the winter, and in the following spring germinate and
produce sporidia, which give rise to a mycelium in the Barberry
leaves (Fig. 217, A, B, and C).
De Bary,f by placing the teleutospores upon young leaves of the
Barberry, succeeded in producing the cecidium stage, thus proving
Barberry rust to be but a stage of Puccinia graminis. Similarly it
has been shown that the tecidiospores of Barberry rust will not grow
upon Barberry leaves, but that when placed on a leaf of wheat, oats,
Frederick Currey. In a paper” On the Affinities of the Uredineas,” pre-
sented to the Iowa Academy of Sciences, May, 1878,1 pointed out that
the structural similarity of Uredinese and Ascomycetes rendered it
probable that the sexual organs of the former preceded the teleuto-
spores. I did not then know of Currey’s paper,
f Published in Monatsbcr. d. Berl. Acad., 1865.ITST1LA GINEJE.
31?
"barley, etc., they send out filaments, wlicili pass tbrougli the stomata,
and give rise to a mycelium, which, in about a week, produces uredo-
spores.
(/) Uredinese are easily obtained for study in either the first, second,
or third stage. In most species the recidium stage occurs in spring or
early summer, the second in spring or summer, and the third in the
autumn ; in some species, however, the teleutospores are produced in
the spring, as in Oymnosporangium and Pueeinia Anemones.
(g) The sporidia may be obtained by placing pieces of grass stems
containing teleutospores in a damp atmosphere, after soaking for a few
hours in water. The teleutospores should be freshly taken in most
cases from those which have remained upon the stems out-of-doors
during the winter.
407. —Order Ustilagineae. The plants which compose
this order are all parasites living in the tissues of Phanero-
gams. Like the Uredineae, the Ustilagineae send their my-
celium through the tissues of their hosts, and afterward
produce spores in great abundance, which burst through the
epidermis. There is, however, in many respects a greater
simplicity of structure in the plants of the present order
than in the Uredineae, and this has induced some botanists
to doubt their relationship to the last-named order ; how-
ever, it appears that the simplicity is one due rather to
degradation than to any essential difference in structural
plan.
408. —The mycelium of the Ustilagineae is well defined,
and consists of thick-walled, jointed, and branching hyphae,
which are generally of very irregular shape. * The hyphae
grow in the intercellular spaces, as well as within the cell
cavities of their hosts. They send out suckers (haustoria),
which penetrate the adjacent cells much as in the Perono-
sporeae ; these are more abundant in the compact tissue of
the nodes of stems than in the long-celled tissue of the in-
ternodes. The mycelium generally begins its growth when
the host plant is quite young, and grows with it, spreading
into its branches as they form, until it reaches the place
of spore-formation. In perennial plants the mycelium is
* The following account of the Ustilagineae is based upon an article on
this order by Dr. A. Fischer von Waldheim, published in Pringsheim’s
“Jalirbiicher fur Wissen. Bot.,” 1869. A translation appeared in the
Transactions of the N. T. State Agricultural Society, 1870.318
BOTANY.
perennial, the fungus reappearing year after year upon the
same stems, or upon the new stems grown from the same
roots; in annuals it must obtain a foothold in the young
plants as they grow in the spring.
409. —The mycelium can be traced in the Monocotyle-
dons often for long distances ; thus in the smut of Indian corn
(Ustilago Maydis), at the time the spores are found in the
distorted grains the hyphae have been detected at all inter-
mediate points down to the lower internodes, and in the
smut on wheat ( Ustilago ccirbo) they have been observed in
every part of the plant, from the root through the stem to
the inflorescence. In neither case, however, are the hyphae
to be found in parts through which it is not necessary for
them to pass in order to reach the point where the sjeores
are formed ; thus they are usually not found in the leaves
unless spores are formed in them.
410. —The formation of spores appears to have some re-
lation to the development of the host plant, as they form
only in certain parts of the latter, and are not produced
until the growth of these parts has taken place. Thus in
the Bunt of wheat (Tilletia caries) the spores are formed
only in the young ovaries; in the anther smut of the Si-
lenew (Ustilago antherarum) the spores are formed in the
young anthers ; in one of the smuts of the sedges (Ustilago
urceolorum) they form on the upper surface of the ovary, and
in the smut of wheat, oats, etc., in the young flowers. In
cases like these it is evident that the time of spore-forma-
tion is dependent upon the development of the flowers of
their host; and if these are earlier or later in their appear-
ance, the spore-formation will vary accordingly. In the
smut of Indian corn (Ustilago Maydis), on the other hand,
the spore-formation may take place in other parts of the
plant, as well as in the ovary ; thus it not infrequently makes
its appearance upon the stems, and even upon the leaves. In
Ustilago hypogma the spores are produced underground
upon the root of the host plant (Linaria spuria), and in
Ustilago marina, in the tissues of Scirpus parvulus, under
water ; with these two exceptions, the spore-formation always
takes place in parts above ground.USTILA QINEJE.
319
411. —Immediately preceding the formation of spores
the hyphEe give rise to many branches, which differ much in
appearance from the ordinary ones. This takes place in
those parts of the host plant where the spores are afterward
produced. These spore-forming hyphse are thicker than the
vegetative ones, and are more gelatinous; they are more or
less granular, and they sometimes contain oil globules.
412. —The spores are formed in Tilletia caries by little
lateral branches budding out upon the spore-forming hvphee,
and acquiring a pear-shaped outline ; they become thicker
and more spherical, and each eventually secretes a dark, thick
wall (Fig. 224, Jc' and k). When mature, the spores become
free by the drying up of the attaching pedicel. In Ustilago
the spore-forming hyphse break up their contents into
spores, and in some cases—as, for example, in Ustilago
Mayclis—the process much resembles the formation of asco-
spores in asci (Fig. 221). It frequently happens that the
spore-forming hyphse fuse together on account of the gelat-
inous nature of their envelopes ; when this takes place, the
spores are formed in very irregular masses (Fig. 222, b).
In Sorisporium Saponarice this fusing takes place to so
great an extent that the real nature of the process is greatly
obscured. The spore-forming hyplue, which are very abun-
dant, become curved at their extremities, and many of these
twist themselves into a little ball, and are fused into a single
gelatinous body, which eventually becomes a mass of spores.
The real nature of the spore-formation is probably indicated
by the “solitary spores,” which appear singly upon those
spore-forming hyphse which do not compact themselves into
balls; in these, the resemblance to asci containing single
ascospores is striking (Fig. 223).
413. —The spores, when ripe, have a double wall. The
outer—the epispore—is thick, usually brown or black, some-
times smooth, but frequently more or less rough by projec-
tions, or marked by reticulations (Fig. 224, e). The inner
wall—the endospore—is a delicate colorless membrane, which
protrudes through the ruptured epispore in germination.
414—The germination of the spores has been made out320 •
BOTANY.
for a few species only. * In all which have been examined
the spore sends out a pro mycelium, which is generally short
and jointed, and upon this several sporidia are produced,
much as in the Uredinese. In Tilletia caries the promyce-
lium produces a tuft of slender branches (Fig. 224, h), which
Fig. 221.—Spore-formation in Ustilago Maydis. a, the end of a spore-forming hy-
pha containing n row of young spores ; b, another spore-forming hypha, containing
two young spores; c, a spore nearly ripe, still surrounded by the gelatinous mem-
brane of the hypha. X 1800.—After Fischer von Waldheim.
Fig. 222.—Spore-formation in Ustilago antheranyn. a. an isoia.'V gelatinous hy-
pha, with the contents distinctly breaking up—at the lower end a portion not yet
broken up ; b, a number of gelatinous byphse fused into an irregular mass, showing
the formation of many spores ; c* a spore nearly ripe, still surrounded by the gelat-
inous hypha membrane, also a young spore upon a lateral branch, a and c X 1800;
b X 900.—After Fischer von Waldheim.
Fig. 223.—Formation of “ solitary spores” in Sorispotlum Saponarice. a, hvphse
•with two young spores; b, aspoie at a later stage; c, hyphse with spores in differ-
ent stages of development; at c' a thin wall has formed around the contained pro-
toplasm as iu b ; at c" the wall is much thicker, and at &" it is still thicker. X 300.—
After De Bary.
have been seen to unite laterally by a kind of conjugation
(not, however, of a sexual nature, in all probability); from
these branches (called by some writers “ secondary spores”))
* According to Fischer von Waldheim, the germination of the fol-
lowing species is known, viz., Tilletia caries, T. Lolii, Ustilago an-
therarum, U. flosculorum, U. carbo, U. destruens, U. Maydis, U. recep-
taculorum, U. longissima, U. Vaillantii, Urocystis pompholygodes.
Uroc. occulta.
f De Bary calls these brandies sporidia, and what are here called
sporidia, he calls secondary sporidia.nSTILAGINEJE.
321
there grow out small sporidia, which germinate by sending
out a slender hypha; when this hypha comes in contact
with the proper host plant, it penetrates the walls of its
Fig. 224 —TiUetia caries, d, transverse section of an infected wheat-grain ; e, ripe
spore ; f, the fir?t stage of germination ; g, the formation of a branching promyce-
lium, with granular protoplasm in its upper end ; 7t, the formation of slender
brauches which unite by a kind of conjugation ; the ends of these branches give rise
somewhat later to very small sporidia, and when the.-e germinate very slend> r hy-
phse are produced, which penetrate the epidermis as at i ; k\ mycelium from tne
young ovary of the wheat—two small lateral branches are shown, from which spores
will develop ; k, spores more fully developed.—d, after CErsted ; e-h, after Tulasne,
X 460 ; ir-k, after Kuhn, X 300.
cells, and thus gains admittance to its interior, where it pro-
duces a new mycelium* (Fig- 224, t). In Ustilago carlo the
* This is upon the authority of Kuhn : “ Krankheiten der Cultur-
s. surrounded by the spirally twisted envelop- " Ilere CtU WdU 1S aP
ing ceiis; c, crown of five cells at apex; J3, parently absentas a re-
sterile lateral leaflets ; large lateral leaf- | • . - ,
1ft near the fruit; bracteoles spring ng SUlt 01 tUlS 11111011, the
from the basal node of the reproductive or- enveloping Cells become
gans. -S, a young antheridium, a, and a 1 °
young carpogoninm. sk: w. nodal cell of thicker Walled., hard, and
Ifaf ; it, iniermediaie cell between w and the , , i j <*
basal node cell cf the antheridinm ; l. cavity dark - COlOl’ed, IOrmillg a
of the internode of the If af ; br, cortical cells i t • , • ,•
of the leaf, a x about 33; b x 240.—After dense and resisting coating
Sachs- to the fully formed carpo-
spore within. The seed-like sporocarp thus formed soon
separates itself from the parent plant and falls to the bot-
tom of the water, where it remains until the advent of favor-
able conditions for germination.
433.—In germination the sporocarp gives rise first to a
simple structure consisting of a single row of cells (the pro-
embryo), and from this the more complex sexual plant is
developed by the growth of a lateral bud-cell. The sexualCHAR A OEJE.
333
plant is composed of a jointed stem, which bears whorls of
leaves at regular intervals. The stem is one-celled in trans-
verse section, as in Nitella, or it has a large axial cell, which
is surrounded by many long narrow ones, which form a
cortical envelope, as in many species of Chara. In some
species the stem and leaves become incrusted with lime, giv-
ing to them a good deal of hardness and brittleness.
(a) Tlie class is readily divisible into two orders — Nitelleae and
Cliareae.*
Order Nitellese.—In this order the stem and leaves are always
naked—i.e., not cor-
ticated ; the leaves
are in whorls of
five to eight, and
hear large leaflets,
which are often
many - celled. The
sporocarps arise sin-
gly or in clusters in
the forkings of the
leaves, and each haB
a crown consisting
■of two superimposed
whorls of five cells
each.
These delicate
plants occur in
ponds and streams,
and are rarely more
than a few centi-
metres in height.
Two genera—Nitella
and Tolypella — are
distinguished by the
position of the antlie-
Fig. 229.—Charafragilis. a, an isolated shield, rn, seen
from within, with manunrinm bearing the filaments, b, in
which the spermatozoids are developed ; c, a small portion
of one of the filaments, the spermatozoids not shown ; d,
two free spermatozoids. a and b X 50; c and d X 300.—
After Thuret.
ridium, which is terminal upon the single node of the primary leaf in
the former, while in the latter it is lateral, and the primary leaf has
two or three nodes.
The species of Nitella (ten to fifteen of which are American) are ar-
* What follows is mainly from a synopsis of the Characete, furnished
for this work by Dr. T. F. Allen, the author of “ Cliaraceae Americanae,”
now issuing in numbers. Use lias also been made of Dr. B. D. Hal-
sted’s paper on the “ Cassification and Description of the American
species of Characem,” published in Proe. Boston Soc. Nat. Hist , 1879,334
BOTANY.
ranged under three tribes ; our more common species only are given
below.
Tribe A.—M J a y Sphagnum, squarronvm. sq, ripe sporo-
in a few cases by Splitting ver- goninm; d, operculum; c, torn calyp-
. . ,, t . 7 , . tra; gs, the elongated pseudopodium;
tlCally yA.UCtTCBCtC6(B) J 111 tlie ch, perichsetial leaves. All magnified.—
small order Phascacece the cap- Aftel Sctumper-
sule is indehiscent, and the spores are set free only by its
decay or irregular rupture. The ripe spores are roundish
or more or less angled, and have a roughened or granulated
Fig. 244.—Development of the sporo-
gonium of Sphagnum ncutifoliuni. A,
longitudinal section of a fimalu flower ;
ar, archegonia ; ch. young perichaitial
leaves; y, upper leaves of the shoot
forming the perianth : B, longitudinal
section of a young sporogoninm, sg;356
BOTANY.
esospore, which is generally yellow in color. Internally
the spores contain, in addition to the protoplasm, oil-drops
and chlorophyll granules.
465.—In the germination of the spores, the exospore is
ruptured, and the endospore protrudes as a tubular filament,
which elongates by the continued growth of an apical cell;
partitions form at close intervals, and the threads branch
freely, giving rise to a green Conferva-like mass, the pro-
tonema (Fig. 245, B). In the Sphagnacece, however, the
protonema is a flattened mass, somewhat like the plant-body
of the lower Liverworts. After a greater or less period of
vegetation, there arise upon the protonema small buds, which
develop into leaf-bearing axes (Fig. 245, B, K). These buds
originate from single cells, which repeatedly divide them-
selves by diagonal partitions ; the apical cell thus formed
in each case becomes the apical cell of the bud, and the
new axis. The leafy axes thus formed sooner or later bear
the sexual organs, thus completing the round of life.
466.—Mosses reproduce themselves asexually, sometimes
in a manner quite similar to that of the Liverworts—e.g., inSPIIA &NACEJE.
357
Tetraphis pellucida, where the leafy axis frequently bears
a terminal cup-shapecl receptacle, containing many lenti-
form stalked gemmae; tliese separate spontaneously, and
give rise to a kind of protonema, and upon this buds after-
ward arise, from which leafy axes are developed. Many
Mosses reproduce themselves by the formation of a pro-
tonema from the leaves and the root-hairs, and from buds
formed upon such a protonema new plants may arise. Even
the protonema is capable of an asexual reproduction of itself ;
sometimes its individual cells become rounded, spontane-
ously separate themselves, become thicker walled, and then
remain inactive for a time; they thus remind one of the
conidia of some Thallophytes.
There are four well-marked orders of Mosses, as follows :
Order Sphagnaceae.—The plants of this order are large, soft, and
usually pale colored; they inhabit bogs and swampy places, and are
known as the Peat Mosses. The protonema is a flat tliallus, or com-
posed of branched filaments, accordingly as it has developed upon a
solid substratum or in water ; the leafy axis is usually much elongated,
and as it dies away below it grows at the summit; the leaves are usu-
ally five-ranked, and are composed of two kinds of tissue, viz., (1) one
made up of small chlorophyll-bearing cells, and (2) one made up of
large perforated cells ; the latter are usually filled with water, and to
them is due the well-known power possessed by the Peat Mosses, of
retaining moisture for a great length of time. Root-hairs (rhizoids) are
present only in young plants, their place being taken by the reflexed
branches, which are always abundant.
The inflorescence is monoecious or dioecious; the rounded (almost
spherical) antlieridia occur singly by the sides of the leaves of catkin-
like branches (not axillary, as stated in some books); the archegonia
are developed upon the ends of certain branches (A, Fig. 244). The
ripe sporogonium (capsule or spore-case) is globose, or nearly so ; its seta
is short, but it is borne upon a more or less elongated pseudopodium,
which resembles a seta. The old archegoaium (calyptra) is ruptured
irregularly by the growing sporogonium, and forms only a very imper-
fect cap to the spore-case. In the development of the spores the cells of
a layer parallel to the surface of the upper half of the capsule become
modified as spore mother-cells (B, Fig. 244). At maturity a circular
portion of the apex of the capsule spontaneously separates as a lid
(operculum), and allows the spores to escape (C, Fig. 244, d).
The order contains but a single genus, Sphagnum, represented in
the United States by twenty-seven species. These are of some eco-
nomic account, as they furnish a most excellent material for “pack-
ing” in the transportation of living plants.358
BOTANY.
Tlie genus Sphagnum was represented in the Tertiary (Miocene) of
Europe.
Order Andrseacese.—In this small order the little plants of which
it is composed have a short-stalked sporogonium, raised upon a pseudo-
podium, as in the Sphagnacece; the sporogoniitm contains a layer of
spore-forming tissue, disposed as in the preceding order; but the ripe
capsule opens by splitting into four longitudinal valves, in this remind-
ing one of the Jungermanniacece. In the growth of the sporogouium
the old archegonium is torn away at its base, and carried up as a cap
(calyptra), which covers the apex of
the capsule.
The principal genus is Andrcea,
represented in the United States by
a few alpine or sub-alpine species of
brownish or blackish rock-loving
Mosses.
Order Phascacese.—These small
Mosses are peculiar in having but
a little development of leafy axis, and
in their persistent protonema. The
sporogonium is short-stalked, or ses-
sile, and the pseudopodium is very
short, or entirely wanting. The
spores are, in the simplest genus (Ar-
chidium), developed from a single
mother-cell, while in the higher ones
they develop from a layer of mother-
cells, much as in the next order.
The capsule is indehiscent, and the
spores are set free only by its decay.
The old archegonium persists as a
calyptra covering the capsule.
The principal genera are Archidi-
um, P/urscum, and Bruchia. The
rounding the columella, and crossed by species are terrestrial, and many are
confervoid filaments; t, inferior con- .
nection of the columella with the tissues annuals.
of the capsule. A and B slightly mag- ]n the Tertiary (Miocene) of Eu-
lulled ; C about 40 diameters.—After „ „ v»t '
Sachs. rope a fossil species of rhascum lias
been found.
Order Bryaceae. — Tlie plants of this order constitute the true
Mosses. They are usually bright green (in a few genera brownish),
and in the great majority of instances live upon moist ground and
rocks, or upon the bark of trees; in a comparatively small number
of cases the species live in the water.
In the development of their tissues and the complex structure of
their sporogonia the* Bryaceae clearly stand at the head of tbe Bryo-
phyte Division. The tissues, as indicated above (paragraph 458), attain
Big. 246.—Funaria hygrometnca. A,
a young leafy plant, g, with sporogo-
nium 8t 11 covered with the calyptra, c.
£, leafy plant, g, with nearly ripe spo-
rogonium, /; e, the calypira; s, seta.
O, longitudinal section of a capsule ;
c, c, columella ; d, operculum or lid,
which will separate from the remainder
of the capsule at a; p, peristome ; «,
spore-bearing layer ; h, air cavity sur-BBYACmlb.
359
in some cases a development which foreshadows the differentiation of
the stem into the epidermal, fibro-vascular, and fundamental systems of
the higher plants. In Polytrichum, for example, there can be no doubt
that the axial and extra-axial bundles of elongated cells with thickened
walls found in the stem represent the fibro-vascular bundles of the
Pteridopliytes and Phanerogams ; the bundles
of elongated tliin-walled cells which pass
downward through the stem from the base of
the leaf, in Splaclinum, must also be regarded
as representing rudimentary foliar bundles.
While these higher Mosses cannot properly
be classed with vascular plants, their tissues
in some cases reach so high a development as
to show that there is no abrupt change in pass-
ing from the so-called non-vascular plants to
the vascular ones.
The inflorescence of Bryaceae is hermaphro-
dite, monoecious, or dioecious. The sexual or-
gans are situated on the apex of the main
stem (Acrocarpie), or of short lateral branches
(Pleuroearpee). The sporogonium, in its de-
velopment, carries up the old-archegonium as
a calyptra, which quickly falls away in some genera (e.g., Bryum,
Bartramia, etc.), while in others (e.g., Polytrichum, Pogonatum, etc.) it
persists as a closely fitting covering of the capsule ; between these
two extremes there are all gradations.
The sporogonium is usually long stalked (Fig.
246, B). The capsule is generally more or less
ovoid or cylindrical. It is at first composed of pa-
renchymatous tissue, which entirely fills up its
interior; as it enlarges, however, an annular in-
tercellular air cavity forms, separating a cylin-
drical axial portion front the outer portion, which
forms the wall of the capsule. The axial cylin-
der remains in connection with the remainder
„,0,. , of the capsule at its top and bottom (t, Fig. 246,
part of the capsule of C), and it is, moreover, slightly connected with
f^sfowiTg^tTe the capsule walls by chlorophyll-bearing confer,
double peristome. The void filaments, which pass across the air cavity.
TZX inner o? The rather dense tissues below and surrounding
cilia. Magnified. the air cavity in the immature capsule are com-
posed of chlorophyll-bearing cells, and the epidermis covering these
portions is supplied with stomata. The spores are developed from a
layer of cells (the third or fourth from the outside) in the axial cylinder
(«, Fig. 246, C); and each cell of the spore-bearing layer produces four
spores. The portion of the axial cylinder within the Bpore-bearing
Fig. 247.—Two capsules
of Bryum argeuteum. The
one on the left is still per-
fect ; at its apex is shown
the lid or operculum; the
one on the right has dropped
its operculum, exposing the
peristome of long fringe-
like teeth. Magnified.360
BOTANY.
layer is called tlie columella (c, c', Fig. 346, C), while the two or three
layers of cells exterior to it constitute the spore-sac.
In all the members of this order, the capsule, when ripe, opens by the
falling away of a lid (operculum), which is composed for the most part
of the epidermis covering the apical portion (Fig. 347). In most of the
genera, when the operculum falls off, one or two rows of teeth (the
peristome) are exposed, surrounding the opening of the capsule (Fig.
348). These teeth, which are always some multiple of four (4, 8, 16,
33, or 64), are in most cases formed respectively of the thickened outer
and inner walls of rows of cells which lie beneath and parallel to the
wall of the operculum, and converge toward its centre. Each tooth
is thus made up of parts of several cells, and the transverse lines seen
upon it are the thickened transverse walls which formerly separated
the original cell cavities.
The peristome of Polytrichum and its allies is composed of bundles
of thickened cells, hence they are much firmer than in those genera in
which they are made of fragments of cell membranes.
The Bryacese include many genera, which are widely distributed
throughout the world. The genera arrange themselves under two
groups (sub-orders), according as the sporogonia are terminal or
lateral, with reference to the main axis ; the first constitute the Acro-
carpa, including Funaria, Bryum, Mnium, Polytrichum, etc. ; those
with lateral sporogonia constitute the Pleurocarpce, and include Fonti-
nalis, Climacium., Hypnum, etc.
In the Tertiary of Europe the order is represented by an Eocene spe-
cies of Muscites, and Miocene species of the modern genera Fontinalis,
Dicranum, Barbula, Polytrichum, Hypnum, etc. A single species of
Hypnum from the Tertiary of Colorado is the only American fossil of
this order yet detected.
The most valuable systematic works for the student of the Bryo-
phytes of this country are “ Musci and Hepaticee of the Eastern United
States,” by W. S. Sullivant, 1871; ‘‘ leones Muscorum,” by the same
author, 1864-74 ; and “Catalogue of Pacific Coast Mosses,” by L. Les-
quereux, 1868; “ Manual of the Mosses of North America,” by Leo
Lesquereux and Thomas P. James, 1884; “Descriptive Catalogue of
the North American Hepaticse North of Mexico,” by L. M. Under-
wood, 1884.CHAPTER XIX.
PTERIDOPHYTA.
467. —The plants of this Division constitute the so-called
Vascular Cryptogams. They present an alternation of sexual
and asexual generations, much as in the Byrophytes, but in
the higher orders it shows signs of disappearing. The first
generation proceeds directly from the germination of the
spore ; it is made up of simple tissues, and is usually short-
lived ; it bears the sexual organs, and hence is called the
sexual generation. The second generation, which results
from the fertilization of a germ-cell developed upon the
preceding one, is long-lived, and made up in most cases
of tissues of a high order, and the plant-body is differen-
tiated into root, stem, and leaves ; upon this second genera-
tion sjDores arise asexually year after year, and from these
spores the sexual generation is again produced.
468. —The sexual generation, called the Prothallium, is
generally a flattened thallus-like growth, somewhat resem-
bling the plant-body of the lower Bryophytes. It is always
small, and composed throughout of parenchyma disposed in
one, or at most a few layers ; on its under surface it generally
produces root-hairs (rhizoids), which serve to fix it to the
ground, and doubtless also serve as organs of nutrition.
The cells of the prothallium are in most cases richly sup-
plied with chlorophyll, by means of which they elaborate
material for its growth.
469. —When the prothallia have become sufficiently large,
they develop the sexual organs, the antheridia and arche-
gonia. These are formed in essentially the same manner as
they are in the two lower orders of Hepaticse (Ricciacece and
A nthocerotem). They are more or less imbedded in the sur-362
BOTANY.
face of the prothallium, and consist of masses of cells, enclos-
ing in each case a single cell, which develops into one germ-
cell (in the archegonia), or a number of sperm-cells (in the
antheridia). The sperm-cells produce spirally coiled sperma-
tozoids, which fertilize the germ-cell by passing down the
canal in the neck of each archegonium. In many of the
plants of this division there is a strong tendency toward
dioeciousness in the prothallia, and in the higher genera it
becomes the invariable rule.
470. —The result of fertilization is the formation of a
young plant, by the growth and successive division of the
fertilized cell. In its first stages the new plant is usually
quite simple, but it soon becomes, in the greater part of the
Division, a leafy plant with highly developed tissues. After
a greater or less period of vegetation the new plant produces
spores by the internal cell-division of certain mother-cells,
each of the latter producing four spores. The particular
structure of the spore-bearing organs and the place of their
appearance are quite different in the different classes. In
many cases they are produced upon the surface of the
ordinary green leaves, in other cases upon modified leaves,
while in still others upon the bases of the leaves, in their
axils. The spores are in most cases of one kind, but in
certain genera there are large spores (macrospores), and small
ones (microspores).
471. —True roots first make their appearance in this
division. A root is developed upon the young plant, but
this never attains a great size, and others form in acropetal
order upon the stem, and even occasionally upon the leaves.
472. —In the Pteridopbytes the three tissue systems—epi-
dermal, fibro-vascular, and fundamental—attain a good de-
gree of development. The epidermis is distinct, and con-
tains stomata similar in form and position to those of the
Phanerogams. In many cases there is a strong development
of trichomes, as in the Ferns, where the young leaves are
usually densely covered with scurfy hairs. The fibro-vascu-
lar bundles are always closed, and generally are what De
Bary calls concentric bundles; in the Equisetinse, however,
collateral bundles occur, and in Lycopodinse radial bundles.EQ UISETINJE.
363
The bundles vary considerably as to the tissues they contain,
but they generally possess tracheary and sieve tissues ; the
former is usually well-developed as spiral, scalariform, or
pitted. Sieve tissue is, as a rule, not so well developed as
the former, consisting for the most part of thin-walled,
elongated cells, in which the characteristic sieves are less
regularly formed. Fibrous tissue occurs only to a limited
extent as a constituent of the fibro-vascular bundles. Paren-
chyma is also found in them, but, like the former, it is
usually not abundant. The fundamental system of tissues
includes various forms of parenchyma and sclerenchyma ;
the latter, however, is frequently wanting. Collenchyma and
laticiferous tissue are not found in the greater part of the
Division ; but the former occurs in Marattiacese, in which or-
der, according to Sachs’ observations, there are also indica-
tions of a rudimentary laticiferous tissue.
§ I. Class Equisetjlyze.
473. —In the plants of this class the plant-body (of the
asexual generation) consists of a hollow elongated and jointed
axis, bearing upon each node a whorl of narrow united leaves,
which form a close sheath (,$, Fig. 249) ; the stem is always
grooved or striate, and is usually rough and hard from the
large amount of silica deposited in the epidermis. The
branches arise by the side of the axils of the leaves consti-
tuting the sheaths, and consequently they are in whorls.
Both the main axis and the branches are in most cases richly
supplied with chlorophyll-bearing parenchyma; in some of
the species (e.g., Equisetum Telmateia and E. arvense) the
stems which bear the spores are destitute of chlorophyll.
All the species develop numerous colorless branching under-
ground stems, which bear roots and rudimentary sheaths,
and which each year send up the vegetating and spore-
bearing stems. Both root and stem grow from an apical cell.
474. —In common with most members of tlrs division,
the Equisetinae are perennial plants. In some species the
underground portions only persist, the aerial stems dying at
the end of each year, as is the case in E. Telmateia, E. arvense,364
BOTANY.
E. sylvaticum, E. limosum, and some other species. In
other species, as E. hyemale, E. Icevigatum, the aerial stems
also persist; the latter are hence known as perennial-
stemmed.
475.—The prothallia are irregularly branched thallus-like
growths, composed of chlorophyll-bearing parenchymatous
cells arranged in one or more layers. Upon the under side
they bear root-hairs, which fix them to the ground. They
are usually small in size, ranging from two or three to ten or
twelve mm. in length. In most species the prothallia are
dioecious, bearing but one kind of
sexual organ upon each, and in such
cases it always happens that those
which bear the antheridia are much
smaller than those which bear arche-
gonia. Both kinds live but for a
short time, the whole period of their
existence usually not extending be-
yond a few months ; the male pro-
thallia appear to endure for a some-
what shorter period than those which
bear archegonia.
476.—The antheridia occur upon
m&eMiSlho ends or margins of the prothal-
SfinternAodtffaihr08pa^e?aCa- lia 5 tliey arise from the repeated
S“u,iiLnatavTs?x2USheirheseph division of a marginal cell, thus
arate apices (teeth); a, a\ a", forming an inner mass of cells rich
basal internodes of lateral . 0
branches.—After Sachs. in protoplasm, and a coYering layer
(an1, Fig. 250, A). By the continued division of the inner
cells 100 to 150 cubical cells are formed, each of which con-
tains a single sperm-cell; somewhat later the walls of the
cubical cells dissolve, and the sperm-cells become free in the
antheridial cavity, from which they are soon allowed to es-
cape by the separation of the apical cells of the enveloping
layer (an, Fig. 250, A). At this time each sperm-cell con-
tains a spermatozoid, which soon escapes by the rupture of
the cell-wall. Each spermatozoid is a thick, spirally coiled
filament of protoplasm, tapering anteriorly, where it is pro-
vided with numerous cilia, which give it motility.EQ UISETINJE.
365
477.—The archegonia arise upon the anterior edge of the
prothallium, from the division of single cells. The mother-
cell of the archegonium undergoes several divisions, result,
ing in the formation of a germ-cell, surrounded by one or
more layers of cells. The germ-cell lies at a considerable
depth beneath the general surface of the prothallium, above
Fig. 250.—A, fragment of a prothallium of Equisetum limosum (in the middle of
July) ; a, an apical cell of a growing point; an, a ripe antheridium, with escaping
sperm-cells ; an', a young antheridium. B, longitudinal section of an archegonium
of Equisetum arvense immediately after the opening of its apex, showing the germ-
cell in the cavity below, surrounded by the parenchyma of thejprothallium. C, longi-
tudinal section of the germ-cell, or rudimentary embryo, of E. arvense, shortly after
fertilization ; it is seen to be already divided into four parts, and the whole is sur-
rounded by the parenchyma of the prothallium. A X 200 ,* B and C X 300.—After
Hofmeister.
which the surrounding tissue of the archegonium is pro-
longed into a four-sided tube. At the period of maturity of
the archegonium, the projecting cells diverge from each
other, and form an open channel to the germ-cell {B, Fig.
250).
478.—After fertilization the germ-cell undergoes division366
BOTANY.
into four cells (C, Fig. 250), and from these the young plant
of the asexual generation is developed. The young plant is
quite simple, having small internodes, bearing sheaths which
contain but three leaves ; lar-
ger shoots soon arise, with lar-
ger internodes and sheaths hav-
ing more leaves, and these are
followed by others still larger,
until at last the full size is
readied.
479. — The spores of the
Equisetinai are produced either
upon the ordinary green stems,
as in Equisetum limosum and
E. hyemale, or upon colorless
or brownish stems, which de-
velop early, and, after bearing
the spores, die and disappear,
as in E. Tehnateia and E.
arvense. The sporangia are
developed upon modified
leaves, upon the ends of the
stems. The spore - bearing
leaves, like the ordinary ones,
are in whorls; each leaf is,
however, peltate in form, and
borne upon a short stalk (st,
Fig. 251, E). These peltate
leaves (usually called the pel-
tate scales) are collected into
cone-shaped clusters, and by
their mutual pressure each
becomes more or less
hexagonal in outline. Upon
the under surface of each scale
there arise five to nine or ten
cellular masses, which enlarge and become sac-shaped spo-
rangia ; certain inner cells become spore mother-cells, and
from each of these four spherical spores are produced. The
of the spike (nat. size); b, sheath of
united leaves ; a, annulus or ring form-
ed of imperfectly developed leaves ; x,
the pedicels of peltate scales which have
been cut off ; y, section of the rachis of scale
the 6pike. B, peltate scales, s, s, in
various positions (slightly magnified);
s<7,the sporangia borne on the under side
of the scales ; st, st, the pedicels of the
scales.—After Sachs.JSQ UISETINJE.
36?
sporangia, when mature, appear as nearly cylindrical sacs
attached by one end to the under surfaces of the peltate
scales (sg, Fig. 251, B); they open at maturity by a slit along
the inner face—i.e., the side next to the pedicel of the pel-
tate scale.
480. —In their development the spores acquire three con-
centric coats, and as they approach maturity the outer one,
which has previously become spirally thickened, splits from
two opposite points into four narrow spiral filaments, which
are united with one another and the spore at a common
point. These filaments are hygroscopic, and they roll and
unroll with the slightest changes in the moisture of the air;
when moistened they wrap tightly around the spore, but
when dry they unroll and become more or less reflexed. By
the changes of position which they undergo, they move the
spores very considerably, and are doubtless useful in empty-
ing the sporangia after dehiscence—hence they have been
called Elaters.
481. —The spores germinate soon after falling upon water
or moist earth ; they first enlarge, and then divide by a par-
tition into two parts of unequal size, the larger of which
contains chlorophyll granules, while the smaller one is color-
less ; the latter grows rapidly into an elongated root-hair.
The larger cell divides first into two cells, and then usually
one of these divides again, and so on, giving rise to a simple
prothallium, composed of a single layer of cells; this en-
larges and increases in size, until it reaches the stage in
which it bears the sexual organs (paragraph 475).
482. Tissues.—The epidermis is remarkable for the large
quantity of silica which it contains, mainly in the outer
walls of the cells. The epidermal cells are mostly narrow
and elongated, and are arranged in vertical rows. The sto-
mata, which are present in all the chlorophyll-bearing parts
of the plant, are arranged with more or, less regularity in
longitudinal rows ; on the stem they occur in the channels
between the numerous ridges. They resemble pretty closely
the stomata of the Phanerogams in their structure. The
fibro-vascular bundles of the stem are disposed in a circle, as
•seen in a cross-section, and they run through the funda-368
BOTANY.
mental tissues from node to node, parallel with, but inde-
pendent of, one another. At the nodes they split into two
branches, which unite right and left with corresponding
branches of other bundles, and thus form the bundles of the
next internode. The bundles of successive internodes thus
alternate with one another. Each leaf of the leaf-sheaths
sends down a bundle, which joins a bundle in the stem at
the point where two descending branches of contiguous bun-
dles from the upper internode unite to form a bundle in the
lower internode. The bundles are thus seen to be of the
“common” type—i.e., they are common to both stem and
leaves. As to their construction, they are collateral, and
contain tracheary, sieve and fibrous tissues (paragraph 139,
and Fig. 99). The remainder of the stem (the fundamental
portion) is made up for the most part of parenchyma; in the
cortical portion of the vegetating shoots it contains an
abundance of chlorophyll, and it is here frequently pene-
trated by large longitudinal canals (I, Fig. 249) ; in the
medullary portion a great central canal soon appears by the
rapid growth causing a rupture of the tissues (h, Fig. 249).
There are frequently found in the hypodermal portions of
the fundamental systems bands of thick-walled tissue, which
are either sclerenchyinatous or fibrous.
(a) This class contains but one living order, the Equisetace.e, hav-
ing the characters of the class as given above. In ancient geological
times the Calamites and their allies constituted a distinct order, the
Calamaricce, now extinct ; they differed from the Equisetaceee in hav-
ing fibro-vascular bundles which increased exogenously. The Cala-
mariece were represented in the Devonian by a species of Aslerophyl-
liles. In the Carboniferous period there were many species of the gen-
era Calamites, Calamocladus, Ca'amostachys, Splienophyllum, etc. In
the Permian the order became extinct.
(J) The order Equisetacece includes but a single genus, Equisetum,
which contains about twenty-five species. None of the species attain
a great size, the usual height being from 20 to 100 cm. (8 to 40 inches) ;
one species (E. giganteum) in tropical South America attains a height
of 9 to 10 metres (30 feet or more), but it is very slender, being no more
than 20 to 25 mm. (1 inch or less) in diameter. The siiicious stems of
E. hyemale, a common species, are sometimes used for scouring knives
and other articles.
(c) The germination of the spores of Equiset.inte may be studied by'FILICIJS'AE.
369
placing fresli spores in water, or upon moist earth or moist pieces of
porous pottery. It must, however, he borne in mind that within a few
days after reaching maturity the spores lose their power of germinating.
(id) The oldest genus of this order is Equisetites, represented in the
Carboniferous by several species. Equisetum extends from the lower
Secondary (Triassic) to the present.
§ II. Class Filiciisl®;.
483. —The plant-body of the asexual generation in this
class consists of a solid stem, bearing roots and broadly ex-
panded leaves, the latter usually on long petioles. The
stems are mostly horizontal and underground, but in some
cases they rise to a considerable height vertically in the
air. The leaves arise singly upon the stems, and grow up-
ward from the rhizome (horizontal stem), or are borne as a
crown upon the more or less elongated upright stem. The
leaves are in nearly all cases supplied with fibro-vascular
bundles, which run as veins through the parenchyma ; there
is usually a prominent midrib, upon each side of which the
parenchyma is permeated with small veins, which are free
(running more or less parallel from the midrib to the margin),
or reticulated.
484. —The Filicinae are for the most part terrestrial plants
of considerable size, a few only being small or of an aquatic
habit. They are all richly supplied with chlorophyll, and
none are in any degree parasitic. Nearly all the species are
perennial, in some cases, however, dying down to the
ground at the end of the summer, the underground portions
alone surviving the winter.
485. —The prothallium in the Filicinas is a small cell-
ular body,* composed in most cases of chlorophyll-bear-
ing parenchyma. It is frequently somewhat heart-shaped,
* Dr. Farlow, in a paper on “An Asexual Growth from the Pro-
thallus of Pteris cretica,” in Proc. Am. Acad. Arts and Sciences, 1874,
and Qr. Jour. Mic. Science, 1874, described certain prothallia in which
scalariform vessels were found by him. These abnormal prothallia
produced new plants directly, without the intervention of the usual
process of fertilization ; the scalariform vessels of the prothallia were
in every case continuous with those in the new plants.370
BOTANY.
and is generally provided with root-hairs on its under sur-
face, by means of which it secures nourishment for its inde-
pendent growth (Fig. 252). In the Rhizocarpece the pro-
thallium is so reduced as to be only a small outgrowth of the
germinating spore.
486.—Both kinds of sexual organs usually occur upon the
same prothallium. The antheridia consist of a few or many
sperm-cells, which may or may not be surrounded by a wall
Fig. 252. Fig. 253.
Fig. 252.—A prothallium of a fern, seen from the under side, h, the root-hairs grow-
ing from the basal end of the prothallium ; an, the antheridia scattered among the
root-hairs ; ar, archegonia near the apex, x 10.—After Prantl.
Fig. 253.— Mature antheridium of Adiantum Capillus- Veneris, p, cells of prothal-
lium ; a, wall of antheridium—the sperm-cells are seen escaping, in each a sperma-
tozoid is coiled up ; s, the spermatozoids ; b, the protoplasm of the sperm-cells still
attached to the spermatozoids. x 550.—After Sachs.
of other cells. In the Ferns (Filices) they are few-celled
bodies, which project from the basal portion of the under
surface of the prothallium ; one of the interior cells becomes
divided into sperm-cells, in each of which is a spirally coiled
spermatozoid (Fig. 253). In the other orders the antheridia
are not confined to the under surface of the prothallium, and
in some of the Rhizocarpece nearly the whole of the contents
of a microspore is developed into one antheridium filled
with sperm-cells.FILMING.
371
Fig. 254.—Young archegonium
of Pteris serrulata, showing a few
cells of the prothallium, contain-
ing chlorophyll, and the axial row
of cells and the germ-cell, filled
with dense and granulated pro-
toplasm. Highly magnified.—
After Sachs.
487. —The avcliegonia of the Ferns are cellular projec-
tions from the anterior portion of the under surface of the
prothallium. The germ-cell is sit-
uated at the base of an axial row
of cells ; the latter dissolve, and thus
form a canal, which becomes open
by the separation of the apical cells
of the archegonium wall (Fig. 254).
The archegonia of the other Fili-
cinae do not differ much as to struc-
ture, but like the antheridia, they
are not confined to the under sur-
face of the prothallium.
488. — After fertilization the
germ-cell divides (in the known
cases) into four parts, as in Equi-
setince, and by the growth and development of these the
young plant of the asexual generation is produced. The
young plant is at first very simple, the
first leaves being much smaller and less
divided than those which appear later
(Figs. 255 and 256).
489.—The spores are developed upon
the leaves. They are contained in spo-
rangia, which occur singly or in clusters
upon the surface, or on the margins of
the more or less modified leaves ; in one
order, the Ophioglossacece, the single spo-
rangia occur in the tissues of the greatly
modified leaves. The spores are all of one
Fig. 255._prothai- kind> excepting in the Rhizocarpem, in
lium and young plant of which there are two sizes, viz., micro-
i Capillus- Ven-
' * spores and macrospores. I he sporangia
of the true Ferns (Filices) have a ring of
cells belonging to their walls, peculiarly
thickened, forming an elastic ring, which
ruptures the mature sporangium ; in the
other orders there is no such elastic ring, and the dehiscence
is usually by the simple splitting of the dried wall.
A diant urn Capillus- Ven-
ei'is, seen from below.
p, the prothallinm j h,
root-hairs of prothallium;
b, first leaf of young
plant; w', the first root
of the young plant; w",
the second root. X 3.—
After Sachs.372
BOTANY.
490.—The Filicinse may be here arranged under four
Pig. 256.—Prothallium and young plant of Adi-
antum Capillus- Veneris, seen in vertical longitudinal
section. p,p, the prothallium ; a, archegonia : h, root-
hair ; E, the young plant; w, its first root; 6, its first
leaf, x about 10.—After Sachs.
orders, as follows :*
I. Isosporece.—
Spores of one
kind.
Order 1. Filices,
the true Ferns.
Sporangia compos-
ed of modified tri-
chomes, each de-
veloped from a sin-
in clusters on the surface of or-
gle epidermal cell, produced
dinary or slightly modified
leaves. Each sporangium
with an elastic ring. No stip-
ules.
Order 2. Marattiacese, the
Ringless Ferns. Sporangia
produced from a group of epi-
dermal cells; the ring either
rudimentary or wanting. The
large, much - branched leaves
with stipules.
Order 3. OpkioglossacoEe,
the Adder-Tongues. Sporan-
gia formed by groups of cells
in the interior of a modified
branch of the sheathing leaf.
The ring is absent.
II. Heterosporem. — Spores
of two kinds.
Order 4. Rhizocarpeae, the
Pepperworts. Sporangia com-
posed of modified trich-
omes (?); the microsporangia
containing many microspores,
Fig. 257.—A, a transverse section of
the stem (rhizome) of Pteris aguilina,
slightly enlarged, r, brown sclerenchy-
ma, forming a hard theath beneath the
epidermis ; p, colorless parenchyma of
the fundamental system : ig, inner fibro-
vascular bundles; ag, the broad upper
band of the outer bundle zone ; pr, a
band of elongated thick-walled cells,
sclerenchyma or fibrous tissue—a second
one occurs on the other side of the cen-
tral bundles. B, the separated upper
fibro-vascular bundle of the stem (rhi-
zome), 8t, and its branches, st\ st"; b,
bundles of the leaf stalk ; it, it, u, out-
line of the stem.—After Sachs.
* This arrangement is essentially that modification of Sachs’ pro-
posed by Professor McNab. See his “ Outlines of the Classification of
Plants,” American edition, Chapter VII.F1LICES.
373
the macrosporangia usually containing only one macrospore.
Sporangia in clusters, enclosed in modified leaves or
“fruits.”
Order Filices, the true Ferns. The protliallia of the Ferns are
green thallus-like structures, growing upon the surface of the ground,
Fig. 257a.—Longitudinal section of the apex of the root of Pteris haslata. v,
apical cell; o, o, epidermis ; e, cortical tissue ; c-c, c-c, the primary fibro-vaeeular
bundles ; n, m, l, k, the root-cap ; k, k, daughter-cells recently cut off from the apical
cell.—After Nageli and Leitgeb.
1 and composed at first of but a single row of cells, but later of extended
layers of cells. They are moncecious, and bear their antheridia on the
basal portion of the under surface, while the archegonia are found near
the apical margin of the same surface. After fer-
tilization the germ-cell divides into four parts, the
uppermost one (or two) of which becomes the foot,
or organ which remains in contact with the prothal-
lium ; one of the other parts develops into the first
root, and the other into the first leaf. The young
plant is thus formed on the under side of the pro-
thallium, from which it grows up as shown in Figs.
256 and 255.
The stems of Ferns are mostly short, or slender
and creeping in our species, but in the tropics they
are often of considerable height and thickness,
some tree-ferns attaining the height of 24 metres
or more (80 feet or more). They increase in length
only, and this takes place by the continued division of an apical cell
They contain fiat fibro-vascular bundles (Fig. 257, A and B), which are
usually disposed in a single circle, as seen in a cross-section, but in
some cases there are bundles in the medullary portion also. On ac-
count of the presence of thick masses of thick-walled cells, (scleren-
Fig. 257S.— Portion
of under surface of a
leaf of Polypodium,
showing sori.—From
Le jMaout and De-
caisne.374
BO TANT.
chyma, or fibrous tissue), the stems are frequently very hard. The
fundamental tissues frequently develop a good deal of mucilaginous or
slimy matter.
Both stems and roots develop from a three-sided apical cell. The
apical cell of the root continually undergoes fission not only parallel to
its sides, but also parallel to its base—i.e., at right angles to the axis of
the root. The daughter-cells thus cut off (k, k, Fig. 257a) constitute the
root-cap (pileorhiza) with which each root-tip is covered.
The leaves, which unfold circinately, are often very large, and in
most cases are more or less lobed and divided, frequently becoming
several times compound. Their development is slow, the rudiment of
the petiole forming one year, and that of the blade the next, while the
opening or unfolding does not take place till the following year. The
growth is sometimes periodic, as in Oleichenia and Lygodium. In the
Mg. 358.—Under side of a fertile leaflet of Aspidium FUix-mas, with eight sori.
i, the indusium. Magnified.—After SachB.
Fig. 259.—A leaflet of Asplenium, showing the elongated sori, each covered by a
laterally placed indusium.—From Le Maout and Decaiene.
Fig. 360.—A leaflet of Adiantum, showing the sori covered by indusia formed by
reflexions of the margin of the leaflet.—From Le Maout and Decaisne.
latter the leaf eventually becomes greatly elongated, resembling a
climbing stem.
The sporangia are usually formed in clusters (sori) on the veins, on
the under side of the leaves, or upon their margins. The sori may
be distinct and rounded or more or less elongated, or they may be
■confluent over considerable portions of the surface. In some cases
the sori are naked (as in Fig. 2576), but quite frequently each one
is covered by a cellular outgrowth of the leaf, called the indusium
(Figs. 258, 259, 260). In some cases the indusium is shield-shaped, its
short pedicel arising in the midst of the Bporangia (Figs. 258 and 261);
in others it is more or less elongated, and attached by one of its edges
to the side of the sorus (Fig. 259); in still others a portion of the mar-
gin of the leaf is reflexed in such a way as to form the covering (Fig. 260).
Many other forms are common, and are to be found described in system-
atic treatises. The sporangia are more or less rounded bodies, usuallyFILICES.
375
home upon slender pedicels. Morphologically they are trichomes,
which undergo a special modification. Each sporangium is at first a
two-celled trichome ; the lower cell of which develops into the pedicel,
while the other becomes divided by partitions parallel to its surface
into outer cells, which develop into the sporangial wall, and an inner
Fig. Wl.—Aspidiwn Filix-mas. A, a section of a leaf through a sorus ; s, a, the
sporangia, borne upon an elevated mass of tissue, the receptacle ; i, i, the indusinm,
seen in section. B, a section of a young sporangium, showing its central cell divided
into four ; r, one cell of the ring, the Bection being at right angles to its plane. C, a
sporangium nearly mature, seen laterally ; r, the ring of the sporangium; d, a
glandular hair—in the interior of the sporangium are seen the nearly ripe spores.
Magnified.—After Sachs.
tetrahedral cell (the so-called central cell), rich in protoplasm ; from the
latter a number of spore mother-cells (twelve, according; to Reess) are
formed, and from each spore mother-cell four spores arise (Figs. 261
and 262). In each sporangium some of the cells of the wall are devel-
oped into an elastic ring (annulus), whicli extends part way around theBOTANY.
37b
spore cavity (Fig. 261, 0, r). By the contraction of this ring the ripe
sporangium is ruptured and the spores set free. In some cases, instead
of forming a ring, the elastic cells are arranged as a group at one side
or end of the sporangium.
Six families or suborders of the Ferns may be distinguished, if we
take into consideration the characters derived from the asexual genera-
tion. They have been arranged as follows : *
1. Qleiclieniucece.—Sporangia sessile, splitting vertically, furnished
with a complete horizontal ring. Sori composed of very few sporangia ;
receptacle not elevated (Fig. 263). Fronds with very distinct dichot-
omous branching. Genera two (Platyzoma and Qleichenia); species
thirty, mostly confined to the southern hemisphere.
2. Hymenophyllaceoe.—
Sporangia sessile, split-
ting vertically, furnish-
ed with a complete
horizontal ring. Sori
composed of numerous
sporangia inserted on a
long filiform receptacle
(Fig. 264). Leaves of
filmy texture (usually of
a single layer of cells),
with pinnate branching.
Genera two (Hymeno-
pliyllum and Trichoma-
nes); species 150 to 200,
mostly confined to the
tropics.
3. Cyatheaceoe. — Spo-
rangia nearly sessile,
splitting transversely,
* The characters and arrangement of the suborders of ferns are
taken from the article “ Ferns,” by W. T. T. Dyer and J. G. Baker, in
the “ Encyclopedia Britannica,” ninth edition, Vol. IX., p. 104. For a
systematic account of the Ferns the student is referred to “ Synopsis
Filicum : a Synopsis of all Known Ferns,” by W. J. Hooker and J. G.
Baker, London, 1873 The student may profitably consult the following
recently published American works, viz ,“ The Ferns of North America,”
by D. C. Eaton, the plates by J. H. Emerton, now being issued in parts ;
"Ferns of Kentucky ” by John Williamson, 1878 ; “ Ferns in Their
Homes and Ours,” by John Robinson, 1878 ; and “ Ferns of the South-
west,” by D. C. Eaton, in Lieut. Wheeler’s “ Report upon U. S. Geo-
graphical Surveys West of the One Hundredth Meridian,” Vol. VI„
1878 ; Underwood’s “ Our Native Ferns, and their Allies,” 1888,
Pig. 262.—Development of the spores of Aspldium
Filix-mas. /..a mother-cell containing a nucleus;
11., the same after the absorption of the nucleus ;
111., the mother-cell, with two large clear nuclei—
sometimes a line of separation is evident, as in the
figure ; IV., the mother-cell, with four clear nuclei,
which appear after the absorption of the two in
III.; V., the four daughter-cells (young spores)
which form from IV.; VI., VII, VIII., different
relative positions of the developing spores ; IX., the
perfect npore. x 550.—After Sachs.FILICES.
377
furnished with a usually incomplete, nearly vertical, or rather oblique
ring. Receptacle prominent, barrel-shaped (Fig. 265). Tree-ferns.
Genera three (Cyathea, Hemittlia,, and Alsophila); species 150, mostly
tropical and subtropical.
4. Polypodiacm.— Sporangia Btalked, splitting transversely, fur-
nished with a usually incomplete vertical ring. Receptacle not prom-
Fig;. 263.—Portion of a leaf of Gleich&nia, with a sorus, a ; &, a sporangium.—Af-
ter Hooker.
Fig. 264.—Portion of a leaf of Trichomanes, a, with five sori; b, a sporangium.—
After Hooker.
Fig. 265.—Vertical section of a sorus, a, of Alsophila, showing the cylindrical re-
ceptacle ; b, a sporangium.—After Hooker.
inent (Figs. 257b to 261). Genera fifty (Acrostichum, Polypodium,
Adiantum, Pteris, Asplenium, Scolopendrium, Aspidium, Cyslopteris,
etc.); species 2000, widely distributed throughout the world.
5. OsmundacecB.—Sporangia stalked, splitting vertically, furnished
with only a faint horizontal bar, instead of a ring (Fig. 266). Genera
two (Osmunda and Todea); species ten to twelve, widely distributed in
north and south temperate re-
gions.
6. Schizceacece. — Sporan-
gia sessile, splitting vertical-
ly, crowned by a complete
small annular horizontal ring
(Fig. 267). Genera five
(Schizcea, Anemia, Lygodium,
etc.); species sixty, mostly
natives of the warm regions
of America and Asia.
Economically the true Ferns are of comparatively little value. The
pulpy interior of the stem of a tree-fern (Cyathea meduttaris) growing
in the Pacific islands furnishes an important article of food to the
natives. In Australia the underground stems of Pteris aquilina
supply an indifferent food. A few species are of doubtful value as
astringent medicines. The long woolly hairs of certain species ol
Fig. 266. Fig. 267.
Fig. 266. — Two sporangia of Osmunda; a,
with the rudimentary ring seen in front view ;
b, with the ring seen in profile.—After Hooker.
Fig. 267.—Lower portion of a fertile i inna. a,
of Schizcea ; b, a sporangium.—After Hooker.378
BOTANY.
Dickson:a growing in the Sandwich Islands constitute the substance
known as Pulu, used somewhat in upholstery. Many ot the species
are now largely grown as ornaments.
Ferns first appeared in the Devonian, in which period no less than
twelve genera belonging to extinct families were represented. In the
Carboniferous the genera aud species were exceedingly numerous, after
which they decreased to the present. Many Tertiary genera extend to
the present, and are now represented by living species.
Order Marattiacese, the Ringless Ferns. The prothallia of the
ringless Ferns are thick, fleshy, and dark green in color. They bear
antheridia in depressions upon both surfaces, and in these are pro-
duced spermatozoids bearing much resemblance to those of true Ferns.
The arcliegonia are also deeply sunken in the tissue of the prothallium,
and, according to Mc-Nab, resemble those of the Rliizocarpeae.
The asexual generation bears a close resemblance to that of true
Fig. 268.—A prothallinm of Botrychium Lnnaria, in longitudinal section, ac, an
archegonium ; av, an antheridium—near to it are others, one not yet mature, and
three empty ones ; u\ root-hairs. X 50.—After Hofmeister.
Fig. 269.—A longitudinal section of the lower part of a young plant of the same, dug
up in September, st, stem ; b, b'. leaves. X 20.—After Hofmeister.
Ferns. The plant-body is usually large ; its stem is generally upright,
short, thick, and unbranched ; the leaves are circinately developed, as
in true Ferns, and are mostly very large, with pinnately or palmately
divided laminae ; they are provided with stipules, and in their petioles
is found the first collenchyma. The stem develops from a three-sided
apical cell, but the root is provided with a group of cells, as in the
Phanerogams.
The sporangia occur on lateral veins upon the under side of the
leaves, and are usually confluent into one body, the sorus (often called
erroneously the sporangium). In Angiopteris, however, the sporangia
are distinct. The spores develop from many mother-cells in each spo-
rangium, instead of from one, as in true Ferns.
The Marattiacese are essentially tropical, extending somewhat into
the wanner parts of the temperate zones. Four genera are known,
viz., Danaia, restricted to tropical America ; Kaulfussia and Angiopteris,OP Jit 0 GL OSSA OEM.
379
found in the tropical regions of tlie eastern hemisphere ; and Marattia,
which is represented in the New and Old World. The whole number
of species probably does not exceed twenty-five.
The oldest members of this order oc-
cur in the Permiau strata.
Order Ophioglossacese, the Adder-
Tongues. The prothallia of these fern-
like plants are thick masses of paren-
chyma, which are destitute of chloro-
phyll ; they develop underground, and
are difficult to study, hence they are
known for- but few of the species. In
Botrycldum Lunaria, according to Hof-
meister* the prothallium is “an oval
mass of firm cellular tissue, whose larger
diameter does not exceed a millimetre
(one twenty-fifth of an inch), and is often
less” (Fig. 268). He discovered them
in the ground at a depth of from two
and a half to seven and a half centim-
etres (one to three inches). The an-
theiidia occur for the most part upon
the upper surface, and the archegonia
upon the lower.
The mature plant (asexual generation)
consists of a short erect underground
stem, which bears annually one or more
stipulate and erect (i.e., not circinate)f
leaves (Fig. 269, b' and b", and Fig.
270). The leaf is usually divided into
two portions, one of which is green and
expanded (Fig. 270, b), while the other
is contracted into a spore-bearing organ
(Fig. 270, /) ; in some cases each seg-
ment is simple, while in others it is one
or more times compound.
The spores of the Oph ioglossacece are
produced from mother-cells developed in Kg ^o.-Plant of Botrychium
the tissue of the fertile segment of the Lunaria, nat. size. the 6hort
, . , ., ,, , - stem : w, roots ; bs. the leaf etalk;
leaf ; hence the so-called sporangia of ^ point where the leaf branches
this order are morphologically quite into the sterile part (6) and the fer-
J ® tile or spore-bearing portion (/).—
different from those of true f erns. After Sachs.
* “ On the Germination, Development, and Fructification of the
Higher Cryptogamia,” etc., by Dr. Wilhelm Hofmeister. Translated
by Frederick Currey, London, 1862.
f The vernation of our species of Botrychium is well worked out in380
BOTANY.
The stems are developed from a triangular apical cell, while the
roots, like those of Marattiacece, possess no apical cell, but a group
of cells instead. The fibro-vascular bundles are arranged in a cylinder
{a circle in cross-section), and they form a network by their anastomos-
ing with each other. According to De Bary, they belong to the ‘ ‘ col-
lateral ” series.
These plants are usually of small size, rarely exceeding 30 centime-
Fig. 271.—A, vertical section of an archogoninm and the rudimentary prothallium
of Pilvlnria globulifera ; w, w, part of the ruptured wall of the macrospore ; p, p,
the rudimentary prothallmm, merging above into the archegonium ; g, the germ-cell
ready for fertilization ; sc, the cavity of the macrospore. X 500. B, a microspore
of the same burst open and allowing the escape of sperm-cells, s, from which sper-
matozoids are escaping, x 600. <7, longitudinal section of a macrospore of Salvinia
natans at the commencement of germination ; p, the young piothallium. x 30. D,
a very young prothallium of the same, detachea, with a fragment of the inner spore-
membrane (m) adhering to it—top view. X 200. E, a vertical longitudinal section of
D. X 200. F a similar section of a more advanced prothallium of the same ; g. the
young germ-cell. X 200. G, vertical section of an unfertilized archegonium of the
same, surrounded by cells of the prothallium ; g, germ-cell ; ar, canal of the arche-
gonium. X 300.—After Hofmeister.
tres (1 foot) in height ; in one Ceylonese species (Ophioglossum pendu-
lum) the slender pendent leaves are sometimes, according to Hooker,
nearly three metres long (15 feet).
There are three genera, viz., Ophioglossum, Botrycliium, and Helmin-
thostachys ; the latter is confined to the southern hemisphere, the others
G. E. Davenport’s paper, Vernation in Botrychia, in the Bulletin of
the Torrey Botanical Club, 1878; it is illustrated by figures.BHIZOCARPEJE.
381
are cosmopolitan. All told, there are probably not more than eighteen
or twenty distinct species, of which we have six within the limits of
the United States.
A species of Ophioglossum has been discovered in the Tertiary strata.
Order Rhizocarpese, the Pepperworts. The prothallia of the
Rhizocarps are dioecious, and are developed
from two kinds of spores (the mac ospores and
microspores, to be more particularly described
below). The antheridia are simple, and con-
sist of small, few-celled outgrowths from the
germinating microspore (in iSalvvria and Azol-
la), or of the transformed contents of the mi-
crospore (in Marsilia and Pilularia, Fig. 271,
B). The spermatozoids are spirally coiled, and
in the two last-named genera are produced in
definite numbers (thirty-two) in each antherid-
ium. The prothallia which produce archego-
nia are small, and barely attain a size large
enough to protrude through the ruptured
wall of the macrospore (p, p, Fig. 271, A).
The archegonia resemble those of true Ferns,
but are more sunken in the tissues of the pro-
thallia (Fig. 271, A and 0). After fertilization
the germ-cell undergoes division, and gives
rise directly to a leafy stemmed plant, the
asexual generation, provided with roots (ex-
cept in Scdvin-
ia). The stem
is horizontal,
and floats upon
the water or
runs through
the mud at the
bottom of shal-
low water. The
leaves are cir-
cinately devel-
oped, and are
simple or quad-
rifid (Fig. 272).
The stem and
root develop
from an apical
cell, which is
Fig. 372.
Fig. 273.
Fig. 272.—Plant of Marsilia salvatrix.
b. bt leaves ; /, /, /, the fruits springing
K, apex of the stem ;
j from the petioles at x.
One half nar.'size.—After Sachs.
Fig. 273. — Longitudinal section through three fruits (the fer-
tile apices of a water-leaf) of balvinia natans. i, i, two fruits
containing microsporangia ; a, one with macrosporangia, x 10.
—After Sachs.
two or three-sided in the stem, and triangular in the root.
The sporangia, which are usually of two kinds, are produced in
“fruits” or receptacles, which are modified parts of leaves. These382
BOTANY.
fruits are one-celled in Salviniaceai, and several-eelled in Mardliacece,
In Salvinia (Fig. 273) tlie microsporangia are small and numerous, and
are contained in separate fruits from the macrosporangia, which are few
in number ; each of the former contains many microspores, and the
latter a single macrospore (by the abortion of three, as four are formed
at first). In Mavsilia and Bilularia the two kinds of spores occur in
the same iruit, and in the former in the same sporangium.
Four genera are known ; these are arranged under two suborders or
families, the Salviniaeem, which includes Salvinia and Azolla, and the
Marsiliacece, which includes MarsiUa and Pilularia. The whole num-
ber of species is sixty-four, of which forty belong to Marsilia, the
others being unequally divided between the remaining genera. All
the species are of small size, rarely exceeding a few centimetres in
height; they grow in ditches and other wet places. Half a dozen
species occur in the United States.
Rliizocarps have been found as fossils in the Secondary (Jurassic) andj
Tertiary strata.
§ III. Class Lycopodium.*
491. —The plant-body of the asexual generation consists
of a solid, dichotomously branched, leafy, and generally erect
stem. The leaves, which have a central fibro-vascular bundle,
or midrib, are small, simple, sessile, and imbricated, and
usually bear a considerable resemblance to those of Mosses.
The roots are mostly slender and dichotomously branched.
The Lyeopodinte are for the most part terrestrial peren-
nials. They are usually of small size, rarely exceeding a
height of 15 or 20 centimetres (6 or 8 inches).
492. —The spores of the Lycopodime are produced in spo-
rangia which are generally (if not always)- axillary appen-
dages of the leaves. In four of the genera (Lycopodium,
Psilotum, Tmesipteris, and Pliylloglossum) the spores are
of one kind ; while in the two remaining genera (Selaginella
and Isoetes) they are of two kinds, the macrospores and the
microspores.
493. —The prothallium or sexual generation is scarcely
known in the isosporous genera ; it appears, however, to be
a thickish mass of tissue, which develops underground, and
* Sachs calls this class the Dichotomm, but as long as we have the
Equisetinte and Filicina, we may, for the sake of uniformity, retain the
old name given above.L TCOPODINJE.
383
bears both kinds of sexual organs. In the heterosporous
genera the macrospores produce small prothallia, which
project slightly through the ruptured spore-wall, and upon
these several or many archegonia are formed; the micro-
spores produce very small rudimentary prothallia, each of
Fig. 274.—A, longitudinal section of a young prothallium of Lycopodium anno-
tinum ; an, two antheridiaj not mature—upon its lower surface are seen the root-
hairs. X 150. B, longitudinal section of a prothallium, p, of the same, after germi-
nation of the young plant; s, stem of young plant; r, its young root; /, the foot, or
portion of the young plant which remains in contact with the pro!hallium. Slightly
magnified.—After Fankhauser.
Big. 275.—Plant (asexual generation) of Lycopodium da/oatwn; horizontal stem
with roots and leaves, the erect branch bearing fertile spikes, s. One half natural size.
—After Prantl.
which bears a single antheridium, in which there are de-
veloped a few spermatozoids.
494.—Three orders of Lycopodinse may be distinguished,
as follows :
I. Isosporece.—Spores of one kind ; no ligules.
Order 1. Lycopodiacese, with small leaves, commonly
moss-like.
II. Heterosporece.—Spores of two kinds ; ligules present.
Order 2. Selaginellse, with small moss-like leaves.
Order 3. Isoeteae, with elongated grass-like leaves.
Fig. 274,
Fig. 275.384
BOTANY.
Order Lycopodiacese.—The prothallium is known only in one case,
viz., Lycopodium amiotinum. It was discovered underground by
Fankliauser in 1872, who described it* as a yellowish white, irreg-
ularly lobed body, sparingly furnished on its under surface with small
root-hairs (Fig. 274, A). In its upper surface the prothallium bears
antheridia, which are
deeply sunken in its tis-
sue (an, Fig. 274, A);
the spermatozoids, which
are numerous, are stout
and slightly twisted.
The arcliegonia were
only seen after the young
plants had grown con-
siderably (Fig. 274, B) ;
they are likewise devel-
oped upon the upper
surface of the prothal-
lium, and appear to bear
a considerable resem-
blance to those of the
OphioglosiaceoB.
The young plant which
results from the growth
of the fertilized germ-
cell is quite simple, but
it soon takes on the form
of the mature plant.
The leaves are crowded
in Lycopodium, but are
less so in the other gen-
era. In many species
the sporangia are borne
in the axils of the or-
dinary leaves, but in
others the leaves which
bear sporangia are col-
lected into cone-like or
spike - like structures,
which terminate certain
branches (Fig. 275). The
which are short-stalked
Fig. 27(i TC. crmination of the spores of Selaginella.
1, longitudinal section of a macrospore of S. Marten-
“ ........................alii ...............
• above the line d is the prothallium, below it the
“ endosperm e, e\ two embryos, the larger one with
its suspensor projecting into the neck of the archego-
nium ; at the left of the larger embryo is a young ar-
chegonium ; several root-hairs are also shown. 2, a
young archegonium of the same species, not yet open.
3, an archegonium of the same species, with the germ-
cell fertilized and divid< d into iwo. Ay a microspore
of S. cavlescens, rendered fran>parent, showing the di-
vision of the contents into the primordial cells; the
small lower cell is the rudimentary prothallium. D,
later stage of the same, showing the large antheridium
filled with sperm-cells : v. the rudimentary prothal-
lium. All magnified—After Pfeifer.
sporangia are more or less globose bodies,
or sessile ; they contain large numbers of small spores, which escape
by an apical slit in the sporangium.
* J. Fankliauser : “ Ueber den Vorkeim von Lycopodium,'
ische Zeilung, 1873, No. 1.
in Botazi*SELA QtINELLJE.
385
Four genera belong to tliia order, viz., Lycopodium, which is common
in tlie wooded portions of the United States ; Psilotum, found in
Florida; Tmesipteris and Phylloglossum, of Australia. The species
number from 115 to 120, of which about 100 belong to the genus
Lycopodium.
The spores of Lycopodium clavatum are gathered in Europe and
sold for various minor uses. Many species have a high ornamental
value.
This order was represented in the Devonian by species of Arctopo-
dium. In the Carboniferous the genus Lycopodium first appeared.
The closely related extinct order Lepidodendrete first appeared in the
Devonian, in which it was represented by two known species of Lepi-
dodendron ; in the Carboniferous this genus was represented by sixty or
more species, many of gi-
gantic size, and the order
by many other genera—e.g.,
Lepidophloios, Lepidontro-
bus, Halonia, etc. In the
Permian this order became
extinct.
Another order—the Sigil-
larieae—was represented by
many species of Sigillaria
in the Carboniferous period.
Like the preceding, this or
der became extinct in the
Permian.
Order Selaginellse.—
The prothallia are dioecious.
Those which develop from
the macrospores consist of a
concavo-convex maoy-celled
structure, which develops upon, and has its concave side applied to, the
convex surface of the spore. Upon its convex surface, which protrudes
through the ruptured wall of the spore, are a few root-hairs and many
deeply sunken arcliegonia (Fig 2TG, 1, 2, 3). The microspores develop
only the smallest rudiments of prothallia. In germination a single
cell (v, Fig. 276, D) is first of all cut off ; this undergoes no further
cha!nge, and is doubtless to be regarded as the prothallium. The re-
mainder of the spore becomes divided in a regular way into a few
large primordial cells (Fig. 276, A), and from these great numbers of
sperm-cells are produced (Fig. 276, D).
After fertilization the germ-cell divides at right angles to the axis
of the archegonium (Fig. 276,3); from the upper cell so formed a
suspensor is developed (Fig. 276, 1), while the lower develops into the
embryo. The embryo, by its rapid growth, comes eventually to occupy
Fig. 277.—/., two young plants of SelaQinella
Murtensii growing from the same spore; at the
top of the spore may be seen the projecting pro-
thallium, p. II., a young plant drawn out of the
spore, showing the foot, f, on the left below, and
the young root, r, on the right. III., a young
plant whose first leaves (cotyledons) have been re-
moved, leaving only their stipulesj e; between the
latter is seen the dichotomonsly dividingpunctum
veyetationis; p, the prothallitt in isolated from the
spore. /. X 5; II. X 3; III. X 30.—After Hoi-
meister.386
BOTANY.
the cavity of the spore itself, in which, by bending upon itself, it lies
at right angles to the axis of the archegonium. The new plantlet
bears some resemblance to the embryo in the Dicotyledons ; it has an
elongated stem, bearing at its summit two small leaves (cotyledons),
having between them a growing bud (plumule); at the lower end of
the stem there is a rudimentary
root, and the structure known
as the foot, which is common to
all Pteridopliytes (Fig. 277, II.).
The young plant grows from
the spore with its cotyledons fore-
most (Fig. 277,1. and III.); this
is only possible by the great
bending of the embryo upon
itself, for at first its cotyledon-
ary extremity points directly to-
ward the centre of the spore—
i.e., away from the opening in
the spore-wall. Usually but one
plantlet growB from each pro-
thallium but occasionally two or
more may be developed (Fig.
277, I.)
The adult plant of the asex-
ual generation is densely leafy
throughout. The leaves are
small, moss-like, and are gen-
erally placed in four rows, of
which two opposite ones are
composed of large leaves, and
the two intermediate ones of
small leaves. Each leaf has a
small scale-like body, the ligule,
on its upper surface at its base.
The sporangia occur singly in
the axils of certain leaves, gen-
erally in those which form the
narrower “ fruiting spikes" (Fig.
278, ^4). Macrosporangia, con-
taining four macrospores in
each, usually occur in some defi-
nite portion of the spike, as nearer the base, or upon one side (Fig.
278, B). Tlie microsporangia contain many microspores, and usually
also occupy definite positions in the spike.
But one genus, Selaginella, is known in this order; it includes 334
epecies of mostly delicate plants, which are mainly tropical, not more
Fig. 378.—A. a fertile branch of Selaginella
in'ceguifolia, wifh the quadrangular spore-
bcarmg spike at the apex ; B. vertical sec-
tion or the spike, showing the microsporan-
gia containing microspores on the left, and
the macrosporangia with macrospores on
the right.—A X 2; B x 15. —After SachsISOETEJE.
387
than six or seven species occurring within the limits of the United
States. Many are cultivated as ornaments.
Order Isoeteee, the Quillworts. The protliallia of the Isoetere are dioe-
cious, and resemble closely those of Selaginelta. The macrospores give
rise to small protliallia, which project through the triangular slit in the
spore-wall, and bear several or many sunken nrcliegonia (Fig. 279). The
microspores, in their germination, first cut off a small cell (a, Fig. 280,
A to C), which, as in Selaginella, represents the prothallium ; the re-
mainder of the spore contents becomes divided into four cells (the
primordial cells), and these give rise to the sperm-cells (Fig. 280, A to
Fig. 279.—1, Longitudinal section of a prothallium of Tsoetes lacustris, four weeks
after sowing the spore ; ar, an archegonium. 2, a poriion of the apex of a prothal-
lium cut through longi- udinally, with two archegonia, ar, ar, still in process of devel-
opment ; g, g, the germ-cells of the archegonia. 3, longitudinal section of an arche-
gonium ready for fertilization. 4, longitudinal section of a fertilized archegonium,
showing the germ-cell transversely divided. 5, a section similar to the last ; in the
lower cell of the embryo-rudiment preparation for division has been made by the ap-
pearance of two nuclei. 1 x 40; 2 and 3 X 300 ; 4 and 5 X 400.—After Hofmeister.
O). The spermatozoids are elongated and provided with cilia at both
ends (Fig. 280,/).
The germ-cell, after fertilization, undergoes transverse division
(Fig. 279, 4 and 5), as in SelagMella, and its subsequent development
is essentially the same.
The adult plant of the asexual generation consists of a very short,
thick, tuber-like stem, which bears numerous long, narrow, grass-like
leaves, which are sheathing at the base. There are also numerous
roots. The sporangia are produced in grooves on the inner side of the
bases of the leaves ; those attached to the outer leaves contain macro-388
BOTANY.
spores, while the interior ones contain microspores. Both macrospcres
and microspores are produced in great numbers iu the sporangia.
The Quillworts are for the most part aquatic plants ; they are found
chiefly in the north temperate and warm regions. The species, ocf
Fig. 280.—Germination of the microspores of Isoetes lacustris. A, a microspore,
side view. B, the same, ventral view : the spore contents have divided into a few
cells, of which v in each figure represents the rudimentary prothallium ; ftt ft are the
ventral, and rf d the dorsal cells. C, a side view of microspore ; the four cells, ftt ftt
p‘&iv, to sever, to separate,
f From Greek eihi'fhpog, free.
| From Greek Sialveiv, to part asunder.
§ The terms moncsepalous and monopetalous were formerly used with
a different meaning from that given here; they were applied to the
forms now called gamosepalous and gamopetalous. This use, errone-432
BOTANY.
penta-sepalous, etc., and mono-, di-, tri-, tetra-, penta-petalous, etc., mean,
ing of one, two, three, four, five sepals or petals respectively. Polysepa-
lous and polypetalous are properly used to designate “ a considerable but
unspecified number” of sepals or petals.* *
In some flowers the sepals or petals, or both, are united to one
another, so that the calyx and corolla are each in the form of a single
tube or cup. This union of similar parts is called coalescence. The
terms gamosepalous •)■ and gamopeta ous (or sympetalous) are used in such
cases. Monosepalous and monopetalous, still used in this sense in many
descriptive works, should be reserved for designating the number of
sepals or petals in calyx and corolla respectively.
Not infrequently the calyx and corolla are connately united to each
other for a less or greater distance. This union of dissimilar whorls is
termed adnation, and the calyx and corolla are said to be adnate to
each other.
The Androecium.—The number of stamens in the flower or the
andrcecium is indicated by such terms as
Monandrous, signifying of one stamen ;
Diandrous, of two stamens;
Triandrous, of three stamens;
Tetrandrous, of four stamens—when two of the stamens are longer
than the other two, the androecium is said to be didynamous;
Pentandrous, of five stamens ;
Hcxandrous, of six stamens ; when four are longer than the remain-
ing two, the androecium is said to be tetradynamous.
Other terms of similar construction are used, as heptandrous, seven
stamens ; octandrous, eight; enneand' ous, nine ; decandrous, ten ; dodec-
androus, twelve; and polyandrous, many or an indefinite number of
stamens.
The stamens may be in a single whorl (monocyclic), in which case, if
agreeing in number with the rest of the flower, the androecium is said
to be isostemouous; they are often in two whorls (bycyclic), and when
each whorl agrees with the numerical plan of the flower, the androe-
cium is diplostemonous.
The various kinds of coalescence require the use of special terms.
When there is a coalescence of the filaments the androecium is
Monadelphous, when the stamens are united into one set;
Diadelplious, when united into two sets ;
Triadelphous, when united into three sets, etc.
ous as it obviously is, has not yet been abandoned in works on descrip-
tive botany.
* Dr. Gray throws the weight of his authority in favor of this use of
these terms (“ Structural Botany,” 1879, p. 244).
f From Greek yuyos, union.GLOSSOLOGY OF ANGIOSPERMS.
433
When there is a coalescence of the anthers the andrcecium is syn-
genesious or synantherous.
The stamens may be adnate to the petals, when they are epipetalous;
in some cases they are adnate to the style of the pistil, as in the
Orchids ; such are said to be gynandrous.
The principal terms which designate the structural relation between
the anther and filament in individual stamens are :
Adnate, applied to anthers which are adherent to the upper or lower
surface (anterior or posterior) of the filament ; when on the upper
surface the anthers are introrse; when on the lower, extrorse.
Innate, applied to anthers which are attached laterally to the upper
end of the filament, one lobe being on one side, the other ou the oppo-
site one. The part of the filament between the two anther-lobes is
designated the connective ; it is subject to many modifications of form,
and often becomes separable by a joint at the base of the anther from
the rest of the filament.
Versatile is applied to anthers which are lightly attached to the top
of the filament, so as to swing easily ; these may also be introrse or
extrorse.
The Gyncecium.—The Gynoecium is made up of one or more carpels
(carpids or carpophylla)—i.e., ovule-bearing pliyllomes, and it is said to
bemono-, di-, tri-, tetra-, penta-, etc., andpoly-carpeUary, according as it
has one, two, three, four, five, to many carpels. In old books the
terms monogynous, digynous, trigynous, etc., meaningof one, two, three,
etc., carpels, are used instead of the more desirable modern ones. When
the carpels are more than one they may be distinct, forming the apo-
carpous gynoecium ; or they may be coalesceut into one compound or-
gan, the syncarpous gynoecium. In the former case the term pistil is
applied to each carpel, and in the latter to the compound organ. Pis-
tils are thus of two kinds, simple and compound ; the simple pistil is
synonymous with carpel ; the compound pistil with syncarpous gynoe-
cium
In the simple pistil the ovules actually grow out from the united
margins (the ventral suture) of the carpophyllum ; the internal ridge or
projection upon which they are borne is the placenta. Sometimes the
ovules are erect—i.e., they grow upward from the bottom of the ovary—
and when single appear to be direct continuations of the flower axis
(Fig. 304). Suspended ovules—i.e., those growing from the apex of the
ovary cavity—are also common.
In compound pistils the coalescence may be, on the one hand, of closed
carpels, and on the other of open carpels. In the former case the pis-
til has generally as many I culi (cavities or cells) as there are carpels ;
this is expressed by the terms uni-, bi, tri-, quadri-, and so on to multi-
locular. Such pistils have axile placentae—i.e., they are gathered
about the axis of the ovary, e.g., Hypericum. In the case of compound
pistils formed by the coalescence of open carpels, the margins only of the434
BOTANY.
latter unite, forming a common ovary cavity ; here the placentae gener.
ally occur along the sutures, and are said to be parieUil—i.e., on the
walls. Between such unilocular pistils and the multilocular ones
described above there are all intermediate gradations. In one series of
gradations the placentae project farther and farther into the ovary cav-
ity, at last meeting in the centre, when the pistil becomes multilocular
with axile placentae. On the other hand, a multilocular pistil sometimes
becomes unilocular by the breaking away of the partitions during
growth. In such a case the placentae form a free central column,
commonly called a free central placenta.
In other cases a free placental column of an entirely different origin
occupies the axis of a unilocular, but evidently polvcarpellary pistil.
In Anagattis, lor example, the placental column grows from the base
of the ovary cavity, and there is at no time a trace of partitions (see
illustrations of the Order Primulacere, p. 507).
The Gyncecium may be free from all the other organs of the flower,
which are then said to be hypogynous* and the gyncecium itself su-
perior. Sometimes the growth of the broad flower-axis stops at its
apex long before it does so in its marginal portions ; a tubular ring is
thus formed, carrying up calyx, corolla, and stamens, which are then
said to be perigynous,\ and the gyncecium half inferior. These terms
are used also in the cases where the gyncecium is similarly surrounded
by the tubular sheath composed of adnate calyx, corolla, and androe-
cium. In some nearly related cases, in addition to the structures de-
scribed above as perigynous, there is a complete fusion of the calyx,
corolla, and stamen-bearing tube with the gyncecium. so that the ovule-
bearing portion of the latter is below the rest of the flower, e.g., Com-
posite. The perianth and the stamens are said to be epigynous\ in such
flowers, and the ovary is inferior. Some cases of epigyny are doubtless
to be regarded as due to the adnation of the calyx, corolla, stamens,
and ovaries ; in others, the ovaries are adnate to the hollow axis which
bears the perianth and stamens ; in still others, it seems probable that
the hollow axis is itself ovule-bearing, and that the true carpels are
borne on its summit.
Certain terms descriptive of relations between the stamens and pis-
tilB which have recently come into use require explanation here.
In many flowers the stamens and pistils do not mature at the same
time, such are said to be dichogamous ; when the stamens mature be-
fore the pistils the flower is preterandrous ; and when the pistils ma-
ture before the stamens they are proterogynous.
In some species of plants there are two or three kinds of flowers,
* From Greek iir
a
r\
A'
representation of the arrangement of the
bundles in the stem of Stachys angusti-
folius. Here each leaf sends down two
bundles, which pass through two internodes and then unite
with other descending bundles at
their middle points. The fibro-
vascular cylinder is thus compos-
ed when complete of repeatedly
branching bundles. A cross-sec-
tion (Fig. 318) through the stem
at some distance above the lower
leaves in Fig. 317
shows that each
internode con-
tains bundles
from two pairs of
leaves—i.e., those
at its summit and
those at the sum-
mit of the one
above. In Fig.
318 the pairs of
bundles marked c and d descend
from the leaves c and d, while
those marked e and f pass down
from the leaves one internode
higher up.
In a similarly constructed dia
Fig. 318. — Cross-
sectiou of the next
to the lower inter-
node in Fig. 317,
showing the disposi-
tion of the bundles,
the lettering as in
Fi» 317.—After Nii-
geli.
Fig. 317.—Diagram showing the ar-
rangement of the fibro-vaecuTar bun-
dles in Stachys angustifolius. a, b,
ftomCU&hIie?’8uc7e8dvehp£rsnif gram of the iibro-vascular cylin-
leavea spring. After Nageli. der of Jber{s amam (Kg, 319j
projected upon a series of transverse and vertical lines to442
BOTANY.
indicate the nodes and the vertical ranks of leaves) the sin-
gle bundles which descend from the leaves are shown to pass
through from ten to twelve internodes before uniting with
22
Fig. 319.—Diagram showing the arrangement of the fibro-vascular bundles in 22
internodes of the stem of Iberis amara.—After NSgefi.
other bundles. It is seen, moreover, that there are running
through the stem five series of branching bundles, which are
not quite vertical, but slightly spiral. In Fig. 320 is shown
the appearance of an actual section of the stem taken be-TISSUES OF AJNGIOSPERMS.
443
Fig. 320.—Cross-section of
the stem of which Fig. 319
is the diagram, taken above
the fifth leaf.—After Nageli.
tween the fifth and sixth leaves of the preceding figure. The
bundles are numbered as in Fig. 319.
542. —In a comparatively small number of instances there
are fibro-vascular bundles in the stem which have no connec-
tion with the leaves. These are known as cauline bundles.
543. —In the Monocotyledons and
many herbaceous Dicotyledons, the
fibro-vascular bundles are closed—that
is, there is no zone of meristem tissue
left between the xylem and phloem after
these have passed over into permanent
tissues. There is, as a consequence, a
definite period of growth for the bun-
dles, and when any bundle has fully
formed all its tissues, no further devel-
opment can take place in it. This gen-
erally results in definitely limiting the growth of the inter-
nodes, and in consequence such plants are as a rule short-
lived. The perennial woody-stemmed Dicotyledons, and
some of the herbaceous annuals, possess bundles which are
open—that is, there is left between the xylem and the phloem
a zone of meristem tissue which
continues to grow long after the
other parts of the bundle have
passed over into permanent tis-
sues. Plants with such bundles
may live and continue to grow for
an indefinite time.
544.—A cross-section of the
stem of a Palm (Fig. 321) shows
it to be composed of parenchyma-
tous tissue traversed by myriads
of fibro-vascular bundles, which
descend from the crown of leaves.
Each leaf sends down from its broad insertion numerous
bundles, which, in a vertical section, are seen first to pass in
toward the centre of the stem, and then to curve downward
and finally outward. The centre of the stem is thus softer
than the peripheral portion, as in the latter the descending
Fig. 321. —Cross-section of the
stem of a palm, ec, cortical zone ;
Ig, the softer interior portion of the
stem ; lg\ the harder peripheral
portion.—After Duchartre.444
BOTANY.
bundles are more numerous. In such a stem it is evident
that there can be no considerable increase in thickness after
it is once formed, and we consequently find that palms
take a long time for the formation of a broad bud or growing
point (punctum vegetationis), and afterward push up a cylin-
drical stem in which little change subsequently takes place.
In the Dragon trees
(Draccena, sp.) and
some other Monoco-
tyledons, there is a
thick layer of paren-
chymatous cortex be-
tween the column of
fibro-vascular bundles
and the epidermis
(Fig. 322, ?■), and in
the deeper layers of
this a persistent meri-
stem tissue is found
(Fig. 322, a;). In this
meristem there are
formed fibro-vascular
bundles, which lie par-
allel to those already
formed, and in this
way the stem slowly
increases in thickness.
545.—In those Di-
cotyledons whose
stems increase in
thickness there always
develops soon a layer
of meristem tissue,
of one fibro-vascular
323). This is made
Fig. 322 —Cross-section of stem of Draccena. e,
epidermis; k, cork ; r, cortex ; b, a fibro-vascular
bundle bending out to a leaf ; m, parenchyma of the
fundamental system ; g. g, fibro-vascular bundles;
co, meristem zone of the fundamental system in
which new bundles and tissues are forming.—After
Sachs.
which connects the cambium layer
bundle with that of the other (Fig.
easier from the fact that in most (but not all) Dicotyle-
dons the bundles lie at nearly the same depth beneath the
epidermis on all sides of the stem, thus forming a cylinder,
or in cross-section, a ring, as in Fig. 323. Both the fascicu-TISSUES OF ANGI08PERM8.
445
frig. 323 —Diagrams of dicotyledonous stems as seen in cros9-section. R, the cor-
tical, 3f, the medullary portion of the fundamental system ; p, the phloem ; x, the
xylem ; b, b, b, groups of bast fibres ; fc, the fascicular, ic, the interfascicular cam-
bium.—After Sachs.
Fig. 324.—Cross-section through a young internode of Sambucus nigra. P, P, cor-
tical parenchyma ; p, o, parenchyma of the pith ; between r — r and P—P, sieve tis-
sue ; g, g, pitted vessels; s, s, and above, spiral vessels; o — c, the cambium zone, x
220.—After De Bary.446
BOTANY.
lar and interfascicular cambium layers are composed of.
elongated cells, which multiply by fission in a tangential di-
rection, and thus give rise to radiating rows of cells (Figs.
324 and 325). In a tangential section the cambium cells
present an elongated outline, and their extremities are
usually more or less oblique (Fig. 326). From these cells
there develop various tissues. Thus, on the one side, the
phloem parenchyma, sieve and fibrous tissues may be pro-
duced by more or less great modifications (Fig. 327). On
the other side (the xylem side) new ves-
sels, fibres, and parenchyma are also devel-
oped (Fig. 328). The development of
these tissues begins in the inner and outer
layers of the cambium, and advances to-
ward the central layers. It never hap-
pens, however, that all the cambium lay-
ers pass over into permanent tissues, there
always remaining one or a few meristem
layers.
546.—A study of Figs. 326-328 will
show the probable mode of development of
the permanent tissues from the meristem
tissue of the cambium. It is evident from
a comparison of Figs. 326 and 327 that
the phloem parenchyma is produced by
the formation of several transverse parti-
tions in each cambium cell, and it is prob-
able that in many cases there is a direct
conversion of cambium cells into sieve
tubes. That the cambium cells may be
converted directly into tracheides is evident from Fig. 326,
and also Fig. 75 (p. 84). In Fig. 328 it is plain that the
fibrous tissue (If) and tracheides (t) have the same origin,
and the indications are that even the large pitted vessels
(gg) are formed from cambium cells by the great increase
in the diameter of the latter, the thickening of their vertical
walls, and the partial or complete absorption of their trans-
verse walls. The origin of the xylem parenchyma from cam-
Fig. 325.—The row of
cells marked x — x in
Fig. 324; r. phlogm : h,
xylem ; ati are seen the
fissions of the cambium
cells. X 600. — After
De Bary.TISSUES OF ANGIOSPERMS.
447
bium cells by the formation of transverse partitions is very
clear in this figure.
547.—In the trees and shrubs of cold climates, or of
those in which there is one annual period of growth, fol-
lowed by a period of rest or the cessation of growth, the
Fig. 326. A tangential section of the cambium region of Cytisus Laburnum, a, bt
c, d, cambium cells enclosing the section of a medullary ray ; h, h, tracheides belong-
ing to the xylem. X 145.—After DeBary.
Fig. 327.—Tangential section of the inner phloem region of the same stem as Fig.
326. 8, 8,8, sieve vessels ; m. section of a small medullary ray ; the remaining parts
of the figure are phloem parenchyma. X 145.—After De Bary.
processes described above take place each year, giving rise
thus to an annual layer of xylem (wood) outside of the pre-
viously formed xylem cylinder, and an annual layer of
phloem (bark) inside of the phloem cylinder. In the wood
these layers are generally quite well marked, and in cold
climates they enable us to determine with accuracy the age448
BOTANY.
of trees and shrubs (Fig. 329). The layers of the bark are
rarely well marked, and they generally become soon obliter-
ated by irregular corky growths in the substance of the bark
Fig. 328.—Tangential section of the stem of Ailanthus glnvdrdosvs, through the
secondary xylem : g, g, pitted vessels ; p, p, xylem parenchyma ; st, st, medullary
rays in cross-section ; If, fibrous tissue \wuod cells); t, tracheldes. Highly magnified.
—After Sachs.
itself. They are, moreover, ruptured by the increase in the
diameter of the woody cylinder, and soon decay and fall
away. It thus happens that while the annual layers of the
wood are constantly increasing in number, reaching in ex-TISSUES OF ANG10SPERMS.
449
treme cases more than a thousand,* the bark rarely shows
more than a few distinct layers, and its thickness is generally
very much less than that of the former.
From what lias been said it is seen that a dicotyledonous stem several
years old is composed of a serieB of larger and larger continuous woody
shells (Fig. 330, 1, 2, 3, 4, 5) surrounded by a corresponding series of
bark shells, which are smaller aud smaller (Fig. 330, 5', 4' 3', 2', l').
548.—The Medullary Rays, In the young dicotyledonous
stems there are thick masses of parenchyma, which connect
the cortical with the medullary (pith) portion of the funda-
mental system of tissues (Fig. 323). However, as the fibro-
vascular bundles increase,
these masses become thin-
ner, until they are mere
plates, often not more than
one or two, or at most a
few cells in thickness (Figs.
326-7-8). From their ap-
pearance and position they
have long borne the name
of Medullary Rays. In
the young stem their cells
may be parenchymatous,
but in older ones they are
frequently sclerenchyma-
tous. Viewed in a radial
section of the stem, they are generally seen to be elongated
in the direction of the radius, having the outlines of right-
angled quadrilaterals. In the increase of the diameter of the
stem there is always an increase in the length of the medul-
lary rays, both in their bark and wood portions ; and when
from their divergence a considerable space intervenes between
two rays, one or more new ones arise between them ; thus
while there may be no more than four or five rays in the
young plant, it may when old have hundreds of them in its
circumference (Fig. 329).
What has been said of the tissues of the Angiosperras must suffice to
Fig. 329.—Cross-section of the stem of an
oak (Quercu* Robur) thirty-seven years old.
m, pith ; Iff, heart-wood ; lff't sap-wood ; m,
medullary rays ; ec, the bark. Much reduced.
—After Duchartre.
* In the Lime (Tilia Europcm) 1076 and 1147, and in the Oak (Quer-
cus Robur) 1080 and 1500, according to De Candolli*.450
BOTANY.
introduce the student to their
study. For further details,
he is referred to De Bary’s
admirable treatise, “Yer-
gleicliende Anatomie der
Vegetationsorgane der Phan-
erogamen und Fame,” in
which copious references are
given. The publications of
Russow will also be found to
be of great value to the stu-
dent.
549.—The systematic
arrangement of the An-
giosperms is by no means
settled. The one mostly
followed in England and
this country is a modifi-
cation of De Candolle’s
system (a.d. 1813),
which was itself a modi-
fication of Jussieu’s (a.d.
1789), which in turn was
based upon the general
system proposed by Ray
(a.d. 1703). In the
“Genera Plantarum,”
now publishing by Ben-
tliam and Hooker, and
in the English edition of
Le Maout and Decaisne’s
“ General System of Bot-
any,” we have the most
recent modifications of
the Candollean system.
On the continent of Eu-
rope other systems have
been used more or less,
and it is probable that
among these are to be
found the best groupings
of Angiosperms to indi-MONOCOT YL ED ONES.
451
cate their real affinities. Unfortunately for us, however,
none of our systematic manuals follow any of the Continen-
tal systems ; W'e are compelled, therefore, to use for the pres-
ent the prevailing form of the Candollean system. In this
book the sequence of the groups is the reverse of that in
most American and English books, in order to bring the ar-
rangement of Angiosperms into harmony with that of the
rest of the vegetable kingdom.
Sub-Class I. Monocoxyledoites.
(Enclogence of De Candolle.*)
550.—In these plants the first leaves of the embryo are
alternate, hence we say
that they have one cotyle-
don. The venation of the
leaves is for the most part
such that the veins run
more or less parallel to
one another, and when
they anastomose enclose
four-sided areolae; rarely,
however, their veins are
irregularly distributed,
and they anastomose so as
to form an irregular net-
work.
The germination of Monoco-
tyledons may be illustrated by
a couple of examples. In the
seed of tlie Indian corn the
embryo lies partly imbedded
in one side of the large endo-
sperm (Fig. 331). The first leaf
of the young plant (the cotyle-
don or scutellum, Fig. 331, $c )
has its broad dorsal surface in contact with the endosperm ; anteriorly
* From the Greek evfiov, within, and yeveiv, to bring forth. The
name was given under the false impression that these plants were
“ inside growers,” and the Dicotyledons “ outside growers.”
Fig. 331.—Longitudinal section of the seed
of Indian corn (Zea Aluis). c, adherent wall
of the ovary; n, remains of the style ;fs,
base of the ovary ; all the remainder of the
figure is the true seed ; eg, ew, endosperm ;
sc — 8$, cotyledon of embryo* e, its epider-
mis ; k, plumule ; w (below), the main root;
ws, the root-sheath ; v> (above), adventitious
roots springingfrom the first iuternodeof the
stem. X 6.—After Sachs.BOTANY.
Fig. 332.—Germination of Indian corn. 7, II, III.,
successive stages. A and B, front and side views of
a i-eparated embryo. In the figures, w, the primary
root; ws, its root-sheath ; w*, w", adventitious roots ;
w"', lateral roots springing from the main root; e,
part of seed filled with endosperm ; so, cotyledon ; r,
its open margins ; k, the plumule ; b, b', b", leaves of
young plant; L fragment of wall of ovary. Natural
6ize.—After Sachs.
Fig. 333.—Germination of the Date (Phoenix dacty-
lifera). /., transverse section of seed ; c. embryo ; e,
endosperm. //.,///., sections of germinating seeds;
c, apex of cotyledon developing into an absorbing or-
gan ; st, stalk of cotyledon ■ 8, sheath of cotyledon ;
b', b", leaves; w, root; w', lateral roots ; h, root-cap.
IV, young plant, natural size, the lettering as in III.
A, section of IV at x — x; B, section at x — y, the
lettering a9 in III. C, section at e — a, the lettering as
in 7/7.—After Sachs.GLUM ALES.
453
it is curved entirely around tlie remainder of the embryo. Under prop-
er conditions the main root pushes through the root sheath (ws, Figs.
331, 332). The plumule, consisting of a minute stem and a few rudi-
mentary leaves, next pushes out through the upper end of the curved
cotyledon (II., Fig. 332). The cotyledon remains in contact with the
endosperm and absorbs nourishment from it for the sustenance of the
growing parts. Lateral roots soon appear upon the main root, and
adventitious ones arise from the first internodes of the stem (w'", w", w',
Fig. 332). The first leaf above the cotyledon is quite small (6), and
each succeeding one becomes larger and larger until the full size is
reached.
In the Date the small embryo lies imbedded transversely in the large
endosperm. In germination the cotyledon elongates and carries the
enclosed root and plumule outside of the seed (II. and III., Fig. 333).
The apex of the cotyledon (c) expands into an organ through which
the dissolving endosperm is absorbed. The root pusheB downward,
and soon develops lateral roots (id'). The plumule grows upward, es-
caping from the enclosing cotyledon, as shown in IV., Fig. 333. The
first leaves above the cotyledon are here, as in the Indian corn, much
less perfectly developed than the later ones.
551. —The sub-class Monocotyledones contains about fifty
natural orders of plants, which are grouped into fifteen co-
horts. Of these only a few need be noticed.
552. —Cohort I. Glumales. Orass-like plants with the
flowers in the axils of scales, which are arranged in spike-
lets ; the stamens are from one to three, rarely more ; the
single ovary contains hut one ovule, and these at maturity
are completely coalesced, forming a caryopsis.
Order Graminese.—The Grass Family. Herbaceous or rarely
woody plants, with round, jointed, and mostly hollow stems, bearing
alternate two-ranked leaves with split sheaths. (Figs. 334-9.)
This very natural order contains about 4500 species, which are dis-
tributed in all climates. In the tropics they are large and almost tree-
like (Bamboo) ; in the temperate climates they cover the ground with
a close mat, while in the colder countries they grow in bunches. Very
many of the species are valuable on account of their starchy seeds or
nutritious herbage. None are poisonous (with possibly one or two ex-
ceptions).
Triticum milgare. Wheat, a native probably of Southwestern Asia,
has been under cultivation in temperate climates for several thousand
years. Remains of wheat grains have been found in the ruins of the
lake dwellings in Switzerland, proving that it was cultivated in Europe
in prehistoric times. By long culture it has formed many varieties;454
BOTANY.
some of these are hardy (winter wheats), others are tender (spring
wneats); some are awned, others awnless; in some the grains are
Figs. 334-9.—Inflorescence of the Oat.
Fig. 334.—Spikelet.
Fig. 335.—Spikelet opened. G, glumes; P, palets ; A, awn ; F, abortive flower.
Fig, 336.—Flower with upper palet.
Fig. 337.—Embryo.
F g. 338.—Section of grain.
Fig. 339.—Diagram of spikelet. Gl, glumes ; B, palets; A, abortive flower.
-dark in color (red wheats), in others they are light colored (white
wheats). Fabre’s experiments about a quarter of a century ago appear
to indicate that wheat was originally derived from a wild grass calledOL UMALES.
455
JEgilops ovata. From it, in the course of from ten to twelve years, he
succeeded in producing the form known as cultivated wheat. (See
Gardener's Chronicle, July, 1852.)
Secale cereale, Kye, is probably a native of Southeastern Europe and
Southwestern Asia. It lias been cultivated for ages and is still much
grown in temperate climates.
Hordeum vulgare, Barley. A native probably of the same region as
Rye ; has also been long under cultivation. One or two other species
are also grown.
Arena sativa, the Oat, was formerly much used as food for man,
especially in cool climates, where it succeeds best. It is now less used.
Its native country is not certainly known, hut it was probably northern
Europe or Asia.
Oryza sativa, Rice, has been long under culture in Southeastern
Asia, of which country it was probably a native. It is now cultivated
also in Egypt, Italy, Brazil, and the Southern
United States. It furnishes food to more human
beings than any other single plant.
Zea Mats, Maize or Indian Corn, a native of
the warmer parts of the New World, was culti-
vated by the aborigines of both North and South
America before the advent of Europeans. It is
one of the most valuable of the cereals, and is
now cultivated almost ail over the world. Of its
numberless varieties the larger are grown in the
hotter, and the smaller in the cooler climates.
The more important forage grasses are the fol- heMgnd™'s_Dfloferm of
lowing : Rice.
Phleum pratense, Timothy or Herd’s Grass, a native of Europe is val-
uable on rich soils.
Agrostis vulgaris, Red-top, a native of Europe, grows well on moist
soils.
Pactylis glomerata. Orchard Grass, a native of Europe, is valuable
because of its growing well in the shade, and so furnishing hay and
pasture in orchards and woodlands.
Poa pratensis, Kentucky Blue Grass, a native of the Eastern United
States and of Europe, is in the latitude of Kentucky the best of all our
pasture grasses. In drier regions it is small and harsh.
Muhlenbergia glomerata and M. Mexicana constitute the Fine
Slough Grass ” of the Mississippi valley prairies. They furnish val-
uable hay.
Several species furnish sugar :
Sacchantm officinarum, Sugar Cane, a native of the warmer parts of
Asia, is a large plant somewhat resembling Indian corn in size and ap-
pearance. From its sweet juice most of the sugar and molasses of com--456
BOTANY.
merce are made. It is cultivated extensively in tlie Southern United
States, Cuba, Brazil, and, in fact, in all warm countries of the world.
Figs. 341-4.— Illustrations op Carex.
It is a curious fact that while the annual production of cane sugar in
the world is now about 4,000,000,000 pounds, yet five hundredLILIA LBS
457
years ago it was but little known to our European ancestors, and even
a century and a half ago it was one of the luxuries. (Simmonds.)
Sorghum vulgare, Chinese Sugar Cane, a native of India, has within a
few years been brought into cultivation in the United States for its
sweet juice, from which molasses and sugar are made. One variety of
this species is the Broom Corn, used in the manufacture of brooms.
Several species of Bamboo (Bambusa, sp.) growing in India become so
large as to supply materials for building the houses of the natives.
B. arundinocea sometimes attains the height of 30 metres (100 ft.).
Its uses are almost innumerable.
Order Cyperacese.—The Sedge Family. Herbaceous plants, with
three-angled solid steins, bearing alternate three-ranked leaves, with
entire sheaths. (Figs. 341-4.)
There are about two thousand species of sedges, which are distrib-
uted throughout the world. They grow in tufts, never forming a con-
tinuous mat, and generally prefer wet localities. They are of little,
value to man, and their stems contain so little nutritious matter that
they are eaten only to a limited extent by animals.
Cyperus esculentus, the Chufa, a native of the Mediterranean region,
is somewhat cultivated for its small, sweet-tasting tubers.
Cyperus textilis is used in India for making ropes and mats; in Egypt
other species are used for the same purpose.
Papyrus antiquorum, Papyrus, is a tall growing plant with stems 3-3
cm. (1 inch) in diameter. It is a native of Egypt and the adjacent
countries, and from it the inhabitants anciently made paper by slicing
its cellular pith, and afterward hammering and smoothing it.
553. Cohort II. Restiales.—This includes three orders of
mostly tropical plants bearing glumaceous flowers.
Orders Restiaceae, Eriocaulonaceae, and Flagellarieae.
554. Cohort III. Commelynales.—Plants with a hexa-
merous perianth, in two whorls, the inner colored and petal-
oid.
Orders Mayaceae, Xyridacese, and Commelynacese.
The latter contains the well-known Spiderwort Tradesr.antia, sp.).
555. Cohort IV. Pontederales.—Marsh plants with a
gamophyllous petaloid perianth.
Orders Philydrese, Pontederiacese, and Rapatese.
556. Cohort V. Liliales.—Plants with a hexamerons
(rarely tetramerous) perianth, the parts united or free, and
usually petaloid.
Order Juncacese.—The Rushes. Natives of temperate and cold458
BOTANY.
climates. The leaves and stems are woven into matting and chair
bottoms, and the pith is used for the wicks of candles (rueh-lights).
Order Liliacese.—The Lily Family. Perennial, mostly herbaceous
plants, with entire leaves, and generally showy flowers. The species,
of which there are about two thousand, are distributed in all climates.
Some of these are valuable as food, others furnish .useful medicines,
while many are among our finest ornamental plants.
The more important food plants are the following :
AUium Cepa, the Onion, a native probably of the Mediterranean re-
gion, is grown throughout the world.
Allium Porrum, the Leek, A. sativum, Garlic, A. ascalonicum,
Figs. 345-8.—Illustrations of Fritillarla.
Fig. 345.—Section of flower.
Fig. 346.—Flower diagram.
Fig. 347.—Section of ovary.
Fig. 348.—Ovule.
Fig. 347. mu. 348
Shallot, and a few other species, all natives of the Old World, are con.
siderablv used.
Asparagus officinalis, Asparagus, is a native of the Atlantic and
Mediterranean coasts of Europe, and of the sandy plains of Central and
Western Asia. It has been cultivated in England for upwards of two
thousand years, but it is an interesting fact that in all that time it has
exhibited very little variation.
Among the medicinal plants may be mentioned
Aloe vulgaris, of the Mediterranean region, and other species inLILIALES.
459
Southern and Eastern Africa, the inspissated juice of whose leaves con-
stitutes tlie drug Aloes.
Smilax officinalis, of South America, and other species, furnish Sarsa-
parilla root.
Fig. 349.—Underground parts of Colchicum autumnale at the time of flowering.
A, front view ; ky old corm; s',scales surrounding flower stalk. B, section show-
ing new stem, h\ with rudimentary leaves, l"; the very long tubular flowers, b, b',
spring from near the summit of the new stem, h'. The following spring h' will elon-
gate and carry the fruit, and leaves V, l", above ground ; the lower part of h/ will en-
large into a corm like k', while at k" a new plant will form as a lateral bud.—After
Sachs.
ScUla maritima ; the sliced bulb of this Mediterranean sand plant is
the drug Squill.
Veratrum album, the White Hellebore of the mountains of Central460
BOTANY.
Europe, and V. mride, Green Hellebore of the Eastern United States,
are poisonous emetics. The rhizome is officinal.
Ornamental plants:
Asphodelus lutevs is the Asphodel of Southern Europe.
Agapanthus umbellatus, the Love Flower of the Cape of Good Hope,
is a beautiful green-house plant, bearing pale blue flowers.
Colchicum autumnale, the “ Meadow Saffron ” or “ Autumn Crocus ”
of Europe, is curious for its producing leaves in the spring, and then,
long after these have died down, in the autumn sending up one or two
long-tubed pale flowers, which soon wither away ; the following spriDg,
by the lengthening of the underground stem, the seed-pod is carried
up, along with the green leaves (Fig. 349). The corms of this plant
were formerly in some repute as medicines.
Oonvallaria majalis, the Lily of the Valley, is a native of woodlands
and shady places in England, Europe, and Siberia.
Drctcama Draco, the Dragon Tree of Western Africa and the adja-
cent islands, is cultivated as a curiosity in green-houses. A tree of
this species on the island of Teneriffe was, at the time of its destruc-
tion by a hurricane in 1867, upwards of 20 metres (70 ft.) high, and 5
metres (16 ft.) in diameter, and from its known slow growth it must
Lave been many hundreds, possibly some thousands, of years old.
Fntfflari'.i imperialis, the Crown Imperial, a native of the south of
Europe and Western Asia, is a showy plant.
Funkia, sp., and HemerocaUis, sp., the Day Lilies, the former from
China and Japan, the latter from Southern Europe, and Hyacinthus
orientalis, the Hyacinth of Asia Minor, are in common cultivation.
IAlium—many species. The True Lilies. Aside from our native
species, L. Philadelphicum, L. Canadense, and L. superbum., which
deserve cultivation, the following are commonly found in gardens :
L. bulbiferum, the Orange Lily, from Southern Europe; flowers
orange.
L. tigrinum, the Tiger Lily, from China ; flowers orange-red.
L. Pomponium, the Turban Lily, from Europe ; flowers red.
L. Chalcedonicum, the Ked Lily, from Asia Minor; flowers red.
L. Martagon, the Turk’s Cap Lily, from Europe ; flowers flesh-
colored.
L. speciosum, the Showy Lily, from Japan; flowers rose-colored.
L. auratum, the Golden Lily, from Japan ; flowers white and
golden.
L. candidum. the White Lily, from Asia Minor; flowers white.
L. Japonicum, the Japan Lily, from Japan ; flowers white.
L. longiflorum, the Long flowered Lily, from Japan; flowers
white.
Myrnphyllumasparagoides, a delicate climber from the Cape of Good
Hope, is grown in windows and conservatories under the name of
Smilax.ARALES.
461
Ornitliogalum unibettatum, the Star of Bethlehem, is a native of Cen-
tral Europe,
Polianthes tuberosa, the Tuberose, a native probably of the East
Indies, bears a tall spike of fragrant white flowers. It is sometimes
placed in the order Amaryllidacete.
Ruscus aculeatus, the Butcher’s Broom of England and Southern
Europe, a curious shrub, with flat leaf-like branches, is rarely cultivated
with us.
Tritoma uvaria, of the Cape of Good Hope, bears a tall spike of red
flowers, and hence receives in cultivation the name of the “ Red-Hot
Poker Plant.”
1’ulipa Oesneriana, the Tulip, is a native of the Levant. It was
brought into Europe about three hundred years ago, and originally
bore yellow flowers, but under long culture it has developed number-
less varieties. To the Dutch we owe much of the improvement in this
flower ; in the first half of the seventeenth century throughout Holland
so much attention was given to its culture, and such high prices paid
for single bulbs of the finer varieties, that a speculative mania (known
aa the “ tulipomania”) arose, resembling the wildest of modern grain
or stock manias.
Yucca, of several species, known by the name of Adam’s Needle,
Spanish Bayonet, Bear Grass, etc., is a genus of fine ornamental
plants, natives of the warmer parts of America. The strong fibres are
sometimes made into cordage. The roots contain saponin, and are
used by the Mexicans instead of soap for washing.
Xanthorrhosa includes the curious Grass Gum Trees of Australia.
557.—Cohort VI. Arales.—A group of dissimilar plants,
some being large trees, and others microscopic floating herbs.
Order Lemnacese.—The Duckweeds. These smallest of Phanero-
gams consist of floating disks (thalli), with no distinction of leaf and
stem, bearing one or several roots beneath (in Wolffia, however, no
roots). They are parenchymatous throughout, or with only rudiment-
ary vascular tissues. Their flower-clusters are sunken into pits in the
top or edge of the disks, and consist of one or two stamens and a single
pistil, representing as many reduced flowers. There are about twenty
species, widely distributed throughout the northern hemisphere. We
have eight or ten species in the United States. (Figs. 350-2.)
Order Aroideae.—The Arum Family. Herbs often large and palm-
like in appearance, with large leaves having reticulated venation. In-
florescence generally surrounded by a spathe. Of the Aroids there are
about 1000 species, distributed mostly in tropical countries, where they
sometimes attain a height of several metres (6-12 feet); in temperate
climates they are much smaller. They possess an acrid juice, which
may be poisonous.462
BOTANY.
Some of the species have been used in medicine, among which are
the Indian Turnip (Ariscema), and Sweet Flag (Acorus).
Caloeasiaantiquorum, a large plant of the tropics, is there grown for
its fleshy farinaceous corm. It is grown with us for its fine foliage.
Richardia Afi icana, the so-called Calla-lily, or Ethiopian Lily, a na-
tive of the Cape of Good Hope, is a common green-house plant.
Symplocarpus foitidus, the Skunk-cabbage of the Northern United
States, is remarkable for the mephitic odor of its bruised leaves.
Amorphophallus Titanum, an Aroid discovered in 1878 by Beccari in
Fig. 350.—Two plants of L. minor. Magnified.
Fig. 351.—Three flowers in a spathe.
Fig. 352.—Section of pistil.
Sumatra, has an enormous spathe, 1.7 metres (6 feet) in depth, and 83
cm. (2$ feet) in diameter.
Order Typhacese, represented by the two genera Typlia and Spa/r-
ganium.
Order Pandanacese.—Mostly tropical plants, some of them of a
tree-like aspect.
Pandanus includes the Screw Pines of the East Indies, so called from
the spiral arrangement of their clustered leaves.
Co.rludomca palmata, a Central American plant, with palmate radical
leaves borne on petioles three metres (8-10 feet) long, is important as
furnishing the material from which the famous Panama hats are.
made.
558.—Cohort VII. Palmales.—Shrubs or trees with di-
vided (rarely simple) leaves. Flowers in a spadix.
Figs. 350-2.—Illustrations op Lemna.
Fig. 350.
Fig. 351.
Fig. 352.PALMALtSS.
463
Orders Nipacese and Phytelephasieae, both of the tropics. In
the latter, Pkytelephas mncrocarpa, of Central America, is remarkable
for the ivory-like endosperm in its large seeds ; hence its name of
Ivory Nut.
Order Palmaceas.—The Palm Family. Trees, shrubs, or woody
climbers ; natives almost exclusively of the torrid zone, or the adjacent
Figs. 353-6.—Illustrations op Pai.mace.p.
Fig. 356. Fig. 355.
Fig. 353.—Fruit of Cocoa-nut. a, exocarp ; b, endocarp ; c, testa ; d, endosperm;
e, embryo ; /, milk cavity.
Fig. 354.—Cocoa-nut seen from below.
Fig. 355.—Vertical section of a Date, showing seed inside.
Fig. 356.—Seed of Date in cross-section, showing embryo.
hotter portions of the temperate zones, being rarely found beyond 40“
North and 35° Soutli latitude. The arborescent species are among the
most striking and majestic of plants; their long cylindrical stems fre-
quently rise to the height of thirty metres (100 feet), bearing at their
summits Bpreading crowns of large leaves, and drooping clusters of fruit.
The whole number of known species is not far from one thousand.
The economic value of the Palms is very great; in fact it may be ques-464
BOTANY.
tioned whether any other order of plants (the Grasses possibly excepted)
approaches them in the importance of the products they furnish. Every
species appears to be useful, and the uses of some of the species may
be reckoned by hundreds. In some countries every want of man is
supplied by one or another of the palms.
I. Tribe Cocoinece.—Atalea juniftra is a Brazilian species of
stout-growing trees, whose fibrous leaves are used in making ropes,
mats, and coarse brooms. The nuts, known as Coquilla nuts, are seven
to eight cm. (3 inches) long, very hard, and are used for making door-
handles, bell-pulls, etc.
Cocos nucifera, the Cocoa-nut Palm, is a native of the coasts of tropi-
cal Africa, India, Malay, and islands of the Indian and Pacific Oceans.
It is now, however, cultivated throughout the tropics. The tree varies
tn height from fifteen to thirty metres (50 to 100 feet), and bears long
pinnate leaves. The nuts, which are borne in clusters of seven to ten
or more, are the well-known cocoa-nuts of commerce. As a new cluster
is pushed out every month, the annual yield of a single tree may be
from 100 to 150 or more nuts, and this may continue for forty years. In
some parts of India and other countries,"the white albumen of the nut
forms nearly the entire food of the natives, and the milk serves them
for drink. In this country great quantities are used as a delicacy and
for culinary purposes.
In cocoa-nut countries the uses of the root, stem, leaves, and fruit are
said to be as numerous as the days in the year, sufficing for all the wants
of the inhabitants. The root is used as a masticatory ; the stem is used
for the most diverse purposes, while the hard case of the base is used
for making drums, and in the construction of huts, the tender termi-
nal bud is highly prized as an article of food. The juice of the
flower-stems is rich in sugar, and this, by fermentation, produces an ex-
cellent wine, and by distillation yields a spirit called arrack. From the
sheaths and leaves the natives construct roofs, fences, baskets, buckets,
ropes, mats, brooms, and numerous other articles. The fibre from the
leaves and sheaths is imported into this country and made into “ coir”
ropes, floor-matting, brushes, and brooms, and used also for stuffing
cushions. Even the hard shell is of use in the manufacture of cups
and ornaments.
Elceis guineenm, of West Africa, produces annually large quantities
of pulpy fruits, each containing a hard nut. From these palm oil is
obtained, which is used in Europe and the United States for making
candles, for the manufacture of soap, and also to some extent for lubri-
cating purposes.
II. Tribe Coryphinece.—Copernica cerifera, the Wax Palm of
Brazil, attains the height of twelve metres (40 feet), with a diameter of
stem of thirty cm. (1 foot). The hard wood takes a fine polish, and is
used for veneering. The young leaves are coated with a waxy secre-
tion which is used in England for making candles.PALMALES.
465
Phoinix dactyttfera, tlie Date Palm, is a native of Northern Africa
and Western Asia, now naturalized in the south of Europe. The tree
is dioecious, and grows to the height of ten to twelve metres (40-50
feet), bearing a crown of leaves, each leaf being four to six metres (15-
20 feet) long. The fruit is produced in large bunches, containing from
twenty to thirty dates. Dates constitute a large portion of the food of
the Arabs of the African and Arabian deserts. They are largely im-
ported into the United States. They are prepared by gathering before'
they are quite ripe, and then drying in the sun.
The cultivation of the date palm has for ages been an object of first
importance in Arabia and Northern Africa. The trees are hereditary,
and are sold as estates, constituting the chief wealth of the inhabi-
tants.
Sabal Palmetto, the Cabbage Palmetto, S. serrulata, the Saw Palmetto,
S. Adansonii, the Dwarf Palmetto, and Chamcerops Hystrix, the Blue
Palmetto, all of the southeastern United States, and Washingtonia fil-
ifera, of California and Arizona, are our principal native palms.
III. Tribe Borassinece.—Borassus flabelliformis, the Palmyra
Palm, is a native of nearly all Southern Asia. It has large fan-shaped
leaves, anda cylindrical stem rising to the height of fifteen to thirty me-
tres (50 100 feet). Wine, or toddy, and sugar are made from the juice ;
the young sprouts of the flowering branches are used for food in the
same manner as asparagus. From the stem is obtained Palmyra wood.
Hyphcene thebaic,a, the Doum or Gingerbread Palm, is a branching
species of the upper Nile region. It produces fruits of the size of an
apple and with the flavor of gingerbread. A resin derived from this
tree is known as Egyptian Bdellium.
Lodoicea sechellarum, the Double Cocoa-nut of the Seychelle Islands
in the Indian Ocean, is a giant among the palms. It attains the height
of thirty metres (100 feet), its stem being forty-five to sixty cm. (1£ to 2
feet) in diameter. It produces large oblong nuts, which have the ap-
pearance of being double, and which weigh from thirty to forty pounds.
They are borne in bunches of nine or ten in number, so that a whole
bunch will often weigh 400 pounds. It takes ten years to ripen the
fruit, the albumen of which is similar to that of the common cocoa-nut,
but it is too hard and horny to serve as food. The leaves are made into
hats, baskets, etc. The demand for the leaves for these uses has become
so great that the trees are cut down in order to obtain them, and as no
care is taken to form new plantations, it is feared that this palm will
eventually become extinct.
IV. Tribe Calameee.—Calamus Rotang and several other spe-
cies include the Rattan or Cane Palms of India and the Malayan
Islands. They have slender reed-like stems which grow to a great
length, often from sixty to one hundred or more metres (200-300 feet),
and are imported into Europe and the United States for making chair-
bottom1'. umbrella-ribs, etc.466
BO TANT.
Calamus Draco, of the same region as the preceding, yields a reddish
resinous substance known as Dragon’s Blood, and which is a secretion
coating the surface of the small fruits. Dragon’s blood is used for col-
oring varnishes and for staining horn.
Sagus Icevis and S. Bumphii, Sago Palms, are trees nine to fifteen
metres (30-50 feet) high, natives of Siam, the Indian Archipelago and
other islands of the East. The sago is obtained by splitting the trunks
*and extracting the soft white pith ; this is thrown into tanks of water,
in which it is repeatedly washed and strained until a pure pulpy paste
is obtained. In’this state, in order to preserve it, the natives keep it
under water, and it forms a large proportion of their food. For expor-
tation it is dried and granulated through sieves. A tree fifteen years
of age yields from six to eight hundred pounds of this nutritious
material.
V. Tribe Arecinece.—Areca Catechu, the Betel Palm of Cochin
China and the Malayan peninsula and islands, produces a fruit of the
size of a hen’s egg, which is the famous Betel Nut or Pinang of the far
East. The nut is cut into pieces and rolled up with lime, gambier, etc.,
in a leaf of the betel pepper, and chewed as tobacco is in this country.
Caryota mens, of India, is one of the wine or “ Toddy” palms. It
grows to the height of fifteen to eighteen metres (50-60 feet), and has a
large crown of compound winged leaves. It is said that this tree will
yield one hundred pints of toddy in twenty-four hours.
Ceroxylon andicola, the Wax Palm of the mountains of New Granada,
is a tall tree, bearing large pinnate leaves five to six metres (15-20 feet)
long. It is found on the mountain sides nearly to the snow line. The
trunk is coated with a resinous wax, which is scraped off by the natives
and used for making candles.
Chammdorea of several species, climbing palms of New Granada are
interesting on account of their stems being used in forming suspension
bridges.
Saguerus saccharifer of the Malayan Archipelago is a valuable Sago
Palm. It is twelve to fifteen metres (40-50 feet) high, and bears enor-
mous pinnate leaves; a tree grown in the Kew Gardens bore leaves
twelve metres (40 feet) in length. Sugar is also obtained from the
juice which flows from the wounded spadix.
559. Cohort VIII. Potamales.—Mostly herbaceous wa-
ter plants, with all of the parts of the flower distinct; the,
embryo large, and endosperm wanting.
Order Naiadacese.—The Pond-weeds.
Order Alismacese.—The Water Plantain Family. This order is
interesting from the fact of its evident relationship to the Ranales
(Cohort 36) among Dicotyledons, as long ago suggested by Adanson,
and insisted upon by Lindley. (Figs. 357-9.)NABCI8SALE8.
467
Alisma and Sagittaria are two common genera.
560. Cohort IX. Triurales, with one small and little
known order.
Order Triurideae.—Delicate, almost colorless herbs of the tropics.
561. Cohort X. Dioscorales.—Climbing herbs or under-
shrubs, bearing reticulately veined leaves.
Order Dioscoreacese.—The Tam Family. Several species of Dios-
corea produce edible tubers.
D. saliva, D. aculeata, and other species of India are extensively
grown there and in the West Indies as potatoes are grown in cooler
climates.
D. Batatas and D. Japonica are known as Chinese Tams.
Testudinaria elephantipes, of the Cape of Good Hope, is a curious
Fig. 357.—Flower cut vertically. Magnified.
Fig. 358.—Seed. Magnified.
Fig. 359.—Section of seed. Magnified.
green-house plant, having a large, woody, above-ground corm-stem,
from which spring every year slender twining stems.
562. Cohort XI. Xareissales.—Plants with narrow, often
equitant leaves, having parallel venation; seeds containing
endosperm.
Order Hsemodoracese.—The Blood-wort Family.
Order Amaryllidacege.—The Amaryllis Family. Distinguished
front the next order by having six stamens, and leaves which are not
equitant. The four hundred species are herbs of temperate and trop-
ical climates ; many possess a narcotic and poisonous principle.
Agave Americana, the, Century Plant of Mexico, is now much grown
in conservatories, and is said to be naturalized in Southern Europe, in
California and its native country it blooms at the age of from ten to
Figs. 357-9.—Illustrations of Alisma Plantago.
Fig. 357.
Fig. 358.
Fig. 359.468
BOTANY.
fifteen years, but in cool climates it requires from thirty to seventy or
more. The mature plant has a cluster of thick, sharp-pointed radical
leaves, each about 2 metres (6 ft.) long, from the centre of which it
sends up a flowering stem 10-15 cm. (4-6 in.) thick, and 5-6 metres
(16-20 ft.) high, hearing hundreds of yellow flowers. The Mexicans
cut out the central bud just before the lengthening of the flowering
stem, and from the juice, which flows out in great abundance, obtain
by fermentation the drink called “ Pulque,” or by distillation the more
generally used “ Mescal.” The subterranean stems possess a detergent
principle, and under the name of ” Amole ” are much used by the
Mexicans in washing. The strong fibres in the leaves are used for
cordage.
Hcemanthus toxicaria, of Sou'*1 Africa, has a poisonous bulb, which
is used by the Hottentots for poisoning their arrows.
Many species are grown for the beauty of their flowers ; among these
. may be mentioned:
Amaryllis, of many species, mostly from South
Africa and Soutli America.
Qnlantlius nivalis, the Snowdrop, of Europe.
Leucojum vcrnum, the Snowflake, of Europe.
Narcissus, of many species; this includes the
Daffodil, Jonquil, Polyanthus, etc., all natives of
Europe.
Order Iridaceae.—The Iris Family. The sta-
mens are only three (by the abortion of an inner
whorl, Fig. 360), and the leaves are equitant. The order contains five
hundred species, which are mainly found in the south temperate clim-
ates, a smaller number occurring in north temperate regions. They
contain a purgative principle, which has been used in medicine.
Crocus vermis and other species are commonly grown for their early
spring flowers ; the dried stigmas of C. sativus constitute the drug Cro-
cus or Saffron used in medicine and also in dyeing.
Gladiolus psittacinus and other species, lrom the Cape of Good Hope,
are deservedly popular as ornamental plants.
Iris Germanica, of Europe, and many other Old World species, are
common in gardens.
Our native I. versicolor, I. cristata, and others, are also worthy of
culture.
Fig. 360. — Flower
diagram or Irida-
cete.—After Sachs.
563. Cohort XII. Taccades.—This includes two small
tropical orders of herbaceous plants.
Orders Taccacese and Burmanniaceae.
564. Cohort XIII. Orchidales.—Herbs with a hexamer-
ous (rarely trimerous) zygomorphic perianth ; the stamens
and style more or less confluent into a common column, andORCHIDALES.
4G9
the minute seeds containing a rudimentary embryo and no
endosperm.
Order Apostasiacese, a small order of East Indian plants, which are
Interesting because of their
evident relationship to the
Orchids, from which they
differ in having the style
partially free from the sta-
mens.
Order Orchidaceee. —
The Orchids. Terrestrial
or epiphytic plants, whose
stamens and style are com-
pletely united into a com-
mon column or gynoste-
miurn. The three thousand
species are found in “all
climates and in all situa-
tions but maritime and
aquatic.” (Hooker.)
This order has long been
highly esteemed for the
many curiously shaped and
colored flowers it affords,
and many hundreds of its
species are to be found in
cultivation in conservato-
ries. They are interesting
also from the fact that none
of them are, unaided, capa-
ble of fertilizing their
ovules, and appear in every
case to be dependent upon
insects for the transport of
the pollen and its deposition
upon the stigma.
This great order is usu-
ally divided into seven
tribes, as under.
Tribe I. Cypripe-
diece, with two pollinifer-
ous stamens containing
granular pollen (Fig. 862).
In this the genus Gypri-
pedium, which contains our native Lady’s-Slippers,is the most important.
Some of the species, notably C. spectabile and C. acaule, are greatly ad-
mired in cultivation.
Fig. 361 —Orchis maculata. A, a symmetrical
vertical section of a flower bud. B, transverse sec-
tion of the bud. 6', transverse section of ovary.
It, mature flower, with one sepal removed ; x,
axis of flower cluster ; b, bract; $, sepals ; p, pet-
als ; l, labellum; ap, its spur ; a and pi, pollen-
mass ; h. its viscid disc ; p's, the column (gyno-
stcminm); near gs is the stigma which projects
toward h; f, inferior ovary, twisted in D ; at, sta-
minodes.—After Sachs.470
BOTANY.
Tribe II. Neottiece, with a single dorsal anther, containing
two or lour soft pollen masses attached to a viscid disc. Our principal
genus is Spiranthes.
Tribe III. Arethusece, with a single terminal anther, contain-
ing two or four powdery pollen masses.
Our native Arethusa and Calupogon are fine representatives of this
tribe. The Vanilla plant (Vanilla planifolia, and other species) of
tropical America, a climbing epiphyte, produces fleshy capsules 12 to
25 cm. (5-10 in.) long, which are highly aromatic, and much used in
the manufacture of confections, beverages, medicines, etc. When first
introduced into the East Indies, where it is now much grown, it failed to
perfect fruit; artificial pollination hav-
ing been resorted to, however, the dif-
culty at once disappeared. (Fig.363.)
Tribe IV. Ophrydew, with a
single anterior anther, containing two
stalked pollen masses, each attached to
a viscid disc (Fig. 361).
Our pretty little Orchis spectdbilis,
and many species of Ilabenaiia, are
our principal representatives of this
tribe. From the tubers of Orchis mas-
cula and other European and Asiatic
species, the starchy-mucilaginous and
highly nutritious substance “ Salep,”
is obtained.
Tribe V. Vandece, with a single
terminal or dorsal anther, containing
waxy pollen masses attached to a vis-
flower of Cipripeaium catceolus, the cid disc
perianth,]), temoved. -4, side view.
A, back view. C, front view. /, the We have no native representatives
inferior.ovary ; g», the column or gy- f tWg tribe Many Gf tlie tropical
noeteminm; aa. stamens; a, sterile J . e
stamen or staminode ; n, stigraa.— species are of wonderful forms; indeed,
After Sachs. as jlr. j)arw;n says Df them, they are
“ the most remarkable of all Orchids.” In some genera they assume
the most curious forms, resembling insects of various kinds, birds, etc.,
etc. In Catasetum sciccatum, a diclinous South American species,
when certain sensitive parts of the column of the male flower are
touched by an insect, the pollen masses are by a peculiar contrivance
thrown out forcibly in such a direction as to strike the insect, to
which it adheres by a viscid disc, and is thus carried to and brought in
contact with the Btigma of the female flower.
Tribe VI. Epidendreae, with a single terminal anther, contain-
ing stalked, waxy pollen masses, these not attached to a viscid disc. To
this tribe belong in the United States Tipularia, Blctia, and Epidert-
drum, the latter an epiphyte, occurring only in the Southern States.
Fig. 362 — Sexual organs of theAMO MALES.
471
■Of the exotics, Ccdogyne, Lcelia,Cattleyn, etc., are to he seen in conserve
tories.
Tribe VII. Malaxidece, with a single dor-
sal, terminal, or anterior anther, which contains four
stalkless, waxy pollen masses, not provided with a
viscid disc.
Calypso, Liparis, Corattorhiza, and other genera
occur in the United States ; the last named appears
to be parasitic. Among the many exotics may be
mentioned Bulbophyttum, Dendrobiiim, Malaxis,
etc.
Amomales.—Herbs
1
565. Cohort XIV.
(some almost arbores-
cent) with hexamerous
and mostly zygomor-
phic perianth; sta-
mens six, generally
from one to five only
polliniferous.
Order Bromeliacese.
—The Pine-apple Family.
Distinguished from the
next by the regular flow-
ers and six perfect sta-
mens. About two hundred
species of almost entirely
tropical plants constitute
this order. But one genus
(Tillandsia) is represented
in the Southern United
States ; of the eight or ten
native species, the Long Moss (T. usneoides) of the
Southern Atlantic coast is the best known. It is
used in upholstery and in the manufacture of mat-
tresses.
Ananassa saliva, the Pine-apple, supposed to be
a native of Brazil, is now cultivated throughout the
world. In cool climates it is grown in hot-houses,
and it is said that these are much better than those
grown out of doors in warm climates. The fleshy
fruits are aggregated into solid cone-like masses (Fig.
364), the well-known Pine-apples of commerce.
Order Scitaminese.—The Banana Family, with
zygomorphic perianth, and one to five, very rarely
six, perfect stamens. Three sub-e-ders are well marked.
W\
Fig. 364. — Spike of the
fruits of the Pine-apple (An-
anassa sativa) terminated
by a tuft of leaves.
m'
m
Fig. 363.—Ripened
ovary of Vanilla, split
open send showing the
seeds.472
BOTANY.
Sub-Order Musce, with five polliniferous stamens (rarely six).
The genus Musa contains several exceedingly valuable plants. M.
sapientum, the Banana, and M. paradisiaca, the Plantain, of the trop-
ics everywhere, are large herbs, 3-5 metres (10-15 ft.) high, with the
sheathing petioles of their large leaves forming a tree-like stem.
Their well-known fruits constitute almost the sole article of food for
millions of people in the tropics, and are also largely exported to all
countries. It has been calculated that from twenty-five to sixty-six
tons of bananas can be grown upon an acre of ground, supplying more
nourishment to man than is afforded by any other plant. They are
considerably grown in bot-houses, both as ornaments and for their
Fig. 365.—Part of a flowering plant of the Banana, showing the unfolding flower-
bud and the youug fruits.
fruits. From their leaves and petioles a good fibre is obtained, and
from the allied M. textilis of the East Indies is obtained “ Manilla
Hemp,” so much used in the manufacture of various textile fabrics.
Strelitzia Begince, of the Cape of Good Hope, is a common conserva-
tory plant.
Sub-Order Zingiberce, with one polliniferous stamen, bearing
a two-celled anther. Several of these tropical plants are important.
Curcuma longa, of the East Indies and tropical Pacific islands, has
a yellow colored rhizome, which constitutes the weH known dye,
“ Turmeric.”
Zingiber officinale, the Ginger Plant, probably a native of India, is
now grown in most tropical countries for its aromatic rhizomes, whichDICOTTLEDONES.
when dried and powdered constitute the ginger of commerce. That
from the West Indies, called Jamaica Ginger, is considered the best.
Slib-Order Canine, with one polliniferous stamen, bearing a
one-celled anther. Aside from Canna, with its many ornamental Bpe-
cies now common in gardens, one other plant deserves mention, viz. .
Maranta arundinaceo, a native of tropical America, now grown ex-
tensively for its fleshy rhizomes, from which a starch known as “Arrow-
root ” is obtained.
566. Cohort XV. Hydrates.—Small aquatic plants, with
a hexamerous regular perianth, and stamens three, six, nine,
or twelve.
Order Hydrocharideae.—This contains the Eel Grass, Vallisneria
spiralis, and Water Weed, Anacharis Canadensis,
common in our ponds ; the latter is naturalized in
England, where it chokes up streams.
Fossil Monocotyledons.—The earliest Mono-
cotyledon, so far as known at present, was a Tri-
assic species of Yuccites, doubtfully referred to the
Liliacese. In the Jurassic the Gramineae, Cyper-
acese, Liliaceae, Naiadaceae, and Pandanaceae were
represented by a few species. In the Cretaceous the
Cannae, Dioscoreaceae, and Palmacese appeared.
A species of the last-named order lias been discov-
ered in the Cretaceous of Western Kansas. In the Tertiary most of the
modern orders of Monocotyledons were represented (however, no orders
of Cohorts II., III., and XIII. have yet been found). Fifteen species
of palms have been described from the Tertiary of the Great Plains
and the Rocky Mountain region,* extending as far north as northern
Dakota and Vancouver’s Island. Their remains are also abundant in
the Tertiary of Mississippi.
Sub-Class II. Dicottledones.
(Exogeim of De Candolle, f)
567. —In the plants of this sub-class the first leaves of the
embryo are two and opposite, hence they are said to have
two cotyledons. The venation of the leaves is for the most
* “Contributions to the Fossil Flora of the Western Territories.
Part II. The Tertiary Flora,” by Leo Lesquereux. Washington, 1878.
f From the Greek i£o, outside, and yevetv, to bring forth. The
name is no longer a proper one, as we now know that these plants
are not, strictly speaking, “ outside growers;” on the contrary, they
increase in thickness by the growth of an internal meristem layer.
Fig. 366.—Diagram
of the flower of Can-
na, showing theoreti-
ca' structure. — After
Sachs.474
BOTANY.
part such that the veins rarely are parallel to each other, and
in their anastomosing they form an irregular net-work.
The germination of Dicotyledons may be illustrated by a couple of
examples. In the seed of the Windsor Bean (Fig. 367) the embryo
entirely fills up the seed-cavity, the endosperm having all been ab-
Fias. 367-8.—Germination op Dicotyledons.
Fig. 367. Fig. 368.
Fig. 367.— Viclafaba. A, seed with one cotyledon removed ; c, remaining cotyle-
don ; kn, the plumule • w, the radicle ; s, seed-coat. B. germinating seed ; 8, seed-
coat, partly torn away at l; n, the hilum ; st, petiole of one of the cotyledons; k,
curved epicotyledonary stem ; he, short hypocotyledonary stem ; h, main root; W8>
its apex ; kn, hud in the axil of one of the cotyledons.—After Sachs.
Fig. 368.—Bicinus communis. /., longitudinal section of the ripe seed. II., ger-
minating seed with the cotyledons still inside of the seed-coat (shown more distinct-
ly in A and B). s, seed-coat; e, endosperm ; c, cotyledon ; he, hypocotyhdonary
stem ; w, primary root; w', branches of root; caruncle, a peculiar appendage to
the seeds of Euphoibiacece.—After Sachs.
sorbed. The thick cotyledons lie face to face, and are attached below
to the small stem of the embryo plant. The stem extends upward a
short distance between the cotyledons, bearing a few rudimentary
leaves and itself ending in a punctum vegetationis (Fig. 369, ss), the
whole constituting the plumule. The downward prolongation of the
stem (commonly but erroneously called the radicle, for it is not a littleBICOTYLEDONES.
475
root) ends in a. very short root, which is continuous with the stem.*
Under the proper conditions of heat
and pushes out through the inicro-
pyle of the seed-coat; at the same
time, the stalks of the cotyledons
elongate and thus bring the plumule
outside of the seed-coat, the cotyle-
dons alone remaining. During the
first few days of its growth the
young plant is nourished by the
starch in the cotyledons, which in
this species remain during the whole
process of germination beneath the
ground enclosed in the seed-coat. In
the common Field Bean (Phaseolus)
the germination is the same, except-
ing that the hypocotyledonary 6tem
elongates, and brings the cotyledons
which have slipped out of the seed-
coat above the ground.
The seed of Ricinus (the Castor
Oil Plant) contains a large embryo
surrounded by a thin layer of endo-
sperm (Fig. 368,/). In its germina-
tion the root and liypocotyledonary
stem elongate, and thus bring the
seed-coat with the contained coty-
ledons above the ground (Fig. 368,
II). The cotyledons remain within
the seed-coat until they have absorb-
ed all of the endosperm ; when this
is accomplished the empty seed-coat
falls away, and the freed cotyledons
expand and assume to some extent
the function of ordinary foliage
leaves.
The venation of the leaves of Di-
cotyledons is easily studied by mac-
erating them so as to remove the
parenchyma (mesopliyll), leaving
only the fibro-vascular bundles.
While there is as a rule a general
likeness between them, there is yet
an almost infinite diversity in the
and moisture, the root elongates
Fig. 369.—Longitudinal section of the
axis of the embryo in the ripe seed of
Phaseolus multiflorus, parallel to the
cotyledons. 88, apex of the stem ; ws,
of the root; ct, swelling near insertion
of cotyledons ; i, the first internode ;
pb, the petioles of the first foliage
leaves ; v, v, f, procambium of the
fibro-vascular bundles ; he, hypocoty-
ledonary portion of the stem (the brace
is too loDg in the figure), x 30.—After
Sachs.
* In some old books, and even a few recent ones, a structure called
the collar or collum is spoken of. Dr. Gray very properly defines it as476
BOTANT.
details. The general disposition of the smaller veins is well illustrated
by Fig. 369a * *
568.—The sub-class Dicotyledones is composed of thirty-
six cohorts, containing in all from 150 to 200 natural orders.
For convenience, the cohorts are separated into three artifi-
cial groups—the Apetalae, Gamopetalae, and Choripetalae
(Polypetalae)—an arrangement which does violence to nature,
separating widely many orders -which are evidently closely
related to each other.
I. APETALiE. Plants whose flowers generally have but
a single floral envelope (calyx),
this even, in some cases, wanting.
569. Cohort 1. — Santalales.
Herbs, shrubs, or trees, mostly
parasitic, with inferior ovary,
generally naked ovules—i.e., no
integuments—and seeds usually
containing endosperm.
Order Balanophoreae. — Fleshy
leafless parasites, mostly of the trop-
ics. One species, Cynomorium coccin-
eum, of the Mediterranean region, is
sometimes eaten.
Order Santalacese.—Leafy herbs,
Fig. 369a.—Fragment of a leaf of a shrubs, or trees, mostly parasitic, num-
Dicotyledon {Psoralen biluminosa), . . , , AAA . _, . , __
showing reticulated venation, r, bering about 200 species, which, are
margin of leaf, x 40.—After De distributed in temperate and tropical
regions.
Gomandra umbellafa, a perennial herb, is our most common repre-
sentative of the order.
Santalum album, the Sandalwood Tree of South Asia, attains a height
of seven to eight metres (25 feet). Its dark red wood is used in cabinet-
making, and for burning incense in Buddhist temples. Other species
from the Pacific islands also furnish sandalwood.
The Quandang Nut of Australia is the edible fruit of a small tree,
Fusanus acuminatus.
4* the name of an imaginary something intermediate between primary
stem and root.”
* The student who wishes to study this subject fully should consult
the papers of Dr. Ettingshausen, published in Denkscliriften and
Sitzungsberichte Wien. Kais. Akad. Wissen. They are excellently il-
lustrated with many “ nature printed” plates.Q UERNALE8.
47?
Order Loranthaceee. Tlie Mistletoe Family. Evergreen shrubs,
parasitic upon other Dicotyledons. About 450 species are known;
these are mostly tropical.
Vtscum album, the Mistletoe of England, Europe, and Northern
Asia, grows abundantly upon the apple and many other trees, rarely,
however, upon the oak. The viscid fruits are used in making bird-
lime, and its twigs and branches are much used in Christmas decora-
tions in England. It was held sacred by the Druids, who made use of
it iu their religious ceremonies.
Phoradendron flavescens, the American Mistletoe of the Southern
United States, is well known. On the Pacific coast, a variety of this
species is common on the oaks.
Six species of Arceuthobium, small brown branching parasites on
Conifers, are known in the United States. A. pusittum occurs in the
Northern States.
570. Cohort II.—Quernales. Trees and shrubs, not at
all parasitic, with diclinous flowers, mostly in catkins, infe-
rior ovaries, and seeds destitute of endosperm.
Order Cupuliferese. The Oak Family. Trees or shrubs with
simple leaves ; fruits (nuts), one-celled, one-seeded, one to three en-
closed in an involucre. This valuable order contains about 300 species,
which are distributed mainly in the Northern Hemisphere ; in the South-
ern Hemisphere they occur in Chili, New Zealand, and the mountains
of South Australia. Most of the species are astringent, which is due
to the tannin they contain.
The order is of great economic importance on account of its valuable
wood, which is used not only as a fuel, but still more in the manufac-
ture of implements and utensils, and in the construction of houses,
ships, etc. It is divided into two sub-orders, which are sometimes re-
garded as orders.
Sub- Order Corylece. Shrubs and small trees.
Carpinus Americana, the Blue Beech, or Hornbeam, is a small native
tree with white, fine-grained, hard wood. As the European C. betulus
is used in turnery, doubtless our species might be also.
Corylus Avettana, the Filbert, is a shrub growing wild in Europe and
Western and Northern Asia, and now cultivated in Europe and the
United States. It is grown principally for its edible nuts, although the
straight rod-like branches are largely used in making hoops, crates for
merchandise, etc. White Filberts, Red Filberts, Cob-nuts, and Bar-
celona-nuts are some of the cultivated varieties. G. Americana, the
common wild Hazel-nut of the Eastern United States, is much like the
preceding, but smaller in size of shrub and nuts. Its nuts are gath-
ered and eaten, and are occasionally found in the markets.
Ostrya Virginica, the Ironwood of the Eastern United States, is a
email tree having a hard, fine-grained wood, which is valuable for fuel.478
BOTANY.
Although capable of many uses iu the arts, it has been, to a great ex-
tent, neglected. The trunks of the young trees are much used for
levers in saw-mills and log-yards, hence one of its popular names.
Lever-wood.
Sub-Order Quercinece. Mostly large trees.
Castanea vesca, the so-called Spanish Chestnut, is a native of Asia
Figs. 370-74.—Illustrations of Quercus Robur.
Fig. 370. Fia, 374.
Fig 370.—Male and female branches, with a ripe fruit at the side.
Fig. 371.—Male flower. Magnified.
Fig. 372.—Female flower. Magnified.
Fig. 373.—Female flower, in vertical section. Magnified.
Fig. 374.—Vertical section of fruit.
Minor and the region eastward to the Himalayas. It is found in Cen-
tral and Southeastern Europe, but it was probably introduced from the-
East 2000 or more years ago. It furnishes a valuable coarse grained
timber, and its fruits are the “Spanish Chestnuts” of the markets.QUERN ALES.
47&
Several varieties occur in North Africa, Japan, and North America. G.
vesca, var. Americana, our native Chestnut, of the Eastern United
States, is a large tree, with smaller and sweeter nuts than the Old
World variety. Its wood, which is light, coarBe-grained and easily
worked, is highly prized for making doors, cases, certain kinds of fur-
niture, etc.
Fagus sylmtica, the Beech of Europe and Western Asia, supplies a
hard wood much used in chair-making, turnery, and in the manufac-
ture of wooden shoes. Purple Beech, often cultivated as a curiosity,
is a variety of this species.
F. ferruginea, the common Beech of the Eastern United States, is a
large spreading tree ; its wood is reddish in color, and of great hard-
ness when dry, and is used in making carpenters’ tools, and for other
purposes. Its nuts, known as Beech-nuts or Beech-Mast, are nutritious,
and, where abundant, are used for fattening swine.
In Southern South America, New Zealand and Australia, there are
six or seven evergreen species of this genus.
The genus Quercus includes the Oaks, in all about 250 species, which
are widely distributed in the Northern Hemisphere ; none occur be-
yond the equator. De Candolle (Prodromus.Vol. XVI.) divides the
genus into six sections, four of which are exclusively Southeastern-
Asiatic.
Section I.—The Scaly-Cupped Oaks. These include the common
oaks of Europe and America. They are again subdivided into two sub-
sections—viz., the White Oaks and the Black Oaks.
(a) White Oaks.
Quercus Rohur, the British Oak, of England and the Continent of
Europe. It is a stately tree, supplying a most valuable timber for all
kinds of constructive purposes, in naval, civil, and military engineering.
It is considered to be superior to all other kinds of oak for its timber.
The bark contains tannin, and is much used in tanning. (Figs. 370-4.)
Q. Lusitanica, var. infectoria, of the Levant, produces the Nutgalla
of commerce ; these are morbid growths on the petioles or midribs of
the leaves, resulting from punctures made by an Hymenopterous insect
of the genus Oynips. Their value lies in the tannin they contain.
Q. alba, the White Oak of the Eastern United States, stands next to
Q. Robur in the value of its timber, which is used in this country as
British Oak is in Europe.
Q. siirens, the Live Oak of the Southeastern United States, and ex-
tending westward to Texas, is a large tree, twelve to twenty metres
(40-60 feet) high, with spreading branches, bearing small entire ever-
green leaves. Its hard and heavy wood is very strong and durable,
and has been much used in ship-building.
Q. chrysolepis, the Canon Live Oak of the canons and mountain-sides
of California, resembles the preceding in many respects, being like it
an evergreen, and sometimes attaining a height of from twelve to six-480
BOTANY.
teen metres or more (40-50 feet). “It furnishes the hardest oakwood
of the Pacific Coast, and is used in making ox-hows, ax-bandles, etc.”
(Vasey).
<2- Sitber, the Cork Oak, is found in Southern France, Spain, Italy,
Sardinia, and, to a limited extent, in Northern Africa. It is a spread-
ing topped tree, bearing oval, dentate evergreen leaves. Certain lay-
ers of cells in its bark retain their power of growth for a long time,
and give rise to a thick mass of cork. This is removed every eight or
ten years by making vertical and transverse cuts in the bark, and then
peeling off all but the inner bark layers. Most of the supply of cork
comes from Spain and Southern France. The tree might very profit-
ably be grown in our Southern States and in California.
Q. cerris, the Turkey Oak of Southeastern Europe, is a fine tree with
deciduous, lobed leaves, and bears a considerable resemblance to our
native Q. macrocarpa, from which it differs, however, in requiring two
years to mature its fruits. Its timber is much used for ship-building
and other purposes.
(6) Black Oaks.
In this are the Black Jack (Q. nigra), the Red Oak (Q. rubra), Scarlet
Oak (Q. coccinea), Quercitron Oak, (Q. ccccinea, var. tinctoria), all of
the Eastern United States. The timber obtained from these is coarse-
grained, and not so durable as that of the white oaks ; the two last fur-
nish a yellow dye, Quercitron, which is derived from the bark. Q. agri-
folia, the Field Oak of California is a broad-topped evergreen species.
Its wood is of but little value.
Section II., the Spiny-Cupped Oak, includes but a single species,
found in California.
<2- densiflora, the California Tan-bark Oak. This is a beautiful tree,
often thirty metres or more in height (100 feet), with curious chestnut-
like fruits.
The remaining sections contain eighty to ninety species, confined en-
tirely to India, China, Japan, and the Malay Islands. They differ in
many respects from our oaks.
Order Juglandaceae.—The Walnut Family. Trees and shrubs
with pinnately compound leaves ; fruit a dry drupe, containing a hard,
one-seeded nut (Figs. 380-382). This family includes about thirty spe-
cies, about equally divided between North America and Asia. They
possess an acrid aromatic principle, which has been used in medicine.
Juglans regia, the Walnut of the Old World, is a native of Asia
Minor and the country eastward, but long cultivated in all parts of
Europe, and, to some extent, in this country. The light brown wood is
highly prized in England for cabinet-making, the manufacture of fur-
niture, piano-cases, gun-stocks, etc. Its tliin-shelled nuts are highly
esteemed, and are imported from Europe in large quantities under the
name of “ English Walnuts.” (Figs. 375-82.)
J. nigra, the Black Walnut of the Eastern United States, is a giantQUERN ALES.
481
tree, often forty to fifty metres (130-160 feet) in height. Its dark brown
timber is fully as valuable as the preceding, and is used for the same
purposes. It is exported in considerable quantities to England. Its
Figs. 375-82.—Illustrations of Juglans regia.
Fig. 380. Fig. 381. Fig. 382.
Fig. 375.—Female flower cluster. Fig. 376. Female flower. Magnified.
Fig. 377.—Female flower cut vertically. Magnified.
Fig. 378.—Male flower. Magnified. Fig. 379.—Male flower cluster.
Fig. 380.—Ripe fruit. Fig. 381.—Endocarp. Fig. 382.—Seed.482
BOTANY.
thick-shelled and stronger-tasting nuts are occasionally found in the
■markets.
J. cinerea, the White Walnut or Butternut, of the Eastern United
States, is a smaller tree, furnishing a valuable lighter colored timber
than the preceding.
Two small species occur in California, Arizona, and Texas.
Carya a ha, the Shell-bark Hickory, and C. sulcata, both large trees,
of the Eastern United States, furnish a white, tough, and hard timber,
useful in the manufacture of agricultural implements, and for many
other purposes where great strength is required. It is not well adapted
to use in large masses, as it is liable to early destruction through decay
and the ravages of wood-boring insects. The fruits, known as
“ Hickory-nuts,” and highly prized for eating, are found in our mar-
kets, and are also exported to England.
0. olmceformis, a small tree of the Southern States, furnishes a thin-
shelled edible fruit known as the “ Pecan-nut.”
Other species of Carya furnish valuable timber, and from the nuts
of this and the preceding species valuable “nut-oils” used in paint-
ing are obtained.
571. —Cohort m. Asarales. Herbs, with mostly mon-
oclinous flowers, inferior ovary, and seeds with integuments,
containing minute embryo usually surrounded with endos-
perm.
Order Rafflesiaceee.—Parasites upon the stems and roots of Dicoty-
ledons. Twenty or more species are known, distributed throughout
the hotter parts of the world.
Bafflesia ArnolcLi, of Sumatra, is the most remarkable member of the
order. It consists of a gigantic parasitic flower nearly a metre in di-
ameter (3 ft.), with five mottled-red spreading petals. It is parasitic
upon a woody climbing plant (Cissus angustifolia) nearly related to the
Vine, and in its growth forms scarcely any stem, developing almost at
once into a giant flower-bud. It was discovered in 1818 by Dr. Arnold.
Order Aristolochiacese.—Mostly tropical herbs, including about
200 species. Three species of Asarum, and three of Aristoloc/iia occur
in the United States.
572. —Cohort IV. Nepenthales. Climbing shrubs, with
diclinous flowers, a superior three to four-celled ovary, whose
many seeds contain an endosperm.
Order Nepenthacese.—Plants of the East Indies and Australia, of
ten or twelve species, all belonging to the genus Nepenthes. The
leaves are prolonged into a slender tendril-like organ, upon whose ex-
tremity there develops a hollow closed body, which finally becomes
open by the separation of its apex in such a manner as to form a
hinged lid (Fig. 383, d, e, /). In the cavities of these pitchers, as theyP1PEBALES.
483
are called, a watery, slightly acid fluid is secreted ; upon their borders
are secreted honey or nectar drops, which attract insects, and these fall-
ing into the fluid within are soon dissolved by it, and then absorbed by
the plant for its nour-
ishment.
573.—Cohort V.
Piperales. Mostly
herbs, with spiked
flowers and superior
one-celled and one-
seeded ovary.
Order Ceratophyl-
leee.—Aquatic herbs of
the Northern Hemi-
sphere.
Order Chlorantha-
cese.—Shrubby plants,
mostly of the tropics.
Order Piperacese.—
The Pepper Family.
Herbs, shrubs, or small
trees, almost confined to
the tropics ; generally
with a pungent and
aromatic principle.
Over 1000 species are
known.
We have one species
of Saururus in the East-
ern, and one of Anemi-
opsis in the Southwest-
ern United States.
Two tropical genera,
Piper and Peperomia,
include nearly all the
species, the first con-
taining 620 and the sec-
ond 382.
Piper nigrum is a
climbing East Indian
plant, with beart-Bhaped leaves ; it bears spikes of berries, which,
when gathered green and dried, constitute the Black Pepper of com-
merce. The ripe berries, when dried, constitute White Pepper. Pep-
per is now grown in the West Indies.
Fig. 383.—Two leaves of JVemiii'ies ampulluria.
petiole; b, blade or expanded part of leaf
a,
ten-
d, e, pitcher ; /, its
short
dril-lifee prolongation of midrib, ,j, ILO
lid. In the other leaf, which is younger, the lid has not
yet separated from the apex of the pitcher.—After Du-
chartre.484
BOTANY.
P. Ciibeba, whose dried unripe berries are known in pharmacy as
Cubebs, is a native of the East Indies.
P. Betle, of the East Indies, is the Betel Pepper, whose bitter aro-
matic leaves are mixed with Areca-nut and lime to form a masticatory.
(See Betel Palm, p. 466.)
From the thick rhizome of P. methysticum the inhabitants of many
of the Pacific islands make a disgusting drink which is very intoxica-
ting.
574.—Cohort VI. Euphorbiales. Plants with mostly
diclinous flowers, with a superior two to many-celled ovary ;
seeds containing endosperm.
Order Lacistemacese. Shrubs of tropical America.
Order Geissolcmeae, containing a single shrub, of Southwestern
Africa.
Order Peneeaceae. Evergreen shrubs of South Africa.
Order Euphorbiace®.—The Spurge Family. This vast group of
upwards of 3000 species cannot be defined by anyone character. They
may generally be distinguished by their three-celled ovaries and milky
juice, although neither of these characters is universal throughout the
order. The species range in size from small herbs to gigantic trees,
and are distributed throughout all climates except beyond the Arctic
Circle. They are much more abundant, however, in tropical countries
than elsewhere. With few exceptions they possess an acrid principle,
which is often poisonous.
Many of the species are of economic importance, a few of which only
can be mentioned here.
Manihot palmata and M. utUissima, slender plants of tropical Amer-
ica, and now cultivated in many tropical countries, have thick starchy
roots. The starch, separated and washed, is imported under the name
of Brazilian Arrowroot. Tapioca is prepared by heating the separated
and washed starch upon hot plates. Cassava is made from the crushed
roots by drying the pulp without separating the starch. These three
substances are highly nutritious, and are much used as food by the
natives, and are, moreover, largely imported into this country. Their
value is all the more remarkable from the fact that the root of the
second named species above is in its raw state deadly poisonous.
Bicinvs communis, the Castor Oil plant, a native of India, is now
widely grown for its oily seeds, from which Castor Oil is obtained by
pressure. It is extensively grown in the Mississippi Valley. In Ger-
many it is grown for its leaves, which are fed to silkworms. It is a
beautiful ornamental plant, and when grown for this purpose is called
the Palma Christa.
Croton Oil from Croton Tiglium, and Pinhcen Oil from Jatropha Cur-
cas, are drastic medicines. Gum Eupliorbium, the dried milky juiceEUPHORBIALES.
485
of various African and Indian species of Euphorbia, Cascarilla Bark and
Melambo Bark from species of Groton in tropical America, are more or
less known in pharmacy.
Eevea Guianensis and other species of the genus, natives of the
northern part of South America, furnish the important substance
Caoutchouc, or India Rubber. The trees are from fifteen to thirty
metres in height (50 to 100 ft.), and bear trifoliate leaves resembling
those of the Scarlet-runner bean in size and shape. The natives make
incisions into the trees, from which the milky juice exudes, and this
evaporated constitutes the crude Caoutchouc. By heating the crude
product with sulphur it is hardened, and is then known as “Vulcan-
ized rubber.”
Exccecaria sebifera, the Tallow tree of China, now cultivated in the
warmer parts of America, has its seeds coated with a white greasy sub-
stance, which yields a valuable tallow from which candles are made.
Aleurites Moluccana, the Caudle Nut tree of India and the Pacific
islands, produces a large oily fruit, which is itself burned and used as
a candle, or from which a valuable oil is extracted.
The most valuable timber of the order is furnished by Buxus semper-
mrens, the Box tree of Europe and Asia. It is a small evergreen
tree, with a very hard yellowish wood, invaluable in wood engraving,
the manufacture of mathematical instruments, etc. Our chief supply
comes from the Mediterranean ports. A dwarf variety of this species
is used for bordering garden walks.
African Teak, a very heavy and hard wood from Africa, is supposed
to be derived from Oldfieldia Africana, which has been doubtfully re-
ferred to this order.
Among the plants grown for ornament are many species of Euphor-
bia, an immense genus of TOO species, distributed very widely : in
Africa they assume a Cactus-like aspect, having thick succulent stems.
These and many other species are to be found in conservatories. The
curious Xylophytta, with flat leaf-like branches, bearing flowers upon
their edges, is also common.
The Sand Box tree of tropical America bears a curious many-celled
fruit which when dry explodes with a loud report.
The juice of many of the species is poisonous when dropped upon the
skin, or into a wound. The Manchineel tree (Hippomane Mancinetta)
of South Florida and the West Indies is extremely poisonous, but many
of the stories told of it are fabulous.
Zebra Poison is the name applied to Euphorbia arborea ; branches of
it placed in water render it sufficiently poisonous to kill the animals
which drink it.
575.—Cohort VII. Amentales. Woody plants, with di-
clinous flowers, mostly in catkins; the one or two-celled
ovary superior, and the seeds with no endosperm.486
BOTANY.
Order Salicaceae.—The Willow Family. Dioecious trees and shrubs
with naked flowers—i.e.y the perianth wanting. The species, of which
there are 180, are principally found in the North Temperate and
Arctic Zones; beyond the tropics they are rare, and none occur in
Figs. 384-9.—Illustrations or Salix caprjsa.
Fig. 384.
Fig. 385.
Fig. 386. Fig. 387. Fig. 388. Fig. 389.
Fig. 384.—Male catkin and separate flower.
Fig. 385.—Female catkin. Fig. 386.—Female flower. Magnified.
Fig. 387.—Cross-section of ovary. Magnified.
Fig. 388.—Ripe fruit and seed. Magnified. Fig. 389.—Embryo. Magnified.
Australia and the South Pacific Islands. They contain a bitter astrin-
gent principle useful in medicine as a febrifuge.
Two genera only are known.
Salix verminalis, S. purpurea, S. caprcea, and other species of the
Old World, are cultivated for basket-making.AMENTALES.
487
S. Babyloniea, the weeping willow of Persia, is well known under
■cultivation.
S. alba and other large species of Europe furnish a light firm wood,
much used for many purposes.
By charring the wood a fine charcoal is obtained, much used in the
manufacture of gunpowder. In ihe prairies of the Mississippi Valley
the species last named is planted in compact rows to serve lor hedges
and to break the force of the violent winds.
Some of the larger of our many native species might profitably be
used for their light timber, which in some cases is quite durable.
Populus Canadensis, the Cottonwood of North America, is a very
large tree, whose white wood is suited to many manufacturing pur-
poses.
The “Lombardy Poplar,” a variety of P, nigra, and a native prob-
ably of Western and Northern Asia, and the Abele tree (P. alba) of
Europe, are commonly grown on large grounds.
Order Casuarinese.—Leafless trees, with pendulous Equisetum-like
jointed stems. Twenty five species, mostly natives of Australia, are
known. Some of them are large enough to supply a valuable timber
for ship-building, and many are favorites for ornamental purposes in
Australia.
Order Myricaceae.—Monoecious or dioecious shrubs, often with a
.glandular waxy pubescence. The thirty to thirty-five species are
widely distributed throughout the North Temperate Zone, and in trop-
ical Asia and Soutli Africa.
The berries of Myriea cerifera. the Bayberry, of the Eastern United
States, and other species in Europe are covered with a wax, which is
gathered and made into candles.
Order Platanaceae. — The Plane Tree Family. A small group of
five monoecious trees, with the flowers in globose catkins.
Platanus occidentalis, the Plane tree, Buttonwood, or Sycamore of
the Eastern United States, is a large tree with thin white bark. Its
reddish wood is valuable, and should be more used. A nearly related
species occurs in California and two in Mexico. The fifth, P. oriental-
is, is the only Old World species.
Order Betulacese.—The Birch Family. Monoecious trees with
flowers in slender catkins. The species, forty or more in number, are
found throughout the North Temperate Zone, and in South America.
Betala alba, of Northern Europe, Northern Asia, and North America,
is a useful species. Its wood is valuable for fuel, use in manufactures,
and for making into charcoal. Its bark is made into shoes, boxes, etc.;
it is used in tanning leather, and from it by distillation an oil is ob-
tained which gives to Russia leather its peculiar scent. The people in
the high north latitudes also use the cellular and starchy part of the
■bark for food.488
BOTANY.
Tlie bark of B. papy raced, of the Eastern United States, is used by
the Indians for making their “ birch bark canoes.”
The wood of species of Alnus, the Alders, is very durable when
placed under the ground or water. It is also made into wooden bowls
and other domestic utensils, and is in some places grown for making
into charcoal.
576.—Cohort VIII. Urticales. Mostly diclinous plants,
with, superior one-celled ovary, and single seed mostly with
an endosperm.
Order Ulmaeese.—The Elm Family. Trees or shrubs of the North
Temperate Zone, having mostly monoclinous flowers, and a watery
juice. About one hundred and thirty species are known.
Ulmus campestris, the common Elm of Europe and Western Siberia,
is a large tree, thirty to forty metres (100 to 130 ft.) high. Its timber is
valuable for works under ground or in water, and is besides much used
by wheelwrights. The tree is common iu American gardens.
JJ. Americana, the American White Elm of the Eastern United
States, and now much grown in Europe, is one of our linest looking
trees, and deservedly popular as an ornament in large grounds. Its
timber is valuable when used entirely under water or in the ground,
or when kept continuously dry ; otherwise it decays rapidly.
17. fulna, the Slippery Elm of the Eastern United States, supplies a
valuable timber, and its mucilaginous inner bark is used for medical
and surgical purposes.
Celtis occidentalis, the Ilnckberry of the Eastern United States, is a
lofty tree which furnishes a white hard timber, which is not, however,
very durable.
Order Cannabineas.—This contains the two dioecious herbs, the
Hemp and the Hop.
Cannabis sativa, the Hemp, is a tall herb, two to three metres (7 to
10 ft.) in height, indigenous in the northern parts of India, but now
generally cultivated in all temperate and warm regions. Under the
names of gvnja, bhang, chvrrus, haschisch, etc., the natives of India and
Central Africa use the dried leaves, stems, flowers, and the resinous
matter which develops on the plant. When smoked, or drank as an
infusion, these are highly intoxicating. The fibre obtained from its
bark is strong, and much used for cordage.
Iiumulus Lupulvs, the Hop, a native of temperate Europe, Asia, and
North America, is grown for its bitter principle, Lupulin, which de-
velops in the female flower clusters, and which is much used in the
manufacture of. beer, ale, etc.
Order Moracese.—The Mulberry Family. Trees or shrubs, con-
taining a milky juice. The order contains between 800 and 1000 spe-
cies, and they are for the greater part natives of the tropics. ManyURTIGALES.
48y
of them contain an acrid poisonous principle, while some are not only
innoxious, but afford wholesome food.
Artoearpus incUa, the Bread Fruit tree, a native of the Pacific Is-
lands, and now common in tropical countries, attains a height of from
six to nine metres (20 to 30 ft.). The fleshy receptacle and agglomerated
carpels form a mass as large as a man’s head. This “ fruit,” when
gathered a little before it is ripe, and halted, looks and tastes much
like bread, and is largely eaten by tropical people. The Jack Fruit of
India (A. integrifolius) is similar, hut not so palatable.
Ficus Garica, the Fig, a native of Western or Southern Asia, has
Fig. 390.—Fleshy concave receptacle of Dorstenia, bearing male and female flowers.
Fig. 391.—Fleshy closed receptacle of Fiona, cut vertically, containing male flowers
above and female below.
been cultivated for ages. It is now found in all tropical and sub-trop-
ical countries. It is grown in tbe Southern United States and in Cali-
fornia. Tlie tree attains a height of from five to six metres (16 to 20
ft.), and bears pear-shaped closed receptacles (Fig. 391), inside of which
are the minute flowers. The ripened and dried receptacles constitute
the Figs of commerce. Our supply comes mainly from the Mediter-
ranean Basin.
Qalcictodendron utile (Brosimum utile), a tall tree, twenty-five metres
liigh (80 ft.), of Venezuela, whose milky juice is used by the natives as
a substitute for milk, to which it bears a close resemblance. The tree
vs hence called the Cow Tree.
Flos. 390, 91.—Illustrations of Moraceas.
Fig. 390.
Fig. 391.490
BOTANY.
Morus nigra, the Mulberry tree of Persia, is now cultivated in Eu-
rope and the United States for its edible fruit masses. Its leaves are
used to feed to silkworms, but not to so great an extent as those of
M. alba, the White Mulberry, which has been used from time imme-
morial for this purpose in China.
M. rubra, a native of the Eastern United States, bears valuable
fruits.
Several of the trees of the order yield Caoutchouc. The most im-
portant of these are Ficus elastica of India, and Caslilloa elastica of
Mexico and the West Indies ; the first named is a common greenhouse
plant.
Gum Lac is a resinous exudation collected from an Indian species of
Ficus, whose branches have been punctured by an hemipterous insect,
Coccus lacca.
The wood of many species is valuable.
Brosimum Guianensis, of Guiana, produces the beautifully mottled
and streaked Snakewood, much prized by cabinetmakers, and for
making bows.
Maclura aurantiaca, a tree eight to fifteen metres (25 to 50 ft.) high,
growing in Arkansas, Texas, etc., supplies a very hard wood used by
the Indians for making bows, hence one of its names, “ Bow-wood.”
Under the name of Osage OraDge, it is much used as a hedge plant.
Its wood yields a coloring matter used as a dye, and from M. tinctoria,
of the West Indies, the dye known as Fustic is obtained.
The bark of many species yields tenacious fibres ; thus from the
Paper Mulberry (Broussonetia papyrifera), a Chinese and Japanese tree
eight to fifteen metres (25 to 50 ft.) in height, the Chinese make paper,
and the Pacific Islanders make cloth. One of the most remarkable is
the Sack tree (Antiaris saccidora) of Western India; its bark is so
tenacious that after beating, it may be removed in sections, which are
used for sacks for carrying rice, etc.
The Upas Tree of Java (Antiaris loxicana) is poisonous, but it is by
no means as virulent as it has been described. It frequently grows in
volcanic valleys partially filled with carbon dioxide and other noxious
gases, and to this fact is doubtless due the marvellous stories told of it.
However, from its juice the natives prepare a deadly poison for tlieir
arrows.
The Banyan Tree (Ficus Indica) is remarkable for its numerous ad-
ventitious roots, which grow down from its horizontal branches, and
thus enable it to extend its top very greatly. One on the Nerbudda,
with three hundred and twenty of such supporting roots, covers an
area two hundred metres (650 ft.) in diameter.
Order Urticacese.—The Nettle Family. Herbs, shrubs, or trees,
with a limpid juice; they occur in all climates, but mostly in the
tropics. More than five hundred species are known. Many of the
species possess a valuable fibrous bark. (Figs. 392-7.)DAP UN ALES.
491
Bmhmeria nivea. the China Grass or Ramie, a perennial herbaceous
plant, may fairly rival Flax in the fine and durable fibres it produces.
It has been introduced into the Southern United States and California.
There is still some difficulty in separating the fibres from the woody
portions of the plant, and this has prevented its more extensive use.
The Stinging Nettles include ten genera, of which the most impor-
tant are Urtica, which includes our common species, and Laportea,
represented by our Wood Nettle ; to the latter belongs the Tree Nettle,
L. gigas, of Australia, which reaches a height of Irom fifteen to forty
metres (50 to 130 ft.), and whose sting is so severe as to produce dan-
gerous results.
577. — Cohort
IX. Daphnales.
Mostly shrubs or
trees, with mono-
clinous flowers ;
ovary superior,
one-celled, with a
single seed con-
taining no endo-
sperm.
Order Protea-
ceae.—A family of
about 1000 species,
confined almost en-
tirely to the South-
ern Hemisphere, and
occurring in greatest
abundance in Aus-
tralia and South
Africa. Many spe-
cies, especially of the
genus Banksia, are cultivated in conservatories. A few furnish valua-
ble timber.
Qremllea robusta, the Silk Oak of Australia, attains a height of
twenty-four to thirty metres (80 to 100 ft.), with a diameter of two
metres or more, and supplies valuable timber.
Knightiaexcelsa is a valuable New Zealand timber tree thirty metres
(100 ft.) or more in height.
Leucadendron argenteum, the Silver Tree of the Cape of Good Hope,
has silvery lanceolate leaves; its wood is much used for fuel.
Protea grandiflora, the “ Wagen-boom ” of the same region, is used
by wheelwrights in the manufacture of wagon wheels.
Order Elaeagnaceee.—A small order, of sixteen species, of treeB or
Figs. 392-7.—Illustrations op Urtica urens.
Fig. 392.
Fig. 393.
Fig. 394.
Fig. 392.—Male .flower. Magnified
Fig. 393.—Diagram of male flower.
Fig. 394.—Female flower. Magnified.
Fig. 395.—Diagram of female flower.
Fig 396.—Seed. Magnified.
Fig’397.—Section of seed. Magnified.492
BOTANY.
shrubs, found mostly ir. the mountains of Southern Asia. The Oleaster
(Elceagnvs tiortensis) of Southern Europe is there much planted for its
odoriferous flowers ; it is occasionally planted in this country.
Shepheidia Canadensis, of the Northeastern United States, and S.
argentea, the Buffalo-Berry of the Rocky Mountains and the Great
Plains, are frequently cultivated for their acid fruits, which are about
as large as currants.
Order Hernandiese, including a few tropical trees.
Figs. 398-403.—Illustrations of Laurus nobilis.
Fig. 398.—Male flower. Magnified. Fig. 399.—DiagTam of male flower.
Fig, 400.—Female flower. Magnified. Fig. 401.—Section of female flower.
Fig. 402.—Diagram of female flower.
Order Thymelseaceee.—Shrubby plants, mostly of the Southern
Hemisphere. Of the 378 species we have in the United States but oue
representative, viz., the Moose-wood or “ Wicopy ” (Dirca palustris), a
small shrub with exceedingly tough bark.
Daphne Mezereum, a poisonous shrub of Europe, is frequently culti-
vated here for its sweet-smelling flowers.
The bark of many species is used in their native countries for makingLA UR ALES.
493
fabrics, cordage, etc. Lagetta lintearia, of Jamaica, is tbe Lace-Bark
Tree, so called on account of its delicate inner bark.
578.—Cohort X. Laurales.—Herbs, shrubs, and trees,
with mostly diclinous flowers ; ovary superior, one-celled,
the single seed sometimes with, and sometimes without
endosperm.
Order Lauraceae.—The Laurel Family. Aromatic trees and shrubs
Figs. 403-5.—Illustrations of Myristica fragrans.
Fig. 403. Fig. 405.
Fig. 403.—Fruit, showing seed and aril. Fig. 404.—Seed and aril.
Fig. 405.—Seed cut vertically, showing embryo below.
{rarely parasitic herbs) with free stamens, and a pendulous seed with-
out endosperm. About 1000 species are known, occurring in the trop-
ical and temperate climates of both hemispheres.
Lawnis nobilis, the Bay or Laurel of Southern Europe, is a fine
spreading-topped evergreen tree, twelve to fifteen metres (40 to 50 ft.l
high. In ancient times its leaves were used to crown heroes, but now494
BOTANY.
they are made use of in flavoring custards, puddings, etc., and are put
into boxes of figs to give them a factitious flavor. (Figs. 398-402.)
Umbellularia Californica (Tetranthera Californicu), the California
Laurel, resembles the preceding, and like it is evergreen. Its wood is
used in cabinet-making.
Persea gratissima, a small West Indian tree, produces a delicious
fruit called Avocado- or Alligator-Pear.
Among the aromatic products are Cinnamon, the bark of Cinna-
momurn Zeylanicum, a small tree of Ceylon; Cassia Bark and Cassia
buds, from G. Cassia, of Ceylon ; Camphor, a gummy matter distilled
from the wood of C. Camphora, a tree of China and Japan ; Sassafras
Bark, from Sassafras officinale, of the Eastern United States.
The wood of the two last-named trees is valuable in cabinet-making,
as is also that of the Red Bay (Persea) of the Southern United States.
Nectandra Rodiei, the Greenheart Tree of Guiana, is a large tree
furnishing an exceedingly heavy, dark colored, and durable timber,
highly valued in naval constructions.
Order Myristicacese.—The Nutmeg Family. Aromatic trees, with
monadelphous stamens, and an erect seed containing endosperm. The
seventy-five species are all tropical, and most of them occur in the In-
dian region. They all belong to the genus Myrislica.
Myristica fragrans, the Nutmeg Tree of the Malay Archipelago, at-
tains a height of six to nine metres (20 to 30 ft.; ; it bears a fleshy fruit
of the size of a walnut and inside of this is a large seed covered with a
red, branching aril (Figs. 403-4). The seed, deprived of its integu-
ments, is the nutmeg of commerce, while the dried aril is the Mace,
both well known condiments.
Some of the other species are occasionally used, but they are much
less valuable.
Order Monimiacese.—Aromatic trees or shrubs of the tropics and
south temperate zone. About 150 species are known. The Tasmanian
“ Sassafras Tree ” (Atherosperma moscliata), the Australian “ Sassafras
Tree” (Boryphora Sassafras), and the New Zealand “Sassafras”
(Laurel-la Norm Zelandice), are large trees thirty to forty-five metres
(100 to 150 ft.) high, whose timber is valuable for ship-building.
579.—Cohort XI. Chenopodiales. Monoclinous (rarely
diclinous) herbs or shrubs; ovary superior, one-celled, the
single seed containing endosperm.
Order Paronychiese.—A small group of mostly herbaceous plants,
the flowers generally with both sepals and petals ; the latter, however,
rudimentary. The order has close affinities with Caryophyllacese, of
which it should probably be considered a sub-order.
Order Basellacese.—Herbaceous, often climbing plants of the
tropics. One species from South America (Boussingaultia baselloides)CHENOPODIALES.
495
is cultivated as an ornamental climber under the name of Madeira
Vine. The starchy tubers of another species, Uducus tuberosus, are
used in Peru as substitutes for the potato.
Order Chenopodiacese.—Herbs, shrubs, or rarely trees, whose
flowers have an herbaceous perianth. About 500 species, distributed
in all climates, are known. (Figs. 406-11.)
Beta vulgaris, the Common Beet, is a native of Southern Europe.
The Sugar Beet and Mangel Wurzel are only varieties of the Common
Beet; the first is extensively cultivated in France for the sugar which
Figs. 406-10.—Illustrations or Beta vulgabis.
is obtained from its sweet juice ; its cultivation in this country is yet
in its infancy.
Ghenopodium Quinoa, a Peruvian annual, is cultivated in Western
South America for its nutritious seeds, which are ground into meal, and
used as an article of food.
C. ambrosioides, Wormseed, from tropical America, used somewhat
in medicine, and other species of the genus, have become common weeds
in fields and gardens.
Spinacia olerarea, Common Garden Spinach, is an Oriental plant
much cultivated as a pot herb.496
BOTANY.
Order Amarantaceee.—Herbs, rarely shrubs, whose flowers have a
scarious perianth. The order, which contains about 500 species, is
mostly tropical, a few occurring in temperate climates, but none at all
in cold ones.
In India some of the species are cultivated for their starchy seeds,
which are used for food.
Several species are cultivated with us for their ornamental foliage,
(Achyranthes) or their colored inflorescence, e.g.,
Cock’s Comb (Oelosia), Globe Amaranth (Gomphre-
na), etc.
Amarantus retroflexus and A. albus, are common
weeds in fields; the latter, in the prairie region,
o/sfedof cSwwmo- gro'n’s in a globular form, and in the autumn breaks
dium. Magnified. 0ff at the root, and is blown for miles across the
country. On account of this habit of growth it is called the “ Tumble
Weed.”
Order Polygonacese.—The Buckwheat Family. Herbs, shrubs, or
rarely trees, mostly with sheathing stipules and knotted-jointed stems ;
perianth often petaloid. The 600 species constituting the order are
mostly natives of temperate regions.
Fagopyrum esculentum, Buckwheat, a native of Central or Northern
Fisa. 413-15.—Illustrations of Fagopyrum esculentum.
Fig. 412. Fia. 413. Fig. 414. Fig. 415.
Fig. 412.—Flower. Magnified. Fig. 413.—Diagram of flower.
Fig. 414.—Pistil. Magnified. Fig. 415.—Fruit. Magnified.
Asia, is now extensively grown in Europe and America for its nutri-
tious seeds, and for its honey-producing flowers. (Figs. 412-15.)
Polygonum amphibium, var. terrestre, a native of the United States,
has been used in the Mississippi valley as a substitute for bark in the
process of tanning. It contains a considerable quantity of tannin.
Rheum officinale. Oriental Rhubarb, is a native of Southeastern
Asia; its roots constitute the officinal Rhubarb. Other species are
often used as substitutes.L AMI ALES.
407
R. Rhaponticum, a native of Western Asia, is commonly grown in
gardens under the name of “Pie Plant,” its petioles are uBed for tlie
pleasant acid they contain.
Many species are weeds of fields and gardens ; sucli are Smartweed,
and Black Bindweed (Polygonum, sp.), Docks and Sorrel (Rumex, sp.).
Order Phytolaccaceae.—Mostly tropical kerbs, sometimes shrubs
or trees, usually with several free or united carpels. About eighty
species are known, most of which are more or less acrid.
Phytolacca decandra, the Common Pokeweed, is our most notable
representative. It is, however, a doubtful native.
Order Nyctaginaceae.—Mostly tropical herbs, shrubs, or trees with
opposite leaves and tumid joints ; flowers gamophyllous. About
200 species are known. The roots of many of the species are purgative
or emetic.
Abronia, of several species. Mirabilis, sp., the Four O’clock, or
Marvel of Peru, and some others, are cultivated as ornaments.
II. GAM 0PETALiE.—Plants whose flowers generally
have both sepals and petals, the latter connately united.
580.—Cohort XU. Lamiales. Plants with zygomorphie
flowers, superior ovaries, indehiscent fruits, with the seeds
solitary in the two to four cells.
Order Labiatae.—The Mint Family. Aromatic herbs or shrubs,
with four-angled stems and opposite leaves. The species, of which
there are about 2500, are abundant in temperate and warm climates,
but are rare in cool regions. We have about 200 native species in
North America. (Figs. 416-18.)
Considering the size of the order, it ranks low from an economic
standpoint. The aromatic herbage has led to the use of many species
as domestic remedies, few of which, however, are really valuable.
Nevertheless, there are many species yielding minor products which
are of some value.
Hyssopus officinalis, Hyssop, a small shrub of Southern Europe, is
commonly cultivated in gardens as a domestic medicine.
Hedeoma pulegioides, American Pennyroyal, is an officinal herb.
Lavandula vera, Lavender, is a shrubby plant of the South of
Europe, cultivated in gardens, and used as a domestic perfume. Oil
of Lavender is obtained from it (by distillation.
Mentha piperita, Peppermint, introduced from Europe, yields Oil
of Peppermint by distillation. It is extensively grown in Southern
Michigan and New York.
MarrvMum vulgare, White Horeliound, of Europe, is commonly
found in gardens; its dried herbage is officinal.
Rosmarinus officinalis, Rosemary, Thymus vulgaris, Thyme, and Sal-498
BOTANY.
via officinalis, Garden Sage, are small South European shrubs, now
to be found in all gardens.
Catnip, Balm, Horsemint, and many others are used more or less as
family medicines, for which purpose they are well suited, being harm-
less and feebly operative.
Several tropical species of Salvia are grown as ornaments, as are also
'Coleus and Perilla, from Southeastern Asia.
Order Verbenacese.—The Vervain Family. Herbs, shrubs, or
trees, usually not aromatic, with mostly four-angled stems. The
species number about 700, and are chiefly tropical. They generally
possess a bitter and astringent principle.
With us the order is esteemed principally for its ornamental value.
Fig. 416.—Flower of Lamivm, side view.
Fig. 417.—Vertical section of flower. Magnified.
Fig. 418.—Diagram of flower.
Besides the several South American species of Verbena in common cul-
tivation, the so-called Lemon Verbena (Lippia citroidora) from Chili,
and the species of Lantana from tropical America, there are to be
found in conservatories many showy species of Clerodendron, from Asia.
Tectona grandis, the Teak Tree of India, is a gigantic tree whose
yellowish durable wood is much used in ship-building. It is said to
resist the attacks of Limnoria terebrans when exposed in sea-water.
Vitex littoralis, of New Zealand, and other species, growing in the
Indo-Australian region, are large and valuable timber trees.
Order Myoporinese.—Mostly Anstralian shrubs, of no value.
581.—Cohort XHL Personates. Plants with zygomor-
phic flowers, superior ovaries, and dehiscent many-seeded
fruits.
Figs. 416-18.—Illustrations op Labiate.
Fig. 416.
Fig. 417.
Fig. 418.PER80NALEB
499
Order Acanthaceas.—Tlie Acanthus Family. Herbs, mostly of
the tropics, numbering about 1500 species. Thirty-five or forty species
occur in North America, mostly, however, in the South and West.
Some of the exotic species are grown in conservatories, e.g., Jaaticia,
Thunbergia, etc.
Order Pedaliaceae.—Herbs with glandular hairs. The most im-
portant species are the Asiatic Sesamum Indicvm and 8. orientate,
whose seeds yield an oil much used as food by the inhabitants of the
tropics.
Martynia proboscidia, the Unicorn Plant of the Southwestern United
States, is notable for its two-hooked fruits.
Order Bignoniacese.—Mostly woody plants, numbering about 500
species, and natives, for the most part, of the tropics. Many are cui-
ng. 419.—Flower. Magnified.
Fig. 421.—Pistil. Magnified,
Fig. 420.—Section of flower.
Fig. 422.—Diagram of flower.
tivated for their fine flowers among these are the species of Bignonia ;
Tecoma, etc.
Gatalpa bignonioides, the Common Catalpa of the Southern United
States, is a fine tree for shade and ornament. Its wood is said to be
very durable. C. speciosa is much hardier than the preceding.
Creacentia G'ujete, the Calabash Tree of tropical America, produces a
large pulpy fruit whose hard rind is used as a water-vessel.
Order Gesneracese.—Mostly tropical plants, represented by Achi-
menes, Gloxinia, Gesnera, etc., cultivated in conservatories.
Order ColumeLliacese.—Evergreen trees or shrubs of tropical
America.
Order Xientibulariaceee. — The Bladderwort Family. Mostly
aquatic or marsh plants, of temperate and warm regions, interesting on
account of the insect-catching bladders of the aquatic species. (ForoOU
BOTANY.
the particulars as to Pinguicula, see Darwin’s “Insectivorous Plants,”
pp. 368-394, and for Utricularia, pp. 395-444.)
• Order Orobanchacese.— Leafless parasitic herbs, numbering 150
species, widely distributed. We have about a dozen native species in
the United States.
Order Scrophulariacese.—The Figwort Family. Herbs or shrubs,
rarely trees, with two-celled ovaries and central placentae. The
species, of which there are about 2000, are found in all parts of the
world, extending in both hemispheres to the limits of vegetation.
Many of the species contain an acrid poisonous principle. (Figs. 419-22.)
Digitalis purpurea, the Foxglove, a small plant of Europe, affords
the drug Digitalis, which is officinal.
Many species are cultivated for their fine flowers ; among these are
the Snapdragon (Antirrhinum), Monkey Flower (Mimulus), Mauran-
dia, Penistemon, Veronica, Calceolaria, etc., etc.
Paulownia imperialis, a small tree of Japan, is planted in the
Southern States.
Verbascum Thapsus, the Common Mullein, is a weed introduced from
Europe.
582.—Cohort XIV. Polemoniales. Plants with alter-
nate leaves, regular flowers, stamens isomerous with the
corolla lobes, and ovary superior.
Order Solanaceee.—The Nightshade Family. Herbaceous or woody
plants with a watery juice ; ovary two-celled, many ovuled. This
large order of from 1200 to 1500 species, which are chiefly tropical, is
pervaded by a more or less poisonous principle. (Figs. 423-7.)
There are, however, a few valuable food plants.
Solanum tuberosum, the Potato, is a native of America from Mexico
to Chili, and a variety of it (var. boreale) even occurs in New Mexico.
The potato was introduced into Spain in the early part of the sixteenth
century, and into England by Sir Walter Raleigh in 1586, but for
nearly a century from the latter date it was little used. It is now,
however, grown extensively in nearly all countries. In its wild state
its tubers are not more than two to three centimetres in diameter, but
by culture and selection they have been increased fifteen to twenty
times in bulk.
Solanum Melongena, the Egg Plant, of South America, is now grown
with us for its egg-shaped edible fruits.
Lycopersicum csculentum, the Tomato, of South America, is grown
in most warm and temperate countries for its wholesome fruits.
Physalis Alktkengi, the Winter Cherry or Strawberry Tomato, of
the South of Europe, is grown in our gardens for its edible fruit, which
is enclosed in the inflated calyx. Our native species of this genus,
called commonly Ground Cherries, are valuable for food.POLEMONIALES.
501
Capsicum annuum, of South America, and other species of the genus,
Figs. 423-7.—Illustrations of Solanaoeu®.
Fig. 423.
Fig. 423.—Flowering stem of Potato.
Fig. 424.—Flower of Bittersweet. Magnified.
Fig. 425.—Diagram of Potato flower.
Fig. 426.—Calyx and pistil of Potato. Magnified.
Fig. 427.—Section of seed of Bittersweet. Magnified.
bear exceedingly pungent pods, known as Peppers. The ground
pods constitute the Cayenne Pepper of commerce.502
BOTANY.
Atropa Belladonna, the Deadly Nightshade, Hyoscyamus niger,
Henbane, and Datura Stramonium, the Thorn Apple, all of the Old
World, supply powerful narcotic medicines. That from the first, un-
der the name of Belladonna, is much used by oculists to dilate the pu-
pil of the eye.
Nicotiana Tabacum, Tobacco, a South American herb, was cultivated
by the American aborigines long before the advent of Europeans. It
was taken to Spain about the beginning of the sixteenth century, and
to England from sixty to eighty years later. It is now extensively
cultivated in many countries, especially in the United States, and is
used by all the civilized nations of the globe. Two or three other
species are also cultivated in different parts of the world.
Among the ornamental plants of the order are species of Ceatrum and
Datura, from South America and Mexico ; Lycium, from Europe;
Petunia, from South America, etc., etc.
The Thorn Apple mentioned above, and the Black Nightshade (So-
lanum nigrum) are common as weeds. The little black berries of the
latter are made into pies and other pastry in the Mississippi Valley.
Order Convolvulacese.—Herbaceous climbers, rarely shrubs, often
with a milky juice; ovary of 1-5 cells, each 2-, rarely 1-4, ovuled.
About 800 species are known, distributed mostly in tropical and warm
temperate regions. They generally possess an acrid principle.
The Common Morning-Glory (Ipomota purpurea) and one or two near
relatives, all from tropical America, are familiar ornamental climbers.
Ipomeea Batatas, the Sweet Potato of India, has long been cultivated
in many warm and temperate climates for its nutritious roots.
The purgative drug Jalap is derived from the root of a Mexican
plant Ipomaa purga.
Convolvulus Scammonia, of Western Asia, yields the drug Scamraony,
and from the wood of C. Scoparius, a shrubby species of the Canary
Islands, Oil of Rhodium is extracted.
Cuscuta, the parasitic Dodder, includes many species.
Order Borraginaceee.—The Borage Family. Usually hispid herbs,
shrubs, or trees, with a four-parted ovary, each part one-ovuled. The
1200 species are distributed throughout the world, although they are
most numerous in Southern Europe and Western and Central Asia.
Many of the species possess a mucilaginous property useful in making
cooling drinks, and the roots of some contain purple or brown dyes.
Anchusa tinctoria, of the South of Europe, is grown in France and
Germany for its roots, which yield the red dye called Alkanet.
Among the commonly cultivated ornamental plants may be men-
tioned the Forget-me-not (Myosotis palustris) of Europe and the Helio-
trope (Heliotropium Peruvianum) of Peru. There are several native
and introduced species which are vile weeds.
Order HydrophyUaeese.—A small order of mostly American herbs,
closely related to the preceding.GENTIANALES.
503
Species of Nemopliila, Phacelia, Whitlavia, etc., are cultivated in
flower gardens.
Order Polemoniaceae.—Mostly herbs of North America and North-
ern Asia, numbering about ISO species.
Species of Phlox, Gilia, Polemonium, Gobcea, etc., are cultivated in
flower gardens.
583.—Cohort XV. Gentianales. Plants with opposite
leaves, regular flowers, superior ovary, and the stamens usu-
ally as many as the corolla lobes and alternate with them.
Order Gentianacese.—The Gentian Family. Annual or perennial
herbs, with a watery juice ; ovary generally one-celled, with many
ovules. The species, of which there are about 500, are found mostly
in temperate and cold climates. They possess a bitter principle, which
has been employed in medicine. We have many very pretty wild
species.
Order Loganiacese.—Woody plants almost entirely of the tropics,
with two-celled ovaries. About 350 species are known ; they contain
a bitter principle which is often exceedingly poisonous.
Strychnos nux-uomica is a small tree of India, bearing an orange-like
fruit containing numerous large flattisli seeds (2 cm. in diameter).
These seeds constitute the poisonous drug, Nux Vomica; they con-
tain two alkaloids to which their activity is due, viz, Strychnia
>
but one superior ovary.
Bentham and Hooker
have arranged the sev-
enty-one genera under
ten tribes, eight of
which only will be no-
ticed here.
Tribe Tomene.—
Shrubs and trees with
simple leaves, ovaries
5 (rarely less), adnate
to and frequently cov-
ered by the fleshy re-
ceptacle (and calyx ?).
Pirus Malus, the
Apple, and P. commu-
nis, the Pear, grow
wild in many parts of Europe. They have been cultivated for ages in
other portions of the world. (Fig. 473.)
P. prunifolia and P. iaccata, Siberian Crab-Apples, of the North of
Asia, are in common cultivation.
P. coronaria, the American Crab-Apple,of the Eastern United States,
might be made a valuable apple by cultivation.
P. Cydonia (or Cydonia vulgaris), the Quince, is a native of the
Levant. (Figs. 474-5.)
The Hawthorns (Cratcegus, sp.) are of some value for their fruits,
and have long been favorites for hedges and ornamental purposes,
Service-berries (Amelanchier, sp.) furnish valuable fruits, and are
ornamental.
Fig. 472.—Leaves of Cephalotusfollicularis. /\ normal
foliage leaf ; ascidium ; b, its incurved border ; /'.
its lid. Natural size.
Tribe Rosece,—Shrubs, with pinnately compound leaves ; ovaries
many, free, but surrounded by the fleshy receptacle (and calyx ?).
Rosa—of many species—the Roses. Not only are our native species
(of which we have about a dozen) more or less cultivated for their beau-528
BOTANY.
tiful flowers, but from eighteen to twenty or more species from
Europe and Asia are commonly to be found in gardens and conser-
vatories. (Fig. 476.)
Tribe Potentillece.—Mostly herbs, with usually compound
Figs. 473-5.—Illustrations op Tribe Pome.®.
Fig. 473.
Fig. 474.
Fig. 473.—Flower cluster of Firm communis.
Fig. 474.—Section of Quince flower (Firus Cydonia).
Fig. 475.—Section of Quince fruit.
leaves ; carpels free, one to many, mostly on a convex fleshy receptacle ;
fruits dry (achenia).
Fragaria elatior, of Europe, F. vesca, of Europe and Eastern UnitedROSALES.
529
States, and F. Virginiana of the Eastern United States, are the species
from which the cultivated Strawberries have been derived, by high
culture and crossing. (Fig. 477.)
Chamaibatia foliosa of the western slope of the Sierra Nevada Moun-
tains in California, is a small fragrant shrub with thrice pinnate leaves,
much gathered by tourists, and deserving a place in gardens.
Cercocarpus ledifoUus, the
Mountain Mahogany, of Califor-
nia, is a shrub or tree, ranging
from two to fifteen metres in
height (6 to 50 feet). Its heavy
dark colored wood is valuable.
Tribe Rubece. — Mostly
shrubs, differing from the pre-
ceding in having fleshy fruits
(drupes).
Rubus Iclceus, the Garden Rasp-
berry, of Europe, is also cultivat-
ed to some extent in this country. Pig. 476.—Section of the flower of Sosa
R. occidentals, the Black rubiglnosa. Natural size.
Raspberry, and R. strigosus, the Red Raspberry, both natives of the
Eastern United States, have given rise to the Common Raspberries of
our gardens.
R. fruticosus, the Blackberry, of Europe, is scarcely, if at all culti-
vated in this country. R. villosus, the Wild Blackberry, of the Eastern
United States, is exten-
sively cultivated.
Tribe Quillajece.
—Trees and shrubs,
with mostly simple
leaves, dry fruits and
winged seeds. Nearly
all are natives of Mexico
or South America.
Quillaja saponaria, of
Chili, is an evergreen
tree, fifteen to eighteen
metres (50 to 60 feet)
high, whose bark contains Saponin (C32 H54 On), and is used instead
of soap for washing. Under the name of Soap-bark or Quillaja-bark
it is imported into this country.
Tribe Spirceece.—Mostly woody plants, of the Northern Hemi-
sphere, with dry fruits. The principal genus Spircea, contains many
species, which, being highly ornamental, are commonly planted in
flower-gardens.530
BOTANY.
Tribe Prunece.—Trees and shrubs, with stems yielding gum,
simple, mostly serrate leaves, and solitary carpel ripening into a
drupe. (Figs. 478-9.)
Prunus communis, tlie Almond, is a native of Western Asia, and
now grown in many warm-temperate countries for its fruits. Two
principal varieties are grown, viz.. Sweet and Bitter ; in tbe former the
kernel is edible, whereas, in the latter, it is hitter and poisonous. An
oil is expressed from both kinds.
The Peach has been until recently regarded as a distinct species
(P. Persica), but it is now supposed to have been derived from the
Almond, by long culture and selection.
P Armeniaca, the Apricot, originally from Armenia, is now exten-
sively grown in many countries.
P. domestica, the Plum of Europe, P. Americana, the Common Wild
Fig. 478.—Flower cluster of Prunus Cerasus.
Fig. 479.—Section of flower of the Peach. Magnified.
Plum, of the Eastern United States, and P. Ohicasa, of the Southern
States, are cultivated for their excellent fruits. The second named is
the original form of most of the varieties grown in the central part of
the United States.
The Cherry, commonly referred to P. Cerasus, is probably derived
from P. avium, the Bird Cherry, of Europe. The wood of the Bird
Cherry is used in Europe for making furniture, as is also that of our
Wild Black Cherry (P. serotina), of the Eastern United States.
Many of the foregoing have, by long and careful culture, developed
double-flowered varieties, which are sometimes to be found in gardens.
Prunus vana, the Dwarf Almond, is well known in the double-
flowered state.
Tribe Chrysobalanece.—Trees and shrubs, with simple, entire
leaves. Mostly natives of tropical America, a few of tropical Asia and
Fig. 478.
Fig. 479.ROSALES.
531
Africa. Some of the latter bear edible fruits. The bark of Brazilian
trees of the genera Licania and Couepia is said to contain such consid-
erable quantities of silica, that it is burnt by the natives and used in
the manufacture of pottery.
Order Leguminosse.—The Pulse Family. Herbs, shrubs, and
trees, with alternate and usually compound leaves ; flowers for the most
part zygomorphic ; stamens usually twice as many as the petals ; pistil
Figs. 480-6.—Illustkations op Pai'ilionace.e.
(480-5, lathyrus odoratus.)
Fig. 480.—Section of flower. Magnified. Fig. 481.—Diagram of flower.
Fiv. 482.—Calyx. Magnified. Fig. 483.—Stamens and pistil Mag.
Fig. 4S4.—Ripe fruit. Fig. 485.—Part offruit, wittt a seed.
Fig. 486.—Section of seed of Tetragonolobus. Magnified.
monocarpellary and free ; seeds generally wanting an endosperm. A
vast order of 6500 species, distributed throughout the world.
The species are usually disposed in three sub-orders, each containing
many tribes.
Sub-Order I. Papilionacece, with zygomorphic flowers ; sta-
mens generally ten, monadelphous or diadelphous. This sub-order
contains a large number of plants of great economic importance.
The food plants mdaie the Pea (Pisum satimim), the so-called English
Bean (Vida faba), the Pole Bean (Phaseolus vu'garis), the Field Bean532
BOTANY.
(P. nana), the Lima Bean (P. lunatus), probably all from India and
Western Asia.
Many more species are now cultivated in India, such as Cbowlee,
Black Grain, Soy, Pigeon Pea, Lentils, etc.
The Peanut (Arachis hypogcea), a native of South America, is now an
important food plant in the West Indies and Africa. After the fertili-
zation of the erect yellow flowers, the peduncles bend down and the
young pods are thrust into the ground, where they ripen. This curi-
ous habit, which must have been at first a protective one, is perpetu-
ated in cultivation, although the need of it apparently no longer exists.
The forage plants include the Red Clover (Trifolium pratense), the
White Clover (Trepens), Lupine (Lupinus albus), Lucerne (Medicago
saliva), Sanfoin (Onobryclius satim), Tares or Vetches (Vida sativa),
all from Europe and the countries adjacent to the Mediterranean Sea.
Many others are grown less extensively.
Of the timber trees, the following are the most important :
Robinia Pseud,-Acacia, the Locust Tree of the Eastern United States,
yields a very strong and durable timber.
Dalbergia nigra, a large tree of Brazil, produces the finest Rose-
wood.
D. latifolia, of India, produces the Indian Rosewood.
The valuable dye Indigo is obtained from Indigofera tinctoria, a
native of India. The flowering plants are cut and placed in vats of
water ; after remaining for a time, the water, now colored, is drawn off,
and after several intervening processes, the coloring matter is allowed
to settle to the bottom ; this when dried is crude indigo.
The wood of Pteroarpus santalinus, a tree of India, when reduced
to chips, is the red dye known as Red Sandal-wood, or Saunders.
Camwood, another red dye, is obtained in a similar manner from
Baphia nitida, a West African tree.
Some species furnish gums and balsams, which are of use in the arts.
Gum Tragacantli is derived from a low shrubby plant, Astragalus
tragacantha, growing in Western Asia.
Gum Kino is produced by large trees of India and Africa belonging
to the genus Pterocarpus.
Balsam of Peru and Balsam of Tolu are the products of species of
Myroxylon, in Central and South America.
But one important medicinal product is furnished by this sub-order,
viz., Liquorice, the dried roots of Qlycyrrliiza glabra, a native herb of
the South of Europe.
In India species of Orotalaria and Sesbania are extensively cultivated
for their strong and durable fibre, much used for making cordage and
coarse cloth.
Of the many ornamental plants, the following only can be mentioned,
viz., species of Lupinus, Cytisus, Laburnum, Petalostemon, C'aragana.
Robinia, Wistaria, Phaseolus, Lathyrus, Sophora, etc., etc.ROSALES.
533
Desmodium gyrans, an East Indian plant, is remarkable for tbe
spontaneous movements of its leaves. The leaves are compound, the
terminal leaflet being large, while the lateral oues are small; under
proper conditions the lateral leaflets alternately rise and fall by quick
jerks, continuing this for hours without any apparent external cause.
Sub-Order II. Ccesalpiniece, with flowers zygomorphic or ac-
tinomorphic ; stamens generally ten, usually distinct.
The Tamarind is the fruit of a North African and East Indian tree of
this sub-order, Tamarindus Indica.
Senna, a medicinal drug, is the dried foliage of African and East
Indian species of Cassia.
Gum Copal, much used in making varnishes, is derived, at least in
part, from East Africa and Madagascar trees belonging to the genera
Tracliylobium and Eymencea.
Copaiva Balsam is obtained from Brazilian trees (Copaifera, sp.) by
making deep incisions into the trunks.
The pulverized wood of Ccesalpina echinata, a Brazilian tree, yields
the red dye Brazil-wood ; that from Ecematoxylon
Campeacluanum, a small tree of Central America, is
the well-known and valuable dark-red dye Logwood.
Many timber trees are of great value—e.g., the
Mora Tree of Guiana (Dimorphandra Mora), whose
heavy durable timber is in great repute in the British
navy yards ; the West India Locust (Eymencea Cour- 4g7 _ Cr06S.
baril), used in ship-building; the Honey Locust of the section of the seed
Eastern United States (OleditseMa triacanthos), •which gjowing^the abum
furnishes a valuable timber used by wheelwrights dant endosperm.—
for making hubs; the Kentucky Coffee Tree of the Magnifled-
Eastern United States (Qymnocladus Canadensis), whose red wood
somewhat resembles Mahogany ; the Judas Trees (Cercis, sp.), whose
wood is prized in Europe for cabinet-making.
Sub-Order III. Mimosece.—Flowers actinomorpliic, small,
and generally collected into close heads or spikes ; stamens distinct,
two to many times the number of petals.
One of the most important of the vegetable gums—Gum Arabic or
Gum Acacia—is furnished by trees of this sub-order belonging to the
genus Acacia. The greatest supply is obtained from -4. vera and A.
Arabica, natives of Northern Africa, Arabia, and the East Indies.
The genus Acacia is abundantly represented in Australia, where
many of its species, called Wattles, vield most excellent timber. That
of A. melanoxylon “is most valuable for furniture, railway carriages,
boat-building, casks, billiard-tables, piano-fortes (for sounding-boards
and actions), and numerous other purposes. The fine-grained wood is
cut into veneers. It takes a fine polish, and is considered equal to the
best walnut.” {Mueller.)534
BOTANY.
Lysiloma Sdbicu, a large Cuban tree, yields a bard and very durable
timber, highly valued for ship-building and for other purposes.
Many species of Acacia and Mimosa are iu cultivation in gardens and
conservatories.
Mimosa pudica, from South America, is interesting on account of its
extreme sensitiveness to a touch or jar. On this account it is commonly
known as the Sensitive Plant. Its leaves expand in the light and con-
tract in darkness, and in the proper temperature close at once upon
Fig. 488.—Expanded compound leaf of Mimosa pudica.
Fig 489.—Closed leaf of the same.
being touched or jarred, opening again, however, in a few minutes
(FigB. 488-9).
Order Connaracese.—Trees and shrubs of the tropics, one of which,
Connarus Lambertii of Guiana, furnishes the beautiful Zebra-wood.
595.—Cohort XXVII. Sapindales. Shrubs and trees,
•with usually compound leaves. Flowers often zygomorphic
and diclinous ; ovary superior ; seeds usually without endo-
sperm.
Order Moringese.—Contains three Old World trees, of doubtful
affinity.
Order Coriariese.—Shrubs of one genus and three to five species,
found in the Mediterranean region, the Himalayas, Japan, New Zea-
land, and South America. Their affinities are very obscure.'
Order Anacardiacese.—The Cashew Family. Trees and shrubs,
with gummy or milky-resinous juice, often poisonous ; fruit usually a
drupe. Species about 450, chiefly found in the tropics. The common
Fid. 488.
Fig. 489.SAPINDALE8.
535
representatives of this order in this country are species of Rhus, of
which R. typhina and R. glabra, Sumach, are highly ornamental, as
well as useful, their young shoots and leaves containing much tannin
and being much used in tanning.
Rhus Toxicodendron, the Poison Ivy, and R. venenata, the Poison
■Sumach, both of the Eastern United States, and R. cliversiloba, the
“Poison Oak” of California, are very poisonous, causing in many per-
sons a severe cutaneous eruption.
Mangifera Indica, of India, but now grown in most warm climates,
produces the excellent fruit known as the Mango.
The Cashew Nut is the product of a large West Indian tree, Anacar-
dium occidentals, and the Pistachia Nut of a tree of Western Asia,
Pistacia vera.
Mastic, a resinous material used in fine varnishes, is obtained by
(making incisions into the stem of Pistacia Lentiscus, a small tree of
the Mediterranean region. Japan Lacquer, so much used by the
-Japanese in the manufacture of many wares, is obtained in a similar
way, from Rhus vernicifera, and probably other species. Japanese
Wax is derived from the waxy-coated seeds of R. succedaneum, a tree
of China and Japan.
• Schinus motte, a Peruvian shrub, is much grown for ornament in the
gardens of California and Italy.
Order Sabiacece.—Trees and shrubs, mostly of the tropics.
Order Sapindacese.—Trees and shrubs (rarely herbs), mostly with
compound or lobed leaves. Species from 600 to 700, widely distributed.
This order includes five well-marked sub-orders, as follows:
Sub-Order I. Staphyleoe, with actinomorphic flowers, and
fleeds with endosperm. Represented in the Eastern United States by
the native ornamental shrub, the Bladder Nut (Staphylea trifolia).
Sub-Order II. Melianthece, with zygomorphic flowers, and
seeds with endosperm. Old World trees and shrubs.
Sub-Order III. Dodoncece, with actinomorphic flowers, and
seeds without endosperm ; leaves alternate.
Ptmroxylon utile, the Sneezewood Tree of the Cape of Good Hope,
furnishes a hard and durable timber, as also a New Zealand tree,
Alectryon excelsum.
Sub-Order IV. Aceriuew, with actinomorphic flowers, and
seeds without endosperm ; leaves opposite. (Figs. 490-2.)
The genus Acer, the Maples, contains nearly all the species.
A. campestre, the Common Maple of Europe, A. Pseudo Platanus,
the Sycamore Maple of Europe and Western Asia, and A. platanoides,
the Norway Maple of Europe, are valuable timber trees, occasionally
planted here as ornaments.
A. saccharinum, the Sugar Maple, A. rubrum, the Red Maple, and536
BOTANY.
A. dasycarpum, the Silver Maple, all of the Eastern United States,
furnish timber much used in the manufacture of furniture.
From the sweet sap of the first much sugar is made in the Northern
United States. Its wood also is harder, and is known as Hard Maple,
to distinguisli it from Soft Maple, derived from the other species.
A. macrophyllum, the Large Leaved Maple, and A. circinatum, the
Figs. 490-2.—Illustrations of Acer Pseudo-Platan us.
Fig. 490.—Section of flower. Magnified. Fig. 491.—Flower diagram.
Fig. 492.—Ripe fruit.
Vine Maple, both of California and Oregon, yield a hard and close-
grained timber.
Negundo aceroides, the Box Elder of the Eastern United States, is a
fine ornamental tree. N. Californicum, of the Pacific Coast, is much
like the preceding.
Sub-Order V. Sapindeai,—Flowers actinomorphic or zygomor-
phic; seeds without endosperm ; leaves mostly alternate. (Fig. 493.)CELASTKALE8.
537
JEsculus glabra, the Ohio Buckeye, and several other species, are
native ornamental trees of the sub-order.
JE. Hippocastanum, the Horse-Chestnut of the Old World, is com-
monly planted.
Kcdreuteria, paniculala, a Chinese tree, and Cardiospermum Halica-
cabum, the Balloon Vine of the Southern United States, are cultivated
as ornaments.
Ni'pTielium Lilchi, a small Chinese tree, produces the pulpy edible
fruits imported under the name of Litchi. N. Longan produces the
similar fruit called Longan.
Melicoeca bijuga, a tree of Guiana, yields a hard and heavy timber,
and from Cvpa7iia pendula, of Australia, is obtained Tulip Wood,
which, in some respects, resembles Mahogany.
The stem of the climbing plant, Paullinia curassavica, of Venezuela,
is made into the walking-sticks called “ Supple
Jacks.”
596. — Cohort XXVIII. Celastrales.
Flowers actinomorphic and monoclinous;
ovary superior entire ; seeds usually with
'endosperm.
Order Ampelidese. — Mostly climbing
shrubs, with nodose stems, bearing petioled al-
ternate leaves ; tendrils and flower clusters op-
posite to the leaves. About 250 species are
known; they abound in the tropics and are
much rarer in temperate climates.
Vitis is the principal genus; it contains all
the true Vines (grape producing), and many
others whose fruits are inedible. (Figs. 494-501.)
Vitis mnifera, the Vine of the Old World, has been under cultiva-
tion from time immemorial. It is indigenous to Southern Asia, from
whence it has been carried to nearly all parts of the world. Its varie-
ties are almost innumerable. From those grown in Southern Europe
wines and raisins are made, the latter being merely the sun-dried
grapes.
In the United States the Old World Vine is grown in the Southern
and Pacific Coast States, and in the latter region fine raisins are made.
In other portions of this country only the native species are grown, viz.;
V. Labrusca, the Northern Fox Grape; from this have originated
most of the common varieties, as Catawba, Concord, Isabella, etc.
V. aestivalis, the Summer Grape, from which we have obtained the
Virginia Seedling, Herbemont, etc.
V. riparia, the River-bank Grape, which has produced the Taylor
Bui lit, Delaware, and Clinton.
Fig. 493.—Diagram of
the flower of AEscuIus ;
the normal circle of sta-
mens shaded black ; of
the interposed ones but
two are fully developed,
shaded lighter, the abor-
tive ones represented by
dots.—After Sachs.538
BOTANY.
V. vulpina, the Southern Fox Grape, which has given rise to the.
Scuppernong and other varieties.*
From these American grapes excellent wines are now made; but no.
raisins have yet been made from them.
The Virginia Creeper, Ampelopsis quinquefolia (or Vitis quinquefolia),
Figs. 494-501.—Illustrations of Vitis vinifera.
Fig. 494.—Flower bud. Magnified.
Fig. 495.—Section of flower-bud. Magnified.
Fig. 49G.—Flower without corolla. Magnified.
Fig. 497.—Flower diagram. Fig. 498 —Fruit.
Fig. 499.—Seed. Magnified. Fig. 500.—Cross-section of seed. Magnified.
Fig. 501.—Vertical section of seed. Magnified.
is one of our finest native ornamental climbers.
Javan and Sumatran species of Vitis, formerly referred to Oissus, are
common in conservatories.
Order Rhamnaceae.—Trees and shrubs, often spinescent, bearing
simple, usually alternate leaves; flowers with valvate calyx lobes.
Species 430. Inhabitants for the most part of warm and temperate
regions. Many possess a purgative principle.
* This distribution of the cultivated varieties is that made by Dr
George Engelinan. American Naturalist, 1872, p. 539.OLACALES.
539
The fruits of some species of Rhamnus yield yellow or green dyes,
which are of considerable importance.
The wood of R. frangula, of Europe, is used for making the best
charcoal for the finest gunpowder.
Species of Zizyphus in Africa and India produce edible fruits, one of
which is the Jujube.
Rhamnus calharticus, the Buckthorn of Europe, is planted in this
country for hedges.
Order Stackhousiese.—Small herbs, mostly confined to Australia.
Order Celastracese.—Small trees and shrubs, often climbing, bear-
ing simple, usually alternate leaves; flowers with imbricate calyx,
lobes. Species about 400, natives of temperate and tropical regions.
Celastrus scandens, the Climbing Bittersweet of the Eastern United
States, is ornamental, and is planted in this country and Europe.
Euonymus utropurpureus, the Waahoo, or Burning Bush of the
Eastern United States, is also found in gardens.
The wood of E. Europaus of Europe is compact and capable of
being split into very fine pieces, and is used by watch-makers under
the name of Dogwood. It is also used for skewers, shoe-pegs, etc.
From the leaves of Catha edulis, an East African Bhrub, a decoction is
made which produces an agreeable excitement. The leaves themselves
are sometimes chewed.
597.—Cohort XXIX. Olacales. Flowers actinomorphic ;
ovary superior, entire, one- to many-celled; seeds with copious
endosperm.
Order Cyrillacese.—Trees and shrubs, numbering eight species,
represented in the Southern United States by Cyritta racemijlora, the
Ironwood, and Gliftonia ligvstrina, the Buckwheat Tree, the latter a
handsome evergreen tree, three to six metres higlt (10 to 20 feet).
Order Ilicinese.—The Holly Family. Trees and shrubs with mostly
evergreen leaves, and three- to many-celled ovary. Species 150, of
tropica] and temperate climates.
Rex Aquifolium, the Holly Tree of Europe, yields a white close-
grained wood much esteemed by turners and cabinet-makers. It is
sometimes blackened so as to resemble ebony. The tree, being orna-
mental, is extensively planted. The bright red berries remain during
the winter, and with the evergreen foliage are used for Christmas
decorations.
I. opaca, the American Holly, of the Southern States and the Atlan-
tic coast from Massachusetts southward, resembles the preceding and
is used for the same purposes. This and other native species are cultb
vated in gardens.
The leaves of I. Paraguayensis, a small South American tree, furnish540
BOTANY.
the Paraguay tea, sometimes called Mate. It contains Caffeine, the
active principle in tea and coffee.
Order Olacineee.—Trees and shrubs, about 170 species, almost en-
tirely of the tropics.
598.—Cohort XXX. Geraniales. Flowers often zygo-
morphic ; ovary superior, entire, lobed, or sub-apocarpous.
Order Chailletiacese.—Tropical shrubs and trees.
Order Meliacese.—Trees (rarely undershrubs),with mostly pinnately
oompound leaves; stamens united into a tube ; ovary entire. Species,
270, nearly confined to the tropics.
Several trees yield valuable timber.
Melia Azedarach, the Pride of India Tree, indigenous throughout
Western Asia, now naturalized in all the Mediterranean region, and
the Southern United States, is a fine tree, whose reddish wood is sus-
ceptible of a beautiful finish.
Swietenia Mahogoni. a native of tropical America (barely reaching
South Florida), yields the well-known Mahogany wood. The trees
are of great thickness, sometimes being as much as two metres in
diameter.
C'edrella odorata, of Jamaica, yields Jamaica Cedar.
C. Toona, of India, produces Chittagong wood.
O. australis, an immense Australian species, resembles the Jamaica
Cedar. The wood of the three foregoing species of Cedrella is fine
grained, and well adapted to many uses.
Chloroxylon Swietenia, of Ceylon and Western India, is a large tree,
whose fine-grained satin-like wood, called Satin Wood, is much prized
in cabinet and furniture making and fine turnery.
Order Burseraoese.—Trees and shrubs, abounding in resinous or
oily secretions ; species, 145, nearly all tropical.
Balsamodendron Myrrha and B. Kataf, small Arabian trees, yield
Myrrh.
B. Africanum, of Eastern Africa, produces African Bdellium.
Olibanum, an incense resin, is obtained from Boswellia thurifera, a
lofty tree of Central India.
Bursera gummifera, West Indian Birch, of South Florida and the
West Indies, yields a gum resin called Chibou or Cachibou.
Order Ochnacese.—Tropical shrubs and trees with a watery juice.
Order Simarubacese.—Shrubs and trees, with scentless foliage ;
leaves generally compound and alternate ; stamens distinct. About
112 species, almost confined to the tropics, are known. The bitter bark
and wood of many species are made use of in medicine. That from
Quassia amara, a small tree of tropical America, is the Quassia of
pharmacy. From a West Indiau tree, Simaruba amara, the drug
Simaruba Bark is obtained.GERANIALES.
541
Aitanthus glandulosus, tlie Tree of Heaven, a native of China, is com-
monly planted in the United States as a shade tree. Its wood is valu-
able in cabinet-making.
Order Rutacese.—The Rue Family. Shrubs and trees, rarely herbs,
with glandular-punctate heavy-scented foliage ; leaves generally com-
pound and alternate; stamens generally distinct. The order as here
considered includes 650 known species, widely distributed in tropical
Figs. 502-505.—Ii/lustkations or Citrus Aukxntium.
Fig. 502.—Section of flower. Magnified.
Fig. 503.—Part of ondrcecium. Magnified.
Fig. 504.—Flower diagram.
Fig. 505.—Calyx and ovary. Magnified.
Fie. 503.
Fig. 505.
and temperate climates. Seven tribes, most of which were formerly
considered to be orders, are recognized by Bentham and Hooker.
Tribe Aurantiece, with actinomorphic, monoclinous flowers,
baccate (berry-like) fruits, and seeds without endosperm. (Figs. 502-5.)
Citrus Aurantium, the Sweet Orange, is an Indian tree, now grown
throughout all warm countries of the world for its well-known fruits.
C. Limonum, the Lemon, is a native of Northern India, now widely
distributed. It was introduced into Europe during the Crusades.
Other species of Citrus yield valuable fruits, as C. medica, the Citron ;
C. limetta, the Lime ; C. decumana, the Shaddock ; C. Bigaradia, the
Seville or Bitter Orange, etc., etc.
The hard yellow wood of the Orange is valued for inlaying542
BOTANY.
Tribe Toddaliece, witli actinomorphic, mostly diclinous flowers,
coriaceous or baccate fruits, and seeds with endosperm.
Ptelea trifoliala, the Hop Tree, of the Eastern United States, Skim-
mia Japonica, a small Japanese shrub, and two species of Phelloden-
dron, from Manchuria, are planted in gardens.
Tribe Xanthoocylece, with actinomorphic, mostly diclinous
flowers, usually capsular fruits, and seeds mostly with endosperm.
Xanthoxylum Americanum, the Common Prickly Ash, of the
Northern United States, and X. Clava-Herculis, the Southern Prickly
Ash, of the Southern States, are ornamental shrubs, and are often
planted.
Tribe Boroniece.—Australian shrubs.
Tribe Diosmece, with actinomorphic, monoclinous flowers, cap-
sular fruits, and seeds without endosperm.
Species of Diosma and Barosma, pretty African shrubs, are to be found
in conservatories. From their leaves the drug
Buchu is obtained.
Tribe Rutece, with generally actinomorphic,
monoclinous flowers, capsular fruits, and seeds
with endosperm. (Fig. 506.)
Buta graveolens, the Common Rue of the gar-
dens, is a native of Southern Europe and West-
ern Asia.
Dictamnus Fraxinella, Fraxinella, or the Gas
Plant, is a heavy-scented ornamental plant,
whose glandular foliage secretes a volatile oil,
which is said sometimes to flash into flame
when a light is brought near to it. (Figs. 116-7.)
Tribe Cuspnriece, with zygomorphic, monoclinous flowers, cap-
sular fruits, and seeds without endosperm.
Galipea cusparia, a large tree of Guiana and Brazil, furnishes a bit-
ter medicinal bark, known as Angustura Bark.
Order Geraniaceee.—The Geranium Family. Mostly herbs (rarely
shrubby or arborescent) ; leaves opposite or alternate, simple or com-
pound; stamens more or less united below; species, 750, mostly of
temperate and sub-tropical climates.
Many are cultivated as ornaments.
Impatiens Balsamina, the Garden Balsam, or Touch-Me-Not, some-
times erroneously called “ Lady’s Slipper," is a well-known annual
from India, which has been cultivated for more than two hundred and
fifty years. The name Touch-Me-Not (referring to its elastically open-
ing fruits) is Bhared by two pretty native species. (Fig. 507.)
Oxalis contains several native species of Wood Sorrel, all of which.
Fig. 506.—Diagram of
the flower of Dictammis
Fraxinella, the interpos-
ed stamens (of later ori-
gin) slightly shaded.—Af-
ter Sachs.GERAN1ALES.
543
are pretty, and many exotic species (mostly South African), which are
in common cultivation.
Tropceolum majus, the Nasturtium, from South America, is in com-
mon cultivation. The edible tuberous roots of T. tuberosum, of Peru,
are used instead of potatoes in some parts of South America.
Pelargonium, is another South African genus, which has furnished
us with many line greenhouse and garden flowering plants, most of
which are erroneously called Geraniums.
The true Geraniums belong to the genus of that name represented in
this country by eight or nine wild species.
Erodium cicutarium, the Alfilaria, of California, “ is a valuable and
nutritious forage plant reputed to impart an excellent flavor to milk
and butter.” (Brewer.)
Order Zygophyll-
acese.—Shrubs and herbs
(a few trees), with oppo-
site compound leaves ;
stamens distinct; spe-
cies, about 100, almost
confined to the tropics.
Guaiacum officinale,
the Lignum-vitas, of the
West Indies, is a tree
six to nine metres (20 to
30 feet) high, whose dark
red, almost black, heart-
wood is exceedingly
hard; it furnishes the
best material for ship's
Fig. 507.—A, the fruit of Impatient Balsamina. B,
blocks, pulleys, etc. the same after dehiscence ; a, a, carpels ; gr, seeds.
Larrea Mexicana, the —After Duchartre.
Creosote Bush of Arizona, is a curious diffusely branched evergreen
shrub, with a very strong creosote-like odor.
Order Malpighiacese,—Trees and shrubs, often climbing ; natives
for the most part of the tropics; species, 580, some of which are culti-
vated in greenhouses.
Order Humiriaceee.—Balsamic trees and shrubs of tropical America
and Africa.
U
Order Linacese.—The Flax Family. Herbs, shrubs, and a few trees,
with alternate or opposite simple leaves ; stamens more or less united
below; species, 135, widely distributed in temperate and tropical
climates.
The most important plant of the order, and one of the most impor-
tant in the vegetable kingdom, is the Flax, Linum usitatissimum, cul-
tivated from time immemorial for its fibres, called linen (the bast fibres544
BOTANY.
of the cortical part of the stem). The mummy cloth of ancient Egypt
is composed of flax fibres, and in the remains of the “lake dwellings”
in Switzerland, fragments of linen cloth have been found. The plant
appears to he indigenous in the south of Europe, as well as in the
regions eastward in Asia; it is now cultivated throughout the North
and South Temperate Zones. The seeds are rich in oil, which is
extracted by pressure, producing the Linseed-oil of commerce; the
Fios. 50S-10.—Illustkations op Lintm usitatissimum.
Fig. 508.—Inflorescence. Fig. 509.—Section of flower. Magnified.
Fig. 510.—Diagram of flower.
compressed refuse is called oil-cake, and is much used as food for
cattle. (Figs. 508-10.)
Erythroxylon Coca, a South American shrub, is cultivated in
Bolivia and New Granada for its stimulating leaves, which are chewed
like tobacco.
599.—Cohort XXXI. Malvales. Flowers usually actino-
morpliic ; stamens indefinite, generally monadelphous ; ovaryMALY ALES.
545
superior, generally three- to many-cellod ; seeds mostly with
endosperm.
Figs. 511-513.—Illustrations or Tiieobko-
ma Cacao.
Order Tiliaceee.—The Linden Family. Trees and shrubs (a few
herbs), with mostly alternate simple leaves; stamens distinct, or some-
what united below. Species
330, mostly tropical.
Tilia Europaa, the Lime
or Linden Tree of Europe
and Siberia, is a large and
valuable tree, yielding a soft
white wood much esteemed
by carvers, musical instru-
ment makers, and others.
The fibre of its bark is used
for making coarse mats, and
its flowers produce a great
quantity of most excellent
honey.
T. Americana, the Amer-
ican Linden, Linn, or Bass-
wood of the Eastern United
States, resembles the preced-
ing, and is equally valuable.
While the wood of our rep-
resentatives of the order is
soft, that of some tropical
species is very hard — e.g.,
Sloanea dentata, a West In-
dian tree, which has received
the significant name of
Break-Ax Tree.
• Corchorus capsularis, a tall-
growing annual of India,
yields the Jute fibre now ex-
tensively used in making
gunny bags, coarse carpets,
and even fabrics of consider-
able fineness.
Order Sterculiacese. —
Trees and shrubs (a few
herbs) with alternate simple
or compound leaves ; stamens more or less united into a tube.
520 species contained in this order are almost entirely tropical.
Theobroma Cacao, the Chocolate Tree of tropical America, attains a
height of five to six metres (16 to 20 ft.), and bears elongated ribbed
Fro. 513.
Fig. 511.
Fig. 511.—Fruit (%j natural size).
Fig. 512.—Seed. Magnified.
Fig. 513.—Seed cut vertically. Magnified.
The546
BOTANY.
fleshy fruits, each containing fifty or more oily seeds (Figs. 511-13).
The seeds are roasted and then ground, and made into a paste and dried,
constituting the Chocolate or Cocoa of commerce, according as vanilla,
sugar, and other substances are, or are not added. Chocolate and Co-
coa contain Theobromine (C7 H8 N« Oa), aD alkaloid similar to Caffeine.
Order Malvaceae.—The Mallow Family. Herbs, shrubs, and trees,
with alternate simple leaves ,* stamens indefinite, united into a tube ;
Fio. 517.
Fig. 514.—Section of flower. Magnified. Fig. 515.—Andrcecium. Magnified.
Fig. 516.—Stamen. Magnified. Fig. 517.—Calyx and pistil. Magnified.
Fig. 518.—Flower diagram. Fig. 519.—Fruit.
anthers one-celled. Species about 700, widely distributed, but most
abundant in tropical regions. (Figs. 514-19.)
Gossypium herbaceum, the common Cotton Plant of tropical and sub-
tropical countries, was probably derived originally from some part of
India. Its culture by the East Indians and Egyptians was known
many centuries before the Christian era. In England the manufacture
and use of cotton cloth began during the latter part of the sixteenthG UTTIFERALES.
547
century. The culture of cotton in North America dates from almost
the first settlements in the Southern States, and the cotton crop is now
more valuable than the product of any other single cultivated plant in
the United States. It is extensively cultivated in the West Indies,
Brazil, Egypt, and India.
The fibre of cotton consists of greatly elongated hairs (trichomes),
which develop in great numbers upon the outer surface of the seed-
coats ; these are at first cylindrical, but upon drying, as the seed-pod
approaches maturity, they collapse and appear flat and more or less
bent and twisted.
Some East and West Indian trees of the genus Bombax produce an
abundance of a similar fibre, which is fine and silky, hence the trees
are known as Silk Trees. It is said, however, that the fibre cannot be
woven, and it is at present only used for stuffing cushions, etc.
The bast fibres of the steins of some species are useful. Species of
Sida in India, China, and Australia, of Playianthus in New Zealand,
and of Thespesia and Hibiscus in tropical
America, are thus used ; from the last the
fibre called Cuba Bast is obtained.
Hibiscus esculentus, the Okra or Gumbo
of tropical America, produces mucilaginous
edible pods, which are much used in the
Southern United States.
Species of Durio in the Malay Archipel-
ago, and of Matisia in New Granada, fur-
nish the inhabitants of those countries with
valuable fruits. The wood of most of the
species of the order is very soft and com-
pressible ; this is particularly the case with of ^ouloniu Lasianthus.
a West Indian tree, Ochroma Lagopus, whose wood, known as Cork
Wood, has been used as a substitute for cork.
The Baobab Tree of tropical Africa is remarkable for the enormous
size of its rounded spreading top and the thickness of its short stem.
Among the more common ornamental plants of the order are Mallows
(Malva), Bose Mallow {Hibiscus), Hollyhock {Althaea), Callirhoe, etc. ,
600.—Cohort XXXII. Guttiferales. Flowers actino-
morphic ; stamens indefinite ; ovary superior, three- to many-
celled.
Order Chlaenacese.—A few shrubs and trees of Madagascar.
Order Dipterocarpeae.—Tropical trees (rarely shrubs), about 112 in
number, the most important of which is Dryobalanops Cataphora, the
Kapor or Camphor Tree of Borneo and Sumatra, which attains a height
of forty metres (130 ft.), and yields a hard red timber used in boat-
building. Its resin is called Sumatra Camphor, and is much used in
China and Japan.548
BOTANT.
Order Ternstrcemiacese.—Trees and slirubs with alternate (rarely
opposite) leaves, and mostly monoclinous axillary or racemed flowers.
Species 260, mostly tropical. (Figs. 520 and 521-5.)
Several ornamental species are indigenous to tlie Southern United
States—e.g., the Loblolly Bay (Oordonia Lasiantltus, Fig 520), a tree
nine to fifteen metres (30 to 50 ft.) high ; O. pubescens, the Mountain
Bay ; and two shrubby species of Stuartia.
The most common exotic species cultivated for ornament is the
Camellia (Camellia Japonica) a well-known hot-house shrub from
China and Japan.
The Tea Tree (Camellia Chinensis or Tliea Chinenm) is aD evergreen
tree three to five metres high, and
a native, probably, of Southern
and Eastern Asia. It has been
cultivated for ages by the Chi-
nese, and has lately been intro-
duced to a limited extent into
other countries. In preparing the
leaves they are carefully picked,
and then are subjected to alternate
drying, pressing, rolling and air-
ing until the proper chemical
changes have taken place, and a
sufficient part of the water is
driven off. The different kinds
and qualities of tea depend upon
the rapidity of the process, and
also upon the age of the leaves
used, the more rapid process and
the younger leaves producing the
finer green teas, the slower pro-
cess and older leaves producing
the black teas. Somewhat appears
also to depend upon the variety of
nil! 626--HalfeinbrJro’inn';lfa‘:e' MaS- the plant, there being, it is gene-
rally admitted, two varieties or
races, viz., var. viridis and var. Boliea.
Tea leaves after preparation contain the alkaloid Caffeine (C8 H10
N4 Oi + Ha 0), which also occurs in roasted coffee.
Order Guttiferese.—Trees and shrubs with yellowish or greenish
resinous juice, opposite leaves, and mostly diclinous flowers. Species
230, all tropical.
Garcinia Morelia, a small tree of Siam, produces Gamboge, a valuable
color used in painting. Incisions are made into the bark, and the juice
which exudes is gathered and dried, constituting the crude Gamboge.
The Mangosteen, a fruit about as large as an apple, and considered
Figs. 621-5.—Illustrations of
lia Chikensis.
Fig. 523. Fig. 525.
Fig. 521.—Ripe fruit. Magnified.
Fig. 522.—Seed. Magnified.
Fig. 523.—Section of seed Magnified.
524.—Embryo. Magnified.CAB YOPUYLLALES.
549
to be one of the most delicious of all fruits, is produced by Qarcinia,
Mangostana, a small tree of the Moluccas.
The fruit of Mammea Americana, a tall West Indian tree, is known
as the Mammee Apple. It is as large as a melon, and its yellow pulp
is said to be delicious.
A Central American species of Calophyllum yields a pale reddish, very
durable timber known as Santa Maria wood.
Order Hypericacese.—Herbs and shrubs (a few trees) with opposite
glandular-punctate leaves, and monoeliuous flowers. Stamens united
into three or five bundles (Fig. 526). Species 210,
mostly found in temperate climates.
Our species are all herbs or low shrubs, be-
longing to the genera Hypericum, and Ascyrum.
A species of Cratoxylon, in tropical India, is a
large tree with dark brown wood.
Order Elatinaceas.—Containing a few marsh
plants.
601.—Cohort XXXIII. Caryophyll-
ales. Flowers actinomorpliic; stamens
generally definite, usually as many or
twice as many as the petals ; ovary superior, one-celled ; pla-
centa usually central and free; seeds with endosperm.
Order Tamariscine®.—Mostly shrubs of the Old World, with mi-
nute alternate simple leaves.
Of the forty species, but three are found in the New World, and all
these reach our extreme Southwestern border.
Tamarix Gattica, the Tamarisk of Europe to India, is a common
ornamental shrub in this country.
Order Fortulacacese.—Herbs and a few small shrubs, with alter-
nate or opposite leaves ; sepals generally two. Species 125, widely dis-
tributed, but most abundant in the New World.
Portulaca oleracea, the common Purslane, is an East Indian, or possi-
bly South European weed. It was formerly used as a pot herb.
P. grandijlora, tbe Portulaca of the gardens, is a pretty flowering
annual.
Claytonia and Calandrinia, which have many native representatives,
are ornamental.
Order Caryophyllacese.—The Pink Family. Mostly herbs with
opposite leaves ; sepals four or five, free or united into a tube ; placenta
central. Species 800, distributed throughout the world, but most
abundant in Arctic, Alpine, European, and Western Asiatic coun-
tries.
Fig. 536.—Diagram of
the flower of Hyperi-
cum calycinum.—After
Sachs.550
BOTANT.
Aside from the ornamental species and the weeds, the order possesses
no plants of much economic importance.
The roots of Saponaria officinalis contain Saponin, and are detergent,
but not sufficiently so to be much used.
Among the ornamental plants are the Carnations and Clove Pinks
(Dianthus sp.), the Mullein Pink (Lychnis), Catchfly (Silerie), Bouncing
Bet (Saponaria), Gypsophila, etc.
Among the weeds are species of Cerastium (Fig. 527), Spergula, and
the Corn Cockle,
Lychnis Githago.
The latter is often
quite abundant in
wheat fields, to the
great detriment of
the flour manufac-
tured from the
wheat.
Order Franken-
ia c e se.— Mari-
time herbs and
low shrubs resem-
bling Caryophyll-
aceae, but with par-
ietal placentae.
602. — Cohort
XXXIV. Poly-
galales. Flow-
ers actinomorph-
ic or zygomorph-
ic; stamens defi-
nite,' as many
as or twice as
many as the pet-
als ; ovary usual-
ly two-celled ; seeds mostly with endosperm.
Order Vochysiacese.—Trees with a resinous juice, and opposite or
•verticillate leaves ; flowers zygomorphic. Species about 100, confined
to tropical America.
Vochysia Guianensis, of Guiana, furnishes the Copai-ye Wood, there
used for making boat-oars, the staves for sugar hogsheads, etc.
Order Polygalaceae.—Mostly herbs with alternate leaves; flowers
■zygomorphic. Species 400, distributed throughout temperate and
tropical countries.
Fig. 62?.—Inflorescence of Cerastium collinum. t, pri-
mary axis : V, secondary axes ; t", tertiary axes ; V", qua-
ternary axes ; V"f, quinary axes.—After Duchartre.PA It I ETA L ES.
551
A bitter principle, which is sometimes emetic and purgative, per.
vades the order.
Some South African species of Polygala are grown as ornamental
plants in conservatories. A few have a little reputation as medicines.
Order Tremandreee, containing a few Australian shrublets.
Order Pittosporacese.—Trees and shrubs with alternate leaves,
and actinomorphic flowers; petals cohering into a tube. Species
ninety, of Africa, India, China, and Australia.
Pittosporum Tobira is a common plant in conservatories.
P. undulatum, of Australia, attains a height of twenty to twenty-five
metres (70 to 80 ft.), and its wood resembles Boxwood.
Climbing species of Sollya and other genera are grown in green-
houses.
603.—Cohort XXXV. Parietales. Flowers actinomorpli-
ic or zygomorjthic ; stamens definite or indefinite; ovary
usually one-celled, with parietal placentae.
Order Bixinese.—Trees and shrubs with alternate simple leaves,
actinomorphic flowers, and generally indefinite stamens ; seeds with
■endosperm. Species 160, mostly tropical.
One or two species of Amoreuxia barely reach our extreme South-
western border.
Bixia Orellana, a small South American tree now cultivated in many
tropical countries, produces fruits whose orange-red pulp when pre-
pared and dried is the valuable dye known as Arnotto.
The fruits of some species are eaten, and a 'few gums are derived
from others.
Order Canellacese, containing four or five species of tropical trees.
Canella alba yields Canella Bark, which is used in medicine.
Order Violacese.—The Violet Family. Herbs and shrubs with
mostly alternate leaves, zygomorphic flowers, and definite stamens ;
•seeds with endosperm. Species 240, widely distributed in temperate
-and tropical regions.
An emetic and laxative principle is common in the plants of this
order.
The genus Viola, the Violets, includes about half of the species of
the order ; many of these are indigenous to parts of the United States,
and nearly all of these, as well as the exotic species, are ornamental.
V. odorata, the Sweet Violet, and V. tricolor, the Pansy, both natives
of Europe, are common in gardens and door-yards. Of the latter there
are almost numberless varieties.
Several Brazilian shrubby plants of the order are cultivated in green-
houses.
The root of Ionidium Ipecacuanha, a Brazilian shrub, is the White
Ipecacuanha of pharmacy.55 2
BOTANY.
A Peruvian tree, Leonia glyvycarpa, produces edible pulpy fruits as
large as a peach.
Order Cistacese.—Herbs and shrubs with actinomorphic flowers.
Species about sixty, mostly of temperate climates.
A shrubby Cistus from the South of Europe is common in green-
houses.
Some of our native species of Frostweed (Helianthemum) and Hud-
sonia are pretty.
Order Resedacese.—Herbs (a few shrubs) with alternate leaves,
mostly zygomorphic flowers, indefinite stamens, and seeds without
endosperm. Species twenty to twenty-five, confined to the Mediter-
ranean region and South Africa, with the exception of two or three spe-
Fig. 528.—Flower diagram. Fig. 529.—Section of Flower. Magnified.
Fig. 530.—Andrmcium. Magnified.
cies which reach India, one of which (Oligomeris subulata) extends to
California.
Reseda odorata is the well-known Mignonette, probably a native of
the Eastern Mediterranean region.
The foliage of R. luteola, an annual of Europe called Dyers’ Weed
or Weld, furnishes an important yellow dye.
Order Capparidacese.—Herbs, shrubs and trees with mostly alter-
nate leaves, actinomorphic flowers, mostly indefinite (never tetradyna-
mous) stamens, and seeds without endosperm. Species 300, mostly
tropical or sub-tropical. An acrid volatile principle prevails in the
order.
Capparis spinosa, a stiff prickly-branched shrub of the Mediterranean
region, is extensively cultivated in Europe for its unopened flower
buds, which preserved in vinegar constitute the condiment known as
Capers.
Cleome integrifolia, a native of the Western Mississippi Valley, andPA1UETALKS.
553
<3. pungens, of South America, are fine flowering plants cultivated in
gardens.
Order Cruciferse.—The Crucifer Family. Herbs and a few low shrubs
with actinomorphic flowers, tetradynamous stamens, and seeds without
endosperm (Figs. 528-41). This large order includes 172 genera and
about 1200 species, which are distributed throughout the temperate re-
gions of the world, but are most abundant in Southern Europe and
Asia Minor. The prevailing principle in the order is pungent and stim-
ulant.
The order is divided by Bentliam and Hooker into ten tribes, distin-
guished by the shape of the fruit and the disposition of the cotyledons
in the seed, whether incumbent or accumbent (Figs. 536 to 541).
The order furnishes a few food plants of some importance.
Brassica oleracea, a wild plant of the Atlantic coast of Europe, is
Figs. 531-5.—Illustrations of Crucifers (Shepherd’s Purse).
Fib 535.
Fig. 531.—Vertical section ot' flower. Magnified.
Fig. 532.—Pistil and stamens. Magnified.
Fig. 533.—Ripe capsule spli ting open. Magnified.
Fig. 534.—Seeds on placenta", the capsule-valves removed. Magnified.
Fig. 535.—Cross-section of capsule. Magnified.
probably the original form from which have been derived by long cul-
tivation the following races, which are now almost, if not quite, entitled
to he regarded as species, differing as they do fully as much from one
another as many wild species .
Race I. Cauliflower, in which the thickened and consolidated flower
peduncles constitute the edible portion of the plant.
Race II Bore Cole or Kale, in which the expanded but tender leaves
of the tall stem are the edible parts.
Race III. Brussels Sprouts, resembling the last, but with thick edi-
ble buds in the axils of the leaves.
Race IV. Cabbage, in which the leaves do not expand, hut form a sin-
gle large thick edible bud or “ head.”554
BOTANY.
Race V. Kohl-Iiabi, in which the short and few-leaved stem becomes,
thick, bulbous, and edible.
B. campestris, of the same regions as the preceding, has given rise to
the various kinds of Turnips. Colza and Rape also are probably vari-
eties ; the latter are extensively cultivated in Europe for their oily
seeds, from which useful oils are obtained by pressure.
Baphanus satims, the Radish, is a native of China.
Nasturtium Armorada, the Horseradish of Europe, has long been
cultivated for its pungent roots, which are used as a condiment. Ac-
cording to Dr. Gray, the plant, for some unknown reason, does not pro-
duce seeds in this country.
N. officinale, Water Cress of Europe, and now run wild in many parts
Figs. 536-41.—Seeds of Crucifeiue.
Fig. 53a Fig. 537.
Fig. 538.
Fig. 541.
Fig. 536.-Seed of Erysimum. Magnified.
Fig. 537.—Longitudinal section of seed. Magnified.
Fig. 538.—Cross-section of seed, showing incumbent cotyledons. Magnified.
Fig. 539.—Longitudinal section of seed of Arabia. Magnified.
Fig. 540.—CroBB-section of seed of Arabia, accumbent cotyledonB. Magnified.
Fig. 541.—Cross-section of seed of Barbarea, imperfectly accumbent cotyledons.
Magnified.
of the United States, and many other rapidly growing foreign and na-
tive species, are used as salads.
Brassica alba, White Mustard, and B. nigra. Black Mustard, both
natives of Europe, are grown for their seeds, which when ground con-
stitute the common condiment Mustard. It is also of considerable
value in medicine.
Isatis tinctoria, a tall-growing European biennial, was formerly ex-
tensively grown for the blue dye obtained from it.
The most important ornamental plants of the order are the Wall-
flower (Oheirantlius), Gilly Flower or Brompton Stock (Matthiola),
Rocket (Hesperis), Candytuft (Iberis), Honesty (Inmaria), Sweet Alys-
Bum (Alyssum), etc., etc.
Several of the species are troublesome weeds— e g., Shepherd’s Purse
(Oapsella), which has come to this country from the Old World ; Pepper-
grass (Lepidium), native and introduced ; False Flax (Camelina) from.
Europe; Charlock and Mustard (Brassica) from Europe.PARIETALES.
555
The curious plant called the Rose of Jericho (Anastatica hierochun-
tica), often sold as a curiosity, is a small annual, native of Arabia,
Egypt, and Syria. The mature plant after ripening its seeds contract
into a rounded mass, and is uprooted and blown about by the wind*
When, however, the dry and dead plant is moistened, it expands, clos.
Figs. 542-5—Illustrations of Papaver Rsceas.
Fig. 542.
Fig. 543.
Fig. 544.
Fig. 545.
Fig. 542.—Vertical section of flower. Magnified. Fig. 544.—Flower diagram.
Fig. 543.—Pistil and stamen. Magnified. Fig. 545.—Ripe fruit.
intacle distinct. Species about 100, mostly natives of cool
climates.
Berberis vulgaris, the Barberry of Europe (Figs. 550-3), is cultivated
as an ornamental shrub, as well as for its edible acid berries. The
flowers are interesting on account of their sensitive stamens, whichRANALE8,
559
move quickly toward the pistil when touched at their bases by an in-
sect searching for the honey secreted by glands upon the petals (Figs.
551-52).
B. Canadensis, of the Southern States, is much like the foreign spe-
cies.
Figs. 550-3.—Illustrations of Bebberis vulgaris.
Fig. 551.
Fig. 550.—Flower diagram.
Fig. 551.—Pistil, with a petal and stamen. Magnified.
Fig. 552.—Upper side of a petal, showing its two glands. Magnified.
Fig. 553.—Vertical section of ovary. Magnified.
Several evergreen species from the Rocky Mountains and Oregon,
and one from Japan, are cultivated under the name of Mahonia.
Podophyllum peltatum, the May Apple of the Eastern United States,
produces an edible, plum-shaped fruit. Its poisonous rootstocks are
Figs. 554-8.—Illustrations of Menispermuh Canadense.
Fig. 554. Fig. 555. Fig. 556. Fig. 557. Fig. 558.
Fig. 554.—Diagram of male flower. Fig. 555.—Fruit. Magnified.
Fig. 556.—Section of fruit. Magnified. Fig. 557.—Seed. Magnified.
Fig. 558.—Section of seed. Magnified.
used somewhat in medicine. A second species occurs in the Him-
alayas.
Caulophyllum thalictroides, of the Eastern United States and also of
Japan, is interesting on account of its young ovaries bursting open and
allowing the ovules to develop into naked drupe-like seeds.560
BOTANY.
Order Menispermaceae.—Woody twining plants, with alternate
leaves ; flowers diclinous ; petals usually six, with a stamen before
{opposite to) each one; carpels usually three, distinct and one-seeded.
Species eighty to one hundred, principally tropical. They generally
contain a bitter principle, which in some is tonic, in others narcotic, or
even poisonous.
Jfenispermum Uanadense, the Moonseed of the Eastern United
States, is a beautiful climber deserving- cultivation in ornamental gar-
dens. Its only congener is a native of Eastern Asia. (Figs. 554-8.)
Figs. 559-64.—Illustrations of Asimina triloba.
Fig. 559.—Section of flower. Magnified.
Fig. 560.—Flower diagram. Magnified. Fig. 561.—Young carpel. Magnified.
Fig. 562.—Section of young carpel. Magnified.
Fig. 563.—Seed. Natural size. Fig. 564.—Section of seed.
Two other genera, Calycocarpum and Cocculus, are represented in
the United States.
Many of the Old World species are more or less in repute as furnish,
ing medicines, but none are of sufficient importance to be particularly
noticed.
Order Anonacese.—Trees and shrubs with alternate leaves ; flowers
trimerous ; stamens indefinite, on a thickened receptacle ; carpels gen-
erally indefinite. Species 400, mostly tropical. The bark generally
contains ati aromatic and stimulating, sometimes acrid principle.RANALES.
561
Aaimina triloba, the Papaw of the Southern United States, and ex-
tending to the Great Lakes, is a small tree producing edible pulpy
fruits six to ten centimetres long. Several other smaller species of the
same genus are common in the South. (Figs. 559-564.)
Anona reticulata, the Custard Apple, A. Gherimolia, the Cherimoya,
A. squamosa, Sweet Sop, and A. muricata, Sour Sop, all cultivated in
the West Indies and tropical America, produce edible fruits; the first is
regarded by some people as one of the finest fruits in the whole world.
Xylopia aromatica is a tree of western tropical Africa, whose dry
carpels are aromatic, and used as pepper under the name of Guinea
Pepper. The ancients used this pepper (“ Piper iEthiopicum ”) long
before the introduction of Black Pepper.
Figs. 565-7.—Illustrations or Magnolia pukpdkea.
Duguetia quitarensis, a small tree of Guiana, supplies a tough elastic
■wood known as Lancewood.
Order Magnoliaceae.—The Magnolia Family. Trees and shrubs
with alternate simple leaves ; flowers mostly monoclinous ; petals and
stamens indefinite ; carpels usually indefinite. Species seventy, mostly
of the tropical and sub-tropical parts of Asia and America. (Figs.
566-7.)
The genus Magnolia contains many beautiful trees, seven of which
are natives of the Southern United States. Of these M. acuminata, the
Cucumber Tree, extends north to the Great Lakes, and sometimes at-562
BOTANY.
tains a height of forty to fifty metres. Its light, whitish wood is valu-
able, and is much used for many purposes.
M. gratidifloia is much like the preceding, but has larger flowers
and evergreen leaves, the former being from fifteen to twenty-five
centimetres in diameter. It grows only in the Southern States, where
its timber is somewhat used.
M. Umbrella and M. macrophyl'a are named Umbrella Trees on ac-
count of the way in which their large leaves spread from the ends of
the branches. The leaves of the last-named species are from fifty to
eighty centimetres (20 to 30 in.) long, and the flowers are from thirty
to thirty-five centimetres (12 to 14 in.) in diameter.
M. glauca, the Sweet Bay, is a shrubby species extending from Louis-
iana to Massachusetts, in the north near the coast only.
The foregoing and most, if not all, the remaining species are quite
■ornamental, and are planted wherever they will endure the winters.
Liriodendrou Tulipifera, the Tulip Tree or Yellow Poplar of the
Eastern United States, is one of our largest and most valuable timber
trees. Its light, whitish or yellowish wood is much used in cabinet-
making, coach-building, and for many other purposes.
Magnol a conspicua is the Yulan Tree of China. Other species of
this genus occur in Japan, China, and the Himalaya region.
Order Calycanthacese.—Shrubs with opposite leaves ; seeds with-
out endosperm. Three species occur in the Southern United States,
one in California, and one in Japan. This order, the structure of
which cannot bo discussed here, is evidently out of place in this Co-
hort.
Order Dilleniacese.—Shrubs, rarely trees, with alternate leaves ;
sepals five, petals five ; stamens indefinite ; ovaries usually distinct, one-
celled. Species 180, mostly tropical.
Two Californian species of the genus Crossosoma, doubtfully referred
to this order, are our only representatives.
Some of the Indian species of Dillenia and Wormia yield hard and
valuable timber.
Order Ranunculaceae.—Herbs, rarely shrubs, with mostly alternate
or radical leaves; sepals usually five or fewer, deciduous, often petal-
oid; petals in one whorl, often wanting ; carpels usually distinct.
(Figs. 568-73.) Species about 500, most abundant in temperate and cold
regions. The herbage usually possesses a considerable acridity.
Formerly many of the species were reputed to be of medicinal value,
but at the present day they are but little used except by quacks. Sev-
eral species, however, still retain their places in the pharmacopoeias;
among these are:
Aconitum NapeUus, Monkshood or Aconite, a native of Europe,
whose roots furnish the drug Aconite.HAN ALES.
563
A. ferox, of upper India, supplies the people of tliat region with a
virulent poison, with which they poison their arrows.
Hetteborus niger, Black Hellebore, H. fcetidus, Stinking Hellebore,
Figs. 568-73.—Iliustbitions of Ranunovlaoe.® (Caltha palustris).
Fig. 568.
Fig. 571.
Fig. 572.
Fig. 573.
Fig. 568.—Flowering stem. Fig. 569.—Vertical section of flower.
Fig. 570.—Flower diagram. Fig. 571.—Youngcaroel. Magnified.
Fig. 572. —Seed. Magnified. Fig. 573.—Section of seed. Magnified.
and H. viridis, Green Hellebore, all natives of Europe, furnish drastic
and poisonous drugs.
Among the ornamental plants of the order may be mentioned the
following :
Anemone, of several species, including our native Hepaticas, now
placed in this genus.564
BOTANY.
Adonis, the Pheasant’s Eye, of Europe.
Aquilegia, the Columbine, including our common Eastern species (A,
Canadensis) and the Rocky Mountain Long Spurred Columbine (A.
cosrulea), as well as the common one of Europe (A. vulgaris).
Clematis, the Virgin’s Bower, of many species, native and foreign, all
pretty.
Delphinium, the Larkspur, of many species, mostly foreign.
Nigella, Love in a Mist, from the Old World.
Pasouia, the Peony, of several species, from Europe, Siberia, and
China.
Ranunculus, Buttercup, of several European species.
Trotting, Globe Flower, from Europe and Siberia.
Very few species afford nutritious products useful for food ; the
tuberous roots of a species of Ranunculus are gathered and eaten in
some parts of Central Europe, and a few fleshy species (as, for example,
Caltha palustris, Ranunculus sceleratus, etc.) are used to a limited ex-
tent as pot herbs.
Fossil Dicotyledons.—No Dicotyledons are known in the periods
earlier than the Cretaceous. In this, however, many modem orders
are represented. In the Cretaceous of the Western Territories of the
United States Lesquereux describes* one hundred species of Dicotyle-
dons. Of these sixty belong to the Apetahe, five to the Gamopetalae,
and thirty-five to the Choripetalae (Polypetalae). The Apetalae include
five species of Populus, six of Salix, eight of Quercus, six of Platanus,
seven of Sassafras, etc. Among the remarkable fossils are a species of
Ficus from Minnesota, two species of Cinnamomum from Kansas, and
two of Laurus from Nebraska. The five species of Gamopetalae repre-
sent the Ericaceae fa single species of Aridromeda), Ebenaceae (two spe-
cies of Diospyros from Kansas and Nebraska), and Sapotaceae (two spe-
cies, one a Bumelia from Nebraska and Minnesota). Among the spe-
cies of Choripetalae are five of Magnolia, two of Liriodendron, one of
Hedera, one of Prunus, one of Pirus, etc., from Kansas, Nebraska, and
Dakota.
In the Tertiary moBt of the more important orders of Dicotyledons
are represented. Here, as in the Cretaceous, there is still a predomi-
nance of Apetalous species ; thus in the Tertiary Flora of the Western
Territoriesf there have been determined of the Apetalae one hundred
and twelve species, Gamopetalae, nineteen, and Choripetalae, seventy-
nine. The Apetalae are principally represented by the Myricaceae
(twelve species of Myrica), Betulaceae, Cupuliferae (a Carpinvs, a Cory-
lus, a Fagus, a Castanea, and eighteen species of Quercus), Juglandaceae
* “ Contributions to the Fossil Flora of the Western Territories.
Part L, The Cretaceous Flora,” by Leo Lesquereux. Washington,
1874.
f Leo Lesquereux, op. cit. Part II., “The Tertiary Flora,” 1878.FOSSIL DICOTYLEDONS.
565
(a Carya, a Pterocarya, and seven species of Jug’ans), Salicaceae (four
species of Salix and twelve of Populus), Platanaceae (five species of
Platanus), Moraceae (twenty-three species of Ficus), Lauraceae (six spe-
cies of Laurus, one of Tetranthera, and four of Cinnamumum).
The Gamopetalae are represented by Caprifoliaceae (nine species of
Viburnum), Oleaceae (four species of Fraxinus), Ebenaceae (four species
of Diospyros), and Ericaceae (an Andromeda and a Vaccinium).
The principal orders of the Choripetalae are Ampelideae (one species
of Ampelopm, two of Vitis, and four of Cissus), Anacardiaceae (five
species of Rhus), Cornaceae (four species of Cornus), Rhamnaceae (ten
species of Rhamnus, five of Zizyphus, three of Paliurus, and one of
Berchemia), Uicineae (four species of Ilex), Sapindaceae (six species of
Sapindus), Myrtaceae (two doubtful species of Eucalyptus), Rosaceae
(a single species of Crataegus), Leguminosae (a Podogonium, a Cassia, an
Acacia, a Mimosites, and two Leguminosites), and Magnoliaceae (four
species of Magnolia).CHAPTER XXI.
CONCLUDING OBSERVATIONS.
605.—The Number of Species of Plants.—It is impossible
at the present time to give with even approximate accuracy
the number of existing species of plants. In the first place,
a great many species in all parts of the world are as yet un-
described ; even in England, where the study of this branch
of Botany has been most energetically pursued, many new
species are discovered every year. In the central and western
countries of the continent of Europe, as in England, while
comparatively few flowering plants have escaped detection,
there yet remain undescribed hundreds of species of the
lower groups, and in the regions eastward there are doubtless
many phanerogams as well as cryptogams which have not yet
been enumerated. A complete “Flora of Europe” will
probably be an impossibility for very many years. In Asia
our knowledge of the plants is still more fragmentary.
Japan and India, with parts of Asia Minor, are the best
known botanically, but even in these regions our knowledge
is almost entirely confined to the phanerogams and higher
cryptogams. In Australia and the islands to the northward
and in Africa, there are enormous tracts which have not yet
been explored. In the New World, from Mexico southward,
the descriptions and enumerations of the native plants are
scattered through many works, not one of which approxi-
mates completeness even for comparatively small regions. In
North America, the “Flora of North America,”begun forty
years ago, is yet unfinished, even for the flowering plants.*
* “ A Flora of North America,” by John Torrey and Asa Gray. Vol.
I., 1838-40. Vol. II. (in part), 1843. Resumed under the title of “A
Synoptical Flora of North America,” by Asa Gray, 1878.AFFINITIES OF TEE 0ROUPS.
567
In the second place, many of the so-called species in de-
scriptive works are but varieties, while in other cases the
same forms have been described under different names. This
is true in all the groups of plants, and scarcely a monograph
now appears in which there are not cases of the reduction of
a supposed species to a synonym or variety.
606. —With these considerations in mind, we may examine
the catalogues and make some general estimates. Steudel in
1834 catalogued in “ Nomenclator Botanicus” 59,684 phan-
erogams and 10,965 cryptogams, making a total of 70,649.
In the second edition, published in 1841, the number of
phanerogams was increased to about 78,000. Lindley, in
1845, estimated the number of dicotyledons to be 66,488, the
monocotyledons 13,953, and the cryptogams 13,480, making
a total of 93,830. De Candolle’s “ Prodromus,” begun in
1834 and continued to 1873, contains, according to Alph. De
Candolle’s historical note in Yol. XVII. of that work, de-
scriptions of 58,446 dicotyledons and 439 gymnosperms.
Duchartre estimates the known species of phanerogams at
about 100,000, and of cryptogams at about 35,000, and ven-
tures to place the whole number of species in the world at
from 150,000 to 300,000. Dr. Gray quotes De Candolle’s
■estimate of the known species of flowering plants, amounting
to from 100,000 to 130,000, and says that “the larger num-
ber may perhaps include the higher orders of the flowerless
■series,” and in speaking of the lower cryptogams says that at
present “no close estimate can be well formed of the actual
number of species.”*
607. —The Affinities of the Groups of Plants.—Many at-
tempts have been made to construct diagrammatic figures
which should indicate the affinities of the different groups
of the vegetable kingdom. While it is impossible to do this
with any great degree of accuracy, we may yet show in this
way certain relations, more clearly than can be done other-
wise. The subjoined diagram may be taken to indicate in a
general way the writer’s present notion of the affinities (i.e.,
* In his “ Botanical Text-Book,” 1879, Part I., p. 346, foot-note.568
BOTANY.
the genetic relations) of the seven great divisions of plants,
so far as they can be shown upon a plane surface :
Gamopetaloe.
Choripetalce.
Apetalce.
Monocotyledones.
Dicotyledones.
Gtmnosferm^e.
Angiosperma:.
.PHANERO-
GAMIA.
PTERIDOPHYTA
BRYOPHYTA
CARPOPHYTA.
OOPHYTA.
ZYGOPHYTA.
PROTOPHYTA.
608.—The Distribution of Plants in Time. If we bring
together what is yet known as to Fossil Botany (Phytopalse-
ontology), as has been done by Schimper,* we find that the
* “ Traite de Paleontologie Vegetale,” par W. Ph. Schimper. Paris,
1869 to 1874. This work of three large octavo volumes (aggregating
2696 pp.) and a quarto atlas of 110 plates is a most valuable one for
the student of Phytopalaeontology.DISTRIBUTION IN TIME.
5G9
Tabular View of the Distribution in Time of the Divisions
of the Vegetable Kingdom.
Silurian.570
BOTANY.
several Divisions of the Vegetable Kingdom are very un-
equally distributed in geologic time. Thus no fossil
Protophyta have yet been discovered earlier than the Ter-
tiary (Miocene), while the Zygophyta, Oophyta, and Carpo-
phyta, with scarcely any doubt, were well represented in
the Silurian. Bryophyta have not been detected in strata
earlier than the Eocene (Tertiary), while Pteridophyta
extend back to the Devonian. Of the Phanerogamia the
Gymnosperms originated in the Devonian, the Monocotyle-
dons in the Triassic, and the Dicotyledons in the Cretaceous.
These facts may be more clearly shown by the table on the
preceding page.
It must be borne in mind that our knowledge of fossil
plants is as yet extremely limited, a comparatively small
portion only of the earth’s strata having hitherto been care-
fully examined. It is very probable that as we come to
know more of the fossil remains of plants some or all of the
lines in the table will be extended downward. On the other
hand, we need not expect to find many remains of the ex-
ceedingly simple organisms which constitute the Protophy-
ta, although they probably have existed in abundance
since pre-Silurian times. So, too, few Zygophytes have a
sufficiently durable plant-body to allow them to be preserved
in a fossil state. The softness of texture and easy perisha-
bility of the tissues of the Bryophyta, especially in the lower
orders, probably accounts for the few fossil remains hitherto
discovered. Doubtless we must in the same way account for
the fact that most of the species of fossil Phanerogams are
trees and shrubs ; the softer tissues of the herbaceous spe-
cies have yielded but few fossils as compared with the harder
and denser ones of the ligneous species.INDEX TO THE ILLUSTRATIONS,
Abies pectinata, 394, 397, 401
Acer dasycarpum, 74
Acer Pseudo-Platanus, 536
Achlya, 40, 255
Aclilya racemosa, 256
Acorus calamus, 114, 115,116
Adiantum, 374
Adiantum Capillus-Veneris, 370,
371, 372
Adiantum Moritzianum, 109
iEsculus, 537
iEsculus Hippocastanum, 141
Agaricus campestris, 326, 327
Ailantlius glandulosus, 125, 448
Alisma Plantago, 467
Allium cepa, 423
Alsopliila, 377
Ampelopsis quinquefolia, 154
Anagallis arvensis, 507
Ananassa sativa, 471
Antlioceros laevis, 348, 350
Arabis, 554
Arcyria incarnata, 210
Aristolocliia siplio, 84
Asclepias, 504
Ascobolus furfuraceus, 288
Asimina triloba, 560
Aspidium Filix-mas, 41, 374, 375,
376
Asplenium, 374
Bacillus ulna, 213
Bacterium lineola, 213
Bacterium Termo, 213
Banana, 472
Barbarea, 554
Beet, 60, 495
Begonia, 30
Berberis vulgaris, 559
Beta vulgaris, 495
Betula alba, 126, 127
Biota orientalis, 396
Bittersweet, 501
Botrychium Lunaria, 378, 379’
Bryum argenteum, 359
Buckwheat, 162
Bulbochaete intermedia, 248
Callitris quadrivalvis, 399
Caltba palustris, 563
Camellia Chinensis, 548
Canna, 473
Capsella Bursa-pastoris, 424, 553
Carya alba, 73
Cassia tora, 533
Castanea vesca, 153
Cephalotus follicularis, 527
Cerastium collinum, 550
Ceratozainia longifolia, 396
Ohara fragilis, 332, 333
Chenopodium, 496
Cherry, 143
Chestut, 153
Chondrioderme difforme, 36, 44,
209, 210
Cichorium intybus, 23
Citrus Aurantiuni, 541
Claviceps purpurea, 290 291,
Clematis Viticella, 439
Cnicus altissimus, 98
Cocoa-nut, 463
Coffea Arabics, 517
Colchicum autumnale, 459
Coleocbaete pulvinata, 272
Collema Jacobaefolium, 300
Collema microphyllum, 300
Collema pulposum, 309
Corallina officinalis, 274
Cosmarium Menenghinii, 44, 226
Cucumis Melo, 521
Cucurbita, 95
Cucurbita Pepo, 29, 77
Cupressus sempervirens, 396
Cycas revoluta, 400572
INDEX TO TEE ILLUSTRATIONS.
Cypripedium calceolus, 470
Cystopus candidus, 259, 262
Cytisua Laburnum, 84, 447
Dahlia vaiuabilis, 27, 33
Date, 452, 463
Diagrams, 33, 38. 138, 139,403, 406,
417, 420, 445, 450, 468
Dictamnua fraxinella, 131, 542
Didymium serpula, 78
Dionrea muscipula, 525
Dorstenia, 489
Dracaena, 444
Dudresnaya purpurifera, 276
Echinocystis lobata, 30, 70, 71,
73, 100, 155, 156
Equisetum arvense, 365
Equisetuin limosum, 365
Equisetum palustre, 110
Equisetum seirpoides, 88
Equisetum Telmateia, 364, 366
Erica cinerea, 509
Erysimum, 554
Erysipke Ciclioriacearum, 281
Erysipke Tuckeri, 279
Eschscholtzia Californica, 419
Eucalyptus globulus, 524
Eupatorium, 515
Euphorbia, 75
Eurotiuui repens, 282
FAGOPYRUM ESCULENTUM, 162, 496
Fern prothallium, 370
Ficus, 489
Foeniculum vulgare, 519
Fontinalis antipyretica, 87, 142, 359
Fragaria vesca, 529
Fritillaria imperialis, 3, 458
Fucksia globosa, 104, 105
Fucus platycarpus, 266
Fucus vesiculosus, 267
Fuligo varians, 4, 209
Funaria liygrometrica, 48, 52, 353
354, 356, 358
Ginkgo bilob a, 399
Gleichenia, 377
Glceocapsa, 216
Gompkidium, 329
Gordonia Lasiantlius, 547
Grape, 79, 80
Grapkis elegana, 309
Hedera helix, 130
Hemlock Spruce, 152
Hickory-nut, 73
Hop, 97
Horsecliestnut, 141
Hoya carnosa, 34
Hyacintlius orientalis, 101
Hydrodictyon utriculoaum, 223
Hypericum calycinum, 549
Iberi9 amara, 442, 443
Impatiens Balsamina, 28, 82, 543
Indian Corn, 2, 6, 55, 67, 113, 154
160, 451, 452
Iridaceas (flower diagram), 468
Isoetes lacustris, 387, 388
Ivy, 130
Juglans regia, 481
Juncus effusus, 20
Juniperus communia, 402, 407
Lamium, 498
Latkyrus odoratus, 531
Lathyrus Pseudapkaca, 440, 441
Laurua nobilis, 492
Lavatera trimestris, 23
Lecanora sublusca, 297
Lejoliaia mediterranea, 274, 275
Lemna minor, 462
Linum usitatissimum, 544
Lycopodium annotinum, 383
Lycopodium clavatum, 383
Lycopodium complauatum, 112
Magnolia purpurea, 561
Mallotium Hildenbraudii, 303
Malva sylvestris, 546
Marckantia polymorpha, 91, 92,
344, 345, 346, 347, 349, 350
Marailia salvatrix, 381
Megalospora affinis, 299
Menispermum Cnnadenae, 559
Micrococcus prodigiosus, 213
Mimosa pudica," 534
Mucor, 338
Mucor Mucedo, 236
Mucor stnlonifer, 237, 238
Musa sapientum, 472
Mustard, 95
Myristica fragrana, 493
Myrtus communis, 524
Navicula aaxonica, 229
Navicula viridis, 228
Nelumbium luteum, 558INDEX TO THE ILLUSTRATIONS.
573
Nemalion multifidum, 275
Nepenthes ampullaria, 483
Nitella flexilis, 331
Nostoc, 37, 217
Nuphar advena, 20
Oat, 454
Ochrolechia palleseens, 299
CEdogonium, 22, 247
(Edogonium ciliatum, 248
CEdogonium gemelliparum, 248
Onion, 76
Orchis mascula, 469
Oscillatoria, 37, 217
Osmunda, 377
Palm (stem), 443
Pandorina Morum, 222
Papaver Rhoeas, 555
Parmelia aipolia, 296
Parmelia tiliacea, 302
Peach (flower), 530
Pediastrum granulatum, 05, 224
Penicillium chartarum, 285
Peronospora, 261
Peronospora Alsinearum, 48, 261
Peronospora calotheca, 258
Peronospora infestans, 258
Pertusaria centhocarpa, 299
Pertusaria Wulf'eni, 309
Peziza confluens, 286
Peziza convexula, 42, 287
Peziza omplialodes, 287
Pliaseolus multiflorus, 43, 475
Phoenix dactylifera, 452
Phragmidiutn bulbosum, 315
Phragmidiuin mucronatum, 315
Pliysarum leucopus, 208
Pilularia globulifera, 380
Pinus Larico, 401
Pinus pinaster, 72, 124
Pinus Pinea, 405
Pinus sylvestris, 25, 26, 394, 395,
398
Piptoceplialis Freseniana, 239
Pirus communis, 528
Pirus Cydonia, 528
Pisum sativum, 54
Plagiocliilia asplenioides, 349
Polypodium, 373
Polypodium vulgare, 108
Potamogeton pectinatus, 129
Potato (flower), 501
Primula sinensis, 97
Prunus Cerasus, 530
Psoralea bituminosa, 122, 476
Pteris aquilina, 24, 27, 72, 81, 83,
107, 371. 372, 373
Puccinia graminis, 311, 313
Puccinia Moliniae, 314
Quince, 528
Quercus Robur, 449, 478
Ranunculus repens, 119
Rhizomorpha subcorticalis, 66
Rh-ubarb, 60
Riccia glauca, 345, 346
Rice, 455
Ricinus communis, 117, 118, 474
Rosa canina, 427
Rosa rubiginosa, 429
Rye, 96
SACCHAROMYCES CEREVISI2E, 39,
214
Salix capraea, 486
Salvinia natans, 380, 381
Sambucus nigra, 445, 446
Saprolegnia, 255
Saprolegnia androgyna, 257
Sarracenia purpurea, 557
Schizaea, 377
Scorzonera hispanica, 75
Scrophularia, 499
Sedum purpurascens, 101
Selaginella caulescens, 384
Selaginella insequifolia, 111, 386
Selaginella Martensii, 384, 385
Sequoia gigantea, 80
Shepherd’s Purse, 553
Silphium laciniatum, 157
Solanum, 501
Sorisporium Saponariae, 320
Sphaeria morbosa, 293
Spliaeropliorus globiferus, 298, 302
Sphaeroplea annulina, 245
Sphaerotheca Castagnei, 280
Spliserotheca pannosa, 280
Sphagnum acutifolium, 355
Sphagnum squarrosum, 355
Spirillum volutans, 213
Spirochaete plicatilis, 213
Spirogyra longata, 45, 46, 51, 233
Stachys angustifolius, 441
Sticta fuliginosa, 295
Sticta pulmonacea, 308
St.ipa spartea, 158
Sunflower, 08574
INDEX TO THE ILLUSTRATIONS.
Taraxacum Dens-leonis, 513
Tax as baccata, 395
Tetragonolobus, 531
Theobroraa Cacao, 545
Thistle, 98
Tilletia caries, 321
Tradescantia Virginica, 12
Trapa natans. 163
Trichomanes, 377
Tsuga Canadensis, 152
Tuber melanosporum, 285
Ulva, 224
Uncinula adunca, 281
Urtica macrophylla, 61
TJrtica urens, 491
Usnea barbata, 302, 304, 308
Ustilago antlierarum, 320
Ustilago Maydis, 320
Vaccinium Myrtillus, 511
Vanilla planifolia, 471
Vaucheria sessilis, 47, 251, 252,
253
Vibrio Rugula, 213
Vicia faba, 38, 69, 474
Viola tricolor, 20, 422, 423
Virginia Creeper, 154
Vitis, 79, 80
Vitis vinifera, 538
Volvox globator, 244
Wallflower, 552
Welwitschia mirabilis, 60, 414
Yeast Plant, 39, 214
Zea Mais, 113,154,160, 451, 452GENERAL INDEX,
Abele Tree, 437
Abies, 81, 151, 394, 397, 409, 411,
412, 415
Abietinese, 410
Abortion of Floral Organs, 431
Abridgment of Life Cycle, 314
Abronia, 497
Absinthe, 514
Absorption of Food, 176, 184, 191
Acacia, 533, 534, 565
Acantliace®, 61, 499
Acanthus Family, 499
Accumbent Cotyledons, 437
Acer, 72, 75, 535
Acerine®, 119, 535
Achene, 436
Achenial Fruits, 436
Acbimenes, 499
Achlamydeous, 431
Achlya, 39, 256
Achnantlies, 230
Achnanthidium, 230
Achyranthes, 496
Acids, 62
Acoliuin, 310
Aconite, 562
Aconitum, 106, 562
Acorus, 58, 114, 462
Acrocarpse, 359, 360
Acroscyplius, 310
Acrostichum, 377
Actinocyclus, 231
Actinodiscus, 231
Actinomorphic, 430
Actinoptyclius, 231
Acyclic Flowers, 429
Adam’s Needle, 461
Adder Tongues, 372
Adiantum, 110,377
Adlumia, 556
Adnate Anthers, 433
Adnation of Floral Organs, 432
Adonis, 53, 564
Adventitious buds, 143
Adventitious stems, 143
iEcidiospores, 312
JEcidium, 312, 316
iEgilops, 455
Aerial roots, 137
iEsculus, 537
jEthalium, 210
iBtliusa, 520
Affinities of Plants, 567
Agapantlius, 460
Agaricace®, 339
Agarics, 241
Agaricus, 39, 323, 328, 329, 330
Agave, 467
Ageratum, 98
Aggregate fruits, 436
Aggregations of cells, 65
Agrimony, 149
Agrostis, 455
Ailanthus, 102, 541
Air in the Plant, 174
Albuminous seeds, 391, 437
Albuminoids, 59
Alders, 488
Alectoria, 308
Alectryon, 535
Aleurites, 485
Aleurone, 57
Alfilaria, 543
Alga, 133
Algae, 53, 55, 86, 135, 204, 205, 221,
337, 340
A1 gales, 337
Alisma. 467
Alismace®. 128, 425, 466
Alkaloids, 62, 182
Alkanet, 502
Allamauda, 504576
GENERAL INDEX.
Alligator Pear, 494
Allium, 458
Allspice, 523
Almond, 530
Alnus, 488
Aloe, 458 ‘
Aloes, 459
Alsopliila, 377
Alternate leaves, 149
Alternation of Generations, 341,
361
Althaea, 547
Alyssum, 98, 554
Amarantaceae, 496
Amarantus, 264, 496
Ainaryllidaceae,461, 467
Amaryllis, 468
Amaryllis Family, 467
Amaurochaeteae, 210
Ambrosia, 264, 429, 515
Amelanchier, 527
Amentales, 485
Aments, 413
American Larch, 412
American White Ash, 505
American White Elm, 488
Ammonia Salts, 170
Amoeba movement, 8
Amole, 468
Amomales, 471
Amoreuxia, 551
Amorpliopliallus, 462
Amount of Evaporation, 171
Amount of Water in Plants, 166
Ampelideae, 537, 565
Ampelopsis, 165, 194, 538, 565
Amphigastria, 344, 351
Amphipleura, 230
Amphora, 230
Anacardiace*. 534, 565
Anacardium, 535
Anacharis, 473
Anaesthetics, 198
Anagallis, 434, 436, 507
Analogy and Homology, 120
Ananassa, 471
Anastatica, 555
Ancestry of Plants, 204
Anchusa, 502
Andraea, 358
Andraeaceae, 355, 358
Andrcecium, 418, 430, 432
Androgynia, 250
Andromeda, 564, 565
Andromedeae, 510
Androspore, 249
Anemeae, 210
Anemone, 102, 264, 284, 429, 563
Anemia, 377
Anemiopsis, 483
Anemophilous Flowers, 421
Angiocarpous Lichens, 297, 298
Angiopteris, 378
Angiospermae, 393, 416, 568
Angiosperms, 79, 85
Angular divergence of leaves, 150
Augustura Bark, 542
Aniseed, 520
Annual layers of wood, 447
Annular Vessels, 118
Annulus, 328, 375
Anona, 561
Anonaceae, 560
Anortheis, 230
Antliemideae, 514
Antliemis, 514
Anther, 394, 417, 418
Antheridial disc, 347
Antheridium, 45, 243, 266,271,331,
341, 361
Anther Smut, 318
Anthesis, 199
Antlioceros, 11, 217, 341, 348, 350
Anthoceroteae, 350, 361
Antiaris, 490
Antipodal Cells, 420
Antirrhinum, 150, 500
Apetalae, 476, 568
Apetalous, 431
Aphyllon, 192
Apical Cell, 38, 86, 88, 153, 343,
352, 363, 373, 378, 380, 381, 425
Apium, 519
Appendages, 281
Apple, 64, 159, 171, 284, 436, 527
Apocarpous, 433
Apocynacete, 77, 119,504
Apocynum, 504
Apostasiaceae, 469
Apothecium, 297
Apricot, 62, 530
Aqueous Tissue, 94
Aquilegia, 564
Arabis, 437
Aracete (=Aroideae), 77
Arachis, 532
Araclinoidiscus, 231
Arales, 461GENERAL INDEX.
Aralia, 519
Araliaceie, 519
Araucaria, 4U9, 413,414
Araucarie®, 413
Arbor Vit®, 411
Arbutus, 509
Arceutbobium, 477
Arcbas, 506
Arcbegonium, 46, 341, 361, 402
Archesperm®, 393
Archidium, 358
Arctopodiuui, 385
Arctostaphylos, 156, 509
Arctoide®, 514
Arcyria, 211
Areca, 466
Arecine®, 466
Aretliusa, 470
Aretkuseae, 470
Argemone, 556
Aril, 437
Arisaema, 61, 462
Aristolocliia, 482
Aristolochiace®, 482
Armeria, 508
Aruica, 514
Arnotto, 551
Aroide®, 119, 461
Aroids, 401
Arrack, 464
Arrangement of Leaves, 149
Arrangement of Roots, 164
Arrowroot, 473, 484
Artemisia, 85, 514
Artbonia, 310
Arthoniei, 310
Artichoke, 512. 515
Artocarpus, 489
Arum Family, 461
Asafoetida, 63, 520
Asarales, 482
Asarum, 482
Asclepiad.ice®, 77. 119, 503
Asclepias, 102, 420
Ascobolus, 288, 289, 301
Ascogonium, 300
Ascomycetes, 214.270,271,273,278,
305, 335, 337, 338, 340
Ascospore®, 339
Ascospores, 40, 214, 278, 315, 319
Ascus, 278, 315, 319
Ascyrum, 549
Asexual Generation, 341, 361
Ash, 436
Ash Tree, 505
Asimina, 561
Asparagus, 458
Aspergillus, 284
Asphodel, 460
Aspbodelus, 460
Aspidium, 377
Asplenium, 377
Assimilation, 62, 178, 185. 191
A Stephan®, 334
Aster, 516
Asterales, 512
Asteroide®, 516
Asterolampra, 231
Asterolampre®, 231
Asteropliyllites, 368
Astilbe, 526
Astragalus, 532
Astrocaryum, 17
Astrotri chia, 520
Asymmetry of Leaves, 146
Atalea, 464
Atherosperma, 494
Atmospheric pressure, 171
Alrichum, 352
Atriplex, 52
Atropa, 502
Aucuba, 518
Aulacodiscus, 231
Auliscus, 231
Aurantie®, 541
Auricula, 506
Australian Pitcher Plant, 526
Austrian Pine, 412
Autogamous Flowers, 421
Autumn Crocus, 460
Auxospores, 228
Avena, 102, 455
Avocado Pear, 494
Axile Placenta, 433
Azalea, 510
Azolla, 381, 382
Baccate Fruits, 436
Baccate Seeds, 437
Bacillariace®, 227
Bacillus, 213
Bacteria, 65, 212
Bacteriace®, 212
Bacterium, 17, 213
Bactrospora, 298
B®omyces, 310
Balanophore®, 476
Bald Cypress, 411GENERAL INDEX.
*78
Balloon Vine, 537
Balm, 498
Balsam, 61, 94, 144, 543
Balsam Apple, 533
Balsam Fir, 413
Balsamodendron, 540
Balsam of Peru, 533
Balsam of Tolu, 533
Bamboo, 453, 457
Bambusa, 457
Banana, 146, 473
Banana Family, 471
Bauds of Protoplasm, 18
Bangiaceae, 339
Banksia, 491
Banyan Tree, 490
Baobab, 474
Bapliia, 533
Barberry, 197, 316, 558
Barberry Cluster Cups, 316
Barberry Family, 558
Barberry Rust, 316
Barbula, 351, 360
Barcelona Nuts, 477
Bark, 118, 134, 301, 393, 409, 447
Barley, 59, 187, 319, 333, 333, 455
Barosma, 543
Bartramia, 359
Basal Cells, 306
Basel! acese, 494
Basidia, 333
Basidiomycetes, 370, 333, 335, 337,
338, 339, 340
Basijiosporeae, 339
Basidiospores, 39, 333, 338
Bassia, 506
Bassorin, 63
Basswood, 545
Bast Cells, 17
Bast Fibres, 74, 76, 119
Bast, Soft, 116
Batbybius, 15
Batrachosperme*, 377
Bay berry, 487
Bay Tree, 493
Bdellium, 465, 540
Bean, 56, 58, 59, 199, 435, 531
Bearberry, 509
Bear Grass, 461
Bedfordia, 514
Bedstraw, 517
Beech, 135, 136,431, 479
Beech Mast, 479
Beech Nuts, 479
Beet, 166, 495
Begonia, 61, 94,143, 146, 531
Begoniaceae, 71, 531
Belladonna, i03
Beilis, 516
Berberidacese, 558
Berberis, 85, 103, 558
Berchemia, 565
Berry, 436
Bertholletia, 58, 533
Beta, 103, 495
Betel Nut, 466
Betel Palm, 466
Betel Pepper, 484
Betula, 103, 174, 487
Betulacese, 487, 564
Bhang, 488
Biatora, 310
Bicollateral Bundles, 131
Bicyclic, 430, 433
Biddulphia, 331
Biddulphieae, 331
Bidens, 364, 515
Bignonia, 81, 85, 436, 499
Bignoniaceae, 499
Big Trees of California, 411
Bilaterality of Leaves, 146
Bilocular, 433
Biota, 409
Biparous Cyme, 439
Birch, 136, 174, 431, 437, 487
Birch Family, 487
Bird Cherry, 530
Birds Aiding in Pollination, 431
Bisexual Flowers, 431
Bittersweet, 539
Bixia, 551
Bixineae, 551
Black Ash, 505
Blackberry, 436, 437, 539
Black Bindweed, 497
Black Grain, 533
Black Huckleberries, 511
Black Jack Oak, 480
Black Knot, 393
Black Nightshade, 503
Black Oaks, 480
Black Pepper, 483, 561
Black Rust, 316
Bladder-nut, 535
Bladderwort Family, 499
Blanching of Celery, 53
Blanc Mange, 377
Blazing Star, 516GENERAL INDEX.
6T9
Bleeding Heart, 556
Bletia, 470
Blood-root, 556
Bloodwood Tree, 523
Bloodwort Family, 467
Blueberry, 511
Blue Beech, 477
Blue Gum, 524
Blue Huckleberries, 511
Blue Mould, 285
Blue Palmetto, 465
Bluets, 517
Bocconia, 556
Boekmeria, 491
Boletus, 330
Bombax, 547
Borage Family, 502
Borassine®, 465
Borassus, 465
Bordered Pits, 251
Bore Cole, 553
Boronie®, 542
Borraginace®, 150, 503
Bostryx, 429
Boswell ia, 540
Botrychium, 879, 380
Botrydium, 134
Botry-Cyme, 429
Botryose Inflorescence, 427, 428
Botryose Mouopodium, 140
Bouncing Bet, 550
Boundary Tissue, 89
Boussingaultia, 494
Bouvardia, 518
Bow-wood, 490
Box Elder, 536
Box Tree, 485
Bracts, 136, 155
Bran-cell, 58
Branching, Modes of, 139
Branching of Leaves, 147
Branches of Stems, 142
Brassica, 98, 102, 150, 553
Brazilian Arrowroot, 484
Brazilian Artichoke, 515
Brazil Nut, 58, 524
Brazil wood, 533
Bread-Fruit Tree, 489
Break-Ax Tree, 545
Bristles, 137
British Oak, 479
Bromeliaceae, 471
Brompton Stock, 554
Broom Corn, 457
Brosimum, 489, 490
Broussonetia, 490
Bruchia, 358
Brucia, 503
Bruniace®, 526
Brussels Sprouts, 553
Bryaceae, 355, 358
Bryophyllum, 143, 526
Bryopliyta, 205, 305, 341, 568, 569,
570
Bryophytes, 10, 40, 59, 67, 72, 87,
90, 124, 140, 143, 145, 265, 341.
389
Bryum, 352, 359, 360
Bucliu, 542
Buckeye, 537
Buckthorn, 539
Buckwheat, 496
Buckwheat Family, 496
Buckwheat Tree, 539
Bud, 139, 140, 181, 189, 199
Bud-cell, 332
Buellia, 310
Buffalo Berry, 492
Bulb, 181, 190, 191
Bulb-axes, 136
Bulbochastacere, 269
Bulbocliaete, 250
Bulbophyllum, 471
Bulgaria, 289
Bumelia, S06, 564
Bundles, Fibro-vascular, 106
Bundle Sheath, 108,114
Bunt, 318
Burgundy Pitch, 412
Burmanniaceie, 468
Burning Bush, 539
Bursera, 540
Burseracese, 540
Bush Honeysuckle, 518
Butcher’s Broom, 461
Buttercup, 564
Butternut, 482
Butter Trees, 506
Button Bush, 517
Button-wood, 487
Buxus, 102, 485
Cabbage, 93.171, 185
Cabbage Palmetto, 565
Cacalia, 514
Cachibou, 540
Cactace®, 94, 520
Cacti, 503580
GENERAL INDEX.
Cactus Family, 520
Caslosphieri um, 21G
Csesalpina, 533
Caesalpiniem, 533
Caffeine, 182
Calabash Tree, 499
Calamandar Wood, 506
Calamarieae, 368
Calame®, 465
Calamites, 368
Calamochidus, 368
Calamostacliys, 368
Calamus, 81, 465, 466
Calandrinia, 549
Calcareae, 210
Calceolaria, 500
Calcium, 175
Calcium Carbonate, 60
Calcium Oxalate, 59, 180
Calendulacese, 514
Caliciacei, 310
Caliciei, 310
Calicium, 310
California Laurel, 494
California Pitcher Plant, 557
Calla, 61, 462
Calla Lily. 462
Calliopsia, 514
Callirhoe, 547
Callisteplius, 516
Callithamnion, 277
Callitris, 399,411
Calluna, 509
Calocasia, 462
Calonemeas, 211
Calopbyllum, 549
Calopogon, 470
Caltba, 436, 564
Calycanthaceae, 562
Calyceraceae, 516
Calycocarpum, 560
Calypso, 471
Calyx, 418, 430
Cambium, 17, 116, 121, 143,
201,407, 444
Cambiform Cells, 111
Camelina, 554 *
Camellia, 548
Campanales, 511
Campanula, 13, 512
Campanulacese, 77,119, 511
Camphor, 63, 494, 547
Camphor Tree, 547
Camwood, 532
Canada Balsam, 412
Canada Thistle, 513
Canal, Intra-fascicular, 111
Candle Nut Tree, 485
Candytuft, 554
Canella, 551 .
Canella Bark, 551
Canellacese, 551
Cane Palms, 465
Cane Sugar, 62, 180
Canna, 473
Cannabis, 488
Cannabineae, 488
Cannacete, 425
Cannae, 473
Canon Live-Oak, 479
Canterbury Bells, 512
Caoutchouc, 78, 485, 490, 503, 504
Capers. 552
Capillitium, 210
Capparidaceae, 552
Capparis, 552
Caprifoliacese, 518, 565
Capsella, 98, 264, 425, 554
Capsicum, 501
Capsulary Fruits, 436
Capsule, 348, 355, 436
Caragana, 532
Caraway, 520
Carbon, 175
Carbonates, 176
Carbohydrate, 178
Carbon Dioxide, 174, 181, 191
Carbon Oxide, 179
Carcerulus, 436
Cardinal Flower, 512
Cardiospermum, 537
Carex, 150, 323
Carica, 522
Carludovica, 462
Carnations, 550
Carnivorous Plants, 182
Carmine, 520
Carpel, 136, 430, 433
Carpellary Leaves, 400
Carpet-weed, 520
Carpids, 433
Carpinus, 477, 564
Carpogoniuui, 271, 300, 330, 331
Carpophore, 436
Carpophyllum (pl.-la,) 419, 433
Carpospore, 332
Carpophyta, 205, 270, 335, 337,
568, 569, 570GENERAL INDEX.
581
Carrot, 519
Cartliamus, 512
Carya, 73, 482. 565
Caryophyllaceae, 494, 549
Caryophyllales, 549
Caryopsis, 436
Caryota, 466
Cascarilla Bark, 485
Cashew Family, 534
Cashew Nut, 535
Cassava, 484
Cassia, 197, 533, 565
Cassia Bark, 494
Cassia Buds, 494
Castanea, 478, 564
Castilleia, 53
Castilloa, 490
Castor Bean, 59, 181
Castor Oil, 62
Castor Oil Plant, 475 484
Casuarineae, 487
Catalpa, 429, 437, 499
Catasetum, 470
Catchliy, 550
Catha, 539
Catkin, 395, 413, 4281
Catnip, 498
Cattleya, 471
Caulerpa, 134, 254
Caulerpites, 254
Caulicle, 404
Cauliflower, 553
Cauline Bundles, 392, 442
Caulome, 134, 135, 243, 271
C'aulophyllum, 559
Cayenne Pepper, 501
Ceanothus, 61, 103
Cedrella, 540
Cedrus, 409, 415
Celastraceae, 539
Celastrales, 537
Celastrus, 539
Celery, 519
Cell Derivatives, 67
Cell Families, 65
Cell Formation by Division, 36
Cell Formation by Union, 44
Cell Fusions, 66
Cell Masses, 67
Cell Rows, 67
Cell Sap, 62
Cell Surfaces, 67
Cellular Plants, 205
Cell Wall, 15, 21, 68, 166, 206
Celosia, 496
Celtis, 61, 85, 150, 488
Cellulose, 21
Cenangium, 289
Centaurea, 513
Central Cell, 331, 375
Centrifugal Thickening, 31
Centripetal Thickening, 31
Century Plant, 467
Cephaelis, 517
Cephalanthus, 517
Cephalotus, 526
Ceramieae, 277
Ceramiaceae. 339
Ceramium, 278
Cerasin, 63
Cerastium, 429, 550
Ceratopliylleae, 483
Ceratozamia, 410
Cercis, 533
Cercocarpus, 529
Cereus, 520
Cereal drains, 181
Ceropegia, 503
Ceroxylon, 93, 466
Cestrum, 502
Cetraria, 308
Chaetocereae, 231
Cbaetoceros, 231
Chaetocladium, 241
Chailletiaceae, 540
Chamaebatia, 529
Chamaecyparis, 411
Chamaedorea, 466
Chamaerops, 465
Chamomile, 514
Channels in Cell-Walls, 24
Chaptalia, 512
Chara, 14, 333, 334
Characeae, 271, 331, 335, 337
Chareae, 333, 334
Charlock, 554
Checkerberry, 510
Clieiranthus, 554
Chelura, 524
Chemical Processes m Cells, 168
Chemical Processes in the Plant,
178
Chemical Rays of Spectrum, 192
Chenopodiaceae, 495
Chenopodiales, 494
Chenopodium, 71, 102, 436, 495582
GENERAL INDEX.
Cherimova, 561
Cherry, 62, 64, 126, 143, 159, 284,
292, 426, 428, 436, 530
Cherry Blight, 140
Cherry Laurel, 173
Chestnut, 58, 154, 421, 478
Chibou, 540
Chicory, 512
Chimaphila, 510
China Aster, 516
China Grass, 491
Chinese Date, 506
Chinese Primrose, 506
Chinese Sugar-Cane, 457
Chinese Yam, 467
Chiodecton, 310
Chionanthus, 505
Chittagong Wood, 540
Chlaenaceae, 547
Chlamydospores, 237
Chloranthaceae, 483
Chlorides, 176
Chlorine, 175
Chlorococcum, 219
Chlorophyll. 50, 70, 94, 155, 178,
191, 205, 206
Clilorospermese, 337
Chlorosporeae, 339
Chloroxylon, 540
Chocolate, 546
Chocolate Tree, 545
Chondrites, 278
Chondrus, 277
Choripetalae, 476, 518, 568
Choripetalous, 431
Chorisepalous, 431
Chowlee, 532
• Chronizoospores, 223
Cliroococcacese, 216, 305, 306, 338
Chroococcus, 216
Chroolepideae, 306
Chrysanthemum, 514
Chrysobalaneae, 530
Chrysopliyllum, 506
Chufa, 457
Churrus, 488
Chylocladiese? 277
Chytridiaceae, 339
Cichoriaceae, 67, 77, 78, 119, 512
Cichorium, 512
Cicinnus, 429
Cicuta, 520
Cilia, 10
Ci'iary Movement, 1ft
Cinchona, 17, 64, 182, 517
Cineraria, 514
Ciunamomum, 494, 564, 565
Cinnamon, 494
Circinella, 237
Circumcissile Dehiscence, 435
Circulation of Protoplasm, 14
Cissus, 482, 538, 565
Cistacese, 552
Cistus, 552
Citric Acid, 64, 182
Citron, 541
Citrullus, 522
Citrus, 541
Cladonia, 306, 309
Cladoniei, 309
Cladophora, 10, 37, 224, 245, 306
Cladoxylon, 415
Classification, 202
Clavaria, 330
Claviceps, 289, 294
Claytonia, 199, 549
Cleavers, 517
Cleistogamous Flowers, 421
Clematis, 564
Cleome, 552
Clerodendron, 498
Clethra, 510
Cliftonia, 539
Climacosphenia, 231
Climacium, 360
Climbing Bittersweet, 539
Closed Bundle, 121, 443
Closing of Flowers, 199
Closterium, 11, 227
Clove Pink, 93, 550
Clover, 197, 428, 532
Cloves, 523
Clove Tree, 523
Cluster Cups, 316
Cnicus, 513
Coagulation of Albuminoids, 188
190
Coalescence of Floral Organs, 432
Coats of Ovule, 401
Cobsea, 503
Cob-nuts, 477
Cocconeis, 230
Cocconidese, 230
Cocculus, 560
Coccus, 490
Cochineal Insect, 520
Cockleburs, 515
Cockscomb, 496GENERAL INDEX.
583
Cocoa, 546
Cocoanut, 464
Cocoineae, 464
Cocos, 464
Cceloblastese, 250, 269, 336, 337
Coelogyne, 471
Coenobia, 221
Coenogoniei, 310
Coenogonium, 310
Co flea, 517
Coffee, 182, 517
Cohorts of Dicotyledons, 476
Cohorts of Monocotyledons, 453
Coix, 93
Colchicum, 460
Coleochaetaceae, 339
Coleochaete, 271, 274, 279, 335, 337
Coleochaeteae, 340
Coleus, 53, 498
Collar, 475
Collateral Bundle, 120, 362, 368,
380, 392, 438
Collema, 295, 298, 300, 301, 305,
306, 309
Collemaceae, 305, 339
Collemei, 309
Collencliyma, 29, 70, 89, 124, 363,
378, 392
Collum, 475
Colocynth, 522
Coloring Matters, 64
Colors of Flowers, 53
Columbine, 564
Columella. 210, 236, 360
Columelliaeeae, 499
Columellif'erae, 211
Colza, 554
Comandra, 476
Combretaceae, 524
Cominelynacese, 457
Commelynales, 457
Common Bundles, 368, 392, 438
Comose Seeds, 437
Compass Plant, 103, 156, 515
Complete Flower, 431
Composite, 62, 94,99, 197, 284, 425,
429, 434, 512
Composites, 153,158
Compound Leaves, 147
Compound Pistil, 433
Compound Raceme, 423
Compounds in Plant-Food, 176
Compound Spike, 428
Compound Umbel, 428
Concentric Bundle, 120, 863
Conceptacles, 265
Concluding Observations, 566
Conducting Tissue, 89
Cone, 397
Conepia, 531
Conferva, 37, 306
Confervaceae, 224, 245, 277, 839
Confervse, 340
Confervites, 242
Conjugate, 225, 242, 336, 340
Conjugation, 45, 47, 225
Conia, 182
Conidia, 39, 241, 260, 273, 279,
289, 292, 294, 312, 315, 323, 357
Conifera, 25, 51, 130, 132, 396, 409,
410, 415
Conifers, 143, 153, 158, 409, 410
Coniocybe, 310
Coniomycetes, 338
Conium, 182, 520
Connaracese, 534
Connarus, 534
Connecting Tube, 276
Connective, 433
Conotrema, 309
Constituents of Plants, 166
Convallaria, .460
Conversion into Mucilage, 35
Convolvulaceae, 77, 502
Convovulus, 502
Copaifera, 583
Copaiva Balsam, 533
Copai-ye Wood, 550
Copernica, 464
Coprinus, 829, 330
Coquilla-nuts, 464
Corallina, 277, 278
Corallineae, 277,278
Corallorhiza, 192, 471
Corcliorus, 545
Cordate Leaves, 146
Coreopsis, 514
Coriander, 520
Coriarieae, 534
Cork, 125, 480
Cork Cambium, 126
Cork Oak, 125, 480
Cork-wood, 547
Corm, 136
Cormopliyta, 203, 205
Cormophytes, 335
Cornacefe, 518, 565
Corn Cockle, 550584
GENERAL INDEX.
Cornua, 518, 565
Corolla, 418, 430
Corpuscula, 393, 403
Cortex, 201
Coryleae, 477
Cory 1 us, 477, 564
Corymb, 428
Coryphineae, 464
Coscinodisceae, 231
Coscinodiscus, 11, 231
Cosmarium, 44, 227
Cotton, 98, 437, 546
Cottonwood, 487
Cotyledon, 526
Cotyledons. 386, 391, 404, 424
Couma, 504
Cowslip, 506
Cow Tree, 489
Crab-Apples, 527
Cranberry, 511
Crape Myrtle, 523
Crassula, 526
Crassulacese, 526
Crataegus, 527, 565
Cratoxylon, 549
Crayfishes, growths on, 257
Cremocarp, 436
Crenate Leaf, 147
Creosote Bush, 543
Crescentia, 499
Cribraria, 211
Crocus, 56, 468
Crossosoma, 563
Crotallaria, 532
Crotou, 484, 485
Croton Oil, 484
Crown Imperial, 460
Crucibulum, 325, 326
Cruciferae, 98, 181, 264, 425, 553
Crucifer Family, 553
Cryptogam, 204,271, 316
Cryptogamia, 204, 205
Cryptomeria, 411
Cryptonemieae, 277
Crypto-Rapliidieae, 231
Crystalloids, 57, 58
Crystals, 57, 59
Cuba Bast, 547
Cubebs, 484
Cuboidal Cell, 19
Cucumber, 522
Cucumber Tree, 561
Cucumis, 14, 80, 522
Cucurbita, 11, 13, 14, 35, 53, 80,85,
522
Cucurbitaceae, 29, 51, 71, 120, 181,
521
Cucurbitaria, 294
Cultures of Lichens, 307
Cultures of Moulds, 239
Cultivated Plants, 182
Cummin, 520
Cupania, 537
Cuphea, 523
Cupresseae, 411
Cupressus, 409, 411
Cups, 136
Cupuliferse, 425, 426, 477, 564
Curare, 503
Curcuma, 472
Currant, 64, 526
Cuscuta, 56, 502
Cusparieae, 542
Custard Apple, 561
Cuticle, 34, 93
Cuticularizing, 35
Cyanophyceae, 215, 336
Cyathea, 377
Cyatlieaceae, 376
Cycadeae, 409, 410
Cycads, 409, 410, 416
Cycas, 399, 410
Cyclamen, 506
Cyclic Flowers, 429, 430
Cyclotella, 231
Cvdonia, 527
Cylindrical Cell, 19
Cymatopleura, 231
Cymbella, 230
Cymbelleae, 230
Cyme, 429
Cvmo-Botrys, 429
Cymose Inflorescence, 427, 429
Cymose Mouopodium, 140
Cynara, 572
Cynaroideae, 512
Cynips, 479
Cynoglossum, 57
Cynomorium, 476
Cyperaceae, 457, 473
Cyperus, 457
Cypress, 411
Cypripedieae, 469
Cypripedium, 469
Cyrilla, 539
Cyrillacese, 539GENERAL INDEX.
585
Cyatidia, 328, 330
C.ystoliths, 60
Cystopteris, 377
Cystopus, 39, 260, 264
Cytisus, 85, 532
Dacrymyces, 289
Dactylina, 308
Dactyl is, 455
Daffodil, 468
Dahlia, 62, 514
Daisy, 516
Dalbergia, 532
Dammara, 413
Dammar Resin, 413
Damea, 378
Dandelion, 512
Dantzic Fir, 412
Daphnales, 491
Dapline, 492
Darlingtonia, 182, 557
Dasya, 277
Date, germination of, 453
Date Palm, 465
Datiaca, 521
Datiscacese, 521
Datura, 102, 502
Daucus, 519
Daughter Cells, 39
Day Lily, 460
Deadly Nightshade, 502
Death from high temperature, 188
Death from low temperature, 189
Decandrous, 432
Dehiscence, 435
Dehiscent, 435
Delesseria, 277, 278
Delphinium, 106, 564
Dendrobium, 471
Dentate Leaf, 147
Denticella, 11
Deoxidization in Assimilation, 179
Dermatogen, 161, 423
Desmidiacese, 44, 225, 242, 336, 338
Desmids, 225
Desmobacteria, 213
Desmodium, 196, 198, 436, 533
Determinate Inflorescence, 428
Deutzia, 526
Diadelphous, 432
Dialypetalous, 431
Diandrous, 432
Diantbus, 93, 550
Diapens'aceae, 508
Diarthrodaclyleae, 334
Diatoma, 227, 231
Diatomaceae, 53, 227, 242, 336, 338
Diatoineae, 340
Diatoms, 34, 227, 242
Diatrype, 294
Dicarpellary, 433
Di centra, 556
Dicliasium, 429
Dichlamydeous, 431
Dichogamous, 434
Dichotomse, 382
Dichotomous branching, 139
Dichotomous Cyme, 429
Dicksonia, 378
Diclinous Flowers, 431
Dicotyledones, 393, 473, 568
Dicotyledons, 93. 118, 123,143,148,
150, 161, 200, 391, 416, 569, 570
Dicranum, 360
Dictamnus, 130,132, 542
Dictydium, 211
Dictyotaceae, 339
Didymium, 9, 10, 188; 210, 432
Diervilla, 518
Diffusion, 174
Digitalis, 500
Digitately lobed leaves, 147
Digitately compound leaves, 148
Digynous, 433
Dill', 520
Dillenia, 562
Dilleniaceas, 562
Dimensions of cells, 17
Dimerous, 430
Dimorphandra, 533
Dimorphous, 434
Dioecious, 249
Dioecious Flowers, 431
Dionaea, 182, 197, 198,526
Dioscorales, 467
! Dioscorea, 467
Dioscoreaceae, 467, 473
Diosma, 54 ’
Diosmeae, 542
Diospyros, 506, 564, 565
I hpetalous, 432
Diplostemonous, 432
Diplostephante, 334
Dipsaceae, 516
Dipsacus, 99, 516
Dipterocarpeae, 547
Dirca, 492
Direction of Spirals, 82586
GENERAL INDEX.
Dirina, 309
Discomycetes, 286, 338
Disepalous, 431
Distribution in Time, 568
Disturbance of the Equilibrium of
Water, 168
Diurnal Positions of Leaves, 199
Division of Cells, 36
Divisions of the Vegetable King-
dom, 205
Docks, 497
Dodder, 53, 56, 502
Dodecandrous, 432
Dodecatlieon, 506
Dodonaeae, 535
Dogbane Family, 504
Dogwood, 518, 539
Dogwood Family, 518
Dormant Buds, 144
Doryphora, 494
Double Coeoa-Nut, 465
Doubly Compound Leaves, 148
Douglas Spruce, 33, 411
Doum Palm, 465
Draba, 98, 264
Dracaena, 444, 460
Dracophyllum, 510
Dragon Trees, 444, 460
Dragon’s Blood, 466
Drosera, 182, 198, 429, 526
Droseraceae, C26
Drupaceous Fruits, 436
Drupaceous Seeds, 437
Drupe, 436
Dry Fruits, 435
Dryobalanops, 547
Duckweeds, 461
Dudresnava, 276, 277
Duguetia, 561
Dulse, 277
Dumontieae, 277
Durio, 547
Dwarf Almond, 530
Dwarf Palmetto, 465
Dyers’ Weed, 552
Earth-Star, 324, 326
Ebenaceae, 505, 564, 565
Ebenales, 505
Ebony, 506
Ebony Family, 505
Ecbaiium, 11, 81
Echinocystis, 74, 81, 522
Ecliites, 504
Ectocarpeae, 339
Ectoplasm, 4, 15
Edible Hymenomycetes, 330
Eel Grass, 473
Egg Plant, 500
Elaeagnaceae, 491
Elaeagnus, 492
Elaeis, 464
Elapbomyces, 286
Elaters, 348, 367
Elatinaceae, 549
Elder, 71, 126,144, 518
Elecampane, 516
Elements of Plant Food, 175
Eleutheropetalous, 431
Elliptical Leaves, 146
Elm, 61, 64, 143, 146,187, 488
Elm Family, 488
Embryo, 46, 391, 404, 423
Embryology, 204
Embryonic Vesicle, 47
Embryo-sac, 11, 41, 46, 66, 137,
389, 401, 402, 420
Eneephalartos, 410
Endive, 512
Endocarp, 535
Endocarpei, 310
Endocarpon, 310
Endochrome, 227
Endogenae, 451
Endoplasm, 4, 16
Endosperm, 11, 41, 390, 402, 403,
420, 423, 425
Endospore, 34. 257, 263, 342
English Bean, 38, 531
English Ivy, 519
English Walnuts, 480
Enneandrous, 432
Ensiforin Leaf of Iris, 159
Entomophilous Flowers, 421
Epacrideae, 508, 510
Epacris, 510
Ephebe, 305, 309
Ephedra, 413, 416
Epidendreae, 470
Epidendrum, 470
Epidermal System, 90, 357, 362,
406
Epidermis, 91, 92, 162, 170, 201,
343, 362, 367, 392, 437
Epigaea, 510
Epigynous, 434
Epigyny, 434
1 Epilobium. 61, 522GENERAL INDEX.
587
Epinasty, 199
Epipetalous, 433
Epispore, 257, 263
Epithemia, 231
Equilibrium of Water, 168
Equisetaceae, 35, 143, 368, 389
Equisetinae, 362, 363, 382
Equisetites, 369
Equisetum, 11, 37, 80, 81,86, 88,
110, 115, 120, 123, 128, 363, 368,
369
Erect Ovules, 433
Ergot, 289, 295
Erica, 510
Ericaceae, 508, 564, 565
Ericales, 508
Ericineae, 508, 509
Erigeron, 98
Eriocaulonaceae, 457
Erodium, 543
Erysimum, 437
Erysiphaceas, 140, 278, 339
Erysiplie, 279, 383
Erysipliei, 283
Erythroxylon, 541
Eschscholtzia, 556
Essence of Cinnamon, 63
Essence of Wintergreen, 63
Essential Oils, 62
Ethiopian Lily, 462
Etiolated Plants, 52
Euastrum, 227
Eucalyptus, 94, 524, 565
Eudorina, 243
Eugenia, 523
Euglena, 50
Eunotia, 231
Euonymus, 539
Eupatoriaceae, 516
Eupatorium, 264, 516
Eupodisceae, 231
Eupodiscus, 231
Euphorbiaceae, 76, 77, 425, 484
Euphorbiales, 484
Euphorbia, 78, 102, 150, 485
.Euphorbium, Gum, 484
Eurotium, 281, 285, 289
Evaporation of Water, 167, 169,
185,191
Evening Primrose, 61
Everlasting Flowers, 515
Evernia, 308
Exalbuminous Seeds, 391, 437
Excretions, 61
Excoecaria, 485
Exhalation of Water, 169
Exocarp, 435
Exogenae, 473
Exospore, 34, 222, 342
Ex tine, 34
' Extrorse anthers, 433
Fagopyrum, 496
Fagus', 17, 150, 479, 564
False Flax, 554
False Raceme, 429
Families of Cells, 65
Farfugium, 514
Fennel, 520
Fermentation, 212
Fermentive Changes, 190
Ferns, 123, 143, 155, 362, 370, 371,
372, 373
Fertilization in Angiosperms, 419,
422
Ferula, 520
Fever Tree, 517
Fibrous Roots, 165
Fibrous Tissue, 74, 89, 106, 112,
119, 123, 363, 368, 392
Fibro-vascular Bundles, 106, 155,
159, 352, 362, 367, 392, 407, 438
Fibro-vascular System,90,106,343,
359, 362, 438
Ficoidales, 520
Ficoidete, 520
Ficus, 94, 102, 489, 564, 565
Field Bean, 475, 531
Field Oak, 480
Fig, 61, 62, 437, 489
Figwort Family, 500
Filament, 394, 418
Filbert, 477
Filices, 370, 371, 372, 373, 389
Filicime, 369, 382, 389
Fishes, growths on, 257
Flagellarieae, 457
Flax, 35, 181, 187, 188, 491, 543
Flax Family, 543
Fleshy Fruits, 435
Flies, growths on, 257
Floral Envelopes, 136. 155
Floral Symmetry, 429
Florideas, 53,186, 271, 273, 335, 337
339, 340
Flower, 842, 353, 391, 394, 417 '
Flower-axis, 136
Flowering Dogwood, 518588
GENERAL INDEX.
Flowering Plants, 203, 205
Flowerless Plants, 203, 205
Flowers, Colors of, 53
Flowers in darkness, 192
Flow of Sap, 174
Fceniculum, 520
Foliage-leaf, 136
Follicle, 436
Fontinalis, 360
Fool’s Parsley, 520
Foot, 386
Forget-me-not, 502
Forked Cyme, 429
Forked Cyrnose Monopodium, 140
Forked Dichotomy, 139
Formation of Alkaloids, 182
Formation of Ice Crystals, 189
Formation of New Cells, 36
Forms of Cells, 18, 19
Forms of Leaves, 146
Forms of Roots, 165
Forsythia, 505
Fossil C'haracete, 334
Fossil Cceloblastese, 254
Fossil Dicotyledons, 564
Fossil Florideae, 278
Fossil Fucaceae, 269
Fossil Gymnosperms, 415
Fossil Helvellacese, 289
Fossil Hyinenomycetes, 331
Fossil Lichens, 3i0
Fossil Monocotyledons, 473
Fossil Protopliytes, 219
Fossil Py'renomycetes, 295
Fossil Zvgosporese, 242
Four O’clock, 497
Foxglove, 500
Fragaria, 528
Fragilaria, 227, 231
Fragilarieae, 231
Framework of the Leaf, 155
Frankeniaceae, 550
Fraxinella, 540
Fraxinus, 505, 565
Free-cell Formation, 42, 47, 49
Free Central Placenta, 434
Free Oxygen, 179
Fringe Tree, 505
Fritillaria, 460
Frostweed, 552
Fruits, 381, 426, 435
Fruit Sugar, 62
Frullania, 341, 351
Frustule, 227
Fucaceae, 35, 53,135, 186, 243.264
268, 269, 336, 337, 339, 340
Fuchsia, 61, 93, 94, 102, 104, 522
Fucoideae, 268, 269
Fucoides, 269
Fucus, 265, 268
Fuligo, 2, 10, 188, 194, 210
Fuller’s Teasel, 516
Fumariaceae, 555
Fumitory, 556
Funaria, 352, 360
Fundamental System, 90, 123, 359,
362, 363, 408, 438
Fungales, 337
Fungi, 13, 39, 53, 56, 66, 67, 86, 90,
192, 204, 205, 337, 340
Funkia, 13, 460
Fusanus, 476
Fusiform Cell, 19
Fustic, 490
Galactodendron, 78, 489
Galanthus. 468
Galipea, 542
Galium, 517
Gamboge, 548
Gamopetalae, 476, 497, 568
Gamopetalous, 432
Gamosepalous, 432'
Garcinia, 548, 549
Garden Balsam, 542
Gardenia, 518
Garlic, 61, 63, 458
Gas Plant, 540
Gasteromycetes, 323, 324, 338, 339
Gaultlieria, 510
Gaylussacia, 511
Geaster, 324, 326
Geissolomeae, 484
Gelidieae, 277
Gelidium, 277
Gemmae, 344, 357
Generalized Forms, 133
Generating Spiral, 151
Genetic Relationship, 203
Gentianaceae, 503
Gentianales, 503
Gentian Family, 503
Genuflexous Conjugation, 234
Georgia Bark, 517
Geotropism, 194, 200
Geraniacese, 542
Geraniales, 540
Geranium, 543GENERAL INDEX.
589
Geranium Faipily, 542
Gerardia, 53
German Ivy, 514
Germ-cell, 341, 348, 362, 390, 420
Germination of Dicotyledons, 474
Germination of Monocotyledons,
451
Germination of Seeds, 181, 187, 404
Gesnera, 499
Gesneracete, 499
Giant Puff-ball, 326
Giant Redwood, 411
Giant Silver Fir, 412
Gigartineae, 277, 278
Gilia, 503
Gills, 328
Gillyflower, 554
Ginger, 472
Gingerbread Palm, 465
Ginkgo, 81, 399, 409, 410
Ginseng, 518
Gladiolus, 468
Glands, 137
Glandular Hairs, 97,130
Glandular Scales, 97
Gleditschia, 533
Gleiclienia, 374, 376
Gleieheniaceae, 376
Globe Amaranth, 496
Globe Flower, 564
Globoids, 57
Gloeocapsa, 216
Glossology of Angiosperms, 426
Gloxinia, 499
Glucose, 62, 180, 181
Glumales, 453
Glycyrrhiza, 532
Glyphidei, 310
Glypliis, 310
Gnetaceae, 396, 401, 410, 413
Gnetum, 413
Golden Lily, 460
Golden Rod, 516
Gomphonema, 229
Gomphonemacese, 230
Gomplirena, 496
Gonidia, 217, 218, 219, 295, 301,
307
Goodeniaceae, 512
Gooseberry, 62, 64, 283, 436, 526
Gordonia, 548
Gossypium, 426, 546
Gourd, 29, 184, 522
Gourd Family, 521
Gramineae, 94,129,322, 425,453,473
Grammatophora, 231
Granulose, 55, 56
Grape, 02, 64, 264, 284, 288, 537
Grape Mildew, 264
Grapevine, 61
Graphidiacei, 310
Graphis, 301, 306, 310
Grasses, 35, 93, 98, 102, 150, 187,
195, 289, 295, 316, 323, 421, 429,
436, 404
Grass Family, 453
Gravitation and Geotropism, 194
Great Laurel, 510
Greenheart Tree, 494
Green Hellebore, 460
Grevillea, 491
Grindelia, 516
Ground Cherries, 500
Ground Tissue, 89, 123
Grouping of Living Things, 203
Growing Point, 87
Growth of Cell-Walls, 22
Guaiacum, 543
Guavas, 523
Guinea Pepper, 461
Gulf-Weed, 269
Gum, 62, 63, 129
Gumbo, 547
Gummy Substances, 96
Gum Acacia, 533
Gum Ammoniacum, 520
Gum Arabic, 61, 533
Gum Asaloetida, 520
Gum Benzoin, 505
Gum Copal, 533
Gum Canals, 129
Gum Euphorbium, 484
Gum Galbanum, 520
Gum Kino, 532
Gum Lac, 490
Gum Opopanax, 520
Gum Storax, 505
Gum Tragacanth, 63, 532
Gunja, 488
Gutta Perclia, 78, 506
Gutti ferae, 548
Guttiferales, 547
Gyalecta, 309
Gymnocarpous Lichens, 297, 298
Gymnocladus, 533
Gymnospermae, 393, 568
Gymnosperms, 60, 80, 85, 118. 123,
391, 393, 437, 569, 570590
GENERAL INDEX.
Gymnosporangium, 314, 315, 317
Gymnosteraium, 469
Gynandmus, 249, 433
Gynoecium, 419, 430, 433
Gypsophila, 550
Gyrostomum, 309
Habenaria, 470
Hackberry, 488
Hsemanthus, 171. 468
Haematoxylon, 533
Haemodoraceae, 467
Hairs, 90, 137
Halesia, 505
Halimeda, 254
Halionyx. 231
Halonia, 385
Haloragese, 525 «
Halosaccion, 277
Hamamelacete, 526
Hamamelis, 526
Haplosteplianae, 334
Hascbiscli, 488
Hauptplasma, 4
Haustoria, 258, 279, 317
Hautscliiclit, 4, 16
Hawthorn, 428, 527
Hazel, 187, 284
Hazel Nut, 477
Head, 428
Heads, Racemose, 429
Heads, Spicate, 429
Heath, 509
Heath Family, 508
Heat-Rays of Spectrum, 192
Hedeoma, 497
Hedera, 103, 129, 165,194, 519, 564
Helenioideae, 514
Heliampliora, 557
Heliantliemum, 552
Heliantlius, 62, 102, 151,284, 514
Helianthoideae, 514
Helichrysum, 516
Helicoid Cyme, 429
Helicoid Monopodium, 140
Helicoid Syinpodial Dicliolomy,140
Heliopelta, 231
Heliopeheae, 231
Heliotrope, 502
Heliotropism, 193, 200
Heliotropium, 502
Helipterura, 515
Hellebore, 563
Helleborus, 563
Helminthostacbys, 380
Helvella, 289
Helvellaceas, 286, 28J, 291 295,
299, 339
Hemerocallis, 159, 429, 460
Hemiaulus, 231
Hemicyclic Flowers, 429
Hemitelia, 377
Hemlock, 520
Hemlock Spruce, 154, 411
Hemp, 61, 188, 488
Henbane, 502
Henna, 523
Hepatica, 147, 187, 563
Hepatic*. 343, 361
Heppia, 309
Heptandrous, 432
Herd’s Grass, 455
Hermaphrodite Flowers, 431
Hernandieae, 492
Hernioid Protrusions, 30
Hesperis, 554
Heterocysts, 206, 217
Heterodermeae, 211
Heteroecism, 314
Heterogonous, 435
Heterogonous Dimorphous, 435
Heterogonous Trimorplious, 435
Heteromerous Flowers, 430
Heteroinerous Lichens, 295, 301
Heterosporete, 372, 383
Heterostyled, 435
Heterotliecium, 310
Heuchera, 106
Hevea, 78, 485
Hexandrous, 432
Hibiscus, 547
Hickory, 144, 158, 482
Hickory-nut, 73, 482
Hieracium, 150
Hilum of Starch, 53
Hippomane, 485
Hippuris, 88
Holly, 94, 539
Holly Family, 539
Hollyhock, 547
Homology and Analogy, 120
Homoomerous Lichens, 295, 301
Honey, 421
Honey Locust, 533
Honeysuckle, 199, 518
Honesty, 554
Hop, 61, 199, 283, 488
Hop Tree, 542
Hordeum, 455GENERAL INDEX.
501
Horehound, 497
Hornbeam, 477
Horsechestnut, 58, 144, 429, 537
Horsemint, 498
Horseradish, 63, 554
Hottonia, 186
Houseleek, 526
Houstonia, 517
Hoya, 61, 503
Huckleberries, 511
Hudsonia, 552
Humiriaceae, 543
Humulus, 103, 488
Hyacinth, 94, 102, 165, 460
Hyacinthus, 460
Hydnum, 328, 330, 331
Hydra, 50
Hydrales, 473
Hydrangea, 526
Hydrocarbons, 63
Hydrocliarideae, 473
Hydrodictyon, 65, 223
Hydrogen, 175, 179
Hydropliyllaceae, 502
Hydrothyria, 309
Hygroscopic Tissue, 157
Hymenaea, 533
Hymenium, 278, 286, 297, 323
Hymenophyllaceae, 376
Hyinenopliyllum, 370
Hymenomycetes, 289, 323, 326, 338,
339
Hyoscyamus, 502
Hypericaceae, 549
Hypericum, 132, 433, 549
Hyphae, 194, 235
Hypliaene, 465
Hyphomycetes, 338
Hypnea, 277
Hypneae, 277
Hypnum, 360
Hypocotyledonary Stem, 404
Hypoderma, 72, 124
Hypodermiae, 338, 339
Hypogynous, 434
Hyponasty, 199
Hypophysis, 424
Hypoxylon, 294
Hyssop, 497
Hyssopus, 497
Iberis, 441, 554
Ice Crystals, formation of, 189
Iceland Moss, 308
Ice Plant, 520
Ilex, 539. 565
Ilicineae, 539, 565
Imbibation power of Protoplasm,
5, 168
Impatiens, 14, 61, 85, 88, 159, 165,
192, 264, 421, 542
Incombustible substances, 35
Incomplete flower, 431
Incumbent cotyledons, 437
Indehiscent, 435
Indeterminate inflorescence, 428
Indian Corn, 52, 56, 57, 59, 62, 70,
106, 113, 114, 131, 155, 157, 165,
166, 187, 318, 323, 451, 455, 522
Indian Turnip, 61, 428
Indian Pipe, 511
India Rubber, 78, 485
Indigo, 532
Indigofera, 532
Individual development, 204
Indusium, 374
Inflorescence, 427
Innate Anthers, 433
Insect agency in Pollination, 421
Insects killed by parasitic plants,
294
Integument of ovule, 401
Intercalarv growth of cells, 22,
140, 246'
Intercellular canal, 114, 409
Intercellular spaces, 70, 99, 128,
156, 167, 171, 197
Intercellular substance, 35, 68
Interfascicular cambium, 408
Intermediate tissue, 125
Internal cell-formation, 36, 39
Internal structure of Leaves, 155
Intine, 34
Intrafaseicular Canal, 111
Introrse anthers, 433
Intussusception, 31, 54
Inula, 62, 516
Inulin. 62, 180
Inuloidese, 515
Ionidium, 551
Ipecacuanha, 517, 551
Ipomcea, 14, 53, 70, 502
Iridacese, 468
Iris, 61,102, 157, 158, 468
Iris Family, 468
Irish Moss, 277
Iron, 175
Iron Bark Tree, 524592
GENERAL INDEX.
Iron Salts, 170
Iron-weed, 516
Irouwood, 284, 477, 505, 539
Irregular dehiscence, 435
Irregular flowers, 431
Isatis, 554
Isoeteie, 383, 387, 389,391
Isoetes, 382, 388, 403
Isomerous flowers, 430
Isonandra, 506
Isosporeae, 372, 383
I sostemonous, 432
Istlimia, 231
Ivory Nut, 463
Ivy, 98, 129, 165, 194, 519
Ixora, 518
Jack Fruit, 489
Jalap, 502
Jamaica Cedar, 540
Jamaica Ginger, 473
Jamaica Rosewood, 505
Japanese Wax, 535
Japan Lacquer, 535
Japan Lily, 460
Jarool, 523
Jarrali, 524
Jasminum, 505
Jatroplia, 484
Jerusalem Artichoke, 515
Jessamine, 505
Joint-Firs, 410, 413
Jonquil, 468
Judas Trees, 533
Juglandaceae, 480, 564
Juglaus, 102, 480, 565
Jujube, 539
J uneaceae, 457
J uncus, 131
Jungermaunia, 150, 349, 351
J ungermanniaceas, 345, 347, 351,
358
J uniperus, 17, 81, 410, 411
Justicia, 499
Jute, 545
Kaki, 506
Kale, 553
Kalmia, 510
Kapor, 547
Kaulfussia, 379
Kauri Pine, 413
Kentucky Blue Grass, 455
Kentucky Coffee Tree, 533
Khenna, 523
Kniglitia, 491
Koelreuteria, 537
Kohl Rabi, 554
Kuhne’s Experiment, 9
Labiate, 71, 132, 497
Laburnum, 532
Lace-Bark Tree, 493
Lacistemaceae, 484
Lacquer, 535
Lactuca, 512
Lactucarium, 512
Lady’s Slipper, 469, 543
Lajlia, 471
Lasvulose, 62
Lagenaria, 522
Lagetta, 493
Lagerstroemia, 523
Lambkill, 510
Lamellae of Cell-wall, 68
Lamiales, 497
Laminaria, 268
Laininariaceae, 339
Laminarites, 269
Lanceolate Leaves, 146
Lance Wood, 561
Lantana, 498
Laportea, 491
Larch, 185, 412
Larix, 81, 409, 411, 412
Larkspur, 564
Larrea, 543
Lateral Buds, 143
Lateral Conjugation, 234
Lateral Stems, 142
Latex, 76
Laticiferous Tissue, 67, 76, 106,
119, 124, 363, 392
Lathrsea, 56
Lathyrus, 532
Latticed Cells, 17, 79, 111
Lauraceae, 493, 565
Laurales, 493
Laurel, 493, 510
Laurel Family, 493
Laurelia, 494
Laurus, 493, 564, 565
Lavandula, 497
Lavender, 497
Lawsonia, 523
Layers of Cell-wall, 34
Lead-pencil Wood, 411
Leaf, 136, 144, 197, 265, 309GENERAL INDEX.
593
Leaf-forms, 146 Leaflet, 147 Leaf-stalk, 145 Leaf-tissue, 155 Lecauactidei, 310 Lecanactis, 301, 310 Lecanora, 309 Lecanorei, 309 Lecidea, 310 Lecideacei, 309 Lecideei, 310 Leek, 61, 458 Left, To the, 199 Legume, 436 Leguminosse, 426, 531, 565 Leguminosites, 565 Lejeunia, 351 Lejolisia, 274, 277 Lemaniaceae, 339 Lemna, 165 Lemnaceae, 461 Lemon, 64, 130, 132, 54J Lemon Verbena, 498 Lennoaceae, 508 Lentibulariacea;, 499 Lenticels, 126, 532 Lenzites, 331 Leonia, 552 Lepidium, 188, 264, 425, 504 Lepidodendrese, 385 Lepidodendron, 385 Lepidophloios, 385 Lepidostrobus, 385 Leptogium, 295, 306, 309 Lessonia, 268 Lettuce, 512 Leucadendron, 491 Leucobryum, 351 Leucojum, 468 Leucopogon, 510 Leucosporese, 339 Lever-wood, 478 Liatris, 429, 516 Libocedrus, 411 Licania, 531 Licea, 211 Lichenales, 337 Lichenes, 295, 337, 339 Lichens, 217, 218, 295, 333 Lichina, 309 Light, 169, 190,197 Lignification, 35 Lignum-vitae, 543 Ligule, 383, 386 Ligustrum, 505 Lilac, 102, 126, 144, 158, 159,' 284. 505 Lilac Blight, 140 Liliaceae, 94, 425, 458, 473 Liliales, 457 Liliutn, 102, 460 Lily, 94, 102, 460 Lily Family, 458 Lily-of-ilie-Valley, 61, 460 Lima Bean, 532 Lime, 64, 541 Lime Salts, 176 Lime Tree, 545 Limits of Temperature, 184 Limnoria, 498 Linaceae, 543 Linaria, 318 Linden, 146, 545 Linden Family, 545 Linear Leaves, 146 Linen, 544 Linn, 545 Linociera, 505 Linseed Oil, 62, 544 Linum, 543 Liparis, 471 Lippia, 498 Liquidamber, 526 Liquorice, 532 Liriodendron, 72, 85, 562, 564 Litchi, 537 Lithospermum, 421, 436 Litmus, 308 Live-forever, 526 Live-leaf, 526 Live Oak. 479 Liver-leaf, 187 Liverworts, 91, 341, 343, 351, 356 Loasacete, 522 Lobelia, 511 Lobeliacete, 77, 511 Lobes of Leaves, 147 Loblolly Bay, 548 Loculicidal Dehiscence, 435 Locust Tree, 61, 532, 533 Lodoicea, 465 Loganiaceae, 503 Logwood, 533 Lombardy Poplar, 487 Lomeut, 436 Lomentaria, 277 Longan, 537 Long-flowered Lily, 460594
GENERAL INDEX.
Long Moss, 47
Longitudinal Tension, 201
Lonicera, 518
Loranthace®, 477
Love Flower, 460
Love-in-a-Mist, 564
Lucerne, 166, 532
Luffa, 522
Lunaria, 554
Lupine, 58, 59, 532
Lupinus, 532
Lupuliu, 488
Lychnis, 550
Lychnothamnus, 334
Lycium, 502
Lycogola, 10
Lycoperdace®, 339
Lycoperdon, 324, 325
Lycopersicum, 500
Lycopodiace®, 80, 123, 383, 384,
389
Lycopodin®, 362, 382, 389
Lycopodium, 81, 112, 121,123,150,
382, 384, 385
Lygodium, 374, 377
Lysiloma, 534
Lysimacliia, 506
Lytlirace®, 522
Ly thrum, 523
Mace, 494
Maclura, 102, 490
Macrocystis, 268
Macrogonidia, 219
Macrosporangia, 373, 382, 386
Macrospores, 362, 371, 373, 381,
382, 386, 389, 403
Macrozamia, 410
Macrozoogonidia, 223
Madder, 518
Madeira Vine, 495
Madrona, 509
Magnesia Salts, 176
Magnesium, 175
Magnolia, 426, 437, 561, 564, 565
Magnoliace®, 561, 565
Magnolia Family, 561
Mahogany, 524. 540
Mahonia, 559
Maize, 455
Malaxide®, 471
Malaxis, 471
Malay Apple, 523
Malic Acid, 64, 182
Mallotiuin, 301, 306
Mallow, 144, 147, 547
Mallow Family, 546
Malpighiace®, 543
Malva, 85, 547
Malvace®, 98, 546
Malvales, 544
Mammea, 549
Mammee Apple, 549
Mamillaria, 151
Manchineel Tree, 485
Mangel Wurtzel, 495
Mangifera, 535
Mango, 535
Mangosteen, 548
Mangrove Tree, 524
Manihot, 484
Manilla Hemp, 472
Manzanita, 156, 509
Manubrium, 331
Maple, 77, 145, 147, 187, 284, 535
Maranta, 473
Marattia, 379
Marattiace®, 363, 372, 378, 380
Marchantia, 14,344, 347, 348, 351
Marchantiace®, 91,350
Marigold, 514
Marmalade, 506
Marrubium, 497
Marsilia, 381, 382
Marsiliace®, 382
Martynia, 98, 197, 499
Marvel of Peru, 497
Mastic, 535
Mastigonema, 218
Mastigonia, 231
Mate, 540
Mathematical Gymnastics, 152
Matthiola, 554
Matisia, 547
Maurandia, 500
Maximum Light, 191
Maximum Temperature, 184
Mayace®, 457
May Apple, 437, 559
Mayflower, 187, 510
Meadow Grass, 166, 185
Meadow Saffron, 460
Mecouic Acid, 182
Medicago, 532
Medullary Ra^s, 408, 449
Megalospora, 298
Melaleuca, 150
I Melambo Bark, 485GENERAL INDEX.
595
Melampsora, 314, 315
Melanospermeae, 268, 337
Melaspilea, 310
Melastomaeeae, 523
Melia, 540
Meliaceae, 540
Meliantlieae, 535
Melicocca, 537
Melobesiaceae, 339
Melon, 522
Melosira, 231
Melosireae, 231
Members of the Plant Body, 133
Menispermaceae, 560
Menispermum, 560
Mentha, 497
Menzies’ Spruce, 412
Mericarp, 436
Merismopedia, 216
Meristein, 86, 168
Meroxylon, 532
Mescal, 468
Mesembryanthemum, 520
Mesocarp, 435
Mesocarpeae, 235, 241, 242
Mesocarpus, 235, 238
Metaspermae, 393
Metastasis, 62,179, 186, 192
Micrasterias, 227
Microbacteria, 213
Micrococcus, 213
Microgonidia, 219, 304
Micropyle, 391, 419
Microsphaera, 281, 283
Microsporangia, 372, 382, 386, 390,
402, 418
Microspores, 362,371, 372,381, 382,
386, 389
Mignonette, 428, 552
Mikania, 516
Mildew, Grape, 264
Milkweed Family, 503
Mimosa, 197, 198, 534
Mimoseae, 533
Mimosites, 565
Mimulus, 197, 500
Minimum Light, 191
Minimum Temperature, 184
Mint Family, 497
Mirabilis, 497
Mistletoe, 53, 94, 182, 477
Mistletoe Family, 477
Mitella, 106
Mitcliella, 517
Mixed Inflorescence, 428, 429
Mnium, 353, 360
Mock Orange, 526
Modes of Branching, 139
Molecules of Cell-wall, 32, 167
Molluuo, 520
Mouadelplious, 432
Monandrous, 432
Monarthrodactvlae, 334
Monera, 15, 207
Monimiaceae, 494
Monizia, 520
Monkey Flower, 500
Monkey Pot, 524
Monkshood, 562
Monocarpellary, 433
Monochasium, 429
Monochlamydeous, 431
Monoclinous Flowers, 431
Monocotyledones, 393, 451, 568
Monocotyledons, 88, 93, 123, 143,
161, 318, 391, 416, 451, 569, 570
Mouocyclic, 430, 432
Monoecious, 249, 431
Monogyncecial Fruits, 436
Monogynous, 433
Monomerous, 430
Monopetalous, 431, 432
Monopodial Branching, 131
Monosepalous, 431, 432
Monosymmetrical Flowers, 431
Monotropa, 192, 511
Monotropeae, 508. 510
Monterey Cypress, 411
Moonseed, 560
Moosewood, 492
Mora Tree, 533
Moraceae, 488, 565
Morcliella, 289
Morel, 289
Moringeae, 534
Morning Glory, 53, 199, 502
Morphia, 182, 556
Morphological Resemblances, 202
Morphological Unit, 20
Morphology, Special, 202
Morus, 490
Mosses, 46, 86, 92, 137, 143. 145,
155,194, 200, 341, 343, 351, 382
Mother-cells, 39
Moulds, 194, 235, 285, 288
Mountain Ash, 64, 201
Mountain Bay, 548
Mountain Mahogany, 529596
GENERAL INDEX.
Movement of Water, 172
Movements due to External Stim-
uli, 197
Movements of Nutation, 199
Movements of Plants, 196
Movements of Protoplasm, 6, 196
Movements of Torsion, 200
Mucilage, 35
Mucor, 212, 236, 241
Mucoraceae, 338
Mucorini, 235, 242, 336
Mulilenbergia, 455
Mulberry, 61, 437, 490
Mulberry Family, 488
Mullein, 98, 500
Mullein Pink, 550
Multilocular, 433
Mummy-cloth, 544
Musa, 472
Musae, 472
Musci, 343, 351
Muscites, 360
Mushroom, 328, 330
Musk Tree, 516
Mustard, 63, 98, 436, 554
Mutisiacese, 512
Mycelium, 235
Mycetales, 337
Mycoderma, 212
Mycoporum, 310
Myoporinese, 498
Myosotis, 502
Myrica, 487, 564
Myricacese, 487, 564
Myristica, 494
Myristicacese, 494
Myrrh, 540
Myrsinaceae, 506
Myrsiphyllum, 460
Myrtaceae, 425, 523, 565
Myrtales, 522
Myrtle Family, 523
Myrtle (Trailing), 504
Myrtle Tree, 524
Myrtus, 524
Myxomycetes, 6, 10, 11, 15, 21, 36,
44, 59, 60,170, 178, 207, 336, 340
Naiadaceae, 128, 466, 473
Naiads, 128
Naias, 14
Naked flowers, 431
Narcissales, 467
Narcissus, 61, 468
Nasturtium, 543, 554
Navicula, 230
Naviculeae, 230
Neck cells, 402
Nectandria, 494
Nectar, 421
Negative Heliotropism, 193
Negundo, 536
Nelumbium, 131, 558
Nemaliaceae, 339
Nemaliou, 274, 277
Nemophila, 503
Neottiese, 470
Nepenthaceae, 482
Nepentkales, 482
Nepenthes, 182, 482, 557
Nephelium, 537
Nephroma, 309
Nereocystis, 268
Nerium, 504
Nettle, 11, 491
Nettle Family, 490
Neutral Flowers, 431
Nicotiana, 502
Nicotine, 182
Nigella, 564
Night-Blooming Oereus, 520
Nightshade Family, 500
Nipaceae, 463
Nitella, 17, 200, 333
Nitelleae, 333
Nitrates, 176, 180
Nitrogen, 175, 180
Nitzscbia, 231
Nocturnal positions of leaves, 199
Norfolk Island Pine, 413
Normandina, 310
Norway Spruce, 412
Nostoc, 37, 206, 217
Nostocaceae, 55, 216, 305, 306, 338
Notelaea, 505
Nucleoli, 16
Nucleus, 16, 206
Number of Species, 566
Number of Stomata, 102, 103
Nuphar, 131
Nut, 436
Nutation, 190
Nutgalls, 479
Nutlets, 436
Nutmeg, 494
Nutmeg Family, 494
Nut-oils, 482
Nut Pine, 412GENERAL INDEX.
597
Nutrition of Parasites, 183
Nutrition of Protoplasm, 180
Nutrition of Saprophytes, 183
Nux Vomica, 503
Nyctaginacese, 497
Nympksea, 131,558
Nymphseacea;, 138, 435, 557
Nyssa, 519
Oak, 64, 147, 173, 384, 431, 436,
479
Oak Family, 477
Oat, 56, 58, 59, 166, 316, 318, 323,
333, 455
Oblong Leaves, 146
Oclinaceae, 540
Ockroma, 547
Octandrous, 433
CEdogoniaceae, 369, 271, 339
(Edogoniete, 246, 269, 338, 337
(Edogonium, 10, 22, 42, 51, 250
CEnothera, 11, 98, 418, 532
Oidiuin, 284
Oil, 62,129
Oil-cake, 544
Oil of Caraway, 63
Oil of Juniper, 411
Oil of Lavender, 497
Oil of Lemons, 63
Oil of Peppermint, 497
Oil of Rhodium, 502
Oil of Thyme, 63
Oil of Turpentine, 63
Oily Matter, 179, 181
Okra, 547
Olacales, 539
Olacineae, 540
Oldfieldia, 485
Olea, 102, 505
Oleaceae, 504, 565
Oleander, 94, 504
Olearia, 516
Oleaster, 492
Olibanum, 540
Dligomeris, 552
Olive, 505
Olive Family, 504
Olive Oil, 62, 505
Omphalaria, 306, 309
Onagraeete, 61, 522
Onion, 61, 63, 77, 93, 199, 323, 458
Onobrychus, 532
Onygeneae, 338
Onygenaceae, 339
Oogonium, 243, 267
Oospore, 46, 56, 243, 268
Oophyta, 205, 243, 269, 335, 337,
339, 568, 569, 570
Oosphere, 45, 243, 267
Opegrapha, 310
Opegraphei, 310
Open Bundle, 121, 443
Opening of Flowers, 199
Operculum, 355, 360
Ophioglossacete, 371, 372, 379, 384,
389
Ophioglossum, 80, 380, 381
Ophrydeae, 470
Opium, 78, 556
Opium Poppy, 182, 556
Opposite Leaves, 149
Optimum Light., 191
Optimum Temperature, 184
Opuntia, 150, 520
Orange, 130, 132, 541
Orang Lily, 460
Orchard Crass, 455
Orchidales, 468
Orchidaceae, 469
Orchids, 137, 433, 469
Orchil, 308
Orchis, 470
Ordeal Poison, 504
Organic Acids, 180
Organic Compounds as Food, 176,
178
Organogeny of the Flower, 426
Orobanchaceae, 500
Orobanebe, 56
Ornithngalum, 461
Orthosticliies, 149
Oryza, 455
Osage Orange, 490
Oscillatoria, 37, 67, 217
Oscillatoriacese, 217, 338
Oscil latorite, 53, 55
Osmunda, 81, 377
Osmundacese, 377
Ostrya, 72, 477
Ourari, 503
Ovary, 391, 417, 418
Ovules, 136, 137, 390, 402, 419
Oxalic Acid, 64, 180, 182
Oxalis, 197, 435, 542 *
Ox Eye Daisy, 514
Oxidation in Metastasis, 179
Oxidized Essences, 63
Oxygen, 175598
GENERAL INDEX.
Pseonia, 426, 564
Palisade Tissue, 156
Paliurus, 565
Palm, 410, 443,463, 473
Palmaceae, 425, 463
Palma Christa, 484
Palmales, 462
Palmately-compound Leaves, 148
Palmately-lobed Leaves, 147
Palmellacese, 51, 218, 306, 339, 340
Palmetto, 465
Palm Family, 463
Palm Oil, 62, 464
Palm Wine, 464
Palmyra Palm, 465
Panama Hats, 462
Pandanacese, 462, 473
Pandanus, 462
Pandorina, 10, 221, 242, 244, 336
Panicle, 429
Panicled Heads, 429
Panicled Spikes, 429
Panicum, 98
Pannaria, 309
Pannariei, 399
Pansy, 551
Papaver, 556
Papaveraceae, 77,119, 556
Papaw, 522, 561
Papayacese( = Passifloraces), 119,
522
Paper Mulberry, 490
Papilionacese, 531
Pappus, 512
Papyrus, 457
Paraguay Tea, 540
Parapbyses, 288, 292, 353
Parasite, 53, 176,178, 182,190, 192,
250, 270, 416
Parasites, Roots of, 137
Parastichies, 151
Paratonio Movements, 196
Parenchyma, 18, 69, 90, 106, 119,
124, 343, 351, 363, 392
Parietales, 551
Parietal Placenta, 434
Parietaria, 150
Parmelia, 296, 298, 301, 306, 309
Parmeliacei, 308
Parmeliei, 309
Paronyehiese, 494
Parsnip, 166, 187, 428, 519
Partridge Berry, 517
Passiflora, 522
i Passifloraceae, 522
Passiflora] es, 520
Passion Flower Family, 522
Pasteur’s Solution, 214
Pastinaca, 519
Pasture Thistle, 514
Paullinia, 537
Paulownia, 500
Pea, 56, 58. 59, 149, 187, 188, 284
436, 531
Peach, 62, 435, 530
Peanut, 532
Pear, 527
Peat Mosses, 357
Pecan Nut, 482
Pectin, 63
Pedaliacese, 499
Pediastrum, 65, 224
Pelargonium, 543
Peltigera, 306, 309
Peltigerei, 309
Kptl