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THE LIBRARY

OF
THE UNIVERSITY

OF CALIFORNIA

PRESENTED BY

PROF. CHARLES A. KOFOID AND
MRS. PRUDENCE W. KOFOID

STKTJCTUKAL AND SYSTEMATIC BOTANY:

BEING

AN ABBANGEMENT OF PLANTS,

FORMING

A BASIS FOR THE STUDY OP BOTANY, EITHER ON THE
LINNJBAN OR NATURAL SYSTEMS.

WITH NUMEROUS MICROSCOPICAL AND OTHER ILLUSTRATIONS.

EDWARD SMITH, M.D., LL.B., B.A.,

Late Lecturer on Botany and Anatomy at the Charing- Cross Hospital Medical

School, London ; Honorary Secretary of the Medical Society

of London ; fyc., fyc.

LONDON:
CHAELES GKIFFIN AND COMPANY,

10, STATIONERS'-HALL COURT.

PREFACE

THE following Treatises are devoted to the consideration of the structure of Plants and
Animals ; and it has been the aim of the authors to write with scientific accuracy, and
with sufficient detail, without introducing discussion upon contested subjects. They
trust that the work will be found intelligible to the unlearned, and instructive to those
also who have obtained an elementary knowledge of the subjects.

Occasional observations will be met with, by which the reader is reminded that
Plants and Animals are not only parts of the same great Creation ; but that so closely
are some plants associated with the so-called higher kingdom, that no definite line of
demarcation can be drawn between them. It is for this reason that the reader is
advised to study Botany in connexion with Zoology ; and it is probable that a closci
acquaintance with the structure and functions of certain parts of plants will ultimately
enable us to trace more correct as well as more striking resemblances between the
members of the two kingdoms than have as yet been conceived. For example, no
nerves, or analogues of nerves, have as yet been found in plants ; and yet it is quite
clear that not only is a low degree of vital sensibility as universal in plants as in
animals ; but that in certain instances, as in the sensitive plant, it is developed to a
far greater extent than is perceptible in animals taken from the lowest point in the
scale of animal life.

This mode of investigation will give greater breadth and interest to the study of
Natural History than the more simple and yet more difiicult one of studying the
parts of plants or of animals as detached points bound together by no universal law ;
and it is one, moreover, which tends to train the mind to habits of reflection as well
as of observation. The authors have endeavoured to aid the mind in this search by
introducing a very large number of microscopic and other illustrative engravings, which
have the merit of showing the extreme beauty and elegance of design existing in
the composition of plants, and offer many new points for analogical comparison
with the exquisitely minute structures of animals. A microscope is now as necessary
to tiie naturalist as a telescope to the astronomer.

d JfREPACE.

in the remarks on Classification, the author of the Treatise on Botany has been
drawn, by force of circumstances, to give much prominence to the Linnaean system ;
and this is the less to be regretted, since the analysis of the system, and the directions
which follow it, may suffice to enable the reader to enter upon the study with facility,
and to learn almost without trouble the positions of nearly all the most important
plants of native origin. He will also find not only that there is a similarity between
plants and animals from the presence of vital functions viz., those of reproduction,
respiration, circulation, digestion, growth, and decay but that the very structures
which give them bulk and form have in many instances close analogical resemblances.
Thus the simple cell, which is the universal basis of animal structures, is, in like
manner, and in equal degree, the universal basis of vegetable tissues. The thick-
walled cells are very like to bone cells, the milk-bearing vessels to capillary blood-
vessels, and their milky juice to the chyle or digested food of animals. Many other
parts are analogous to those of. animals in appearance ; whilst others, again, are like
them in function.

In accordance with the train of reasoning which this close connexion between
Plants and Animals suggests, the ordinary method of arranging the animal kingdom haa
been reversed ; the arrangement adopted having the obvious advantage of bringing
together those plants and animals which so closely resemble each other as to render it
sometimes doubtful to which of the kingdoms of Nature they belong.

"With these few remarks we conclude the Natural History of PLANTS And INTER-
TEBRATED ANIMALS. The remaining portion of Organic Nature, which embraces the
nigher forms of animal organization, commencing with the Fishes and terminating
with Man, will be concluded in another volume.

LONDON, January, 1855.

CONTENTS

TREATISE ON BOTANY.

PAOB

Important objects of BOTANT ... 1
History of the Science, and its distin-
guished Promoters 2

Early Classification of PLANTS ... 8

Definition of a Plant 8

Sensitiveness of Plants 4

AXATOMT or STBUCTUBE of Plants . . 6
Elementary Tissues and Formative

Fluid 5

Elementary Membrane 6

Elementary Fibre 7

Cellular Tissue, or Parenchyma . . 8

Intercellular Spaces 12

Thick- walled Cells, or Sclerogen . . 12

Fibro-Cellular Tissue 14

Multiplication of Cells 16

Pitted Tissue 17

Woody Tissue 18

Woody Fibre 19

Uses of Woody Fibre 20

The Flax Plant 22

Flax, Cotton, Wool, and Silk ... 23

The Palmyra Palm 24

The Vascular Tissue 25

Spiral Vessels 25

The Ducts 27

Unity of Design pervading the whole

Structure of Plants 28

Lacticiferous, or Milk-bearing Vessels 28

The Banyan Tree 80

Caoutchouc and Gutta-Percha ... 81

SECRETIONS or PLANTS ... 81

FAOB

Various Plants which secrete pur*

Starch 32,83

The Arum Maculatum 83

The Sago Palm, containing a large

quantity of Starch 84

Starch Granules 8ft

Cellular Character of Starch . . 36

Starch Cells 37

Cells of the Potato 40

Vegetable Secretions Kaphides . . 41

Vegetable Oils 42

Fixed Oils Olive Oil 43

Palm Oil Cocoa-nut Oil Linseed

Oil 44

Rape OU Castor Oil Poppy Oil,

&c ...,.,..,., 45

Vegetable Butters, Tallow, and Wax . 48

Volatile Oils 47

Gums and Resins 48

Gum Arabic Gum Senegal, &c. . . 48
Reservoirs of Secretion Turpen-
tine - ... 48

Tar, Pitch. Resin, Lac, Assafoetida,

<fec 49

Plant of the Dracaena Draco .... 49

Vegetable Acids, and Tannin ... 50

Opium, and the Poppy Seed ... 51
Sugar, and the Sugar Cane . . . 51, 52

Colouring Principles of Plants ... 53
Dyea Indigo, Logwood, Brazil-wood,

<fec. 54

Vegetable Secretion of Silica ... 55
Proportions of Silica in the Ashes

of Vegetable Substances . . S7

yiii

CONTENTS.

PAOK

OBOANS or PLANTS 57

The Stem, and the Vegetable Nodes . 58

Stems of Herbaceous Plants ... 59

Cuticle of Herbs 60

Stomata of Plants 61

Number of Stomata found on the

leaves of different Plants .... 63

Hairs of Plants 65

Prickles and Scurf 68

The Ramenta and Glands .... 69

Stems of Plants 70

The Conn and Bulb 71

Bulb of the Lily 71

Aerial Stems The Sucker, the Run-
ner, the Ginger Plant, <fcc. .- . . 72
Wooded Stems The Beech Tree, &c. 73, 74

EXOGENOUS STEMS The Pith, &c. . 75

Medullary Sheath 76

Medullary Rays and the Bark ... 77
Bark of the Lace Tree ..... 78
The Wood, and its annual growth . 79, 80
Sections of Exogenous Stems, exhi-
biting each year's growth .... 81
Immense Growth of Trees .... 82

Longevity of Trees 83

Cellular Structure of Trees ... 84, 85

ENDOGENOUS STEMS 86

Cuticle of Endogenous Stems ... 87

The Vascular Structure 88

Pith of Endogenous Plants .... 89

Descending Axis or Root of Plants . 90

The Pandanus, or Screw Pine . . . 91

Appendages of the Stem 92

LEAVES OF PLANTS 93

Forms of Leaves 95

Simple Leaves QQ

Arrow-headed Leaf of the Sagittaria . 98

Compound Leaves 99

Leaves of the Gleiditzia, the Chestnut,

and the Strawberry 99

Pinnate Leaves .... JQO
The Petiole, or Foot-stalk of the

Leaf

101

FAOI

Stipules of Leaves 103

Pitchers of various Plants .... 103
The Ochrea, or Sheath of the Stem . 103

The Leaf-bud 103,104

Imbricated Scales of Leaves ... 104

OBOANS OF REPRODUCTION .... 105

The INFLORESCENCE 105

The Receptacle the Spike and the

Raceme 105, 106

The Bract the Cupule the Spathe

the Involucre the Perianth and

the Calyx 108, 109

The Corolla, and the Petals . . . .112
Representation of a perfect Rose . .113
Sexual organs of the Flower . . . .116

The Stamens 116

The Filament the Anther the Pol-

len and the Fovilla . . . 118 121

The Pistil 123

The Stigma the Style and the

Ovary 123, 124

Apocarpus and Syncarpus Ovaries . 125
Ovule of the Flower .... .128

The FRUIT and the Pericarp . 129, 130
Classification of Fruits Apocarpi
Aggregati Syncarpi and Antho-

car Pi 131, 132

Various kinds of Fruits the Pomum
the Drupa the Strobilus, the

Glans, &c 133

The SEED, and its internal Anatomy . 134

The Nucleus 134

The Seed in Monocotyledonous, the
Dicotyledonous, and the Acotyle-

donous Plants 135 133

TheAmnios the Placenta the Funis'
and the Aril J3g 137

FLOWERLESS PLANTS .
The Tree Fern . .
Ferns, and their Varieties
The Germinal Frond
,'lub Mosses .

. . 138
. . 140

138-141

141

142

CONTENTS.

PAOR

Urn Mosses 143

Liverworts, and Scale Mosses . . . 144
Lichens . . 145

Fungi, or Mushrooms 146

Algae, or Seaweeds 147

Sexual Organs of Flowerless Plants . 148

SYSTEMATIC BOTANY; OR THE CLASSIFICATION OF PLANTS.

On the Necessity of Classification . . 149

Its numerous Difficulties 150

The LINN.EAN SYSTEM 151

Tabular Schemes of the Linnjean

System 152,153

Class I. Monaadria II. Diandria . 153

III. Triandria 154

IV. TetrandriaV. Pentandria . 155

VI. Hexandria 157

VII. Heptandria 158

VIII. Octandria 159

IX. Enneandria X. Decandria 160

XT. Dodecandria 161

XII. Icosandria 161

XIII. Polyandria 162

^ XIV. Didynamia 163

XV. Tetradynamia 164

XVI. Monodelphia 165

XVII. Diadelphia 166

XVIII. Polydelphia .... 167

XIX. Syngenesia 167

XX. Gynandria 168

XXI. Moncecia , .169

Class XXII. Dioecia 171

XXIII. Polygamia 172

XXIV. Cryptogamia .... 172

AlgJB and Fungi 172,173

Lichens, Mosses, and Ferns . 174, 175
Practical Application of the Linnsean

System 176

Characteristics of Plants 181

NATURAL SYSTEM OF PLANTS . . . 183
Natural Order, according to Dr.

Lindley 184

CLASSES, and their distinguishing

Characteristics 184

Class I. Thallogens 185

II. Acrogens III. Bhizogens . 186

IV. Endogens 186

V. Dictyogens 187

VI. Gymnogens VII. Exogens. 188

Sub-Class I. Diclinous Exogens . . 188

II. Hypogynous Exogens . 189

III. Perigynous Exogens . 190

IV. Epigynous Exogens . 191

INDEX, GLOSSAKIAL, EXPLANATORY, and REFERENTIAL

193

BOTANY.

THE objects which we now proceed to contemplate have exceeding interest, not only
in themselves, but in their relation to the other parts of this fair creation, and more
especially to man. They were the first vital existences which appeared when the fiery
mass which constitutes the earth had become covered with a stony crust of a cooler
temperature, and they are the last to linger when the rigours of a Polar clime chase
away all vitality. They are still the sole inhabitants of isolated spots on the burning
plains of central Africa, and are the harbingers of animal life on the remotely issued
lava, and the more recently emerged coral island of the southern seas.

They are found universally within limits bounded, on the one hand, by the per-
petual snows of the Arctic regions, or the summits of our own Snow don; and, on the
other, by the parched sands of tropical deserts ; and cover, as with a carpet, the magni-
ficent prairies of India and America, the wild haunt of the buffalo, or jealously hide the
long-lost cities of Assyria, which once teemed with wealth and myriads of human
beings as busy as ourselves. Not only do they exist upon the surface of the soil,
but their remains constitute a large part of the soil itself; so that seeds, which subse-
quently germinated, have been thrown up from considerable depths, after having lain
buried more than two thousand years. The solid crust of the earth is also, in part,
of vegetable origin, as in the instance of the widely-spread coal-beds, with their remains
of primeval forests. Moreover, the very air which covers the earth is not free from
these objects ; and the waters of the rivers and the seas abound in vegetable life.

They offer the most wonderful diversities of features and proportions. There are
the varied flowers which, as the daisy and buttercup, form the nosegay of infancy and
the garland of youth ; as the sweet violet which, on its mossy bank, slieds perfumes

ORGANIC NATURE.- No. XIII. B

HISTORY OF BOTANY.

on the loves of gentle maidens ; as the blooming rose which adorns the bridal, and as
the gloomy cypress which guards the tomb. There are the microscopic mould, which
lends age to our mouldering ruins ; and the gigantic forest-trees which, in the penal
settlement of Norfolk Island, soar to the height of more than two hundred feet; or the
celebrated chestnut-tree of Mount Etna, which sheltered one hundred horsemen.

They exist of every age, from the cell of the mushroom, which perishes in an hour,
to the hoary Baobad of Senegal, which is computed to have lived since long before the
days of Abraham. They quietly submit to the revolutions of centuries, with the changes
of clime ; and, as in the case of our own England, when the heat ceases to give life to
cocoa-nut bearing palm-trees, and tree ferns, they gradually and silently appear as the
modest primrose or the sturdy oak. They had traced long eras of the world's history
when no human being marked their form ; and they will, doubtless, bear testimony to
the progress of events until time shall be no longer. The antiquity of the blade of
grass is far higher than that of the noblest families.

They have done essential service to their more highly endowed cousins of the
animal kingdom, by having, directly or indirectly, fed all and clad many. They have
formed the shelter of man and animals, and the chief part of the utensils and instru-
ments of the former since his creation ; and, even in our day, are presenting new
treasures of infinite value for his use, as in the India-rubber and gutta-percha, so
recently derived from their juices.

Thus the objects of our investigation should lose no dignity when we remember
their remote antiquity, their universality, variety, beauty, and utility.

The consideration of these objects constitutes the science of Botany a science
which may be more exactly said to treat of plants, their internal and external parts,
general and medical properties, geographical distribution, and classification. "We purpose,
in this essay, to limit our attention to the first and last portions of the subject viz., the
anatomy and classification of plants.

History of the Science. The various considerations which we have already
adduced, may enable us to conjecture that this science, in its rudimentary condition,
must have existed from remote antiquity. If any further evidence short of direct
proof were wanting, it might be gathered from the pages of sacred history, in which we
find a constant reference to this division of created existences. The first authentic
records on this subject are connected with the Grecian and Roman eras, and extend as
far back as about the sixth century before Christ. The cultivators of the science did
not then receive the wide appellation of Botanists, but the more humble and restricted
one of Rhizotoma, or root-cutters; since they chiefly directed their attention to the
medicinal properties of plants.

Aristotle, of Stagira, who lived in the fourth century before Christ, is regarded
as the founder of the science of botany; and from his days, through the Grecian,
Roman, and Arabian eras, down to the eleventh century, considerable additions
were made to their knowledge of this subject. Amongst those who cultivated this
science most successfully, we may instance Mithridates, and several Grecian kings,
with the younger Juba, king of Mauritania. These potentates established botanical
gardens partly, no doubt, from the love which they bore to the science, but in the
instance of some of them, at least, more with a view to the cultivation of the
deadly plants from which the poisonous juices were derived which killed Socrates,
and which, at that period, was not an uncommon mode of execution. Tyrtamus,
of Lesbos, who accompanied Alexander the Great in his victorious progress

EARLY CLASSIFICATION OF PLANTS.

through some of the regions of Asia and Africa which now acknowledge the
British sway; Meander of Colophon, Cato, Yarro, Columella, Virgil, Pedacius,
Dioscorides of Silicia, who followed the Roman armies in their expeditions during the
fourth century ; and, lastly, the elder Pliny. Up to this period, therefore, we owe our
knowledge of hotany to the Greeks and Romans ; and then, as now, war, notwith-
standing its desolation, was made to promote the interests of science.

The Arabians, in the eleventh century, were the next cultivators of botany, as they
were the most learned people then existing. After them the darkness of the middle
ages set in, during which no science was cultivated, except by a monk, here and there,
secluded in his gloomy cloister ; and it was not until the rise of the illustrious Marco
Polo, of Venice, that the darkness became dispelled. He examined the treasures of
middle and southern Asia, and the eastern coasts of Africa, and described plants from
India and the Indian Ocean. From his days to the present the science has progressively
advanced ; first, in the addition to our knowledge of the names of plants, and, secondly,
of their structure and physiology. The Italians, and then the Germans, in the sixteenth
century, rendered good service to the science, as did also, at the same period, the Por-
tuguese by their conquests in India, and the Spaniards by their discovery of America.
From this and the succeeding century the science of botany, as it is now under-
stood, may fairly be dated ; since then, for the first time, an attempt was made to
classify the plants which had been discovered and named, and the microscope enabled
them to analyze the minute structures. Our own country now claims a distinguished
share in the honours of discovery. The Society of London for the Promotion of Science,
which was liberally supported by Charles the Second, gave much attention to the sub-
ject, and more particularly its secretary, Nehemiah Grew, who published his observa-
tions on the "Anatomy of Plants" in 1682. Another of our countrymen, Robert
Morison, Professor at Oxford, distinguished himself in the department of classification, by
the publication of various works, and especially of his " Historia Plantarum Universalis,"
with plates, in 1715. He was quickly followed by a yet more distinguished man,
John Ray, an English clergyman, who enunciated the true principles of classification,
and demonstrated the sexual characters of plants. Dr. Hans Sloane, the President of
the Royal Society, who died in 1753, and John Parkinson, the Superintendent of the
Medical Botanical Garden at Chelsea, and several successors of the latter, were honour-
ably distinguished.

We have not space to enumerate even the most distinguished names which have
adorned this science during the past two centuries. It must suffice to state that the
great Linnaeus, a native of Sweden, is by far the most eminent, and established the
sexual system which now bears his name. After him came De Saussure and Du
Hamel, Link, Rudolphi, Mirbel, Kieser, Schleiden, Darwin, and Quekett, in reference
to anatomy and physiology, and Jussieu, De Candolle, Robert Brown, Sowerby, Sir
J. E. Smith, Sir "W. Hooker, Sir J. Paxton, and Lindley, in reference to classification.
No country has a greater claim to boast of the advantages which it has rendered to
botanical science than our own. It has established the best botanical gardens, as the
Royal Gardens of Kew and of Hampton Court, and the Medical Botanical Gardens at
Chelsea ; and it has led the way in the investigation of minute structure. At the
present moment, it claims a multitude of most distinguished men labouring in one or
other of the departments of the same field.

Definition of a Plant. Definitions are at all times difficult, and not the less so
that they appear easy. In this instance, as the three great kingdoms of nature pass

SENSITIVENESS OF PLANTS.

so insensibly the one into the other, it is impossible to show, with rigorous certainty,
where the one ends and the other begins. It is a curious fact that, as science is
extended and knowledge is increased, our difficulties arising from ignorance are
increased in at least an equal proportion. Years ago the definition of a plant was not
considered impossible ; but now he would be thought a rash man who should attempt
a satisfactory definition of a mineral, a plant, or an animal. This is one of the
evidences that knowledge was intended to humble us by showing us our ignorance.
The saying of Linnaeus, that minerals grow, plants grow and live, animals grow, live,
and feel, is now held to be an insufficient definition. The value of this terse mode of
expression is concealed in the assumption that the properties thus added in succession
do not belong in any degree to the classes preceding. Thus all three classes grow, but
only two live, and only one feels. This is now known to be incorrect. Thus, certain

plants not only grow and live, but feel,
as in the instance of the mimosa, or
sensitive plant, which closes its rows of
leaves on a slight shock, or the Dionaca
muscipula, Yenus' fly-trap (Fig. 1), the
leaf of which folds up and incloses any
unhappy fly which may alight upon
the three hairs (A). The disposi-
tion of most flowers to seek or shun
the sunlight, and of the ears of corn in
the growing corn-field to droop when
the sun has set, might be adduced as
instances in proof of the sensibility,
apart from the mere vitality, of plants.
But in addition to this, it is well known
that the spores, or undeveloped young
plants of Conferva and of sea-weeds (Fig.
2) move about by the action of their own
cilia or hairs, until they have found a rest -
Tig. 1. DION.EA MUSCIPULA, on VENUS' FLY-TRAP, ing-place to which to attach themselves.

A, the three sensitive hairs on the expanded leaf. Thus we may add a degree of locomo-

B, a fly entrapped by the folding of the lobes of the ^ fo ^ qualitieg of

and say

that, in some instances, they grow,

live, feel, and move. On the other hand, the sponges (Fig. 3), in their developed state,
are denied the faculty of
locomotion, although they
undoubtedly belong to the
animal kingdom.

These characters having
failed to mark the distinc-
tion between plants and
animals, it has been stated
that an internal stomach,
and the chemical prin-
ciple called nitrogen or
animals only ; but this is incorrect, since the sponge has

Fig. 2.

Ciliated spores of the Conferva:,
Avhich at this stage of develop-
ment have u degree of locomo-
tion by means of the hairs or
cilia attached to them.

azote, are found in

Fig. 3. SPONGE.

The sponge as it is found grooving
and attached to a rock.

STRUCTURE OF PLANTS.

no internal stomach, and nitrogen is present in the seeds of almost all plants. More
recently, it has been averred that the'presence of a secretion, or product known as starch
( Fi g- 4 )> would clearly establish the existence of vegetables ; but recent microscopic
researches have shown that starch is also met with in the lower classes of animals,

Fig. 4. Section of a potato, showing the
grains of starch inclosed -within cells.

Fig. 5. Varieties of DF.SMIDIJE.E, or SKA-WEEDS.

A, clusters of Protococcus viridis.

B, filament of Schizogonium murale.

C, a similar filament, subdividing laterally at D.

and in the brain and spinal cord of the higher animals, and even of man himself. Lastly,
certain of the Algce, or sea-weeds, as the Desmidiea and Diatomacea (Fig. 5), are still
claimed equally by the botanist and the zoologist.

Thus simple as at first sight it might seem to state what a plant is as distinguished
from an animal, we find it impossible to distinguish the lowest plant from the lowest
animal ; and have therefore no alternative than to say that we cannot give an unim-
peachable definition of a plant.

Definition of the Subject. We shall assume that our readers can recognise a
plant, although we cannot define it, and proceed to a description of those various parts
of which a plant is composed, and of the arrangement of plants into classes. These
two branches of the subject viz., structure and classification have a necessary
dependence upon each other ; for the idea of classification implies that certain members
have some properties or parts in common such, for instance, as the leaf or flower ; or
in other words, that their structure corresponds. Therefore a knowledge of structure
is essential to classification ; and before we describe the latter, we must indicate the
internal and external parts of which plants are composed.

ANATOMY OR STRUCTURE OF PLANTS.

Elementary Tissues. In proceeding to a consideration of the anatomy of
plants, it will be evident that, as plants in general have external organs, as leaves and
flowers, so must they have more minute parts of which these organs are composed.
These will correspond with the flesh and bones of the various parts of our body, and
are termed " elementary tissues." "We shall take them first in order, since they are
formed before the organs can be developed. They will also furnish us with drawings
of some of the most exquisitely-minute beauties of nature.

Formative Fluid. But as the formation of a leaf, for example, implies the
previous existence of elementary tissues, so does the presence of an elementary tissue
imply the production of a material fluid, out of which the elementary structure was
formed. This latter is called the " formative fluid," or " organic mucus," or " cambium,"
or " organizable matter" (all of which terms have the same original signification), and
is the sole source of production of every tissue foxmd in plants. It is, in this respect,

tween the bark and the wood
in the early spring.

THE ELEMENTARY TISSUES.

similar to the blood of animals j for that fluid is the source of all the solid parts of the
body. It is semi-transparent and semi-fluid in the
internal parts of many plants, and of young plants, and those
with thick leaves, more particularly. In this condition it
is also found in great abundance between the bark and
the wood of all trees in the early spring months ; and then
separates those parts (A, Fig. 6), so as to permit the bundles
of young wood to pass down from the leaves, and thus
enable the tree to grow. It is under these circumstances
that the woodman strips the bark from trees which are to be
cut down, since then it does not adhere to the wood. The F ig. 6.-Section of the stem of a
t- 4-v.' a oi-Hiatirm "WhpTi this tree, the -white line showing
fluid is termed cambium in this situation. the colourless cambium, or

formative fluid is met with in the external parts of plants, formative fluid, deposited be-
it is still semi-transparent ; but it is then solid, as may be
observed by scraping the surface of a box-leaf.

Elementary Membrane. The first step in the formation of any tissue from
this formative fluid is the production of a solid structureless fabric, caUed elementary
membrane, and a modification of that fabric termed elementary fibre. It will be ob-
served that these elementary parts are structureless, and are produced, apparently, by
inspissation or thickening of the formative fluid. The process may be grossly illustrated
by a reference to the manufacture of paper, in which the rag-pulp (viz., rags torn into
threads and soaked in water) correspond^ to the formative fluid, and the paper, which
is subsequently produced, to the elementary membrane. The paper thus obtained is
fitted for the manufacture of books, and other articles ; and, in like manner, the ele-
mentary membrane is the solid material out of which vegetable tissues are formed.

Elementary membrane, then, as in Fig. 7, is

structureless; but, theoretically, it is assumed to

consist of a layer of rounded particles, which lie

side by side, and leave most minute spaces between

them. This must

be so, when we

reflect that all

fluids, including

the formative

fluid, are made

up of rounded

Fig, 7. Cells of EPIDERMIS, from the
seed of the Gourd.

drops, with spaces between them ; and that M r hen a
fluid is inspissated the drops are brought closer toge-
ther. Thus, whilst evident openings are no t naturally
met with in membrane, except as shown by Pro-
fessor Quekett, in the leaves of a moss called sphag-
num (Fig. &), it must be highly though invisibly po-
rous, and permit certain fluids to filter through it.

It is at first thin and translucent, as may be
seen in the membrane covering the seed of the
gourd (Fig. 7) ; but in many cases it subsequently
becomes thicker and more opaque. In the struc-
tures of the ferns (JHices) it assumes a decidedly brown colour ; and in the elaters of

Fig. 8. Leaf of the SPHAGNUM, showing
at a the natural openings through the
tissue.

THE ELEMENTARY TISSUES.

, a kind of moss (Fig.10), it is of abeautiful red colour; these variations,
and especially in thickness, result from the
altered duties which it is required to perform.
Thus, in the structure of bark and fruits, it is
not merely thickened, but is lined by a deposit
of hard sedimentary matter, of great power
of resistance, in order to increase its strength
and to resist decomposition. This hardened
tissue is called sclerogen, or hard tissue (Fig. 9).
In less extreme cases the deposit is in much
smaller quantity, and appears only as minute
grains scattered over the surface. Such is
the case in the pith of the elder (Sambucus
niger Fig. 11). A yet more interesting in-
stance of this scattered mode of deposit is

found in the hairs of the fornix (a part of the flower) of the Anchu&a
italica (Fig. 12). These are covered with a series of tubercles, which
are nothing more than isolated masses of a new deposit. In other
instances still, the thickening of the membrane appears to have been
produced by a deposit of the ordinary transparent organic mucus of
which it was originally composed, and still remains transparent, and
beyond this differs only from ordinary membrane in that this new
matter is laid on unequally, and certain transparent spaces are found
where the deposit has not taken place. These spots are oftentimes found arranged

Fig. 9. Thick walled
cells of the Pinus Web-
biana, showing the
amount of deposit be-
tween the cavity a and
the outer cell wall.

10. Fibres
of the Junger-
mannia crossing
each other spi-
rally, and, in
their natural
state, of a red
colour.

Fig. 11. Pith of the ELDER (Sambucus
niger), showing the dotted tissue.

Fig. 12. Tuber-
cles on the hair
of the fornix of
the Anchusa
Italica.

Fig. 13. Section Fig. 14. Elementary
of the stem of fibre free from mem-
the VINE ( 7i- brane.
tis Vinifera],
showing the
vacant spaces
or dotted tissue

with great "regularity, and sometimes in a spiral manner ; so that the tissue becomes
one of the most beautiful of vegetable microscopic objects. Such tissue is termed
" dotted" tissue, and is found in most plants, but more particularly in the common cane
(Rattan), and^he vine ( Vitis vinif era-Fig. 13). The use of this tissue is not well known.
Elementary Fibre (Fig. 14) is not formed from membrane, as though the latter

CELLULAR TISSUE.

were cut up or drawn out into threads of almost inconceivable fineness, and therefore a
production of membrane ; but both it and the elementary membrane are alike formed out

of the formative fluid. Moreover, it is not regarded
as a substance separate from membrane, but as a
deposit upon one side of a pre-existent mem-
brane. Whenever it is found detached from
membrane, we must assume that the membrane
which supported it has been removed, or that
it has detached itself from the membrane. This is
admirably shown in Fig. 15, in which the fibre is
in process of being denuded by the destruction of
the membrane. It is usually, perhaps invariably,
solid, and commonly has a rounded figure. It is
also transparent, except in a few eases, as in
those of the Jungermannia, before referred to,
(Fig. 10.) Its use is clearly that of supporting the
more extended membrane, and of preventing any
folds of it from approximating too closely to each
other.

Cellular Tissue, or Parenchyma.
Having now considered the "raw material" we
may proceed to describe the structures which
are produced from it. These structures are very
varied in appearance, and are ultimately applied
to very varied purposes ; but yet, in accordance with the simplicity which marks all
the works of God, all this may be reduced to one tissue, a structure which, in addition
to its being the fundamental tissue, is, in its own proper form, the most widely dis-
tributed of all tissues. This is termed Cellular tissue, to signify that it is made up of

Fig. 15 Tube from the RICINUS COM.
MUNIS, or castor-oil plant, showing the
fibre at a, and the edge of the broken
enclosing membrane at b. Magnified
200 diameters.*

i 1 Fi ;,, 16 '~ DetachedCens< Fig. 17.-Cells with Fig. 18. SAKCIXA, magnified

a, cells of the yeast plant ( Torula cerevisia;) only two attach- 800 diameters, found in the
with their granular contents. ments. stomach in states of disease.

b, the same cells in process of forming new It is a vegetable of low or-
cell8,a 88 eenbythebuging 8 . ganization, and resembles

c, similar cells of the sugar plant found in . somewhat the ornament for-
the urine in diabetes. mer l y worn on tne breagt of

the Jewish high-priest. It
consists of a mass of cells.

hollow cases or cells. It is, moreover, that tissue which is the first found in all plants.
* This and a large portion of the subsequent drawings have been made from original specimens

Others have been derived from various sources, and more particularly from the excellent lectures of

Professor Quekett, delivered at the Royal College of Surgeons.

CELLULAR TISSUE.

, 19 ORAXGE.
the cell-wall.

The cells of which it is composed may be either detached wholly or partially (Fig.
16), or be more or less conjoined in masses, (Figs. 17 and 18). Their characters are of
course the best seen when they are detached from each other.

The only difficulty, if any, in reference to tissue is in obtaining a correct idea of
the simplest of all structures the cell. This may be likened to an orange (Fig. 19),
when the rind, a, will correspond to the cell-wall, or boundary of the cell, and the
juicy part, b, will represent the contents of the cell. Thus an
orange is a cell on a large scale. Or it may be compared to a
fowl's egg, when the shell will represent the cell- wall, and the
white, with the yolk, the contents of the cell. The egg, therefore,
and all similar inclosed bodies, are magnified cells. But the egg
has other points of resemblance to the cell. Thus, if the white
of the egg be drawn from the shell through a small hole, so that

the latter shall remain empty (a process very familiar to school-

, . . 5 ' . . iT _ i, n -.

boys), we may form a just estimate of the cell-wall as separate b, the contents of the

from its contents. A cell in botany, therefore, consists of a cell- cel1 '

wall and contents, although it be so small as to be undiscernible by the unaided sight.

"We have already stated that cellular tissue is formed from elementary membrane ;
and therefore the cell-wall is nothing more than elementary membrane folded, with
the edges adherent together, so as to be able to inclose the contents.

The contents of cells are, however, of another nature, and are not produced from
elementary membrane. They are of three kinds. 1st, a substance lining the inner

side of the cell-wall, as illustrated

by the white of egg, and called the

primordial utricle of Mohl. It is

well shown by the shading in Fig.

20, A. This substance is of ex-

ceeding importance in the develop-

ment and growth of the cell, and in

the production of its other contents.

2nd, a roundish, tolerably - large

body, or nucleus, or cytoblast, re-

presented in Fig. 21, b, met with

in various parts of the cell, but

usually near to some part of the cell-

wall. This may be likened to the

yolk of the egg, and bears the like degree of importance to the

other parts of the cell that the yolk bears to the egg. 3rd, cer-

tain lesser bodies varying in size, shape, and number, termed
nucleoli, formed within the nucleus.

It appears that the nucleus is a central point of all actions proceeding within the
cell, but that the primordial utricle is the efficient agent. All these parts may be fami-
liarly and readily observed in the common strawberry (Fragaria), or the mistletoe berry
(Visctim album), or any other juicy fruit. "We assume that our readers have a small
microscope of some kind, which may be obtained for a sum varying from 2 to
4 of any respectable optician, with pieces of glass and other apparatus needful
for microscopic observation. Take then, with the point of a needle, a piece from the
centre of the strawberry, not larger than a pin's head; place it in the glass slide,

Fipr. 20. Cell after
Unger. The out-
lines, C, are intend-
ed to represent the
boundary of the cell,
or the cell-wall.

B is the central nu-
cleus or cytoblast.

A, the lining of the
cell-wall or the pri-
mordial utricle of
Mohl.

21. Cells from the flower-
ing stem of the leek (Allittm
Porrum), showing at athe cell-
wall, and at b the nucleus
and the nucleoli. The other
contents of the cell are trans-
parent.

CELLULAR TISSUE.

l-'i-. 22. Cells from the Straw-
berry, showing their oval
shape, loose connexion, large
nucleus, and translucent
walls.

and add a drop of water. Pull it to pieces by the help of two needles, and then cover
it with thin glass, and place it under the microscope. It
will be found to consist of a mass of large cells (Fig. 22),
with transparent walls, and a slightly coloured fluid, in-
closing the large rounded nucleus. It is of importance
to'obtain clear notions of a cell, since it is the foundation
of all other tissues, and since it contains the starch and
all other secretions of plants.

The figure of the cell is unimportant, and varies very
greatly. It is believed to be generally accidental, as the
phrase is, the accident being that of pressure : not that by
the term " accident" is meant that the figure is a matter of
chance ; for in certain parts of plants, as in the pith, for
example, the figure, whatever it may be, is always the
same. If pressure, therefore, in such cases be the efficient
cause, it is exerted in determinate degrees and directions in the various parts of plants.
\Vhen the schoolboy blows bubbles of soap-and-water he makes rounded cells, because
the walls are of equal weight, and the pressure of the air of an even degree all round.
If, however, a drop of water be attached to the bubble it will destroy its rounded
form, and elongate it in the direction of the earth, rendering the ceil more or less oval.
But if the same soap-and-water be well shaken in a half-filled bottle, the unequal
pressure will drive the cells together, and render them distinctly six-sided.

This little experiment will convince the reader that the figure of the cell does, in a
great degree, depend upon pressure, and that it may be altered as the direction or
degree of pressure is changed.

So also in plants when each cell is detached from every other, as in decomposing
vegetable infusions ; or aa in the yeast plant (Torula Cerevuia-Fig. 16), the form is
spherical or ovoid ; when it lies loosely in juicy fruits, as in the strawberry (Fragaria
Fig. 22), it is large and nearly round ; when two or more cells are attached end to end,
as in the mushroom (Fig. 23), they are ovoid or elongated;
and when they are numerous and inclosed in a common skin
or bark, they become more or less six-sided, as in the pulp
of the orange (Citrus), from mutual and surrounding pressure
(Fig. 24). It will then be readily understood that the figures of
cells may be innumerable ; but experience has shown that hexa-
gonal and octagonal forms are those which most abound. These
are the forms observed almost uni-
versally in pith, cuticle, leaves, flow-
ers, and fruit ; but it should be re- mush attached end
membered that regularity of outline, to end.
although of common occurrence, is by no means'essential.

But, whilst it must be admitted that the figure, in most
instances, results from pressure, in other instances it pro-
ceeds from a more determinate source ; viz., the direction
of the growing process. This is readily understood, if we
imagine a spherical cell in which the growing process
is not equally carried on all over it, so that it may

'ir\

Fig. 24. Hexagonal cells.

Continue to grow spherical ; but whilst the process is arrested at one point it proceeds

CELLULAR TISSUE.

at an opposite one.

Fig. 25. Elongated cells of a mushroom
(Boletus) resembling tubes.

This will terminate in an elongated cell, such as those observed in
the mushrooms (Fungi
Fig. 23), and more parti-
cularly in a gigantic kind
of mushroom termed the
Boletus (Fig. 25), in which
the length of the cell ex-
ceeds the hreadth by many
diameters. In this mode
it is conceivable that a
tube might be formed
from a single cell, or from

a series of cells, if placed Fig. 26. Diagram showing
end to end, and the parti-

series of cells which,
the breaking up of their

tions broken down, al- partition walls, are form-
though no satisfactory ing a tube,
illustration of this mode of conversion of cells into tubes has yet been discovered
(Fig. 26).

The terms, oblong, lobed, square (Fig. 27), nmriform (Fig 28 ), prismatical, cylin-
drical, compressed, sinuous (Fig. 30), and stellated, have,
amongst others, been devised to indicate other forms of
cells than those above indicated.

The cell varies as greatly in size as its figure ;
so that, on the one hand, they may be seen by the
naked eye, as in the pulp of orange, lemon, or shad-
dock ; on the other they are so minute that it is neces-
sary to examine them with a high magnifying power,
and ! poo parts of an inch in diameter.

I I ' I

I , I . I I

I.I.I I I

Fig. 27.
Cubical or

Fig. 28. Muri-
form cells, or
cells resembling
the bricks in a
wall.

square cells.

The limits of variation are

Some form of cellular tissue constitutes the whole of most of the lower classes of
plants, as the Fungi; and in all other plants it is found in the roots, or subterranean

(as the potato, radish, and tur-
nip) ; in bark, pith, leaves, flowers,

seeds, and fruit. The cuticle of

leaves, in general, is furnished

with cells, having a sinuous or

wavy outline, thence termed the

sinuous variety (Fig. 29).

The most interesting variety of

cell is that termed stellate, or star-
like, from the radiating form which

it assumes. This is well seen in the

rush (Fig. 30), in the sweet-burr

reed (Sparganium ramosum Fig.

*>). * ^ yellow water-lily (Ifu-

phar lutea), and in many other

water-plants of loose tissue. "We have also met with a beau-
tiful illustration of it in the partitions of the cells constituting the thick central parts
of the long leaves of the Banana tree (Jtfusa paradisaical}. The construction of this

Fig. 29. Very irregular
stellate cells from the foot-
stalk of a leaf of the sweet-
burr reed (Sparganium\ra-
mosum). showing the la-

Fig. 30. Star -shaped cells
of regular character, frdni
the stem of a rush, having
lacunae at a, bounded by
cell-walls, and the union
of the cells indicated by the
transverse line at the mid-
dle of each arm or ray.

CELLULAR TISSUE.

from of tissue is simple, and results from a puckering inwards of the cell-wall towards

the centre. If an orange "be cut through, and the
contents partly removed, and the rind be then
pressed by two or three fingers and a thumb until
the projected portions approach the centre, we may
form a correct idea of this form of tissue. Some-
thing more, however, is necessary.

Inter-cellular Spaces. When a number of
cells are pressed closely together, so closely even as
to cause them to assume the form of a many (say
twelve) sided figure, there will yet be spaces of
triangular shape at each corner, at which the walls
do not absolutely touch. These are termed inter,
cellular spaces, and are the larger by so much as the
Fig. 31. The fibrous structure of the -n t c i ose i v applied to each other. When

fowl's eo-z-shell, almost exactly simu- UU11& " ., i j -T.

lating the cells of the Boletus (Fig. 25). these inter-cellular spaces are placed one over the

other for some distance, they constitute inter-cellular passages,

and are very abundant in all aquatic plants. The relation which

the inter-cellular spaces bear to the stellate cells is this, that

when the cell-wall is pressed inwards, in various direc-
tions, towards the centre
of the cell, the cell seems
to be reduced to a series
of arms (Fig. 30), whilst
the spaces between the
cells now appear to be a
series of cells themselves
(Fig. 32). These enlarged
inter-cellular spaces are
termed lacunce.

The uses of the inter-
cellular spaces and pas-
sages are of great importance, since, in aqua-
of an aquatic tic P lants ("* wnicl1 &ey chiefly abound), they
contain the air which imparts buoyancy, and re-
tains' it on the surface. This fact may, in some
degree, account for the great size of these spaces in many aquatic plants (Fig. 33).
In other plants, their use is chiefly that of a depository of secretions.

ing the formation of in-
ter-cellular spaces in
disease.

Fig. 33. Air-chambers
plant the LIMNOCHAIUS PLUMIERI, ex-
kibiting_extreme regularity of form.

Before concluding our account of cells we must briefly refer to some modifications.

The DOTTED CELL differs from the ordinary cell only in having been constructed from
dotted membrane in place of plain. This form is very abundant, and especially in the
stem of the vine (Fig. 13) and other fast-growing plants, in the bark of most wooded
trees, and in the roots of many plants, as of the common horse-radish. They are
usually of large size.

Thick-walled Cells, or Sclexogen, are the result of the deposit of the
peculiarly hard tissue termed sclerogen, on the inner side of the cell-wall. This
substance is usually found deposited in concentric layers (Fig. 34), so that at length

CELLULAR TISSUE.

g. 34. Beautiful thick wall-cells
from the seed of the IlUcium ani-
satum, or star-anise, showing the
concentric layers, central cavity,
and radii.

Fig. 35.

A, a mass of thick wall- cells from
the PEAK, known as the gritty
tissue.

B, a cell more highly magnified.

the cavity of the cell is nearly filled. There is, however, always a central vacuity,

and this is in direct connexion with the cell-wall

by a series of canals, which pass through the various

layers of hard tissue. This is absolutely necessary,

since all actions proceeding in the cell must require

the direct communication of the cell- wall.

The thick- walled cells constitute the gritty tissue

of the pear (Fig.3o)

a tissue found in

the form of small

hard grains near to

the centre of the

fruit. It is also

abundant in the

so-called bulbs of

many orchids, as the

Mirchantia poly-

morpha ; on the

covering of the seeds

of many plants, as

of the star - anise

(IlUcium anisatum

Fig. 34), and the

apple (malus Fig.

36) ; in the strong

part of many nuts,

as of the ivory nut

(Figs.37,38),nowso

usefully supplying

the place of ivory ;

in the common haw-
thorn ( Cratfeffus") ,

plum, and our garden

Fitr. 36. Sclerogen immediately in- fruits, and in the
eiosing the seed of the apple. C ocoa-nutshell(Fig.

39). It is also met

with in the bark of

almost all trees, as

on the beech (Fig.

39). This structure

is well seen by cut-
ting a thin section,

and placing it in a

drop of water in the

ordinary way ; or.

Fig. 37.

b, perpendicular section of the bark
of the IVORY NCT (Phytelephus
macrocarpa} .

a, longitudinal section.

Both show the lines of communica-
tion between the centre and the
circumference.

Fig. 38. Transverse section of thick n . ,.-,, -, ' ,
wall-cells of the IVORY NUT. (Phy- better stlll > "7 P lac ~
telephas macrocarpa). ing it in Canada

balsam. If the section is too thick it must be ground down on a whetstone, in the

Fig. 39. Thick wall-cells from the
COCOA NUT shell, with their central
cavities and communicating tubes.

CELLULAR TISSUE.

Fig. 41. Fibre cell from the leaf
of the PLECROTHALLIS, having a
single fibre.

in which sections of tone are prepared for examination, It is impossible to

examine these interesting structures, and to observe

how admirahly they are adapted to give strength and

power of resistance to parts which pre-eminently

require it, without being reminded of the great

similarity between them and bone cells in the bones

of animals. There are, however, several points of

dissimilarity; and, amongst others, that the cell-
wall, which is retained in thick-walled cells, is lost

in bone cells.

Fibre Cellular Tissue This form of cell

is marked by having one or more fibres wound in

a spiral direction on its inner side (Figs 41 & 43). ri 40 . _ Concentric laycr , of Sclero .

The fibre may be loose in the cell, as in the Opuntia gen j n ^ ce n s of the bark of tue

vulgaris (Fig. 42), where it is flat, or in the elongated BEECH TREE (Fagus).

cell of the hairs on the seed of the Cottomia grandiflora, or of the common sage, where
'it is round.

We have already re-
ferred to elementary fibre
(p.7); and have only further
to remark that it obtains
its spiral direction by the
growing process being car-
ried on at the free end,

hilst the other part of the fibre is attached to the mem-
brane. In this mode the
resistance is unequal, and
a circular or spiral direc-
tion is given to the new
structure. This form of
cell is very abundant, and
is probably more or less
filled with air, since the
inclosed fibre is well fitted
to prevent the collapse of
the two sides of the cell.

It is usual to find the
cells not isolated, but in
clusters, and oftentimes
arranged in masses with

much symmetry, as may be seen in the drawing (Fig. 44) of the fibro- cellular tissue

lying in situ in the leaf of the Pleurothallis.

There is no [structure in animals corresponding with the nbro-eellular tissue in
vegetables ; but cellular tissue in the simple form is exceedingly abundant, and, in the
form of fat cells (Fig. 45), bears great resemblance to cells of vegetable origin. It is

also an interesting fact that the cartilage of the ear of the rat and mouse (Fig. 46), and

mere particularly of the rudimentary spinal column of the lamprey, is so modified
as almost exactly to simulate a vegetable cell.

Fig. 42. Fibre cell from the
OPUKTIA VTJLGARIS, show-
ing a flattened fibre lying
detached from the cell-
wall.

43. Fibre cell from the
leaf of an ORCHIS (Saccola-
bium guttatum), having seve-
ral fibres wound in opposite
directions.

CELLULAR TISSUE.

the Pleurothallis ruscifolia.

This resemblance between animal and vegetable structures is equally well seen in
the tissue of
the egg - shell
(Fig. 31), when
contrasted with
the elongated
cells of the Bo-
letus (Fig. 25).
It is an evi-
dence of the
power and wis-

Fig. 44. Cells of fibro-cellular tissue dom'of the De-
in situ, A, in the leaf of an ORCHIS,
~* " -"- ity that all the

tissues, both in

animals and plants, are produced from one simple

structure the fundamental cell.

The uses of the cellular tissue are :
1st. To contain various important secretions, as
that of starch, and the organs of reproduction in all
classes of plants.

2nd. To carry on the circulation more or less in
all plants, but more particularly in those which con-
Fig. 46.-Cartilage from the sist only of this tissue. This is well exemplified in
ear of the rat, closely re- fa e i ea f O f the Vattisneria (Fig. 47), in which the
sembling loose cellular , ,. , ,,

tissue in vegetables. circulation may be seen proceeding under the

microscope. 1

Fig. 45. Fat cells in animals.

Fig. 47. Leaf of an aquatic plant, the VALLISNERIA SPIRALIS, showing the circulation in plants.

1 represents the leaf after the upper surface has been sliced off, and shows at B the cellular tissue,

with small rounded grains, chiefly composed of starch, and a larger detached body the nucleus.
The portion at C is a bundle of woody fibre, in which the circulation is also proceeding. The
circulation proceeds around each cell separately, and the arrows indicate its direction along the
bottom of each cell.

2 has been drawn from the surface of the leaf, and shows a number of starch granules in cells

chiefly aggregated together, and which do net circulate. Magnified two hundred diameters.

MULTIPLICATION OF CELLS.

n
Paper,

3rd. By the tenacity of its structure, and the looseness of its parts, to bind the
component parts of the plant together, and to increase its elasticity.

4th. It has for thousands of years been of great use to man for various eco-
nomic purposes :

First, in the form of papyrus, or the paper derived from the stem of a rush of that
name, and employed as such by the ancient Egyptians, Grecians, and Eomans, until
long after the birth of Christ. In a similar way it is still used by the Chinese,
and by them is derived from the pith of a plant (JEschynomene Fig. 48), which

they cut into very thin slices. This material
lends a charm to Chinese drawings, since its cellu-
lar character enables it to absorb the colour-
ing materials in great abundance.

Secondly, as a textile fabric. The mummy-eloths
of the Peruvians, who existed long before the era
of Montczuma and the Spanish invasion, are com-
posed of this tissue only. At the present time we ob-
tain cotton (Fig. 62 B) chiefly from America, where
it is derived from the seeds of the cotton plant (Gos-
sypiuin). It is far less resisting and durable than
woody fibre or linen ; but its comparative abun-

!. Section of the Chinese rice- dance, low price, and easy working have obtained
, or JSschymomene, showing large m, -.-, -,

cells with a scattered deposit. for it great favour. The present war with Russia

will probably induce a determination to use the cotton cell to the still greater exclusion
of the woody fibre ; and it has recently been shown in America that ropes made
of cotton are far stronger and more durable than has hitherto been believed.

Paper is made from the manufactured cotton, and also from the refuse part of the
raw material.

Multiplication of Cells. It is not within the limits of this essay to enter upon
the interesting question of the production of cells ; but we may state that a common
mode is that of division of the cell into two or more cells. This is effected in the fol-
lowing manner : First, there is an aggregation of the con-
tents of the cell around the nucleus, whilst the nucleus
manifests a disposition to divide itself into two by a line
of construction on either side. Secondly, the cell- wall is
bent inwards towards the point of division of the nucleus,
and by degrees insinuates itself between the two parts of
the nucleus as the division of the latter proceeds, until at
length the cell- walls from opposite sides meet at the centre
of the nucleus, and the nucleus is divided, and two cells pro-

luced. Each of the new cells contains half the original Fig . ^.-various stages of de-
Mis, which now constitutes the nucleus of each cell ; velopment of the HJBMATO-
and after a period it is prepared to subdivide and to form
another cell, and thus progressively, so long as the vital
process lasts. In this way it is conceivable that an im-
mense multitude of cells may be produced ; and should the d, a divided cell again repeating
division be speedily effected, we may form a conception of thc process of subdivision - ^
the astounding fact, that in some of the fast-growing cellular plants as the mushroom
-the cells have been produced at the rate of sixty-six millions in a minute.

C t Vl ccus ,

the%%?eparing to divide.

PITTED TISSUE.

Fig. 50. Section of the
root of the ALDER TIIEE
(Alnus), sho-sving the
large-sized pores, or se-
mi-transparent spaces,
of its pitted tissue.

It is proper to state further, that certain authorities attribute the production of cells
to the evolution of bubbles of gas in an azotized fluid, and they are of opinion that only by
that mode can we account for the extreme rapidity with which cells are developed.

Bothrenchym, or Fitted Tissue; "We now proceed to describe the various
modifications of the fundamental cellular tissue, and first, that of Bothrenchym, since
it is very nearly allied to cellular tissue. It is so called from two Greek words signify-
ing pitted tissue, to indicate that a number of translucent spots are distributed over its
surface. We have already described the mode of formation of
this tissue when considering dotted cells, p. 7. It differs from
dotted cells chiefly in size ; for it may be regarded as a series
of very large cells, placed end to end, and separated from each
other by obliquely-placed partitions. At a later period of life
it puts on the character of a tube by the breaking-up and
removal of the partitions. Its ordinary position in plants is in
the stems of wooded plants, and more particularly of such as attach
themselves to other trees for support, and grow rapidly. Thus
it is met with on a thin longitudinal section of almost all trees,
but more readily in the alder (Fig. 50), vine, clematis, cane
(Rattan}^ and similar fast-growing plants, and wherever a rapid
circulation is proceeding. In this respect it differs from mere dotted cellular tissue,
since that is more commonly found in the herbaceous than wooded plants. This, in
common with other vegetable tissues, retains its^ characters perfectly for thousands of
years, as may be observed in the annexed figure of a duct (Fig. 51),
taken from a piece of anthracite coal.

It is not uncommon to find a spiral fibre associated with the dotted
tissue, as in Fig. 52, when the tissue may be regarded as a spiral duct
with pores. It is a microscopic object of much interest, and very easily
obtained. Take a piece of common cane, and having cut away a por-
tion of the outside, take a thin section down the cane, and place it
under the microscope in a drop of water. The little
pits will be seen with much ease, as also the large size
of the tissue as compared with the woody tissue which
accompanies it. We have found the best illustration
of it in a piece of deeply-coloured rose-wood, for
there the dark tint of the secretion gave a peculiar
distinctness to the tissue.

Its chief use in plants is to carry on the circulation with great
rapidity, and is therefore particularly necessary in such plants as grow
in southern and eastern climes, and yield refreshing juices, as, for
example, the vegetable fountains of India. The importance of this tissue
to all plants may be inferred from the large amount of vapour which
they throw off by perspiration. Thus an ordinary-sized cabbage, in our
climate, was found to perspire to the extent of 1 Ib. 9 oz., and a sun-
flower to that of 1 Ib. 14 oz. in a day of twelve hours ; and it is
evident that the great heat of southern climes must induce a far greater amount of
perspiration, and, by consequence, require a more active circulation. The fluid thus
exhaled is supplied chiefly by the bothrenchym, which therefore has a circulation
proceeding from the roots towards the leaves of the plant. This function is not

Fig. 51 Porous
duct, from An-
thracite coal.

Fig. 52. Pore?,
and a spiral
fibre, from the
ELM TREE ( Ul-

mus).

ORGANIC NATURE. No. XIII.

18 WOODY TISSUE.

seriously if at all impeded by the partitions which lie across the tube, as would at first
r h U P pear for even should such partitions be perfect, they readily penmt the proper
S to niter through them. The great size of this kind of tissue, and the large quantity
of fluid which it contains, render it imperative that it should be supported ^ ct ^ e3
more resisting than its own. For this reason it is always found surrounded by bundles
of stem- woody tissue. Another function assigned to it in later life is that of conveying
air into the interior of the plant. This occurs when the walls of the cell or tube have
become imperfect, and would permit contained fluid to pass out of them ; and then th
fluid disappears, and its place is supplied by air. A third, and not less important duty,
is that of a depository of the secretions of the plant. This only occurs when the tree
is mature, and the central parts of the trunk, which are not then devoted to the rapid
conveyance of fluid for the purposes of perspiration. The deep-colouring matter of
rose-wood and mahogany, and all similar trees, is chiefly found in this tissue.

From the above remarks it will be evident that bothrenchym is a tissue of great
interest and importance, and is seen in its integrity only in the early life of a plant.
Its large size, thin walls, and active functions, seem to predispose it to injury ; ai
therefore such tubes have the duty assigned to them of conveying air, or of storing
up secretions which do not circulate.

Gridiron Tissue.-Under the term of gridiron tissue, Professor Quekett has
described an interesting structure, oftentimes met with at the end of
the ducts of pitted tissue. It consists of a series of bars which pass
transversely across the tube, and occupy the position of the usual
transverse septum. It is probably not a distinct structure, but only
the remains of the original septum. We have met with fine examples
of it in several trees, but more particularly in the alder and white
birch (Betula alba). A similar condition has also been observed in
a fossil palm found at St. Vincent's.

Pleureiichym, or Woody Tissue. The tissue most closely
allied to bothrenchym, and yet widely removed from both it and
cellular tissue, is pleurenchym, or woody tissue. This constitutes
the mass of the stems of our forest trees, and is thus of the utmost
social use to man. It is, also, found in all young and tender
shoots, and in bundles in the stems of all, even the most delicate O f a dotted duct in
flowering plants. Its peculiar characteristic is that of great tena- the alder ( Alnus )-
city and power of resistance, and for this its structure is admirably adapted. As these
characters are opposed to those of bothrenchym, we are prepared to find a tissue dif-
fering widely from that large and wide structure. The contrary is found in woody
tissue, for it consists of bundles of very narrow fibres, with tapering extremities, and
so placed end to end that the pointed ends overlap each other. Each fibre is very
short, and the partitions which result from the apposition of the fibres, end to end,
do not interfere with the circulation through them. Moreover, the tube is not com-
posed of simple thin membrane only ; but, in addition, has a deposit within it, which,
without filling the tube, adds very greatly to the strength of the fibre. Perhaps we
have here as good an illustration of the wisdom and power of the Creator as can
readily be produced nz., an arrangement whereby the greatest strength and power
of resistance and elasticity shall be obtained, and at the same time the functions of cir-
culation uninterruptedly maintained. The strength is mainly due to the shortness of
each fibre, the connexion by apposite ends of many fibres almost in one direct line,

WOODY FIBRE.

from the root upwards ; and, lastly, to the deposit on the inner side of the membrane.

This sentiment is irresistible, when we remember the various economic purposes

to which man in all ages has applied the
wood of forest trees, and also the power
of resistance and elasticity which trees are
required to offer while supporting large
branches at a considerable angle, and to
prevent their being uprooted or broken to
pieces by violent storms, all of which is
mainly due to the tissue now under con-
sideration.

There are two kinds of woody tissue
viz., the plain and the glandular. The
plain we have already described. The
glandular is that form which more nearly
resembles bothrenchym, and indeed may
easily be mistaken for it. It consists of a
plain fibre or tube, such as that already
described ; but, in addition, there is super-
imposed, with great regularity, a series of
rounded translucent bodies called, or rather
their m i sca lled, glands (Fig. 56). These are, for

Fig. 54. Bundles of
woody fibre of the
flax plant fJMnim),
considerably mag-
mfied -

de p 0s it and

pointed extremities , -.,

overlapping each the most part, arranged in single rows, and

other< are so large as to occupy the whole face

of the fibre.

There is great difference of opinion as to the nature of these so-called glands ;
some authors regarding them as simple concavities in the nature of a simple pit, whilst
others believe that there is a pit, and in that pit is deposited the rounded, flattened
body termed the gland, or bordered pore.

Professor Quekett adopts the opinion that these bor-
dered pores lie in concavities between two adherent fibres
(Fig. 57). The bordered pore is hollow, and biconvex, so
as to fit into the two cavities. They are best seen in a
section of wood, taken parallel to the medullary rays.

It is not a little remarkable that this form of woody
fibre should be found only in one class of trees viz., the

Conifer ce, or fir tribe, with their allied genera ; and in such Fig. 56. Section of common fir
plants it is the only form of woody tissue met with. If
a very thin section of a piece of fresh fir tree, or of a piece
of deal or cedar, be examined with the microscope, as before
directed, the glands will be seen very distinctly (Fig. 56) ;

and if a piece of rotten fir be selected, it will not be difficult to find a spot at which the
gland appears to have fallen out. Such also is the case with the coal shale, a large
portion of which is composed of the stems of the fir tribe, which have been buried
during thousands of years ; and if care be taken to grind down a thin section, not only
may the glands and their remains be seen, but in some instances the pits which once
contained the gland.

This, however, is chiefly a matter of curiosity, since we do not know anything of

wood, or deal; showing the
pointed extremities of the
woody fibre and the gland, or
bordered pores, in a single
row on each fibre.

USES OF WOODY FIBRE.

the especial functions of this kind of woody tissue. The botanist, however, attaches
value to it, since it enables him to demonstrate, in recent and fossil woods, the^exist-
ence of the Conifora, or fir tribe of plants.

It is not uncommon to find a spiral fibre associated with this glandular structure,
and sometimes, as in the yew (Taxus baccata, Fig. 60), there are two which are wound

Fig. 57. Fig. 58. Fig. 59. Fig. 60.

Fig. 57. A lateral view of two adjoining fibres to show the concavity in each, and the space
formed by both for the reception of the bordered pore. B, bordered pores from the Salisburia adian-
llfolia, which are naturally found in cavities similar to those in A.

Fig. 58. Similar arrangement of tubercles and cavities of the Aporum anceps. A, a fibre with
the tubercles or glands in situ, and projecting. D, the glands detached. C, the concavities on one
fibre whence the glands have been removed. B, the spaces for the lodgment of the glands formed
by two adjoining fibres.

Fig. 59. Rows of bordered pores on the woody fibre of a fossil member of the fir tribe, which
had been long buried in the State of Ohio.

Fig. 60. Porous woody fibre in the yew (Taxus baccata), with the spiral fibres wound in opposed
directions.

in opposite directions, and give the appearance of a net- work. This is presumed to
assist in maintaining the patency of the tribe.

The uses of woody fibre are very varied, and most important, and may be divided
into two categories, 1st, such as benefit the plants ; and 2nd, such as benefit man,

1st. Such as benefit the plant.

It is the chief organ of the circulation in all wooded plants, and for this purpose
pervades the plant from the root to the branches, and even to the minutest leaves and
flowers. The current in this tissue is slow and uninterrupted, and is directed upwards
from the shoot through the stems to the leaves, and downwards from the leaves through
the bark to the root. Thus its current has a twofold direction ; the ascending and chief
one being for the purpose of taking the raw sap from the ground, to be digested in the
leaves, and the descending being devoted to the removal from the leaves of the digested
sap, to be applied to the purposes of the plant, and also of the refuse matter to be car-
ried to the roots, and thence thrown out into the soil as a noxious material. These
functions are carried on more vigorously during the spring and summer seasons; but
it is probable that even in the depths of winter it does not cease.

^ Another function of woody fibre is to be the store-house of the perfected secretions.
It is well known that as trees advance in life, the wood assumes a darker colour, and
more particularly that lying near to the centre of the stem. This is due to the deposit
of the perfected juices in the woody fibre at that point; and when age has matured the
tree, it is probable that the woody fibre so employed is no longer fitted for the circu-
lation of the sap ; and also, that the perfected sap, when once deposited, does not again

USES OF WOODY FIBRE.

join in the general circulation. The dark colour of the heart of oak, as contrasted with
oak of very recent growth, is an illustration of this fact, as is also the deep colour which
is met with in ebony and rosewood.

A third duty under this head is that of giving stability to the tree. It only requires
a moment's reflection to enable the mind to appreciate the vast power of resistance
which is placed in forest trees. The oaks of an English forest have stood a thousand
years, notwithstanding the hurricanes and storms to which they have been yearly sub-
jected ; and a familar illustration of the most violent storms, of which we hear and
read, is that of the tearing up by the roots of the large forest trees. How mighty must
be that power which can withstand influences so terrific as those which each person
must have occasionally witnessed ! This power is partly due to the mere mechanical
hold which the roots have of the soil ; but the tenacity of that hold is almost entirely
due to the woody tissue contained in the roots and stem. Again, it is no uncommon
occurrence in our old English parks to find branches of old trees which stretch from the
trunk to the distance of fifty feet, and which in circumference are as large as trees of
considerable growth. These do not stand perpendicularly from the ground, but pass
out of the stem at an angle which is in some instances nearly a right angle, and must
therefore be kept from falling directly in opposition to the effects of gravity. The strain
exerted by such a branch is enormous ; and yet the branch is maintained in its posi-
tion for hundreds of years by the simple cohesive strength and tenacity of a series
of woody fibres, each one-sixth smaller than a human hair, and too minute to be
appreciated by the naked eye. It is probable that no mechanical agency at present in
operation could cifect that_ which is thus so readily effected by nature with the most
simple agencies.

2ndly. Such as benefit man.

We do not refer to the almost infinite uses to which wood, in boards or masses, is
applied by man, and the vast multitudes of beautiful objects which his ingenuity has
enabled him to prepare out of the varieties of wood which nature has so bountifully
provided.

Not less useful is the same woody fibre when reduced to very minute bundles or
threads.

"When the fibres are obtained in tolerably large bundles, they are used in place of
bristles for street brooms, and especially when obtained from the cocoa-nut palm.

The flax and hemp which are imported so largely into this country, consist of
woody fibre, obtained not from the wood of large trees, but from the stems of slender
plants. From this raw material, ropes, sacks, linen, lawn, and other textile fabrics, are
now made, as some of them have ever been by all nations. Uncivilized, or partially
civilized nations, have been accustomed to use the bark of various trees offering this
woody fibre in a very divided condition ; and from this have prepared ropes and other
articles of utility. It has long been known that cordage of a very strong kind was
used by the ancient Egyptians, anterior, in all probability, to the building of the Pyra-
mids ; and Mr. Layard has recently exhumed sculptures which show that the yet more
ancient Assyrians removed their gigantic winged bulls and other objects by cables of
great size and strength.

The bark of the lace-tree (Lagetta lintearia) yields a net-work of woody fibre of
exquisite beauty, and of great utility, and is used by* the natives of that clime as a
ready prepared fabric.

An indisputable proof of the antiquity attaching to the use of this fibre is afforded

THE FLAX PLANT.

in the fact, that the mummy cloths of the ancient Egyptians, which are nearly five
thousand years old, are found to be composed of this material.

At the present day, this tissue is abundantly used, and is derived from very various
sources. Its relative value depends upon the fineness and evenness of the fibre,
and upon its elasticity. It has been found that certain kinds of flax have very great
powers of resistance when exerted in a straight line, but readily break when they are
bent. This is the case with the Is"ew Zealand flax ; and its brittleness is to be attri-
buted only to the nature of the material deposited within the tube. The flax obtained
in this country, in Ireland, and India, from the Cannabis, has less resisting characters ;
but as it does not break so much in the process of hackling, has a higher marketable
value. The pine-apple fibre is very capable of minute subdivision, and is very resisting,
and consequently very fitted for the manufacture of fine fabrics. Cocoa-nut-palm fibre
is also very strong from the presence of secondary deposits.

The cost of flax has induced mercantile men to use woody fibre of less durability,
bat at the same time of a less costly kind such as that derived from the China-
grass, a species of nettle ( Urtica}; and from it much of the less durable linen cloth and
pocket-handkerchiefs are now produced. It is well known that the tissue now under
consideration occupies a medium between silk and cotton, as it regards resistance
durability, and cost.

Silk is the produce of a mem-
ber of the animal kingdom (Fig.
62 D), and occupies the highest
position in the qualities referred
to. Labillardiere ascertained
that bundles of fibres of equal
size, of silk, flax, and cotton,
gave the following unequal
powers of resistance, on the
application of a weight :
Silk supported, -without break-
ing, a weight of . . . 341bs.
New Zealand flax (Phormiuin

tenax} . . . . .23*
Hemp (Cannabis) . . . igj
Flax (Linum) . . . . 11| ,
Pita-flax (Agave Americana). 7
The resisting powers of cotton are
much below the lowest now in-
dicated.

In order the better to appre-
ciate the characters of these tex-
tile materials, single fibres of
each have been selected and
placed side by side (Fig. 62), and
to these have been added hairs,
or fibres of wool, and silk. These
have not only been used largely
for centuries in the manufacture

injnummy cloths obtained from 0^^'

orl-LAx PLANT.

is found woven with

FLAX, COTTON, WOOL, AND SILK.

The last vise to which we shall now refer, is that of affording saccharine juices to man.
This is known familiarly in this country in the wine obtained from the fermented juice
of the birch tree (Betula alba] . It is still better known in the Northern and "Western States
of America, and in Canada, from the sugar-yielding maple (Acer saccharinum}. This is

Fig. 62. Fibre of flax, A ; of cotton, B ; of wool, C; and of silk, D ; placed side by side, so that
their relative size and markings may be readily contrasted. The fibre or cells of cotton are
manifestly much thinner, and less resistiag, than those of the other substances.

still a greatly valued^product in the less accessible parts of the country ; but the introduc-
tion of the cane sugar of the Southern States is gradually supplanting it in public esti-
mation. The sugar obtained from it is very brown, "but sweetens well, and will probably
be one of the treasures of the happy housewife ia the fertile paradise of the " far west"
for many years to come. In both of the above instances the juice is collected in a similar
way wz., by boring one or more holes into the stem of the tree at the period of the year
when the sap has most accumulated ; and, as the sap exudes, collecting it in vessels
placed at the foot of the tree. The sugar is thence obtained by mere evaporation
and subsidence ; but the wine requires tlie subsequent process of saccharine fermen-
tation.

The spruce-beer in use in Norway, and i&e refreshing juices of India, are obtained
in a similar way, and from the same vessels- viz., woody and pitted tissues.

Palm- wine is a delicious beverage, obtained from various species of palm, but espe-
cially from the cocoa-nut palm (Cocosnucifero), the gomuto palm (Soguerns saccharifer),
and the magnificent Palmyra palm (Borassus flaJbelliformis}. The latter is the most
widely distributed of all the palm tribe, since it inhabits all the various regions of the
Continent and Islands of India. Mr. Fergusson, in the first illustrated book which
proceeded from Ceylon, has given a most valuable account of the palm trees of Ceylon.
We counsel our readers to peruse it attentively, and especially that portion which
describes the Palmyra palm and its products. The juice is procured by crushing the
young inflorescence, and cutting off the upper part. It is then collected in a vessel
attached to the cut end, and the daily discharge of the sap is facilitated by cutting a
new slice every day. The fresh sap, called taree, or toddy, is very refreshing ; and, if
allowed to evaporate, yields a deposit of coarse sugar, or jaggery. "When fer-

THE PALMYKA PALM,

tnented, it becomes a very excellent wine, and the most intoxicating of all tropical
beverages.

Fig. 63. The PALMYRA PALM (Borassus flabelliformis) yielding Palm Wine.

The size of woody fibre varies from T ^ to ^u part of an inch, and is the larges
in hot climates, for the reasons already indicated.

THE VASCULAR TISSUE.

The position of woody fibre is readily determined,
stems of wooded trees, but is found in single bundles
in the stems of delicate herbaceous plants, and may be
readily seen there when the stem is torn across. In
a similar manner it occupies the thin cuticle of herbs,
and may be readily observed in the ridges, or veins,
which run from the root upwards. It is also met with
in the bark of all trees, in the veins of leaves and
flowers, and even accompanying the spiral vessels
into the fruit of plants.

Vascular Tissue or Trachenchym. The tis-
sues which we have already described are chiefly de-
voted to the circulation of fluids, or to the inclosure
of solid substances. Those, under this head, are in
great part associated with the transmission of air within
the plant. They arc divided into two classes viz., spiral
vessels and ducts, and are, perhaps, the most beautiful
microscopic objects in plants. It is not at all times
easy to distinguish between these two classes of struc-
tures, since both consists of thin'membrane in a tubular
form, and inclosing a fibre wound in a spiral direc-
tion. The theoretical distinction is, that the fibre of
the spiral vessel may be unrolled without' breaking,

It constitutes not only the
A

Fig. 64. Spiral Vessels.

A, a simple spiral vessel, that is,
having but one fibre. The lines
bounding tbe pointed extremity
represent the inclosing mem-
brane.

B, a compound spiral, or a vessel
composed of many fibres, wound
in a spiral manner.

C, a compound spiral from the
Canna bicolor, with five spiral
fibres : more highly magnified.

r hilst that of the duct is inseparably connected with
the membrane, and cannot be unrolled in its integrity. This general distinction is
doubtless correct ; but an unrolled spiral vessel, and a duct, in which the membrane con-
necting the spiral fibre has been destroyed, have a very close resemblance to each other.
It is highly probable that the distinction is less one of nature than one established by
botanists as a matter of convenience.

The SPIRAL VESSEL is a cylindrical tube with conical extremities, and having one
or more fibres wound as a right or left-handed screw, which may unroll without
breaking. It has been disputed whether the fibre is placed within or without the
membrane, and whether it is solid or hollow ; but we are of opinion that it is inclosed
by the membrane, and that it is always solid. These vessels are not individually

of great length, but are con-
nected together by their coni-
cal extremities; and it is not
unusual to find the intervening
partition ruptured. When but
one fibre is inclosed the vessel is
termed a simple spiral vessel (Fig.
64 A) ; but when two or more
exist, it receives the appellation of
compound (Fig. 64 B & C). In
some instances, upwards of twenty
fibres have been counted in a
compound spiral vessel. The
spiral vessels are very numerous in

Fig. 65. A bundle of spiral vessels from the veins of the
hazel nut (Corylus avellana), showing their great num-
ber and very minute size. They are embedded in a mass
of hexagonal cellular tissue, as represented at a. Mag-
nified 200 diameters.

THE \ASCULAR TISSUE.

all flowering plants, but more so in certain bulbous plants, as that of a squill growing in
the neighbourhood of the Mediterranean. The inhabitants collect them, and tie them in
bundles to be used in the lighting of cigars an office for which their smouldering flame
renders them well adapted. They are met with in all parts of plants except the roots,
but more particularly immediately surrounding the pith, and in all parts emanating
from it viz., branches, leaves, flowers, and fruit. They may be readily obtained
by cautiously cutting through the cuticle of the footstalk of the strawberry -leaf (Fra-
ffctria'), and then gently separating the divided^ portions, when they appear as very
fine threads arrange:! in loose spires.
They abound in the veins of leaves,
and even in the minutest parts of the
most delicate flowers. They are also
found in the foot-stalks of all fruits,
and in the vascular bundles which
enter the minutest seeds. This may
readily be seen by tearing the seed
of the strawberry from the fruit,
and placing it in water under the
microscope. The spiral vessel is
there exceedingly minute and beau-
tiful.

Perhaps, of all positions in which it Fig- 66> _ A por t ion of a bund i e O f spiral vessels from

may be the best inspected, that of the the stem of the potato plant (Solatium tuberosum),

., , embedded in loose cellular tissue, as represented at a.

veins running over the brown coat- The tubular character of the tissue is well seen at 6,

ing of the common hazel nut ( Corvlus where the separation of the fibres permits the observer

77 I?- ^K\ L J.T- i MI to look within the tube. At that point also the in-

MMUfHUjJtlg. bo), alter the shell has closing membrane is well delineated. These are

been removed, is the most accessible of lar ^ e size > and > with tQOSe of Fi - 65 ma l wel1 re -
mi -, , present the two extremes of development. Magnified

Ihe brown membrane should be 200 diameters.

soaked in water for a short time,

and then the veins carefully torn open with needles, and placed under the microscope.
If the light be not passed through them, but be allowed to fall upon them, they
appear as bundles of beautifully- white glistening lines, consisting of scores of very
minute spires.

Such is also the case with other similar fruits, as those of the walnut (Juglans
regia] and chestnut (Fagus castanea). They are seen to great advantage also in cer-
tain succulent stems, as those of the potato, by cutting the stem across obliquely
with a knife in bad condition, and the section placed under the microscope (Fig. 66).

They are of very delicate structure, and require other tissues to inclose and protect
them. This is chiefly performed by the woody fibre, and thus each vein of a leaf or
herbaceous stem has its central bundle of spiral vessels inclosed in a covering of
woody fibre.

The use of the spiral vessel has been the subject of much investigation, and it
appears probable that at some period it conveys air charged with an increased per
centage of oxygen, and thus becomes a system of internal respiration, much after the
manner of the distribution of the trachea? in insects. At a later period of its existence
it is probable that it contains fluid. The spiral fibre is valuable at either of these
periods as keeping the tube open, but more particularly when the cavity is filled by
air only.

THE VASCULAR TISSUE.

Ducts are tubes with conical or rounded extremities, and their sides marked by
transverse lines or bars. Their size is about twice that of spiral vessels.
Their appearance is very various, and depends upon the direction of the
spiral fibre which assimilates ducts to spiral vessels, or the presence of
other internal deposits, which renders them not unlike pitted tissue.

When the spire is so arranged as to differ from that of the spiral
vessel only in that it cannot unroll, the vessel is termed a closed duct.
When it is broken up at intervals, so that single coils shall be" detached,
the term annular is applied (Fig. 67), and properly represents the rings
which are so commonly found in ducts. This form is said to be due to
the rapidity of the growth, whereby the fibre is carried along more
rapidly than the membrane can be produced.

The reticulated duct is perhaps the most interesting of the various
kinds of ducts, and appears to be formed either by two fibres wound in
opposite directions so as to cross each other, or by a single fibre which
breaks and anastomoses at intervals. The characteristic feature is that of
a net-work. All these various forms of duct, and also other modifica-
tions, may be found in the stem of a full grown
garden balsam. The succulent stems of herbaceous
plants are the more common positions in which
' ducts are found ; but they are abundantly met

with in the softer kinds of wood, as of the lime-
tree (Tilta), willow (Saliz), or birch (Betula).

We cannot omit to refer again to the analogies which exist
in the structure of animals and vegetables. Thus, in the animal Fig. 68. The tracheae
kingdom, we have a tube which very closely resembles a spiral of & th w C 'er beetle 1
vessel, viz., the tracheas of insects. This is clearly shown in having many of the
the accompanying figure of the Dyticus (Fig. 68), which repre-
sents a tube made simply of a fibre inclosed by membrane.

It is unnecessary to refer to all those forms of duct in which we find a secondary
deposit so arranged as to give the appearance of pits^ since we have already considered
similar structures under the head of Bothrenchym (pp. 7 and 17).
But there is one not described as yet viz., the Scalariform or ladder
duct. This is so called from the resemblance which the transverse
lines bear to the rounds of a ladder. The scalariform duct is of con-
siderable size, and usually six-sided, and has a deposit so arranged,
on its inner side, that either its presence or its absence causes
certain transparent lines to appear at very regular intervals. In
some instances so many as twelve sides have been observed ; but
whatever may be the number of sides, they are separated by
clearly defined perpendicular lines. The transverse bars do not
Fig. 69. Scalariform P ass 9*>ite so far as the boundary line of the side a circumstance

vessel, showing the -which gives a greater degree of resemblance to the figure of a

transverse oars on . . .

nine sides, and the ladder. As there are transverse translucent spaces of about equal

open character of the size and at equal distances, there will, of course, be alternate

transverse and equal bars separating these spaces. These bars

are continued with the] boundary line of the side ; and, upon the whole, it appears

probable that the deposit has been placed at these points, and that the translucent

THE LACTICIFEROUS VESSELS.

lines or pores are the parts at which no deposit has occurred. It is still in dispute

if this deposit has taken place in the spiral direction so commonly

found in vegetable deposits ; but it is quite certain that in a few

instances the scalariform has unrolled like a spiral vessel (Fig- 70).

The use of these vessels differs little, if at all, from that of other

ducts, viz., that of conveying fluids with rapidity ; but there

is this great peculiarity, that they are found only in one class of

plants viz., the ferns (Filices), and there supplant all other forms of

vascular tissue (Fig. 71). Thus there are two great classes of plants

which have distinguishing anatomical characters ; viz., the Conifer a ^ 70 _ \ portion of

or fir tribe, distinguished by its glandular woody fibre, and the a * large scalariform

fern tribe, known readily by its scalariform tissue. The scala- Jg^gBjSS

riform tissue is also enduring in a vessel, and showing

remarkable degree, as was stated of ^fJ^SSS^

the glandular woody tissue ; for
'ferns, like firs, are abundantly found in the coal measures,

and Professor Quekett discovered it in a funereal urn dug

up in the island of Anglesey.

This appears a favourable point at" which to request
the reader to look back and observe the unity of design
which appears to pervade the whole structure of plants.
We have just seen that there is not, in truth, any essential
Fig. 71.-Bundle7f scalariform distinction to be made between the three classes of vas-
yesselsinclosed in cellular tis- cular tissue now described spiral vessels, ducts, and scala-
L> riform vessels, all of them being composed of a mem-
branous tube, with a secondary deposit assuming the spiral
direction. It is also evident that these differ in no essential respect from Bothrenchym
or pitted tissue ; and from dotted cells and fibre cells, only in size and figure.
Thus we have traced the essential identity of the tube with the cell, and of the highly-
figured vascular tissue with the simpler cells with a secondary deposit. The woody
tissue is, in like manner, an elongated cell of thickened membrane.

The arrangement or classification of these structures is not as yet in a satisfactory
condition, and it is yet a desideratum to find out some general feature by which they may
be grouped in a less artificial manner. That one which has already been referred to
viz., the simple membrane and the membrane with a secondary deposit as the
basis of all tissues, is a step in the right direction. It is clearly xmphilosophical to
regard mere markings as points of distinction, where there is not real difference in
structure and functions. So far as we have now accompanied our readers there can
be no difficulty in acknowledging that we have simply passed through modifications of
a simple cell.

Laticiferous, or Milk-bearing Vessels. There is jet another very inte-
resting and somewhat less simple form of tissue to be described viz., the milk-bearing
tissue so readily inferred to exist from the white exuding juice of the cut dandelion
(Leontodori), and poppy (Papaver], or the yellow juices of the Chelidoniurn. The essential
characteristics of this tissue is its branched distribution, and the intermitting or pul-
satory motion of its contents. In both these respects it differs from other vegetable
tissues, and corresponds very closely with the blood-vessels of animals. It is well

THE LACTICIFEROUS VESSELS.

known that nature never progresses by bounds, but by gentle ascents, and that, not

only does one fundamental structure run through the whole of vital_existences (whilst

the anatomical characters of widely - separated

classes are yet very distinct) ; yet that there are

certain similarities which become, as it were, the

larger links which unite them together. The

structure now under consideration is the large

link which binds vegetables and animals together.

No other vegetable vascular tissue uniformly

branches, and none has a pulsatory motion of its

contents ; but both these conditions are universal

in the animal kingdom. There is yet another

similarity : The Lacticiferous or milk-bearing tissue

(Fig. 72), is devoted to the maintenance of the

vitality of the other vegetable structures, and not

to any extraneous object whatever. If a stem be Figl : 7 l'~ M - iIk V 7 ess ^ ls from tbe . stipules

J J of the Jftcus elastica, or India-rubber

in great part cut through, the effect is to kill the fig-tree, showing the branched and

plant-not so much by destroying its functions as S^S^SS^ofthd? Stints^

by pouring out the milky juice, which should

maintain the life of all the structures in fact, by bleeding it to death. This is not the

Fig. 73. The smallest vessels or capillaries of the frog's foot, as seen by the microscope, -whilst the
circulation is proceeding, a indicates a vessel of a larger sixe, which subdivides at b into c'iie
capillaries. The vessels anastomose with each other, and branch in every direction, and con-
tain the oval bodies, or blood globules, which correspond to the granules in Fig. 74.

Fig. 74. Milk-vessels of a water-plant the| Limnocharis Hiimboldtii, showing their granular con-
tents ; and the walls apparently made up of a series of oblong cells of cellular tissue, aud the whole
inclosed in hexagonal cells, as shown at b. The arrows indicate the direction of the current.

case with the woody tissue ; for if that were nearly drained of its contents the plant
would not necessarily perish ; but if the milky juice be withdrawn too -abundantly

THE BANYAN TREK.

-as from the cow-tree (Palo de Vacca] of Ceylon, or the hya-hya tree, of British
Guiana, which yields refreshing juices-the plant droops and dies.

The similarity between this structure and the blood-vessels of animals is weU
seen in diagrams, Figs. 73 and 74, which represent, side by side, the capillaries or
smaller blood-vessels in the frog's foot, with the contained blood highly magnified, and
the lacticiferous tissue, with its contents.

The undulatory or pulsatory motion of the contents of the tissue may be well seen
in the Limnocharis Hamboldtii, a water-plant found in hot-houses (Fig. 74), if a portion
be cut off, and exposed to the sun for a short time, and subsequently placed in water.
The exposure to the sun causes so much evaporation as to greatly lessen the quantity
of fluid in the vessels ; and the subsequent immersion in water enables the plant

Fig. 75. The BANYAN TREE (Ficus rdigiosa), showing its original trunks, and the branches which
have passed down to the ground and taken root, and have become new centres of growth and
nourishment. This troe is so large that a regiment of soldiers may take refuge in its shade.

to supply its wants, and to pump, so to speak, vigorously. This diagram is also illustra-
tive of the opinion formed by certain authors as to the relations of this tissue viz.,
that it is very analogous to mere inter-cellular passages. In this view, it is not a
distinct tissue, although it may have special functions.

The latex, or milky fluid, is of immense service .to man, in two ways more parti-
cularly :

First As already intimated, it constitutes refreshing beverages, readily obtained,
and in large quantities, to travellers in the sunny climes of Asia. Such are the cow-
tree of South America, the kiriaghuma (Gymneuralactiferum), and hya-hya (Jabernce-
mantana utilvi] before-mentioned, and also the Euphorbia balsamifera, of the Canary

CAOUTCHOUC AND GUTTA-PERCHA. 31

Islands, the juice of which, as a sweet milk, or evaporated to a jelly, is taken as a
great delicacy, and the Banyan tree (Ficus reUgiosa Fig. 75). Many of these juices
also contain medicinal properties of great value.

Secondly In the production of caoutchouc, or India-rubber. This invaluable sub-
stance is found in all plants, but more particularly in the Fig, Euphorbia, and Cactus
trees of the East Indies, South America, and Africa within the torrid zone. Of all
these, the fig, known as the Ficus, or Siphonia elastica, is the most valuable ; but in the
countries where the manufacture of India-rubber is a daily occupation, it is not
exclusively selected. This increased quantity of caoutchouc in the latex of hot cli-
mates is believed to be due to the powerfully elaborating property of the sun's rays in
those climates.

The following is the mode in which the India-rubber is prepared from the milky
juice :

The natives having selected a fine specimen of the Siphonia elastica, sixty feet in
height, make deep incisions into its smooth, brownish-gray bark; after which the
white juice flaws forth in considerable abundance. Before it dries upon the trunk, or
in a hole at the foot of the tree, it is spread over bottles of unburnt clay, and dried
over a smoking fire ; care being taken to prevent the flame burning it. When it is
dried, another coating of the juice is placed upon it, and that again is he^d over the fire ;
and the process is thus repeated, until the required thickness has been attained. When
the process is completed the bottle of clay is broken and the pieces extracted ; after
which the Indian-rubber is ready for the market. It is met with in commerce of various
colours, terminating in a deep black ; but the juice is originally colourless, and the
colour is produced by the smoke in which it is immersed in the process of drying.

This tissue is found in all parts of a plant ; but, from its ramifications amongst
other tissues, cannot be readily separated. It is most readily seen in the fresh stipules
of the Ficus elastica.

Gutta-percha is another invaluable substance, recently obtained from the latex
of certain plants, and especially of the class called Sapotacea, abounding in the Indian
Archipelago. The trees whence it is obtained are large, but not otherwise valuable.
The gutta-percha is obtained by incising the bark and collecting the milky juice, which
speedily coagulates. Each tree yields from twenty to fifty Ibs., so that the destruction
of a large number of trees is required in order to meet the present enormous demand
for this article of commerce. It appears that the proper term is Gutta-Pulo-Percha
gutta signifying gum in the Malay language, and Pulo-Percha the island whence it is
obtained. When translated into English words, it is " gum of the ragged island."

The Secretions of Plants. We now proceed to describe the chief secretions
of plants, some of which are of the utmost value to man. They are Starch, Eaphidcs,
Silica, Oils, and Fats, and the colouring principles of plants.

Starch. This alimentary substance was, until recently, believed to be peculiar to
vegetables ; and, although it is not strictly, it is almost exclusively confined to them.
It is, moreover, the chief element in vegetables, which renders them fit to be the food of
animals, and enjoys, therefore, a position of the utmost importance. Starch is not to
be understood as directly represented by the article of commerce which bears its name ;
for, although that is starch, it has been so prepared as to lose the anatomical charac-
teristics which starch in its'natural state possesses. All plants, probably, possess this
substance, but in very unequal degrees ; and it is only when it" exists in quantities
much greater than the plant requires for its own purposes that it is sought after by

32 THE SECRETIONS OF PLANTS STARCH.

man. As a rule, a vegetable, if nutritious at all, is so in proportion to the amount
of starch which it contains ; but there are many plants which yield starch in tole-
rable abundance, but which are inedible from the presence of acid or poisonous fluids.
In selecting articles of food, it is needful to bear both these facts in mind. It is
most abundantly found in the seeds of plants, and especially in the cereals, or wheat
tribe ; and thence this article of diet is accounted to be very nutritious. It is also
met with in the cellular tissue of plants, and especially in the cellular matrix of
such underground stems as the potato, turnip, and radish, and the stems of such
plants as the sago-palm-fig, whence it is obtained in large quantities. Green vegetables
contain a considerable proportion of starch at the period of their maturity ; but they
are nutritive beyond the quantity of starch contained by them, since the vegetable
structure itself has a very similar chemical composition to that of starch. Starch is also
found in the bark of trees ; and, during periods of famine, the bark of certain trees in
this country has been made into bread.

This practice ,was more common in the northern countries, where Nature has less
bountifully distributed her treasures. Mr. Laing, in his interesting " Journal of a
Eesidence in Norway," states 'that he observed many trees which had been thus dila-
pidated; and, after referring to the country mode of grinding meal, remarks " This
mode of grinding and baking makes intelligible the use of bread of the bark of the fir-tree
in years of scarcity. Its inner rind (liber], kiln-dried, may undoubtedly be ground along
with the husks and grain, and add to the quantity of meal it may even be nutritious.
I had previously been rather disposed to doubt the fact, and to laugh at the idea of a
traveller dining on sawdust pudding and timber^bread. In years of scarcity, however,
this use of fir-bark is more extensive than is generally supposed. The present dilapidated
state of the forests is ascribed to the great destruction of young trees, for this purpose,
in the year 1812."

But, notwithstanding its universal distribution, it is to be found in quantities
only in the storehouses provided by nature viz., the seeds and fruit of plants ; the
potato (Solanum tubcrosum), carrot (Daucus carota), turnip (Brassica rapa), and similar
underground stems, as they arc termed ; and, lastly, the stems of palms, and similar
cndbffenotu plants.

Amongst plants Avhich yield an acrid juice with the starch, we may first mention
the tapioca plant, or Yucca duke, the sap of which is used to poison the arrows ;
but the starch is fitted for food after the roots have been beaten, dried, heated,
washed, and pressed. The common arum of this country was formerly collected
on account of the starch or arrowroot contained in its corm or underground stem ;
but the aridity of the juice was so great as to cause the hands of the operator to
inflame.

The horse-chestnut is not edible for the like reason, although it contains much
starch, and is excellent food for some inferior animals. It is also known that whilst
the tubers of the potato are so wholesome, the berries are poisonous. The horse-
chestnut was tried in this country as an article of diet in 1846, but its acidity arrested
its use.

Those plants which offer the starch unmixed with deleterious matters are :
1st. All the grasses, including, wheat, oats, barley, rye, and all trinclar seed-bearing
plants.

2. Many leguminous and cruciferae, or pod-bearing plants, such as the pea, bear.,
and lentil, cabbage, and turnips.

STARCH.

3. The Marantn arundinacea, or arrow-root plant.

4. The sago palm.

5. Several bulbs and tubers, as the
onion and potato.

6. A species of plantain, which
offers it so abundantly and in small
masses that it was introduced and sold
in this country as flour.

The most interesting illustration of
the admixture of deleterious and edible
substances is that of the preparation of
the Cassava meal, a kind of arrow-root,
from the Mandiocca farinha, a tree pos-
sessing excellent starch, and, at the
same time, the most poisonous juices.
Its preparation is thus graphically de-
scribed by M. Schleiden :

" In a dense forest of Guiana the
Indian chief has stretched his sleeping
mat, between two high stems of the
magnolia; he rests indolently smoking
beneath the shade of the broad-leaved
banana, gazing at the doings of his
family around. His wife pounds the
gathered mandive roots, with a wooden
club, in the hollowed trunk of a tree,
and wraps the thick pulp in a com-
pact net, made from the tough leaves Fig> 76 The AR MACULATUM, with its cormus, or

, ,., , root, containing starch.

of the great lily plants. The long

bundle is hung upon a stick which rests on two forks, and a heavy stone is fastened to
the bottom, the weight of which causes the juice to be pressed out. This runs into
a shell of the calabash gourd (Crescentia Cujete) placed beneath. Close by squats a
little boy, and dips his father's arrows in the deadly milk, while the wife lights a fire
to dry the pressed roots, and by heat to drive off more completely the votalilo poison-
ous matter. Next, it is powdered between two stones, and the cassava meal is ready.
Meanwhile, the boy has completed his evil task ; the sap, after standing some con-
siderable time, has deposited a delicate, white starch, from which the poisonous fluid
is poured off. The meal is then well washed with water, and is their fine white tapioca,
resembling in every respect arrow-root." Let not our readers be alarmed when they
eat their next tapioca pudding; but yet it may be well to remember how closely life and
death are associated.

Starch is met with in two forms :

First, amorphous; that is in Bne powder, without any distinct form or marking, as
in the Salep, commonly sold in this country.

Secondly, and almost universally in the form of variously-figured cells.

We have nothing tc add in reference to the former, except that, in common with
the other form, it is found inclosed in the large cells of vegetables, as may be seen in the
section of the potato (Fig. 83), and that the presence of both alike mar be chemi-
TOL. ii. 'D

34:

THE SAGO PALM.

cally demonstrated, if a drop of a solution of iodine be added to the smallest quantity
of starch and water, and placed under the microscope. The chemical effect of the
iodine is to colour the starch of a beautiful deep violet shade. We may also add, that
as starch has the property of polarizing light, its presence may be readily shown by
placing it in the microscope with the polarizing apparatus.

Fig. 77. The SAGO PALM (Cycas revoluta), contain 1 ! g a large quantity of starch in its stem.

Further attention is, however, necessary to the consideration of the second kind of
starch, or that consisting of cells ; and chiefly on the ground, that it is possible to dis-
tinguish the starch grains or cells of one plant from those of another, and thus to
detect the adulterations which are practised in reference to flour, bread, arrow-root,
and other articles of farinaceous food. Much attention has been given to this mattei
during the past ten years, and with the result, it is believed, of having lessened, at Least,
the frequency with which fraud has been perpetrated.

Starch grains are distinguished from each other by their size, figure, and markings.

STARCH GRAINS.

In reference to their size it will suffice to glance at Fig. 78, to show that it varies
very greatly, and that it is very small in the rice (Fig. 78 a), and very large in the Tous
les Mois (Fig. 78 b] ; whilst wheat (Fig. 78 c) and potato (Fig. 78 d] starch occupies a
medium position. The ordinary figure is rounded or oval, sometimes much flattened, as
in the Curcuma leucorrhiza, or East Indian arrow-root ; less flattened, as in the wheat
and barley ; oval and roundish, as in the potato and the pea (Fig. 78 t). The figure,
however, although permanent in
each variety is. its general charac-
acteristics, varies considerably.
In every specimen a multitude of
smaller or imperfectly-developed
granules will be observed; and
they do not assume the form
which is obtained by the perfect
granule. The consideration of
the markings and their nature is
the most interesting and impor-
tant part of the subject, inasmuch
as they are most permanent, and
imply an acquaintance with the
structure of the cell. "We shall
therefore say a few words in re-
ference to the composition of the
starch grain before we describe the
markings which distinguish the
various kinds of starch.

A reference to Fig. 78 will
show that in almost all instances
there is a central spot (Fig.
78, 1), called the hole or hilum,
and that a series of lines arrange
themselves around it. This will
be better seen in Fig. 78 c, which
represents the cell much more Fig. 78. The more common forms of the starch cell,
highly magnified. The nature of f ** TSS^SSlgSft^,.

c, wheat, do., do., faintly marked with concentric lines.

d, potato ; medium size, flattened, and with well-inarked

lines.

e, the same, more highly magnified, so as to show the

nucleus, 1, and the markings, 2.
/, Tout les Hois, the largest kind of starch, of oval shape,

well-developed markings, and sometimes with a double

hilum, 1.
g, the same, ruptured by the application of heat, so that

the membrane at h is retracted and corrugated, and the

contents exposed.
t, the starch of the common pea (Pisum), with its deep

central folding or cavity. The precise figure of thui

cavity or folding differs in various grains.

both of these is the point in dispute.
There is a cell-wall, as may be
seen in Fig. 78 y, in which, on the
application of heat, it has rup-
tured, and is a little reflected.
But is there no central cavity, and
do the lines observed on the gra-
nules correspond with layers
within the cell-wall ? There

have been two leading views on
these points.

1st. That the starch granule is really a vesicle or cell, having an inclosing wall
differing in consistence, and perhaps in chemical characters, from the starch-itsel

36 STARCH GRAINS.

2nd. That it is a solid body, constituted by layers one upon the other, beginning
either -within (centripetal), or without (centrifugal).

On the first of these theories the markings upon the surface are produced by the
folding of the cell-wall ; and on the second, by the successive layers of the solid starch.

Leeuwenhoeck, a celebrated microscopist, published certain investigations made
by him nearly a century and a-half ago, in which he showed the cellular character
of starch. Since his era many eminent observers have adopted his views, with
certain modifications ; and very recently two, whose experiments we shall describe,
viz , M. Martin, the librarian of the Imperial Polytechnic Institute at Yienna,
and Mr, Busk, a distinguished naval surgeon and microscopist. Both these gen-
tlemen agree in the theory of the constitution of the starch granule m., that it is a
cell, having a cell-wall much larger than the contents of the cell in the dried state,
and, therefore, puckered and plaited, as indicated by the lines upon the surface. M.
Martin says, that "the primary form of the starch grain is a spherical or ovate cell. If
this be considered as empty, and so contracted that one-half lies in the other half, a
watch-glassrshaped basin is formed, which, after boiling and pressure between two
glasses, appears, in consequence of the delicacy and elasticity of the membrane, as a
flat, round^edged disc." Thus, in his opinion, the ovate cell is inrolled upon itself.

Mr. Busk has not satisfied himself in reference to this unfolding of the membrane,
but thinks that the swelling up of the cell by the addition of strong sulphuric acid
rather indicates the distinction of plaits or folds, and more particularly in such
varieties of starch as have, when dried, a puckered centre, as is exhibited in Figs. 78 /,
and 80. As this is a most interesting and undetermined question, and one, more-
over, which our intelligent readers who have microscopes may be desirous to investi-
gate, we subjoin the methods adopted by the observers just mentioned.

In any examination of starch it is only necessary to take a pin's point of flour of
wheat, or of some other grain, or to scrape a very little morsel from the cut surface of
a potato, and in both cases the starch will be found partly in free grains and partly
inclosed as masses of grain within the cellular tissue of the plant.

The grains of Tous Us Mois (Fig. 78 /) are the largest, and therefore, in many re-
spects, the most convenient for examination ; as also those of the horse-chestnut (Fig.
79), and pea (Fig. 78 ), when it is desired to notice the unfolding of the central
puckerings.

M. Martin's method was as follows : " Between two very thin glasses, of the same
size as the stage of the microscope, a little starch, with a sufficient quantity of water,
is to be put, and the former well spread out with the finger, to prevent, as much as
possible, the formation of bubbles, The number of starch grains in the field of view
should not exceed ten or fifteen. The glasses should He freely on the spring-piece,
which must be raised by means of two pieces of cork, introduced below it, so that
while the two glasses are lying right upon the object-bearer, a current of cold air will
ascend from below, and permit the little flame to continue burning in the hole of or
below the stage. As the glasses are wide they protect the microscope from too great
a heat or other danger. The small flame is to be obtained from a common thread,
doubled and slightly waxed. This, when ignited, gives a flame quite sufficient to boil
the starch." The object of this experiment is to cauee the distension of the cell-wall
by the introduction within the cell of hot water, and thereby to notice what changes
take place in the markings upon the surface.

Mr. Busk seeks the same end by applying the most powerful of acids m., concen-

THE STARCH CELL.

trated sulphuric acid, or oil of vitriol. Our readers, whilst repeating this experiment,
must exercise the greatest caution lest they burn their fingers and clothes. The fol-
lowing is Mr. Busk's method : "A small quantity of the starch is placed upon a slip
of glass, and covered with five or six drops of water, in which it is well stirred about ;
and with the point of a slender rod of glass the smallest quantity of solution of iodine
is applied, which is to be quickly and well mixed with the starch and water. Any
excess of water must be allowed to drain off, leaving the moistened starch between,
and a portion of it
is then to be covered
with a piece of thin
glass. It must then
be placed on the
microscope, and a
quarter or one-fifth
object glass brought
to a focus close to
the upper edge of
the piece of thin
glass. With a slen-
der glass rod a small
drop of sulphuric
acid is to be care-
fully placed imme-
diately upon, or
rather above, the
edge of the cover,
care being taken
that it does not run
over it. The acid,
of course, quickly
insinuates itself be-
tween the glasses,
and its course may
be traced by the
rapid change in the
appearance of the
starch grains with
which it comes in
contact. The course
of the acid is to be
followed by moving
the object up wards ;
and when, from its
diffusion, the re-
agent begins to act
more slowly, the

peculiar changes in the starch granules, now also less rapid, may be readily witnessed."
M. Martin thus describes the changes observed by him : " First the starch grain

Fig. 79.

THE STARCH CELL.

sinks in that place where the nucleus is situated. On the surface minute fissures
appear, two of which almost regularly diverge towards the thicker end of the grain.
The grain continues to be depressed inwards until a cavity is formed, which is sur-
rounded by an elevated edge. In proportion as the grain swells up, this ridge increases
in circumference, and decreases in breadth ; that is, continues to get flatter, until fissures,
mostly of a star-like form, appear in the hitherto little altered thicker part of the grain.
The process is not very rapidly developed, and it is very difficult for the eye to follow
it. Suddenly something is torn off, the grain is extended lengthways, and in the next
moment a wrinkled skin of a rounded, generally oval shape, lies on the glass." Fur-
ther examination shows that they are collapsed bodies, consisting of an extremely fine,
but strong and elastic, membrane.

Mr. Busk obtained a different impression from his experiment. He considered that
the line upon the surface were simply plaits or foldings, and that the whole process
consisted of unfolding these plaits, and, by distending the cell, to render the cell-
wall perfectly plain and free from any markings. In Fig. 79 A, we have the starch
of the horse-chestnut in its unaltered state, and at B is i epresented a stage of the
unfolding which results from the use of the sulphuric acid. Fig. 79 c, D, and E,
represent other views of this process, showing that the cell becomes gradually larger,
until it reaches the great size figured at F. The fringe around the figures c, D,
and E he regards as plaits in the process of being unfolded.

Figs. 80 a b, have been copied from Schlieden's work, and represent the starch
from the cormus or roots of the Arum maculatum,
of our hedges, and of the Colchicum autumnale, in
which the star-like centre is presumed by Mr.
Busk to indicate the central folding of the mem-
brane referred to by him.

On a review of the whole evidence now offered,
we may infer that the starch granule consists of
a cell- wall, contracted and plaited when dry, and
smooth and distended when heated with mois-
ture, and also of contents in insufficient quan-
tity to fill it, and thereby leaving a central
cavity.

On this principle, it is difficult to conceive
that the plaits can retain the same characters
in the same plants under all atmospheric condi-
tions ; and it is proper that we should state that
Dr. Allman of Dublin has, during the present
year, published an article in the Quarterly Fig. SO.-Starch cells copied from

Journal of Microscopic Science, in which, by a fhnflp ft . Schlieden.

.-L, - ,, ' * i those of the Colchicum autumnale.

the same processes as those above indicated, he *, those of the Arum maculatum, both

has come to totally opposite conclusions. In his foldTn^o^cavfr 611 * degrees the central
opinion the statement of Fritzsche is correct c, the centra? clvi^y well developed in the
viz. , that the starch cell is in fact a series of cells, 8tarch f the Ia18 -
placed within each other, as exhibited in Fig. 80 . He sums up his opinions in the
following words :

1st. That the starch granule consists of a series of lamella, in the form of closed
hollow cells, included one within the other, the most internal inclosing a minute cavity

THE STARCH CELL.

filled with, amorphous (?) starch ; that the concentric striae visible in the granule indi-
cate the surfaces of contact of these lamellae ; and that the so-called nucleus of Fritzsche
corresponds to the central cavity.

2nd. That while the lamellae appear to be all identical in chemical constitution,
yet the internal differ from the external in consistency or other conditions of inte-
gration.

3rd. That the order of deposition of the lamellae is centripetal.

4th. That while the starch granule is thus a lamellated vesicle, it cannot be included
in the category of the true vegetable cell, from which it dffers, not only in the absence
of a propei nucleus, but in presenting no chemical differentiation between membrane
and contents.

So widely do equally eminent observers disagree in their description of the same
object as seen by the same means !

Rice (Fig. 78 a) is known by the small size of its grains, by their angularity, and
the absence of evident markings.

Sago starch (Fig. 78 b] is very much larger than that of rice, but still less than
that of wheat ; it is rounded, and its surface is rather granular than plaited.

Wheat starch (Fig. 78 c) occupies a medium position in point of size, and is more
regularly round than any grain of similar size. Its markings are not so distinct as
those of the potato.

Potato starch (Fig. 78 d) is distinguished from wheat starch by its large size
irregularity of outline, and flattened lenticular figure. The plaitings on its surface are
very distinct, as is also the hilum around which they are gathered.

Pea starch (Fig. 78 i) is in size about equal to that of wheat; but it differs
remarkably in its flattened figure and the star-like plaits which invariably occupy its
centre.

Tous Us mots (Fig. 78 g] is the largest of all known forms of starch, and from its size,
void figure, and concentric rings, is not unlike a cocoon. It has occasionally two
hilums or holes, and its markings are usually very regular. This article enters largely
into the commerce of the day.

The starch grains, found in the Euphorbias (Fig. 82 a) are very characteristic, and
are readily distinguished by their dumb-bell form
from those of any other plant. The same grains
are seen in Fig. 82 A, floating in the milky juice
of the laticiferous tissue.

Wheaten flour, when adulterated with inferior
starch, is usually mixed with potato, pea, or rice
starch, each of which may be distinguished under
the microscope. So also with wheaten bread, if
the smallest crumb be broken up in water, and
examined in the ordinary way.

It is not known if the varieties of starch
possess any variation in the degree of their nutri-
tive properties. It is therefore the quantity of pure
starch which any substance can yield, conjoined
with the abundance and ease with which the sub-
stance may be obtained, that gives the market-
able value. It is also of importance to determine the state of perfection of any

Fig. 82. Starch cells in the EUPHORBIAS.
6, floating in the milk vessels.
a, greatly magnified, so as to show their
dumb-bell figure.

THE STARCH CELL.

starch-yielding plant, since, in reference to fresh vegetables, the quantity of starch

differs with the season of the year. Thus in the potato the least proportion of

starch is found at an early and a later period, and consequently the full-developed

potato is the most valuable. Moreover, the state of health of a plant is of moment ;

for in disease the secretion of starch diminishes.

This has been painfully investigated in connexion

with the potato blight ; and it has been shown

that not only does the quantity of starch diminish

with the advent of the disease, but cells of another

and an injurious nature appear. These new cells

are of the lowest order of growth, such as the

mushroom, and received the name of the " potato

fungus."

The diagrams, 83, 84, and 85, represent this con-
dition ; Fig. 83 showing the potato in a healthy and
vigorous condition, with the cellular meshwork
filled with starch granules ; Fig. 84 shows the
same cells nearly emptied of their contents ; and
Fig. 85 the diseased cells occupied by the fungus
growth. The inference to be derived from these facts is, that old potatoes are not
valuable, and that the diseased parts should be carefully removed.

Fig. 83. Potato in its healthy and
mature condition.

Fig. 84.- A slice of a potato, as it appears
after germination, when it is thoroughly
withered ; or as produced by disease, at
the commencement of the "potato dis-
ease." The cell-wall remains, but nearly
the whole of the starch has been removed.
A few grains remain, as shown at a.

Fig. 85. Diseased potato, showing the pre-
sence of a fungus at b, and the isolated grain
of starch at a.

The ordinary starch of laundresses is oftentimes prepared from potatoes which are not
fit for the food of man ; but the purest kinds are obtained from rice. It is prepared by
Bimply breaking up the pulp so as to disengage the starch from the cellular meshes ;
then, by maceration, heat, and motion, to rupture the cell- wall of the granule, and
to effect the escape of its contents. Lastly, it is filtered, in order to obtain the starch
separate from the membranous cell- wall.

VEGETABLE SECRETIONS.

Raphides. Another secretion found very abundantly in plants is certain crystal-
line bodies termed Raphides, from the resemblance of some of them to a needle
(raphis). The term, however, is not a happy one ; since many varieties of these
crystals exist which have no resemblance to a needle. They are not secreted in the
form in which we see them, but are deposited from the secretions. They occupy
both the cavities of the tissues and the passages which lie between the tissues, but
are the most abundant in the cells of succulent plants.
They may be observed with great ease in the stem of the
common garden rhubarb (Rheum), or of the balsam, and
in the bulbs of the onion, and all bulbous garden plants. In
the former case they have a square outline, and are isolated
(Fig. 87), or they are aggregated into separate star-like
bodies (Fig. 88) ; whilst in the latter they are usually needle-
form, and lie in dense bundles (Fig. 86) . Their number is so
great as to impart a grittiness to rhubarb-root when bitten ;
and the most so in the finest specimens of Turkey rhubarb.
Their chemical composition is that of oxalate, phosphate,
tartrate, malate, or citrate of lime, and in size they
differ from one-fortieth to one-thousandth of an inch.
Phosphate of lime is found abundantly in the bones of
the animal body, but not in the precise form in which we
observe it in Raphides. "We have no instance of oxalate
of lime crystals in the body ; but they are not unfre-
Fig. 86. Rhapides ; acicular quently met with in the urine of persons, both in apparent
LXn^VebS tKquili health and in disease ; so that it has been inferred that
(Scilla mauritanica). ft^y have b een introduced with the food.

We do not know the uses of these substances in the vegetable economy; but
although they render certain plants brittle, it
is not ascertained that they are the result of any
diseased action. This brittleness is the best seen
in some of the large Cactus plants (Fig. 89).
One which was re-
moved, after a lapse
of a thousand years,
from the woods of
South America to the

Fig. 88.

Royal Gardens at
Kew, was wrapped in

Fig. 87. Raphides found in the common
onion (Allium).

A, octohedral. B, prismatic.

C, a stellate or star-like cotton, and packed as

mass of crystals found in though it were the

rhubarb root.

most fragile of sub-
stances. They are readily seen on microscopic examination, if a thin section of an
onion be placed in water in the usual way ; but as they are found in all parts of a
plant, from the rough bark (Fig. 90) to the delicate spiral vessels and the pollen, they
will be observed in almost every investigation.

They have beea produced artificially, and, so far as may be seen, in a state as
perfect as those deposited from the vegetable juices. The late eminent botanist, the
brother of Professor Quekett, produced the stellate and rhomboihedral forms artificially

VEGETABLE SECRETIONS.

in cells, but could not produce tlie needle-shaped crystals. He took a portion of rice-
paper, and placed it in lime-water under an air-pump, in order to fill the cells with the
fluid. The paper was then removed and dried, and the process repeated until the cells
were filled. After this the paper was immersed in weak solutions of oxalic and phos-
phoric acids, and the crystals appeared at the end of three days (Fig. 91). This,
however, is a mere chemical experiment, and has no relation to vegetable tissue,

Fig. 89. Fig. 90. Fig. 91.

Fig. 89. Raphides. A mass of crystals from the cuticle of a Cactus.

Fig. 90. Raphides from the bark of the LIME TREE (Tilia Europva), of considerable breadth and

prismatic figure.
Fig. 91. Crystals of oxalate of lime raphides, produced artificially in the cells of rice-paper.

except in so far that a detached morsel of vegetable structure was used as the containing
vessel.

Oils and Fats. The most widely distributed of all vegetable secretions, next to
that of starch, is essential and fatty oil, of various degrees of consistence ; and, with the
exception just referred to, none has so high a value for economic purposes.

There are probably few, if any, plants from which some portion of oil cannot be
obtained by distillation ; but it is more particularly in the hot climates of India, China,
New Holland, Africa, South of Europe, and South America, that they attain their
highest degree of perfection, and are found in the greatest abundance. The mustard-
seed, for example, which is grown in our climate, yields oil only in a non-remunerative
degree ; but in the continent of India, with its burning sun, the produce is of great
value. So also with the otto or atar of roses an exquisite volatile oil, obtained from
the rose-leaf growing in Persia, but scarcely perceptible in our northern climate. This
is doubtless due to the chemical influence of the sun's rays, by which all vegetable
secretions become highly elaborated.

The oil is most commonly found in the seeds, as in the linseed and rape-seed, of our
climate ; for as the seed is the product of the plant in its most mature condition, it is
the most fitted to be a depository of the most mature secretions. It is, however, found
to a great extent in the leaves of plants, as the rose and the peppermint, and in the
wood of a comparatively few trees for example, the Sassafras and the Sandal- wood.
The bark is not an unfrequent depository of oil secretions.

A recent discovery made by Mr. Young, of Scotland, has demonstrated the wonder-
ful length of time during which vegetable oils retain their distinctive characters. He
has obtained by distillation, at a low red heat, no less than 20 per cent, in weight of

VEGETABLE OILS. 43

oil from cannel coal. When was that oil first formed ? Thousands of years ago : and
yet its quality remains so good that it is now compared with sperm oil. Its non-oxi-
dizing property renders it peculiarly fitted for the lubrication of machinery.

As respects the varied social purposes to which it is applied, we may refer to the
perfumes of Eau de Cologne and Lavender ; the immense quantities of candles and soap
which are manufactured in great part from vegetable fats ; the oiling of machinery,
which is carried to so great an extent, that the London and North "Western Railway
Company alone use about 50,000 gallons of oil per year ; the support of artificial light
by lamps ; the exhibition of oil for medicinal purposes as the castor and cocoa-nut
oils ; and the employment of oil as an article of diet by the inhabitants of all extreme
climates. Thus but few articles of commerce can more materially influence the well-
being of the community than that under consideration.

It is also worthy of remark how closely the production of oil links together the
animal and vegetable kingdoms, not merely in the general chemical and economic
characters of the substance, but in its minuter details. Thus we have the fluid oils, as
the olive oil, and the semi-fluid, or such as require a higher temperature than that of
the air in order to render them fluid, and which closely resemble the fat of animals.
There is also vegetable butter, which is largely used in India to adulterate the ghee, or
animal butter ; and vegetable wax and tallow may, in some sense, rival the like produc-
tions from the animal kingdom. There is, however, this remarkable difference viz.,
that the fat of animals and of vegetables, each abound in climates the most opposed to
each other. The vegetable oils and butters are chiefly derived from the Palm trees of
the hottest climates ; but the animal oils and fats are met with in greatest abundance
where the rigours of a polar clime call for the internal use of such articles of food in
order to maintain the animal heat. Thus the fat of animals is, for the most part,
smployed by the Laplander as food ; whilst that of vegetables is chiefly used by the
Asiatic and African for external inunction, as a defence from the action of the sun's
rays, and as a perfume, which is more than a luxury in the stifling atmosphere of the
sunny south. Nature has thus bountifully provided for the wants of man, and in g?-eat
wisdom has selected, as her depositories, that division of vital existences which is the
most abundant in their respective climates. The inhabitants of temperate regions, ts of
England, find within their own territories only feeble representatives of the products of
the two classes ; and in order to enjoy them they require to collect the animal oils from
the Polar Seas, northern forests, and the banks of Newfoundland, and the vegetable
oils from the neighbourhood of the tropics. Commerce, therefore, is to them a necessity.

This branch of trade is as yet in its very infancy, for {he Great Exhibition of 1851
has shown that a very large proportion of vegetable oils is unknown to the commerce
of the world ; and the great effort which has been of late put forth to increase it, has
led us to infer that multitudes of vegetable sources yet remain untouched.

"We cannot enter largely into this question, but shall now proceed to indicate some
of the more ordinary and useful sources of this substance.

Fixed Oils, Olive Oil is produced from the Olea Europcea, a shrubby tree, culti-
vated with great sare in Spain and Italy, Syria, and other shores of the Mediterranean
Sea. It thrives hest in stony ground, and requires a southern clime, in order to perfect
the oil contained in the olive berry. The virgin oil is produced by simple pressure of
the olives ; but that of the inferior qualities is such as is drawn off after the virgin oil
has been removed, and which requires heat and water in order to obtain the full
quantity remaining. It is mentioned as an article of food in the Sacred writings j and

VEGETABLE OILS.

in eastern, and southern climes is almost indispensable to the inhabitants, both as food
and for inunction. It is less commonly used in this country than is desirable, since it
is highly conducive to health.

Its chemical composition, per cent., is, carbon, 69*38 ; hydrogen, 13*47 ; nitrogen,
058 ; oxygen, 17'092.

Palm Oil is an article but recently introduced into commerce, and has the great
commendation of offering the most effectual means for the suppression of the slave
trade. It is obtained from the seeds of various palms, and more particularly from those
growing in barbarous states on the western shores of Africa. It is far more con-
sistent than other oils, and approaches to the condition of ordinary fat; so that it is well
fitted for the manufacture
of candles, and when mixed
with sulphur is the most
valuable grease for railway
carriage wheels. In the
countries in which it grows,
it constitutes an important
article of food ; and, from its
golden colour and consist-
ence, may be said to be a
substitute for butter.

Cocoa-Nut Oil has a re-
lationship to palm oil, in-
asmuch as it, too, is pro-
duced from the palm tree.

Fig. 93. Globules of con-
crete oil, filling the hexa-
gonal cells of the cocoa-
nut.

Fig. 92. COCOA-NUT PALM (Cocos Nucifera).

It is a concrete oil, and is found in the cells of the seed of the cocoa-nut before germi-
nation. It is likewise obtained by pressure ; and is of great value in the production of
artificial light. Colonel Rowcrofthas shown to us some very excellent candles, prepared
in India, from an admixture of wax and cocoa-nut fat. It is also used not unfrequently
as an article of food, in the form of butter in India, and of cocoa and chocolate in
this country, and has recently been introduced as a medicinal agent in the treatment of
consumption.

Its chemical constitution is carbon, 69'62 ; hydrogen, 12*49 ; nitrogen, '060 ;
oxygen, 17*850 per cent.

Linseed Oil is obtained by pressure, with and without heat, from the seeds of

VEGETABLE OILS. 45

the flax plant (Linum), grown in the British Islands, America, and the Continents
of Europe, and of India. It is a common article of food to the serfs of Eussia, and is
regarded as the highest luxury by the Greenlanders and other inhabitants of polar
climes ; but it is chiefly used in the arts. It is prepared by distillation for drying, and
then is fitted for the preparation of paint. A large proportion of this seed is grown in
England and Ireland; but it is chiefly imported from Russia: no less than 482,813
quarters out of a total importation of 626,495 quarters of the seed having been received
from that country in the year 1850. It is considered a profitable crop, and is now
much cultivated in Ireland. The pressed seeds from which the oil has been partly
extracted, constitute the oil-cake, much used in the fattening of cattle.

Rape Oil is in like manner extracted from the rape-seed, which is the product of the
Brassica Napus, and other species of the cabbage genus of plants. It is considered to be
better adapted, when purified, for the lubrication of machinery than any other oil ; so
much so, that 90 to 100 gallons of it are yearly expended upon each locomotive railway
engine. It is also inferior to few, if any, oils in the production of artificial light in
lamps. Mr. Brotherton affirms that the English grown seed is to be preferred to that
imported from the Continents of Europe and India ; and so profitable is the crop, that
an acre of land will yield five quarters at 50s. per quarter, or 12 10s. yearly. It is,
however, probable that the foreign seed is equally good with the English production,
and that the inferior quality of the oil may be attributed to its careless and unskilful
preparation. The importation of rape-seed in 1850 was 29,490 quarters.

Turnip-seed Oil (Brassica rapa) is very nearly allied to the rape-seed oil, and is
much employed in Egypt.

Castor Oil is obtained from the seeds of the Ricinus commttnzs, which grows chiefly
in the East Indies and the United States of America. It is much used in medicine, but
more particularly in the arts, and the manufacture of pomatum. When intended to be
used medicinally, it is obtained by pressure without heat, and is then colourless and
tasteless, and will so remain for a lengthened period ; but that which is employed for
other purposes is obtained by heat and pressure, after the first or virgin oil has been
removed. This is slightly coloured, and has a rancid odour and taste, and conse-
quently realises but a very inferior price. The seeds do not grow to perfection in our
climate. The importation of the oil, in 1849, was 9,681 cwts., of which 9,315 cwts.
were obtained from our Indian possessions alone.

Ootton Seed (Gossypium) yields a large quantity of oil on pressure ; but, on account
of the difficulty of removing its colouring and other impure matters it has been hitherto
but little used. The seeds are very abundant, and as large as orange seeds, and are
either wasted or iised as manure and for the fattening of pigs. It is believed that the oil
would be of great value if purified ; and it could be obtained in any quantity. The
seed is chiefly produced in America, Egypt, and India. "W s have seen immense quan-
tities of it rotting around ^every cotton plantation we have visited in the Southern
States of America.

The Indian corn (Zea Mays'), or maize, in the State of New York, has been found to
contain a valuable oil.

Ground-Nut Oil, obtained from the seed of the Arachis hypogcea, is used largely
in India, Malacca, and Java, both as food and fuel for lamps. It is a clear, pale yel-
low oil, and constitutes fully one-half the entire weight of the seed.

Poppy Oil is produced from the seeds of the Opium Poppy, or Papaver somniferum,
whether grown in this or other countries. It is, however, chiefly produced in India,

46 VEGETABLE BUTTEKS, TALLOW, AND WAX.

since there the plant is scientifically and extensively cultivated by the Honourable East
India Company for the opium which it yields. It has many valuable properties, and
is a very good substitute for salad oil.

Mustard Oil is expressed from the seeds of the common mustard plant (Sinapis), and
chiefly in the various parts of India. That our English mustard yields oil, is familiar
to the eyes of every housewife who has kept it in paper, or has mixed it with warm
water in its preparations for the table.

Croton Oil possesses powerful medicinal properties, and is procured by pressure from
the seeds of the Narpaula, and other species of croton. It is prepared in India and
other eastern countries.

Sesamum Oil, derived from the seeds of the Sesamum orientals, and the Eam-til oil,
from the seed of the Guizotia oleifera, are well known, and greatly valued in India.
The seed yields from thirty-four to forty-five per cent, of oil.

Vegetable Butters. The plants which yield vegetable butters, are (besides the
palm oil to which we have referred) chiefly the various species of Bassia, all indigenous
to India and "Western Africa. These oils consist of saccharine matter, spirit, and oil,
and therefore are as well adapted for food as for fuel.

The Epie Oil is obtained from the seeds of the Bassia latifolia, and is common in the
Bengal Presidency. It begins to melt at about 70.

The Ilpa oil is expressed from the seed of the Bassia longifolia in the Madras Presi-
dency. It is white and solid at ordinary temperatures, and until a heat of 70 or 80
has been produced. It is therefore well fitted for the preparation of both candles and soap.

The Bassia butyracea is the plant which yields the purest vegetable butter, and
is common on the hill districts in the eastern part of Kemaon, and in the Province
of Dotee. It is white and solid at a temperature under 120, and is so abundant
and agreeable that the butter from milk is largely adulterated with it.

Shea butter is obtained from another species of Bassia viz., the Bassia Parkii, in
Bambara (Western Africa), and at Egga, on the banks of the Niger. It melts at 97.

Kokum butter is obtained from the seeds of a Mangosteen (Garcinia purpurea], and
is not only used largely to adulterate butter, but is forwarded to this country to serve
the like purpose with genuine bear's grease.

Cacao butter is solid up to 120, and is the produce of the Theobroma Cacao, growing
in Trinidad.

Crab, or Carapa oil, from British Guiana, is also another kind of butter derived from
the Carapa guianensis, but of inferior quality. The natives, in its preparation, boil the
kernels, leave them in a heap for a few days, then skim them, and at length beat them
into a paste in a wooden mortar. This paste is then spread on an inclined board, and ex-
posed to the heat of the sun, until the butter has trickled into a vessel placed to receive it.

Vegetable Tallow is procured from the tallow tree of Java, known as the Minyak
kawon, and from trees, probably of the genus Bassia, growing in the western countries
of the Archipelago.

Piny tallow is another variety produced by the Vateria indica, a fast growing
plant, common in Malabar and Canara. It is white and solid, and melts at about 97.

Vegetable tallow differs from oil chiefly in the higher temperature required to render
it liquid, and its solidity at the ordinary heat.

Wax is obtained from a variety of trees growing in similarly

Outta Podah is a wax of a bright-green colour, obtained from Biliton.

VOLATILE OILS. 47

Myrtle or Candle-berry wax, has been made, without admixture, into candles in
New Brunswick.

Wax of very good quality has been obtained from trees growing at Shanghae, in
China, in Japan, and in St. Domingo ; and in connexion with this it may be mentioned
that a fungoid growth, found in decayed branches of our English trees, has recently
been shown by Professor Quekett to so far resemble wax, that it is not possible to
distinguish it by the microscope from the waxy comb of the wasp's nest.

Volatile Oils. The aromatic and volatile variety of oil is exceedingly extensive,
and is largely employed in medicine and perfumery.

Amongst the English specimens we may mention the peppermint (Mentha piperita),
and spear-mint (Mentha viridis), lavender (Lavandula\ rosemary (Rosmarinus), fennel
(Meum fceniculatum], thyme (Thymus), from the leaves of all of which essential
aromatic oils are procured. The seeds of the carraway (Carum carui], aniseed
(Pimpinella Aniswn), dill (Anethum graveolens), coriander (Coriandrum sativwn), are
well known to yield medicinal aromatic oils on distillation.

It is, however, to hotter climes that we turn for the spices and perfumes which we
covet, and especially to the inter-tropical regions.

The atar of roses is at the head of this series, and is produced in its highest perfection
in Persia, Turkey, the Raapootana States, and other parts of the great Continent of
India. The quantity of rose-leaves required to obtain a tea-spoonful of this princely
perfume is almost fabulous, and more than accounts for the high price which the oil
obtains. It is much adulterated, and chiefly with the oil of geranium, 'or Andropogon.

The atar of Ecova, derived from the fragrant flowers of the screw-pine (Pandanus
odoratissimus), and the jasmine atar, from the Jasmimim grandiflorum, and Sambac,
aro favourite perfumes in India. So also with oil of aloes wood, of saffron, and of
sandal wood (Santalum album).

Orange flowers (Citrus) also yield a most exquisitely scented oil, as maybe familiarly
observed by walking through the orangeries of this country and of France, when Che
orange tree is in blossom. It is obtained chiefly from Turkey.

Oil of cloves is obtained from the Caryophyllum aromaticus, in India and the Archi-
pelago ; and oil of lemons from the rind of the fruit of Citrus Limonum ; and oil of cin-
namon from the Cinnamomum zeylanicum.

Oil of bitter almonds (Amygdalus amard) is obtained from the seed, and is highly
poisonous. It is produced in Asia.

Cajeputi oil (Melaleuca), from India, with oil derived from the Leptospermum and the
Eucalyptus piperata, of Western Australia, in addition to the medical properties of the
first, have the power of dissolving India rubber and various resins, and might therefore
be used in the manufacture of varnishes.

There are two other vegetable volatile oils, to which we will refer, on account of
the favour with which they have long been regarded in India, and are now being viewed
in this country.

The grass oil is a stimulating aromatic oil, obtained from the seed of the Andropogon
tckcenanthus, or Calamus aromaticus ; and the lemon grass oil, from other species of the
same genus. Both are used to the skin medicinally, and as valued perfumes.

The peculiar odour and great durability of Russian leather is attributed to the
employment, during the process of tanning, of a volatile oil obtained by the distillation
of birch bark (Setula}. The oil has a brown or black colour, and after it is dried up,
it leaves upon paper the odour peculiar to Russian leather

48 GUMS AND RESINS.

Camphor is a substance fitly associated with oils, since it is a volatile oil in a solid
Btate. It is derived from various sources, but the best is the Barus camphor, from
Borneo, the product of the Dryobalanope CampJiora, growing in Sumatra. It is chiefly
exported to China, where it realises a price one hundred times greater than that of
ordinary camphor. Its flavour is exceedingly fine.

The Dutch camphor, or that obtained by the Dutch from Japan, is prepared by
boiling chips of the root ai)d stem with water in an iron vessel, to which an earthen
head containing straw is adapted. The camphor is volatilized by the heat, and con-
denses on the straw. The process is varied somewhat in the preparation of China
camphor. The chopped branches are steeped in water, and boiled until the camphor
begins to adhere to the stick used in stirring the fluid. The liquid is then strained,
and by standing the camphor concretes. It is then sublimed by placing alternate layers
of finely-powdered dry earth and camphor in a copper basin, with a similar one inverted
luted upon it, and heat applied, until the camphor passes off, and condenses upon the
upper vessel.

Gums and Resins. These two classes of secretions are distinguished from each
other by the solubility of gums and insolubility of resins in water, and the solubility of
resins and insolubility of gums in alcohol. In some instances the substance is partially
soluble in both menstruums ; in which case it is called a gum-resin. Each of the classes
is used abundantly in the arts, and in medicine ; and almost every member of them is
obtained from Asia, Africa, and islands of the Southern Sea.

The cheapest gum is that obtained from roasted starch, and is used largely in calico-
printing.

Gum-arabic, obtained from many species of Acacia and other genera, is carefully
collected in Turkey, Egypt, Tripoli, and India. It stands at the head of this series in
the quantity imported ; and amounted to 33,136 cwts. in 1849, from the following
sources : India, 13,687 cwts. ; Egypt, 6,232 cwts. ; America, 6,OG4 cwts. ; South
Africa, 4,876 cwts. ; Italy, 664 cwts. ; Gibraltar, 460 cwts. ; Aden, 397 cwts. ; Australia,
372 cwts. ; France, 212 cwts. ; miscellaneous, 172 cwts. It varies very greatly in
quality ; and it appears that no very great care is exercised by the collectors in separating
the inferior from the better specimens.

Of gum-senegal and the cherry-gum, or Tragacantha (Astragalus gwninif era), &c., from
Syria, there was an importation of 6,577 cwts. and 314 cwts. respectively, in the same
year.

Of the resins and oleo-resins, the most abundant are turpentine and lac, both of which
are of essential value in the arts.

Turpentine is obtained from the fir tribe of plants, and
chiefly from the Pinus palustris, by making incisions into
it, and subsequently distilling the exuded secretion. It is
found in special vessels in the plant, which were dis-
covered so early as the seventeenth century by the great
vegetable anatomist Green, and also in blisters under-
neath the bark (Fig. 94). It is of the utmost value in its
power of dissolving resins, and in mixing and drying
paints. The quantity imported in 1849 was 412,042 cwts.,
Fig. 94.-Ite8ervoir8 of secre- nearl y tte whole of ^ hich was from fa Q United g tates of

America.
The distillation of impure turpentine, or turpentine as it is obtained from the tree.

THE RESINS.

U effected through the medium of water, by which the volatile oil passes over and is
collected, and the resin with which it is naturally associated is left behind.

Tar and pitch are also produced from the fir tribe of plants at the same time that the
turpentine is collected. The wood is cut into billets, and piled up in a hole made in the
ground. It is then covered with turf, or some similar covering, and set on fire.
During the slow combustion, the tar runs down the wood, and is collected in the dam
prepared in the ground for its reception. This tar contains a portion of turpentine, but
may be made from trees which have ceased to emit turpentine on incision.

Pitch is obtained when the tar is distilled ; so that an inferior kind of turpentine
passes over, and the pitch remains,

Resin results from the distillation of turpentine, or from the drying of the secretion
as it exudes from the tree. It is brought to this
country in large quantities from the United States,
Asia Minor, and other parts of Turkey. It is
produced from various species of. Abies and Pinm.
Burgundy pitch and frankincense are obtained
from another pine, the Abies excdsa of the north
of Europe, and Canada balsam from the Abies
balsamea.

Lac is furnished to this country almost ex-
clusively by India, and amounted to 14,786 cwts.
in 1849. It is obtained from a great many sources,
but chiefly from the Coccus lacca, and some of the
firs, as the Ficus Indica and Ficm religiosa, or
Banyan tree (Fig. 75). Its varieties are known
by the designations of stick lac, seed lac, orange
and ruby shell lac, lump and buton lac, lac dye,
and white or bleached lac. It is produced by the
injuries inflicted upon the young shoots of various
trees by an insect, the coccus lacca, which feeds
upon them. It is employed in the manufacture
of varnishes.

It is not possible to name even the great mul-
titude of members of this class, and it must suffice
to mention the sources of the following well-
known substances :

Assafcetida is the product of the Narthax assa-
foetida, in India ; benzoin of the Styrax benzoin, in
Singapore ; copal from the Hyrnencea of Western
Africa, Dammara aiistralis of New Zealand, and
Trachylobium martinianum of South America;
dragon's blood from the Dracaena Draco of India;
(Fig. 95) ; gamboge, from Siam ; myrrh, from the
talamodendron myrrha of Persia, and yellow gum
from the Zanthorhcea hastilis of New Holland.

It is highly probable that the magnificent gum trees of the continent of Australia,
which have hitherto been a great inconvenience to the settler in the clearing of his land,
will ere long yield gums and resins which will convert them into sources of great wealth,

95. A younpr plant of the DRAC.ENA

DRACO.
A specimen in the island of Teneriffe is

to be very ancient in the year 1406.

50 VEGETABLE ACIDS TANNIN.

Acids. Various acids are yielded by vegetables, chiefly from their fruit, but very
abundantly from the distillation of their -wood. Of the former are citric acid, from the
lemon Citrus, the acid juices of the apple (malic acid), pear, gooseberry, and other fruits
of our own climate, and the oxalic acid from the leaves of the sorrel, or Oxalis Acetosella.
All these acids appear to have distinct chemical characters, and to require distinct
names.

Pyroligneous acid, or wood vinegar, is obtained from the distillation of almost all
kinds of wood, and is capable of perfect purification. It is colourless, abundant, and
cheap, and has therefore greatly lessened the demand for the coloured vinegar derived
from the fermentation of beer or wine, and more particularly in the preparation of such
pickles and other substances as would be deteriorated by immersion in coloured fluids.
The process is simple viz., the burning of billets of fast-growing wood, as poplar, in
closed iron tubes or kilns, and the separation of the empyreumatic oils, and other impure
substances, from the acid. This acid can be obtained in a highly-concentrated state,
a'nd is usually sold so that one part is equal in strength to eight of wine vinegar. It is
thus a convenient as well as necessary article for the use of persons on ship-board, or
for residents in new countries, where vinegar has not hitherto been made.

Gallic acid is obtained from gall-nuts, and tannic acid from all sources supplying
tannin.

Tannin. This is the chemical principle which is employed in the tanning of
leather, and produces its effect by acting upon the gelatine contained in the skin. It
is obtained from a great variety of sources, and not only from the oak bark, as is usually
supposed ; although it is probable that the excellence of good oak bark, and the ready
supply of it aiforded by our own country, will ever give it a preference in the estima-
tion of the manufacturer. Notwithstanding the supply of oak bark from our own forests,
so large a quantity as 1,200,000 cwts. of tanning materials were imported in 1849 ; but
it must be understood that the tanning principle forms but a small portion of the
barks and other materials thus imported. The following are the commercial substances
which contain tannin in quantity sufficiently large to render them efficient in the
tanning of leather :

Oak bark, from various species of Quercus, but particularly the Quereus pedunculate* ,
growing in England and the north of Europe.

Cork-tree bark, from the Quereus Stiber, imported from Laruche and Rabat.

Valonia, from another oak, the Quereus JEgilops, flourishing in the Morea, and the
south of Europe, and Asia. No less than 333,420 cwts. of this substance was imported
in 1849.

Oak-galls, from the Qncrcus infcetoria of India and Turkey.

Terra Japonica, Kutch, and Catechu, extracts from the Acacia Catechu, growing in the
East Indies. These substances contain a very large quantity of tannin.

Sumach, in powder and in leaves, from Sicily and the south of Europe. It is the
product of the Rhus Coriaria.

Besides the above principal sources may be mentioned Kino, the extract of the
Buchanania latifolia, of India; Divi-divi, of the Ccesalpinia coriaria, from South
America ; mimosa bark, and bark of the black wattle tree, Acacia mollisima ; hemlock
barf:, from the fir, Abies Canadensis, of the United States of America ; the bark of several
trees growing in New Zealand ; and the larch bark, Pinus larix, of Scotland.

Opium. This highly important medicinal substance is procured from the Con-
tinent of India, and chiefly from the provinces of Behar, Benares, and other parts of

OPIUM AND THE POPPY-SPIED. 51

the Bengal and Agra Presidencies, in our East Indian possessions, and the Independent
States of Malawa, and others in the south of India. It is the produce of the white
poppy (Papaver somniferuir), almost exclusively, in our Indian territories ; hut in the
Independant States it is also obtained from the dark-red and other varieties of
poppy.

The poppy-seed is sown in the months of October and November, in shallow beds
of about seven feet square, and the plant is thence regularly irrigated throughout the
season. The capsules (ovaries) are ready for bleeding, or patching, as it termed, about
the end of January, when this process commences, and proceeds during the whole of
the month of February. It is effected by making incisions into the poppy-head at about
four o'clock P.M. daily, and allowing the milky juice to exude and thicken by evapora-
tion upon the capsule during the night. The next day it is scraped off, placed in porous
earthen vessels, and allowed to inspissate further. In this crude state, it is carried to
the factory, where the drying process is carried on until the opium has attained a cer-
tain standard of spissitude, when it then retains from 25 to 30 per cent, of water. It
is then made into large round balls, technically termed cakes, each ball being enveloped
in a case composed of the petals of the poppy, cemented together by means of thin crude
opium in lieu of paste. When the balls have become hard they are ready for the
market ; forty of them constitute a chest of opium, and weigh about 160 Ibs. The
produce of one agency, that of Patna, in 1853, was 35,000 chests, or about five and
a-half millions of pounds.

The East Indian Company exercise no control whatever over the growth and pro-
duction of opium in the Independent States, but impose a tax upon it on its exporta-
tion to Bombay. In the territories of the Company, however, the government not only
watches over its production, but are, in fact, the sole growers of the drug. Any indivi-
dual growing opium is bound to deliver it to the government agent at a fixed sum per
pound ; and upon his undertaking to do so, the government makes advances of money
from time to time to enable him to prepare the ground, and to plant, irrigate, and
gather the crop. In this mode a great many thousands of persons become the servants
of the Company, not by compulsion, but from the greater profit attending upon
this, than upon other agricultural produce. The opium thus delivered to the Com-
pany is in a crude state, and still requires much attention before it is fitted for the
market. No fewer than 1,200 persons are engaged in the Company's factory at Patna
alone.

The opium, when packed in chests, is offered to public sale by auction for exporta-
tion, and is purchased by dealers of all nations, but chiefly with a view to the supply
of the Chinese market. The profit made upon this one Indian production is the most
important element in the income of the East Indian Company.

[We are indebted for the above account to Colonel Rowcroft and Dr. James Corbet,
both distinguished officers of the E. I. C. Dr. Corbet for some years held an appoint-
ment at the Patna opium factory, in the province of Bekar].

Sugar. Sugar is not exclusively a vegetable production, since it is found abun-
dantly in honey and in milk, both of which are natural animal products, and in the blood
and excretions in certain instances of disease. It is, however, chiefly obtained from
vegetables, and always so when it is separated from all other substances and made
marketable.

Vegetables yield it largely in their fruits, as those of the grape and apple ; and
many in their sap ; but as an article of commerce it is obtained from three sources :

THE

the wgar-cane (Saccharinum offlcinale), beet-root (Beta vulgaris), and the sugar-maple

(Acer saccharinum],

Beet-root alone can he grown in our climate, hut not as a remunerative crop tor tle

production of sugar. It is, however,

largely cultivated in France, Belgium,

Austria, and Prussia ; since those coun*

tries have no colonies whence they can

derive cane sugar.

The sitgar*maple is also a tree of

somewhat northern latitudes, and one of

great value to the new settler in Canada

and the United States, since it not only

yields the sugar which he so much needs,

and which -in his distant and solitary

habitation he could scarcely otherwise

ohtain, hut is valuable as wood also.

The sugar is readily obtained by boring

holes in the tree, so as to permit the juice

to exude, and then causing evaporation

of the latter by exposure to the air or by

heat.

The quality of sugar derived from

the fruits of plants, and also from the

beet and the sugar-maple, is much infe-
rior in sweetening powers to that ob-
tained from the next source the sugar-
cane.

The sugar-cane is a member of a

family which abounds in sugar, and
grows readily in low alluvial lands of
all southern climes, and especially in

the countries bordering upon, or lying
within, the tropics. Such are the states
bounding the Lower Mississippi, up to
about 33 of N. latitude; the West

Indian Islands; the East Indies; fte **' 96 - THE SUGAR-CAKE (Saccharinum
Mauritius, and parts of China. The cultivation requires a large capital and the
employment of a great number of hands ; so that, with the exception of the Indian
crop, it is the product of slave labour, The plants are set at regular intervals, and
grow luxuriantly with a single stalk and large waving leaves (Fig. 96), to the height
of ten or twelve feet; so that a sugar plantation, with its wellrcultivated .fields, large
red boiling-house, planter's mansion, and village of negro huts, is a picturesque scene.
It is also a busy scene during the period of cultivation, but more particularly at that
of boiling, when the process is not stayed night or day until it is finished. "We have
inspected many, and have been struck with the air of richness and wealth which
usually pervades them,

When the plant is mature it is cut down near to the root, and carried in wagon loads
to the boiling-house, where it is crushed between powerful rollers, impelled by steaia,

THK COLOURING PRINCIPLES OF PLANtS. 53

until the juice has been thoroughly extracted. The juice, mixed with quicklime, in
then transferred to large boilers, where it is evaporated, and afterwards set aside to
crystallize. The larger portion of the sugar is thus separated from the fluids in which
it was secreted; but a considerable quantity remains uncrystallized in the mother-
liquor, and constitutes the molasses so abundantly used in those climates as food, and
for the distillation of rum. The colour of the sugar is more or less brown, and is
purified either in this country or in the country of its production, by filtration
through animal charcoal. Bullock's blood was formerly used for this purpose. The
coloured uncrystallized liquor which then remains is the treacle of commerce.

We may mention that, as a curiosity, some cane sugar was made from sugar-cane
grown in this country, and exhibited at the Great Exhibition of 1851.

Good specimens of giape sugar were forwarded to the Great Exhibition from Tunis
and the Zollverein States. Palm sugars have hitherto been mere curiosities, but they
have been made from the date palm of the Deccan, the Gomutus palm (Arenga sacchari-
fera] of Java, the Nipa palm stem, and the flower of the Bassia latifolia, and might,
doubtles, be procured from all palms yielding refreshing and fermenting juices.

Colouring Principles. The colours presented by plants are exceedingly varied,
and all alike depend upon the presence of colouring principles in the cells of colourless
tissue.

There are eight principal colours recognised in vegetables viz., white, gray, brown,
yellow, green, blue, red, and black; and each of these has many distinct shades.

Of these shades of colour, nine have been associated with white : pure, snow, ivory,
chalk, and milk white ; with silvery, whitish, turning white, and whitened.

A similar number is also attributed to gray, and are designated ash, lead, slate, and
pearl gray ; smoky, hoary, and rather hoary, and mouse-coloured.

Twelve have been computed in connexion with brown ; viz., brown, chestnut, deep
and bright brown, rusty, red, brown, rufous and cinnamon-coloured, with lurid, sooty,
and liver-coloured.

Yellow has twenty shades ; thus, lemon, yellow, golden, pale, leather, waxy, and
Isabella yellow ; sulphur, straw, ocre, orange, apricot and saffron-coloured ; testaceous,
tawny, and livid.

There are seven varieties of green, of the shades of olive, grass, sea, yellowish,
apple, meadow, and leek.

Bed has seventeen shades : carmine, rosy, purple, sanguine, scarlet, eumaba, vermil-
lion, coppery, brick, flame-coloured, &c. ; whilst its compound blue has but seven viz.,
pmssian, blue, indigo, lavender, violet, lilac, and sky blue"; and black has four: pure,
coal, raven, and pitch black.

Thus as many as eighty-six different shades of colour have been determined to
exist in plants; but only two chemical colouring principles have been discovered viz.,
chlorophyl and chromule.

Chlorophyl is so called from its imparting a green colour to plants ; that is, that
kind of green which is universally met with in all plants growing in the light. It is
distributed to the tissues themselves, but more particularly to the surface of the starch
cells, which are abundant in all green plants.

Chromule is the general term for the colouring principle of all other colours,
although they may be so closely approximated that adjoining cells may have totally
different colours.

Dyes. Another highly important series of vegetable secretions are such colouring

54 VEGETABLE DYES.

matters as are capable of being used as dyes of textile fabrics. These are very varied,
and are also chiefly found in southern countries. This series comprehends nearly all
the known dyes, since but few (as the cochineal insect) belong either to the animal or
mineral kingdom. The chief substances are

Indigo, of which no less a quantity than 70,482 cwts. were imported in 1850. It is
the product of the leaves of the Indigofera tinctoria, and I. anil, growing in the low
districts of India and South America. It is a fast dye, if in the process of dyeing it
be first deoxidized, but otherwise it is not permanent. It yields the Indigo colour,
and also a green when mixed with yellow.

Madder is one of the most useful and common dyes, and is derived from the root of
the Rub-la tinctori-i. Its home is Naples, France, and the North of Europe. 2,985 tons
were imported for this purpose in 1850. It forms one of the most permanent dyes, and
constitutes the Turkey red dye, so celebrated for its brilliancy. Garancine is the red
principle of madder, obtained by the action of sulphuric acid. 2,985 tons of this sub-
stance were imported from France in 1850.

Logwood is the wood of the Hcematoxylon campechianwn, found in the Bays of Cam-
peachy, and Honduras, in Central America. Its value is sufficiently great to cause the
right cutting it to be the subject of a treaty between this country and the States in
which it grows. Its colour is red, but black when precipitated with iron, purple with
tin and alum, and brown with copper. 3,500 tons were imported in 1850.

Brazil wood, from the Ccesalpina braziliensis, is one of the largest importations of
dye woods, 3,120 tons were imported in 1850.

Amongst the remaining dyes are alkanet root, from the Anchusa tinctoria, grown in
Asia and the North of Europe ; Nut-galls, an excrescence on an oak, the Quercus infectoria,
in Turkey ; Saffloiver, produced in Southern Asia, Egypt, and the Levant, from the
dried flowers of the Carthamus tinctoria ; Annatto, a South American orange-colouring
matter, from the seed of the Bixa orellana ; Turmeric, from the root of a cucumber, the
Circuma, longa of India ; Peach wood, or Nicaragua wood, of the Ccesalpina, from South
America ; Fustic, the wood of the Rhus cotinus of Cuba ; Camwood, from the Baphil
nitida of Sierra Leone ; Quercitron bark of South America, from another oak, the
Quercus tinctoria ; the alder bark of this country, from the Alnus glutinosa ; Catechu,
an extract of the wood of the Indian Acacia Catechu ; red sanders, from the Pterocarpus
santalinus of India ; the Persian berries, from the Rhamnus infectoria of the Levant ;
and many others of less note.

It is worthy of remark, that the lowly- organised Cryptogamic cellular plants, or
lichens, afford colouring matters in great abundance, under the designations of Orchall
and Cudbear. The following are the chief : Ramdnia furfuracea, from Angola ;
Rncccllafuciformis, from Mauritius, Madagascar, Lima, and Valparaiso ; Roccella tinctoria,
from the Cape de Verd Islands ; Parmelia perlata, from the Canaries ; with the Parmelia
tartarca, Umbilicaria pustulata, and Gyrophora murina, of Sweden.

We have purposely avoided the chemical questions which naturally arise when
considering the interesting and important vegetable products which have been passed
in review ; but we cannot omit to state here, that, although the widely-distributed
substances starch, sugar, and gum are apparently so very diverse in their external
characters and general properties, they have very close chemical relation. Indeed, so
closely are they associated that they are daily and hourly converted in the living
plants, the one into the other, in the order in which we have placed them viz., starch

THE VEGETABLE SECRETION OF SILICA.

sugar, gum. In the early stages of development, the major product is starch; but, as
maturity approaches, this is gradually changed to sugar ; and to gum when the period
of decay ensues, or the starch at once passes into the state of gum. So in the malting
of barley : the object there is to convert the starch into sugar ; but if the process of
germination be carried a little too far, the sugar begins to disappear, and is supplanted
by gum. The prolonged cookery of any farinaceous substance has always this ten-
dency ; so that biscuits not unfrequently contain a portion of gum, difficult of digestion,
with the starch which is capable of ready conversion into the material of the blood.

Silica. The last secretion to which we shall now refer, is one of peculiar interest
vis., silica, or flint. This is a mineral substance ; and, apart from vegetable structures,
is so indestructible that the strongest chemical acid is required for its solution, and yet
it has structures so delicate that a stem of wheat can dissolve it with facility. It is not
pretended that vegetables have the power of producing flint, but only that they are
enabled to dissolve it in their juices, when water and other fluids alone cannot dissolve
it. This power seems to reside at the extremities of the rootlets, for it is impossible
that flint could be taken into their delicate tissues until it has been dissolved. The
sources of silica or flint, are

1. The sand which is so largely met with in almost all kinds of soil, and which has
the further valuable property of permitting the rain to percolate to the roots of the
plant. Its composition, is chiefly that of silica, as may be familiarly inferred from its
essential presence in the manufacture of glass.

2. From the flint nodules which are found in the chalk formations, and which
themselves are the productions of long-buried sponges, mosses, and minute animalcules.

3. From the skeletons of animalcules which
still remain in the soil. These skeletons are com-
posed of flint, as may be proved from their non-
solubility in boiling nitric acid (Fig. 97). So
numerous are they that Richmond, in Virginia,
United States, is built upon a stratum eighteen
feet deep, and upwards of thirty miles in length ; a
stratum representing an innumerable number of
animalcules, when it is borne in mind that each
animalcule is almost too small to be seen by the
naked eye. Similar deposits also exist in the old
world.

These skeletons are also found in other posi-
tions. Thus guano, a substance consisting of the
excrements of birds, contains vast numbers,
chiefly of three genera, Actinocyclus, Gallionella
(Fig. 97), and Coscinodiscus. A powdery sub-
stance is known in Germany as Berg Mehl, or
mountain meal, which is chiefly composed of Fig:. 9 7 - SilHous pkeletons of the Diato-
them. This is the produce of the strata through ^UT^^^^t^S-
which the mountain torrents run, and is brought lodtscus ch/peus, both found in guano.
down by the waters. From its resemblance to
flour, it is used in certain localities as an article of diet.

4. From the remains of plants in the form of manure or otherwise, which contain
silica ; as, for example, the wheat straw.

fr m

THE VEGETABLE SECRETION OF SILICA.

i?. 98. Silicious cuticle from the husk
of the wheat (Triticum), showing cups
for the insertion of hairs, and also
spiral vessels.

The parts of plants in which the silica is chiefly found, are the external layers
of the cuticle, as in the shining straws of our corn fields-, and the canes and
bamboos of hotter climates ; and certain rough straws*, as that of the Equisetum

hyemale, which is so rough as to be used in the
polishing of metals. It is also found in the
interior of the joints of certain bamboos, and
then is termed tabasheer, and from its rarity com-
mands a high price. It is also found in the hard
grains themselves, as- cf wheat and oats, and more
particularly of the rice; from which cause the
Caribs, the Malays, the South Australians, and
other savage nations have their teeth ground down
by the trituration of the uncooked grain.

The layer is exceedingly thin, but yet it is-
one of pure flint, as may be proved by its non-
solubility in boiling nitric acid. It o-verlays the
vegetable tissue, and
assumes its form,
and therefore varies
greatly in appear-
ance, according to the object examined.

In Fig. 98 we have an illustration of its appearance
in the common wheat. From this silex the flinty haira
of the oat arc formed ; and it is well known that animals
living much on oats are liable to intestinal accumu-
lations of these indigestible hairs ; and in a lesser degree
men eating oatmeal are liable to a like inconvenience.
The common meadow grass (Fe-stuca pratensis, Fig.
100), presents a silicious coating of considerable beauty.
The most beautiful examples are the Eqwsetum
ffyemale, the Pharus Cristatus (Fig. 101), the common rice (Oryza sativa), and the
stellate hairs of the Deutzia seabra (Fig. 102).

It must be clearly understood that this substance constitutes no part of vegetable
structure, neither does
it assume any form of
organization, its sole
and most important
duty being to give
strength to the slender
stem, and to protect
the delicate tissues
from atmospheric in-
fluences.

That the quantity
101. Silica in square and star- required to supply the

wants of a field of corn Fip. 102 Sinous cells and stellate
is .cry considerable, %%. ^ k * "' *
may be proved from the following table ; and tbe more

Fig. 100. Cups of Silica on the
chaff or palese of the common
meadow grass (Festucu pra-
ten&is.)

THE ORGANS OF PLANTS. 57

so, when it is remembered that the layer is so thin that it cannot be removed without
detaching also a portion of the vegetable tissue.

Proportion of Silica, or flint, in 1000 parts of the ashes left after burning the following

vegetable substances.

Oat straw . . . . .45-

Barley ...... 38-5

Wheat ...... 287

Indian corn . . . . .27*

Oak leaves . . . . .15'

Ferns ...... 10'4

Pea straw . . . . .10'

Potato tops . . . . 8'

Heath . . . . . 5'S

Beans ...... 2'2

Bean straw . . . . .2*

Cabbage . . . . .2*1

Buckwheat . . . . .1-0

This subject has an important bearing upon the rotation of crops, for it is manifest
that if successive crops of corn, and especially of oats, be obtained from the same land,
there must be an enormous expenditure of this necessary article ; but that a much less
quantity suffices, if potatoes, pease, beans, or cabbage be given as intermediate crops.
So, also, with regard to manures. It is clear that a manure must not only contain the
carbon which forms the straw, and the salts which are always found with it, but there
must be a constant and abundant supply of silica. This is effected by using corn, and
especially oat straw, as manure, and also by the use of guano, which contains a large
per centage of silicious skeletons.

THE ORGANS OP PLANTS.

Having now considered, in such detail as our space has permitted, the various ele-
mentary tissues which have been discovered in vegetables, and the juices and secretions
which they contain, we proceed to describe the parts or organs which are formed by
their combination. Such are the leaves, flowers, and fruit, and the structures which
support them.

The modes in which we might proceed are numerous, and partly arbitrary, varying
with the fancy of each author ; for no one arrangement of the organs of plants is found
in Nature which is acknowledged by all investigators to be more natural than any
other.

The nearest approach to Nature will be found in proceeding either centripetally or
centrifugally : that is, either first to describe the seed, and thence pass to the centre of
the stem, through the fruit, flowers, leaves, and other appendages to the stem : or to
commence at the stem and roots, and then clothe these organs with leaves, flowers, and
fruit, in the order which nature has selected. Of these two we prefer the latter
course, and shall proceed to describe the stem, with its root, and the various organs
supported by them.

THE ORGANS OF PLAOTS.

The Stem. In all flowering plants the stem proceeds from the seed and that part
of it termed the plumule ; whilst, at the same time, the root is developed from another
part of the same seed viz., the radicle. These two newly- formed organs thence assume
diverse directions, the root passing downwards to fix the plant firmly to the earth, and
to abstract nutriment from the ground ; whilst the stem usually emerges from the soil,
and grows in a perpendicular direction, so as to bear the leaves and other organs of
growth and reproduction from the ground, and expose them freely to the action of the
light, air, and moisture. The point in the seed whence the stem and root diverge is
known as the collum or neck (Fig. 100 i), and even in trees which attain to a consider-
able size this line remains more or less distinct.

When the seed has begun to germinate, and the growing points just referred to have
lengthened, the other parts of the seed viz., the cotyledons, or seed-leaves, enlarge, and
take on the function of nutrition by converting the starch contained within them into
sugar. At length, by their elongation, they emerge from the soil, and appear as two
opposite roundish leaves, which are capable of absorbing
oxygen from the air, and fixing carbon within the tissues
which are then in process of formation. At this stage,
then, we find a root, stem, collum, and seed-leaves, all of
which are represented in'Fig. 103.

The current of sap having been set in motion by the
action of the cotyledons, or seed-leaves, the latter disappears,
and the plumule, or young stem, continues to elongate
rapidly, and until it arrives at the point whence its first
leaf is to issue, is technically termed a node. At this point
the stem swells, and the structures of which it is composed
are bent out of their former direction, and, in part, enter
within the structure of the newly-developed leaf. The
stem may now fairly take on the term of ascending axis,
which is usually given to it, since it has begun to develop
the organs which are subsequently to be arranged around
it as their centre. It has also received a variety of other
names, which it may be useful to mention viz., the cau-
dex intermedius and ascendens, truncus or truncus as-
cendens, with culmus and stipes. All these have a similar
signification.

The growth is not arrested by the development of a
node and leaf, but proceeds for a certain period, until ano-
leaves7wh7clTave' appeared ther leaf and node are formed ; and so on progressively

point of the stem, elongated then a scries of nodes and spaces between them, which
Det ^thVcollumf s e e ( p a 1 I : ating (or s P aces are termed internodes. A stem may thus be said to
rather connecting-) the part of consist of a number of nodes, with their internodes.
KS^^^rtbTm Nodes.-These are well seen, in all grasses, as the
it, the descending axis. ordinary grass of this country; with wheat, oats, and other

grasses ; and more particularly in the bamboos and canes
of southern climes. It is there found as a distinct bulging
around the stem, of a hard and rounded character, and oftentimes bending the stem
from the perpendicular direction. Ifi wooded plants, or trees, in general, it is less per-

Fig. 103. Exhibiting the parts
of a plant soon after the com-
mencement of germination.
c, the cotyledons, or geed-

d, the radicle, with the root-
lets proceeding from it.

VEGETABLE

ceptible, since the small swelling at tlie base of the single leaf which is there developed,
bears but little proportion to the size of the trunk of the
tree.

The essential difference in structure between a node
and an internode is, that the bundles of wood are com-
pressed and turned aside in the former, so as to enter the
leaf, and thus a slight interruption to the course of the
general circulation ensues ; whilst, in the internode, the
bundles of woody fibre pass perpendicularly, and lie parallel
to each other. In some instances, as in the grasses with
hollow stems above mentioned, this compression or con-
traction of parts is so great, that a septum is formed across
the stem, dividing it into
two or more cavities. This
may readily be seen on
malting a perpendicular sec-
tion of a stalk of wheat, or
of the bamboo, and with the
septum of the latter may
sometimes be found the
flinty deposit before men-
tioned, under the term of
tabasshcer. They are then
said to be closed, in opposi-
tion to the pervious or open
condition, found when the
pith passes through it.
When the node surrounds
the stem, as in the grasses
and the hemlock, it is desig-
nated as entire; and when otherwise, as in trees, it 18
termed divided.

As the essential element of a node is a new disposition
of the woody and other tissues, to meet the require-
ments of a leaf, it is manifest that wherever a node
exists there must be, or have been, a leaf, perfectly
or incompletely developed. In many instances the grow-
ing process ends after the formation of a node and before
the entire development of a leaf; and then will be formed
a leaf-bud, immediately above the base of a leaf. "When
such leaf-bud is evident, the node is termed compound ;
and when otherwise it is called simple.

So far this account may suffice for both herbaceous and woody stems, but it is need-
ful here to interrupt our description, and consider herbaceous and woody stems sepa-
rately. This results from the great difference which is observed in the structure, as
well as in the degree of delicacy of organization of the two kinds of stems.

Steins of Herbaceous Plants. Herbaceous plants are, for the most part,
annuals that is, such as are produced and die in the same season. It is, therefore, not

a a the nodes, will
woody fibre passm;. 1 : from their
parallel course in the stem to
enter the leaf bud or the foot
stalk of a leaf.

Figr. 104. A stem of the family
of grasses, showing at o
theenlargeme ts indicating
the existence of nodes.
The interval between the
two nodes is termed an inter-
node.

60 THE CUTICLE OF HERBS.

necessary that they should possess the rudeness and strength of texture which appro-
priately belong to plants that have to combat the power of the elements through a
long series of years.

The stem, for the most part, is small, seldom attaining to a greater diameter than
one and a-half inch ; and, with the exception of twining plants, and such grasses as
the bamboo, do not exceed six feet in height.- The structure is delicate, being composed
of cellular tissue of a somewhat loose kind, with bundles of woody fibre running at
intervals from the root upwards. They are thus but ill-fitted to resist the influence of
strong winds, or the destructive propensities of animals. There are, however, some
circumstances which tend to increase their strength. Such are firsty the cylindrical
form of the stem ; secondly, the hollowness of the stem ; and, thirdly, the inclosure of the
stem by a tough cuticle or bark, and, in sqrne instances, a further layer of silica or flint.
That the cylindrical form is stronger than any other is well known ; but it may not be
so commonly understood that a hollow cylinder, with moderately thick walls, is
stronger than a solid rod of the same material. Thus that vacuity, which at first sight
is indicative of weakness, is really fitted to impart increased strength. The cause of
the hollowness is the more rapid development of the perpendicular than the horizontal
layers of the stein.

The stem of an herbaceous plant thus consists of three parts : a central pith, which
is frequently wanting ; an external envelope or skin ; and an internal mass of cellular
tissue and woody fibre. The pith is composed of cellular tissue, of the hexagonal or
octagonal form. The woody fibre of the stem is not found in even layers, but in bun-
dles lying detached from each other, as may be readily seen by tearing a stem across,
when the bundles of tough fibres will be stretched, and project somewhat from the
broken surface. It may also be seen through the cuticle of the common parsley, in
ribs passing in parallel lines from the root upwards into the leaves. Each bundle is
usually inclosed in a mass of cellular tissue, to which it gives firmness.

Cuticle. The cuticle of herbs is an interesting structure, and the seat of a large
part of the respiration and digestion which proceeds in those plants. It consists of two
layers an epidermis or scarf-skin, and a true skin, with certain appendages viz.,
stomata, hairs, prickles, warts, and reservoirs of secretions.

The Epidermis is a layer of inspissated organic mucus, which sometimes may be
readily detached from the cuticle,
as in the common box-leaf, but
at others requires maceration in
water for some time before its exist-
ence can be demonstrated. It
covers all the external surface of
the plant, except the stomata and
the free end of the stigma, and it
even forms a covering for the hairs.
Mohl considers it to be a secretion
poured out from the external sur- , 6> outer layer of the cuticle, composed of compressed cells,
face of the cells, the walls of the d > a subjacent layer of larger cells, with vacuities, or pareii-
cells themselves being at the same c , S?S5&g%^S& the cutide to the air
time thickened by internal depo- cavities above.

Bits. It is not a cellular structure, although, when removed from the surface of the
cuticle, it has a cellular outline ; but is a simple layer, with markings corresponding to

THE STOMATA OF PLANTS.

Pig. 107. Exhibiting a front
vie\v of four stomata at , im-
bedded in hexagonal cellular
tissue.

the cell-walls over which it is placed, Hartig has divided it into three layers an
internal, an external, and an intermediate layer ; but such is not the experience of
other observers. Its use is to protect the delicate structures lying beneath it, and is
analogous to the scarf-skin which protects the skin of man.

The True Cuticle is composed of one or more layers of cells, the outer one being
much flattened (Fig, 106 a). The cells are mostly of hexagonal figure and wavy out-
line. Some anatomists have denied the cellular nature of this structure, on the grounds
that the cells are not demonstrable, and that the skin may readily be peeled from the
subjacent tissue ; but this theory is not usually admitted.
Moreover, in the cactuses and orchids, and also in the Ne-
rium Oleander, there are several layers of cuticular cells, the
whole of which may be demonstrated (Figs. 106 d, and 1 10).
Whenever any shred of cutis is removed from the stem
of a herb, some portions of woody fibre are removed with
it, so that it may be questioned if woody tissue is not a
.component of the skin ; but it is perhaps more correct to
associate the wood with the structures immediately be-
neath the skin rather than with the cellular skin itself.

Stomata (Fig. 107) are mouths by which respiration
and exhalation are carried on in vegetables. They con-
stitute openings into and channels through the epidermis,
and lead into cavities beneath (Fig, 108, A). Their
structure is somewhat complicated, since, for the most

part, there are a series of rounded cells bounding the opening, with two larger kidney-

sb.aped cells in the centre, pressing

A < closely against each other when the

a stomate is closed, and cemented to the
surrounding cells by something in the
nature of a hinge, which permits
toem to rise and fall with consider-
able force (Fig. 108, C a). In the
centre of the stomate there is a raised
line when it is closed, and a slit when
it is open (Fig. 108, C c) ; and through
this opening an entrance is effected to
the cavity beneath (Fig. 108, A c).
This cavity varies in figure and form ;
but it is always surrounded by cells,
which communicate freely with other cells of the epidermis (Fig. 108, A). It is thus
that air and moisture, having entered by the stomata, act not only in the cavity beneath
that organ, but in the surrounding open cellular net- work of the leaves or cuticle.

Such is a general description of the stomata; and before entering further into
detail we will request our readers to verify the above account by an examination of
these structures. Take a very thin slice from the under surface of a leaf or flower of any
plant, as of the lily (Fig. 109, A), the Zea Mays (Fig. 109, B), or the common geranium ;
or strip a thin piece of the cuticle of a herb, as of the parsley, and place it in water
between two pieces of glass, and examine it with the microscope. First examine tho
outer surface, on which may be seen the cells and slit referred to, and then turn over

Fig. 108.

A, stomata of the IRIS, a a, green cells bounding: the
orifice, b b, cells of the parenchyma, c, air chamber.

B, the same as seen from above, a a, cells of the stoma.
c, opening between them.

C, stoma of the apple leaf, a, cells of the stomate. bb,
cells of the cuticle, c, opening of the stoma.

THE STOMATA OF PLANTS.

the object, and carefully notice the cavity into which the slit is directed. The minute
and regular arrangement of the various parts of each stomate, and of all the stomata on

Fig. 109. View of ordinary stomata, as seen between the veins of the leaf of the LILY, A, or, ZEA
MAYS, B, both endogenous plants, and of an exogenous plant at C.

Their regularity in figure and position, and the uniformly oval outline, will be observed.

the cuticle, will excite admiration ; and the more so when, on examining a variety of
plants, the little organ is found very variously figured.

The general outline of the stomate is commonly circular or oval ; hut in the flax
plant, the Agave Americana (Fig. 61), and a somewhat similar one, the Yucca gloriosa,
it is quadrangular. In Marchantia they resemhle funnels, and are composed of several
cells arranged in tiers, and forming tubes, which perforate the epidermis, and terminate
in the cavity beneath. In the oleander (Nerium Oleander] the cells have disappeared,
and the cavity is simply protected by hairs. This may readily be seen, if a portion
of the leaf be placed under the microscope, as above directed. The Myrodendron,
punctulatum, growing on trees in the antarctic regions, has a remarkable modification
of the stomata. Dr. Hooker states that the stomate expands on both sides into a kind
of cup a condition which results from the hour-glass construction which is met with at
the aperture.

But whatever may be the figure of the organ it is so uniform in the same species
that certain botanists, as Brown, are of opinion that they might be made a basis of clas-
sification. This, however, would be very difficult, on account cf their minute size
and the necessity for the constant use of the microscope ; and further, from the fact
that a few plants present more than one form of stomate. Thus, in the Nepenthes
or pitcher plant, there are two forms of stomata, one being semi-transparent and
nearly colourless, of an oblong figure, and with pellucid globules within the cells
whilst the other is roundish, red, and more opaque, and rests not over a cavity, but
upon a gland.

It is proper to state that certain observers of eminence have denied the accuracy of
the above statement, as to the construction of stomata, and have affirmed that they do
not lead into a subjacent cavity, and consequently have no opening at the slit. Some
German anatomists have affirmed that the supposed opening is simply a thinner
translucent portion of the membrane, and that the slit is the thickened border of this
space. Brown believed them to be usually imperforate, and to be formed by an opaque
and sometimes coloured membrane. Such, however, is not the opinion commonly
entertained ; and we may confidently appeal to the investigations of our readers to
refute it.

Stomata are not found upon all plants, the exceptions being such as are submersed

THE STOMATA OF PLANTS.

in water, or grow in darkness, and also the lowest classes of plants, as mushrooms, sea-
weeds, and lichens, except mosses. Neither are they found upon all parts of any plant,
but are absent from the roots and ribs of leaves. They are most abundantly found on

Fit,'. 110. Fig. ill.

Fig. 110. A side view of the modified stomata of the NKRIUM OI.TSANDER, and of a BANKSIA, in
which they are seen clustered together at the bottom of a pit, a, the entrance of which is defended
by hairs, b.

Fig. 111. A front view of the same organ.

the under surface of such leaves as present one surface to the soil (Fig. 106), hut on both
surfaces equally, if the edges only be directed vertically. They are also met with on
the cuticle of stems, on flowers, and even on the seeds of a few plants, and on their
cotyledons.

The number of stomata found upon a moderate-sized leaf is sometimes prodigious,
amounting in some instances to 160,000 on each square inch of surface. Thomson
gives the following enumeration, which shows not only the total number but the
relative quantity on the two surfaces of the leaf:

On each square inch
of upper side, and of under sicJe.

12,000

none.

38,500

Alisma Plantago (Water plantain) .....

Coboea scandens

Dianthus Caryophyllus (Pink)

Daphne Mezcreum (Mezercum) none.

Jlypericum Grandiflorum (St. John's Wort) . . . none.

Ilex (Holly) none.

Iris Germaniea (Iris) 11,572

Olea Europoea (Olive) none.

Pseonia (Pseony) none.

Pvrus (Pear) none.

"Rurnex Acetosa (common Sorrel) 11,088

Tussilago Farfara (Coltsfoot) 1,200

Vitis vinifera (Vine) none.

Viscum album (Mistletoe) 200

Syringa vulgaris none.

6,000
20,000
38,500
4,000
47,800
63,600
11,572
57,600
13,790
24,000
2*0,000
12,500
13,600
200
160,000

Of 28 plants in this table which had been examined, 15, or more than- half, had no

64 THE STOMATA OF PLANTS.

stomata on the upper surface ; 6 had fewer stomata on the upper than en the under
surface ; and 5 had an equal number on both surfaces, leaving only two instances in
which the number was greater on the upper than on the under surface of the leaf.

The number and position of the stomata must have an immediate reference to their
function. It is commonly understood, as has already been intimated, that the function
is that of admitting air and moisture to promote the digestion of the crude sap
which had been brought to the leaves, and that for this purpose they are endowed with
the faculty of opening and closing according to the momentary requirements of the
plant. This will explain the necessity for their conformation. As to their position,
that seems to be due to several causes. First, that by being placed on the under surface
they are shaded from the direct action of the sun's rays, and are thus permitted to
carry on their functions without being impeded by too great a degree of evaporation.
Secondly, they are also more sheltered from the injurious deposition of dust. Thirdly, the
exhalation of moisture from the ground is in the form of vapour, which, from its specific
gravity, rises, and thus reaches and enters the under surface more certainly than the
upper surface. It is not presunied that in any case water enters the stomates as such,
but only in the state of vapour ; for although plants are refreshed after a shower, it does
not follow that the rain was bodily introduced within them ; and it seems inconceivable
that bodies of so minute a size should at the same time be fitted for the admission of
gases, and of fluids of such density as water.

There are those, however, who maintain that such is not the function of the
stomata, but that they arc in the nature of glands. Link says that he cannot 2nd a
distinct connexion between the stomata and the subjacent cavities in the cellular
tissue of the leaves. Moreover, he cannot understand how organs of so distinct a
structure should only lead to mere cavities in the cellular structure; and the obstructing
and covering matters which they produce have always led him to consider them as
organs of secretion. Brown also affirms that they are rather of the nature of glands ;
but there cannot be a doubt that in the vast majority of instances this view is incorrccv,.
It is true that in a few instances the stomata are modified both in figure and in function
to perform the office of glands. Such is the case in the Dionsea Muscipula, or Venus'
fly-trap (Fig. 1), in which the stomata are reduced each to a pair of parallel green
cells, which are placed upon the surface of the leaf, and secrete a tenacious mucus ; but
such are exceptional cases.

It would be interesting if we could determine with certainty the precise mode in
which these beautiful organs are formed; but such seems hitherto to have been a hopeless
task. Mohl sought to determine it by examining the different parts of a growing
hyacinth, in the expectation that the parts of the leaf, which are successively developed
from above downwards, would have stomata of various degrees of perfection. He
noticed that in the lower part of the leaves, or that most recently developed, small
quadrangular cells, with a slit of about equal diameter either way, were placed between
the layers of the epidermis. These sometimes contained a granular substance, which,
higher up in the leaf, became a compact mass. At the same period a partition waa
formed in the middle of the cell, at first slightly, but subsequently more strongly
marked, and at length unfolded, so that the simple cell became divided, and a stomate was
formed. After this the surrounding cells enlarged, and the central slit increased at a still
greater rate. All this and the subsequent completion of the stomate may be observed by
any of our readers who may have a tolerable microscope, and will obtain, by practice
a certain delicacy in cutting minute structures.

THE HAIRS OF PLANTS.

Hairs are minute, semi-transparent, transparent, or opaque thread-like processes,
attached to the cuticle by one
extremity, and remaining free
at the other (Fig. 112). They
are always of a cellular charac-
ter, the cells, if more than one,
being larger and more numer-
ous at the bottom, and then
piled one upon the other, and
laid in one or more rows, until
the apex is attained, with its
single elongated, rounded, or
pointed cell. The figure and
minute anatomical characters
vary considerably, so that the
above general description may
require modification when ap-

a hair.

mity.

hair.

a, a gland, surmounted by
b, a hair with an enlarged and secreting free extre-
>, e, simple hairs with pointed extremities, d, branched

plied to individual instances.

Thus the hairs of certain plants

are attached by their middle,

and have both ends free. Such

are those of Indigofera, Cap-

sella, and Astragalus asper ; but

in order to bring these within the definition above-mentioned, it is customary to assert

that it is not one single hair attached by its middle, but two hairs springing from the

opposite sides of an elevated cell. Such, doubtless, is the correct

explanation of hairs which assume a stellate or star-like form, and

which are really clusters of hairs attached each by one extremity.

This variety is met with readily on the leaves of the MaUows, in

which, with the assistance of a small hand magnifier, the stars may

be perceived. The most beautiful illustration, however, is that of

the hairs of the Deutzia scabra and corymbosa (Fig. 102), and the

Elceagnus, which, as has already been demonstrated, are coated with

a layer of silica or flint. They are very resplendent when viewed

with the light thrown upon, and not through them that is, as

opaque objects, and may aptly be compared to the jewelled star of

the Most Noble Order of the Garter.

Certain hairs are bent at the points of articulation of the cells,
whilst others have their points only thus distorted. This latter
variety is seen familiarly in the common teasel (Dipsacus), and has
been used with much sagacity by cloth-workers, for the purpose of Fig. 113.-A prickle
raising the nap of the cloth. The extremity is hooked, and by that f^/ Sd^S"
means adheres to an object with great pertinacity, as any one may * fuUomtm)',
prove by placing the fruit of the teasel in his hair (Fig. 113). f sistin s ? m eih a a t

Another and very interesting modification is that in which the bent

hair consists of a single ceU, but having an elastic spiral fibre coiled

up within it

cell, thick-
by layers,
embraced at

Such hairs are almost imperceptible, so long as they the base by amass
sometimea with a crackling

THE HAIKS OF PLANTS.

Bound, on their immersion in -water. They are found in the common mustard (Sinapis],
which any one may examine after immersion for three hours, and hare the form of an
elongated cell, terminated by a bell-shaped expansion. In the seed-covering of the
Collomia grandiflora and common sage (Salvid), each hair is simply an elongated cell of
even diameter, terminated by a rounded obtuse end, and with a single coiled elastic
fibre proceeding from the base to the apex. This is an interesting object, but requires
considerable dexterity and quickness to see it with advantage. Slice the smallest portion
of the outside of the common sage, and place it dry between two glasses tinder the micro-
scope. No hairs will then be perceived ; but if, whilst it is so placed, and the eye is upon
it, a drop of water be insinuated between the glasses, until it touch the seed, there will
instantly start out scores of long fibro-cellular hairs ; and as the complete development
occupies a perceptible interval of time, the eye may readily trace the process of elonga-
tion. "When the change has been entirely effected, the object has no longer a defined
smooth border, but is bounded all round by thread-like projecting points. A similar
structure has been discovered in the hairs of the seed of Acanthodium, but with this
difference, that two or three spiral fibres have been traced in one cell ; and in some
instances the fibres are broken up into numerous rings. This is doubtless a beautiful
object.

All the foregoing varieties of hairs may be termsd single, but there are others which
may fitly be designated as compound. Such are toothed hairs, in which there are short
cellular projections on both sides of the hair ; and branched hairs when the teeth are
greatly elongated (Fig. 112 rf). In a few instances this development is carried yet fur-
ther, and the branches themselves are
toothed, and the hair is said to be plumose.
In others, the branches are restricted to
one side of the hair, when the latter is
termed one-sided.

But perhaps the most interesting cir-
cumstance in connexion with the anatomy
of hairs, is, that in some plants, as the
Sago-palm (Cycas revolutaFig. 114), the
cuticle of the hair can be unrolled spirally.
Professor Quekett has described this upon
the fruit of that plant, and has delineated Fig> nJf^tions of hair from the fruit of the
t in Fig. 114. Sago-palm (Cycas revoluta), exhibiting a spiral

The foregoing remarks have exclusive dis P sition of the membrane,
reference to one great division of hairs r/z., the Lymphatic, or such as bear innocuous
fluids ; but there is another large division which have a different conformation, and
contain juices of highly acrid and poisonous properties. The sting of the nettle (Urtica)
is a familiar and painful illustration, but the hairs of the leaves of certain tropical
plants are yet better examples. These contain juices so poisonous, that if the hand
grasp a leaf, it speedily inflames and swells, and so disturbs the whole system, that life
is endangered. Such is the Jatropha when growing in our hot-houses even, and is
handled only with the protection of a pair of thick leathern gloves. Moreover, if any
part of the body be placed under this tree during a shower of rain, the poison which
is washed from the- plant by the water would, in like manner, cause very serious
ease.

The anatomical difference between the lymphatic and secretive variety of hairs is, that

THE HAIKS OF PLANTS.

in the latter there is a bulging at the free end (Fig. 112,3), or immediately beloir

the hard sharp-pointed apex (Fig. 112, e), which co mmuni<;ates with ^

the other cells of the hair, or at the base of the hair, and contains a

poisonous juice. "Whenever such a hair is seized the sharp point

enters the skin, and the end breaks off immediately below the point,

and the contained fluid is emitted with a great impetus into the

wound produced by the puncture. The juice in the perfect hair is

maintained at a high state of tension, so that it may be emitted with

violence, after the fashion of the poison in the poison-fangs of the

serpent.

It will be inferred, from these remarks, that there must be a circu-
lation of the sap in all kinds of hairs. Such is the case ; and the
circulation proceeds in currents from the base to the apex of the leaf
and back again (Fig. 115, B). It may be seen proceeding under the
microscope in the Tradescantia virginica, and appears to proceed
between an internal and an external wall of tissue. At a certain
period, a cytoblast (page 9) may be detected, and then the current
appears to proceed from and return to it.
"When the hair has emitted its contents it
shrivels, and in some instances (Fig. 116)
retracts like the parts of a pocket-telescope.
Hairs are not found upon roots, nor upon
any part of the plant which is buried in the
ground or covered by water ; and whenever
they appear on one side of a leaf only, it is, with
few exceptions, on the under side. When a
portion only of any surface is covered by
them, it is uniformly the ribs or veins. They
are sometimes found within the cells of water
plants, as of the white and yellow water-lilies,
Nymphcea alba and Nuphar luteum. Their
functions appear to be that of promoting
perspiration and of absorbing moisture, inde-
pendently of that of secreting fluids.

Hairy surfaces have received various

names, according to the nature of the hairs which cover them, as rough, silky, arachnoid
(resembing a cobweb), stellate, bearded. The hairs themselves are also variously desig-
nated ; thus, stings when they emit an acrid juice, and glandular hairs when the end is
tipped with a fluid exudation (Fig. 112 b}. Hooks, barbs, bristles, and velvet are terms
which explain themselves. Cilia are long and sparse hairs, arranged in a row on the
margin, as in the horse-leek, Sempervivum tectorum. Hairiness expresses a form of hair
f a rather long and soft character, as seen in the common hemp nettle (Galeojpsit
tetrahii) ; pilosity, when the hairs are longer and more erect, as in the carrot (Daucus
carffta) ; and villous, when very long, straight, erect, and soft, as in the JSpilobium.
The term tomentum expresses a mass of hairs entangled and closely pressed to
the skin, as in the Geranium rotundifol'ium. The longest hairs are probably
those which envelop the cotton seed (Gossypium, Fig. 62, B), and constitute
the cotton of commerce. They are also very long on seeds of the ccitton tree^,

Fig. 115. Stinging Hairs.

A, 1, club-shaped hair, filled with the poison-
ous .secretions of the Stinking Hellebore
(Helleborus fastidus). 2, a pimilar
hair, which has discharged its contents,
ai'd then collapsed.

B, pointed one-celled hair of the WIOANDIA
URKNS, filled with poison. The dotted
lines show the current of the circulation,
and the arrows its direction.

THE PRICKLES OF PLANTS.

and in the willows of our own country. On ferns they are scattered, long, brown,
and entangled.

Fig. 116.

Fig. 117.

Fig. 116. Two hairs from the style of a CAMPANULA, showing in a the circulation proceeding, and
in b emptied of its contents. The latter is not only collapsed, but retracted within itself.

Fi?. 117. Representing the mode of growth of hairs from a single epidermal cell ; a, club-shaped;
6, pointed. Both from the Evening Primrose (^NOTHERA).

The development of hairs appears to be usually a very simple process, being none
other than the inordinate growth of a cell of the cuticle on its free surface. Such is
figured by Schleiden (Fig. 11 7).

Prickles are hard unyielding processes, with an acute and usually slightly curved
extremity, well fitted to hold and tear any object which may be carried against them.
They are very common in the rose (Rosa), and bramble (Rubus), in which plants they
are the growth of a single year. In other plants, as the Xanthoxylum juglandifolium,
they are the result of two or three years' growth. They are essentially allied to hairs,
since they are cellular prolongations of the cuticle, but differ greatly from them in
their far greater development, the rudeness of their texture, and the functions which
they perform. They have also a less real but a greater apparent resemblance to spines,
as of the sloe tree (Prunus spinosa), inasmuch as both are large and rude, and sharply
pointed ; but there is this essential dissimilarity viz., that the spine is a prolongation
of the wood of the tree (in other words, an abortive branch), whilst the latter is simply
connected with the cuticle or the epiphloeum of the bark of herbaceous shrubs. Their
use is not well known ; but they are not depositories or secretions, neither have they
any independent circulation. They are well adapted to enable the long and slender
branch to support itself by attachment to stronger plants, and also (if we may apply
such an expression to a mere vegetable), to enable it to defend itself from the attacks of
animals. They may be detached from the cutis by the force of the thumb and finger.

Scurf has been regarded as a production analogous to hairs, inasmuch as it is a
cellular structure and is a process from the cutis There, however, the analogy ends,
and it fails in the most essential point viz., a similarity in function. It consists of
scales of various forms and sizes, adhering to the cutis by the whole or only a part of

THE RAMENTA AND GLANDS OF PLANTS. 69

the surface ; and when hy a part only, it is the central portion ; and the edges become
irregular in outline and crenate. This latter peculiarity has induced a belief in the
mind of an acute observer, Dr. "VYillshire, that the crenate scale in the Adelia and the
Eleceagnus marks a transition from the simple scale to* the beautiful stellate hairs of
which we have just spoken, p. 65. Scurf is commonly met with in plants, and gives
a spotted or leprous appearance to the cutis, as may be seen in the pine apple.

H amenta are thin, scales abundantly found on the backs of the leaves of ferns
(Alices), and on the young shoots of many plants. They are slightly foliaceous in
their appearance, and not unlike the leaves of some mosses ; but they want the structure,
the position, and the leaf-buds of true leaves. Their function, as well as that of scurf,
is unknown.

Glands. We have now to consider a series of organs about which there has been
much controversy one party regarding them as reservoirs of secretions and true secreting
organs ; and another (represented by M. Schleiden), doubting if such organs can be
found in vegetables. M. Schleiden writes : " I have already remarked that I can
connect no precise and definite idea with the term gland, as referred to a plant. No
attentive observer can avoid seeing how different is life in different cells, whether they
are found in different plants or in the same plant, or near each other. It appears to
me quite foolish to denominate that cell or that group of cells which contains different
matter from its neighbours a gland or organ for secretions; for there are many plants
and parts of plants which would then consist only of glands. It is ridiculous to call a
cell containing volatile oil a gland, and to refuse the name to one that contains red or
yellow colouring matter ; and should we call the last glands, then almost all petals
would consist only of glands. The epidermis would be sometimes an epidermis, but
sometimes a glandular surface, and with many single cells we should have to admit
they are partially glands and partially not so."

The force of this reasoning will be perceived when we remember that all cells have
contents, and that these contents have been secreted or produced within the same cell.
Each cell is therefore both a secreting and a containing organ. Again, there is no
anatomical structure in vegetables which is peculiar to these organs called glands, as
distinct from mere ordinary cells of cellular tissue. In animals, on the contrary, there
is in most instances a special glandular structure, and beyond this there is a series of
cells called epithelium, to which is confided the duty of producing the larger part of
the secretions of the body. These latter offer the nearest points of analogy to the
glandular structures of vegetables,

But whilst admitting that there is a difficulty in defining a gland, there cannot be a
doubt as to the existence of certain small hardened masses of cells, which perform the
office of glands. Thus the nectarium, on the claw of the petal of the common Ranunculus,
secretes a sweet honey-like substance, and is a true gland. So, also, with the glands situate
beneath the cuticle, also the base of the pitchers of the Nepenthes and other pitcher
plants. These pitchers contain a considerable quantity of water, not from having col-
lected it from the air, but from the action of the glands referred to. In the latter
instance there is a broad line of distinction between such bodies or glands and that of
an ordinary secreting cell ; for whilst in the latter case the secreted matter is retained
within the cell, and the quantity corresponds with the size of the cell, in the former
the secretion is altogether emitted from the gland, and its quantity is infinitely greater
than the size of the organ which produced it. The subject is, however, involved in
great obscurity, and it is probable that ere long it will be necessary to exclude such

70 THE STEMS OF PLANTS.

cellular organs as the lenticular glands of the willow, and to include such reservoirs aa
the vittse or receptacles of the volatile oils of plants.

Glands are sessile or sitting when resting immediately upon the cutis, aa may be
teen near the base of the ovary or seed-vessel of such pod-bearing plants as the Cruci-
ferae. They are also found upon the calyx of some campanulas, and upon the petiole
or foot-stalk of the leaves of the peach, the cassias, and the passion flower. Their
forms, colour, and appearance are very various, and of many it may be doubted if they
are true glands.

Stalked glands (Fig. 118), are such as are elevated from the cuticle by something
in the nature of a hair, and are simple if they consist of one or perhaps more cells and
have a stalk of but one conduit, and compound where there are several cells and several
conduits. This division of glands has been termed indifferently stalked glands or
glandular hairs. They are common in the rose and brambles, the Hypericums, the Rue,
the Tatropha, the Snapdragon (Antirrhinum!) , the Lysimachis, the Drosera or sun-dew,
and many other plants. In the sun-dew the hair of the leaf has an internal fibre, and is
therefore a fibre cell ; and the gland head consists of several layers of cells, the outer
ones being small and cuticular, whilst the inner ones are long and columnar, and some-
times contain a spinal fibre.

Before proceeding to a consideration of the stems of wooded plants we will direct
attention to two modifications which are met with, not exclusively, but chiefly, in
herbaceous plants viz., first an enlargement of that part which is under ground, and
which lies between the roots or rootlets below, and the true stem above ; and secondly,
such stems as take a horizontal rather than a perpendicular course above ground. These
are termed respectively subterranean and aerial stems.

Subterranean stems, as the potato, onion, and turnip, include almost all the recep-
tacles of starch, except seeds, provided for the use of man. There can be no doubt as
to their analogies, seeing that they do not possess the anatomical and physio-
logical properties of roots, and do, notwithstanding their deformity, resemble stems.
They are commonly arranged under four heads the bulb, conn, tuber, and creeping
fltem.

The creeping stem (soboles), unlike the others is unimportant as an article of food, but

yet is of great value from the property which
it has of insinuating itself rapidly amongst
the sandy particles of loose soils, and binding
them together. It may thus lay the foundation
of hills of sand which shall suffice to resist the
encroachments of the sea. It is represented by
the couch grass (Triticum repcns), the bane of
farmers, not only from the property above
mentioned, but from the rapidity with which it
multiplies itself whenever the stem is broken

Fi*. 118.-The underground stem of the ^ the farmers> efforts to clear the land '
potato (Solanum tuberosum), -with its The tuber or potato is an irregularly ovoid

S b o^ pS Sct^to^the? enlargement of the stem, having upon its surface
by small bundles of fibre, 6. a number of growing points, familiarly termed

eyes. The tubers of the same plant are all con-
nected together and to the parent stem by
single bands of small diameter, consisting chiefly of woody fibre for the purposes of the

THE CORM AND THE BULB OF PLANTS.

circulation of the plant. The precise mode in which the tuber enlarges is unknown
but it is quite clear that it must be freely supplied with circulating juices from the
stem. This is effected by the woody fibre, and bundles of it ramify within, the tuber,
and pass to each growing point.

The structure of the tuber is very simple, being only a large mass of cells containing
starch, inclosed in a layer of condensed cells or cuticle. The woody fibre and other
structures bear no proportion whatever to the cellular tissue, and are not readily de-
tached. The cellular character is at once evident by placing a very thin slice of it under
the microscope, when a number of straight lines will be observed forming cells of much
regularity, and inclosing a large number of starch cells (Fig. 83). The starch may be
demonstrated by the addition of a watery solution of iodine whilst the section is uader
examination, when a beautiful violet colour will be instantly produced.

This form of stem is also found in arrow-root, and has a more regular figure in the
asparagus potato.

The Corm, as in the crocus, colchicum,

and arum (Fig. 119), is a rounded, flattened,

solid organ, bearing a bud upon its point or

at its side, and leaves from its upper part.

It is a compressed stem, and is restricted to

monocotyledonous plants, and intervenes

between the true roots and the reproductive

buds. It usually contains much starch,

accompanied by an acrid poisonous secretion,

which militates against its employment as

an article of food.

The bulb, as of the onion and lily, is also

an underground stem, or a stem in the rudimentary state of a

leaf-bud. It is a fleshy, conical body, with scales surrounding

Fifr. 119. The Cor-
mus of the ARUM
MACCLA.TUM, con-
taining starch.

Fi. 120. A tuni-
cated bulb. with,
tern and roots.

Fig. 121.

A, naked bulb of LILY, showing its lateral stem and foliaceous covering.

B, section of a bulb, showing its growing point at a.

AERIAL STEMS.

a growing point, and emitting roots from its base, and thus theoretically resembles the
leaf-bud of an aerial stem. It reproduces itself by developing buds, or cloves, at the

base of its leaves or scales,
which buds grow at the ex-
pense of the parent plant, and
at length destroy it. There are
two kinds, according to the
arrangement of the leave?
First, the tunicated (Fig. 120),
when they more or less sur-
round the whole organ, and
cohere in a membranous sheet
of tissue. Such is the case
in the onion (alliutri). Secondly,
the naked, when the scales are
Fig. 122. The RUNNER, emitting roots and leaves at intervals, smaller and more fleshy, and

are imbricated in rows one

above another, as in the tulip. Both of these forms contain much starch (Fig. 121)

and also many raphides (Fig. 87).

They are not so exclusively com-
posed of cellular tissue as was

noticed in the structure of the

tuber ; but also contain vascular

and woody structures.

Aerial Stems are of five kinds,

the Sucker, the Vine, the Eoot-

stock, the Runner, the Offset, and

the Pseudo-bulbs of orchidaceous

plants.

The Sucker is common in mo-

nocotyledonous plants, as the

pine-apple, and consists of a

branch proceeding from the col-

lum of a plant underground,

which becomes erect and bears

leaves, and subsequently emits

roots from its base. In other

instances it proceeds from the

stem downwards to the earth,

and there takes root.

The Vine, as in the Vine (Vi-

tis vinifera) and Cucumber

(Cucumis), is a slender twining

stem, which situates itself amongst

and adheres to other plants for Fig. 123. The GINGER plant (Zingiber officinale), with

support*,.. It does not give off lts rhlzome from whi CQ the leaves and flowers spring.

foots along its course.

The Runner^ on the other hand, is also a creeping stem ; but it emits a bundle of

WOODED STEMS.

Fig. 124. The tubers, or pseudo-bulbs,
of the SPIDER orchis.

roots and leaves at intervals, and, in fact, forms new plants (Fig. 122). Such is the

Strawberry (Fragaria).

The Offset, as in the House-leek (Sempervivum

tectorutri), is a short branch terminated by a cluster

of leaves, and capable of independent existence

after separation from the parent plant.

The Hootstock, or rhizome, is a thickened root-

ing stein, as in the Ginger (Fig. 123), and Iris,

which produce young branches or plants yearly.
The Pseudo -bulbs of orchadaceous plants (Fig.

124) very closely resemble tubers, except that they

retain the marks of leaves which they once bore.

They exist above ground, and contain amorphous

starch.

Wooded Steins. Having now offered such remarks on herbaceous stems (dis-

tinguished from woody stems) as seemed to be required by their greater delicacy, we

proceed to describe woody
stems and their appendages.
When treating of the mo-
difications of herbaceous
stems (page 59), we inti-
mated that such changes
also affected woody stems,
but in a lesser degree, and
shall therefore not again re-
fer to them under this head.
There are, however, a few
preliminary remarks which
are necessary as to the
general conformation of the
tree before we enter upon
an examination of the in-
ternal structure.

The general divisions of
a stem are called branches
(nwm), and the arrangement

*i&r?5&~~^ f '-~f3&s&&&a&mx nmrsrti ia^s^^eg?^ ^ them as a whole is termed

corona, a head, as that of
a forest tree. (Figs. 125,
126.) "When they pro-
ceed from either side of the
stem, and then pass from the
base to the apex of the tree,
it is called a caulis excurrens,
but when the stems break

Fig. 125. The BEECH TREK (Fagus), showing the corona, or head,
of forest trees.

up into a mass of branches, it is known as a caulis deliquescens. Incompletely grown
Bhoots are termed innovations, and ramuli, or twigs, when very young. If the shoot is
long and flexible, it is called a vimen ; and when it proceeds from the stem at nearly a

WOODED STEMS.

right angle, it is called Irachiate. This arrangement of the branches is further used
to distinguish trees, shrubs, and herbs. A tree (arbor) is composed of a trunk supporting
perennial branches ; and, when small, it is called arbusculus. A shrub differs from a
tree in there being no central stem or trunk, but the branches proceed directly from
the earth. This is called frutex, fruticulus when small, and dumosus when low. The
undershrub (suffrutex) has the same arrangement of branches ; but it approaches
nearer to the herb, since it wholly or partially dies annually. It has, however,
wooded branches, and not merely, or chiefly, cellular ones. The stem of a forest tree, and
of any other which has not its growth terminated by a flower-bud, or any other organic
cause, is said to be indeterminate, and determinate when otherwise.

126. Representing a variety of trees, all of exogenous growth.

Th j science of Botany is rich in descriptive terms ; and although they may be
disagreeable to a student, are very welcome to the botanist who would intelligibly
describe a plant. We must therefore counsel our readers not to pass them hastily by,
but to read them attentively, and, if possible, commit them to memory.

Wooded Stems are divided into two great and well-defined classes, according to their
internal conformation viz., such as grow from without (exogenous), and such as enlarge
from within (endogenous). The former are more common in cold, and the latter in hot
climates. There are, however, the following points of resemblance : Each has &

EXOGENOUS STEMS.

cellular basis through which the bundles of wood pass, and each is inclosed by a cuticle
or bark (endogens are said to have no bark). The cellular system is horizontal, and
constitutes the woof of the structure ; whilst the vascular and woody system is longi-
tudinal, and corresponds to the warp.

Exogenous Stems. On examining a section of the stem of an oak, or any other
of our forest trees (Fig. 127), we observe the following parts first, the pith, , or its
remains, in the centre ; secondly, the B

bark, rf, on the outside ; thirdly, a mass
of wood, b, between the two, broken
up into portions by the concentric
deposition of its layers, and by a
series of lines or rays, c, which pass
from the centre to the circumference.
Thus there are always pith, bark,
wood, and medullary rays (Fig. 127).

It has already been mentioned that

Fig. 127

A, transverse, and B perpendicular section of an exo-
genous stein, showing parts of which it is composed.

a, the central pith ; b, four layers of woody fibre ; c, the
cambium in the spring ; d, the bark ; e, the medullary
rays.

each stem has two systems, the cellu-
lar and the vascular ; and the parts

just mentioned must belong to one

or other of those systems. Thus the

pith, medullary rays, and bark belong

to the horizontal or cellular system, and the wood, with its associated ducts, constitutes

the longitudinal or vascular system.

This division of stems comprehends nearly every wooded plant of our climate.
The Pith occupies the centre of the stem (Fig. 128, a), and remains throughout the
period of growth of some trees, as of the elder
(Sambucus nigra), or is absorbed after a few years,
as in the oak and almost all large trees. In the
latter class of plants there are some remains of
the pith for many years after the process of ab-
sorption has commenced ; but at length no vestige
can be detected, and its position is known only
by the central spot around
which the wood is placed
in circles. It is, however,
at this period found in
young shoots just as it
was at the earliest mo-
ment of the formation of
the plant (Fig. 129).
When it exists, it passes

Fig. 128.- -A scheme of the parts of an
exogenous stem.

a, the pith ; ft, the bark ; c, medullary
rays uniting the pith and the bark
(greatly exaggerated) ; d, woody
fi

bre.

uninterruptedly from the ri ?- 129.-*ection of young

*_ shoot of the MAPLE TREK

root to tne end ot each

branch and leaf-bud ; but is sometimes thickened, and rendered
more dense, as in the ash, at the nodes the place, indeed,
where all the structures are somewhat compressed.

Its structure is at all times cellular ; and, for the most
part, the cells are hexagonal in form, as shown in Fig. 11. The cells are commonly

(Acer campestre), show-
ing the large size of the
pith, a; the bundles of
wood of one year's growth,
and the bark with its
hairs.

76 THE PITH THE MEDULLARY SHEATH.

of large size, and may be well examined in the pith of the elder. Their colour is
green whilst they freely perform their function ; but subsequently the tissue is nearly
colourless. In the old age of the plant the pith often assumes a colour which it has

obtained from the juices which have been

deposited within it. In a majority of
instances the pith forms a solid cylindrical
mass ; but in certain fast-growing plants,
as in the hollow stems of the Umbelli-
ferce, it is torn, and vacuities are left.
Fig. 130. Chambered pith in the WALNUT TREE. I n a f ew plants the ruptured pith assumes
a very regular form, and is thence termed chambered pith, since it is divided into a
series of compartments which pass across the column in small stems. Such is the case
in the walnut (Fig. 1 30), as may be readily seen by selecting a very young shoot and
slicing away a portion of one or both sides. According to the researches of Professor
Morrison this change depends upon the lateral elongation of the cells, and the conse-
quent disappearance of the contents of the cells, and is induced immediately by the
absorbing action of the leaf 'bud.

The connexions of the pith are highly important, and demand special enumeration.
It has already been intimated that it does not exist in the root, at least, of tolerably
grown plants, and therefore its functions are confined to the stem. First. It is in
direct and unbroken connexion with every branch, leaf, bud, and flower, and is the
structure which first conveys fluids to, and receives fluids from, the newly-developed
leaf. It thence becomes the main organ of nutriment ; and, at the same time, the chief
depository of the secretions. Secondly. It is in equally direct and unbroken connex-
ion with the bark, through the medium of the medullary rays ; and thus becomes the
centre of all the movements of sap which proceed in the horizontal system ; it is that
system which more especially presides over the life of the plant.

The mode in which its ultimate disappearance occurs has been a matter of doubt
and speculation. It seems quite clear that it is not converted into wood, as was asserted
by Mirbel, and there are certain facts which militate against the opinion that it is
gradually compressed by the wood ; but since it is known that in the growth of the
plant much compression of the previously formed wood must occur, and since this
compression is a reasonable theory by which to account for the disappearance of the
less resisting pith, it is now pretty generally admitted to be at least one of the causes
of this occurrence.

As a general rule, the pith, so long as it exists, is not mingled with other than
cellular structures ; but, in a few instances, woody fibre has been found with it ; and
in others, as Nepenthes, spiral vessels have been detected.

The economic uses of pith have not been numerous, but amongst them must be
mentioned the rice-paper used in China, and prepared by cutting the pith of the
-ZEschynomene (Fig. 48), and the Aralia papyrifera, in a circular manner, so as to obtain
large, thin, and evenly cut sheets. It is used for drawing and for writing. The
cellular pith-like stems of the JEschynomene aspera, called "shola," have been forwarded
to this country from India, and have been made into various ornaments, models of
buildings, hats, boxes, and life-buoys. Its lightness, and non-conducting property of
heat, render it very fitted for the manufacture of hats.

Medullary Sheath. Immediately surrounding the pith of all exogenous plants
there is a layer of vascular tissue, which has received the name of medullaiy sheath

MEDULLARY RAYS THE BARK.

b 6

Fig. 131. Vertical

(Fig. 128). This sheath has no special walls, but is simply bounded by the pith on the
inner, and by the wood (when it exists) on the outer side. It is in this situation that
we may find ducts of various kinds, and spiral vessels ; and in all cases it conveys the
vascular structure from the root direct to each leaf and flower. The integrity of this
structure is therefore highly necessary to the life of the plant. It is said to retain its
green colour to the latest period of the existence of the plant; thus showing the impor-
tance of the functions assigned to it.

Medullary Rays. These structures come next in order ; and, as has been already
intimated, belong to the horizontal cellular system of the stem. They constitute the
channels of communication between the bark and pith, and are composed of a series of
walls, of single muriform cells resting upon the root, and pro-
ceeding to the apex of the tree, and radiating from the centre.
They lie between the wedge-like blocks of wood, and, as
they have a lighter colour than the wood, they are evident
on a section of any stem, and are called the silver grain
(Fig. 131). Their colour and number suffice to enable us to
distinguish various kinds of wood, and greatly increases their
beauty. They cannot, of course, exist before the wood is

of an egenou formed, and are therefore not met with in the earliest condi-

across the medullary tion of the plant. They begin to exist with the first deposited
ravs, showing their open /. -, ^ -n

character and their rela- Ia 7 er of wood, and continue to grow outwardly, or nearest to
tive position to the wood, the bark, so long as the wood continues to be deposited.

a. Dotted duct. , i -, i -n -, i .

b. Woody fibre. The Bark. As the medullary rays terminate in the bark
e. End of medullary rays. on their outer s {^ we are naturally next led to a considera-
tion of that structure. It forms the outer covering a sheath of the tree, and, in some
form or other is present in all plants. "When discussing the constitution of the cuticle
of herbaceous plants we explained the points of difference between the two varieties
of the same structure, and showed that the rudeness of the bark of wooded trees had
destroyed many of the characters of the cutis, such as stomata and hairs. We have
now to regard it as a dense cellular organ, well fitted to endure the influences of sea-
sons through a long series of years.

It may anatomically be divided into two structures viz., an outer one, which is
cellular, and an inner one, which is vascular or woody. The former is sub-divisible
into three parts, whilst the latter is composed of several layers of the same material,
and forms a link between the wood and the bark.

The three divisions of the cellular part are the Epidermis, the Epiphlaoum, and the
Mesophlaeum.

The Epidermis is the most external layer, and is continuous with that upon the
leaves. Its cells are flattened and lengthened, and but very rarely possess stomata.

The Epiphleeum has acquired much importance from the fact of its being the part of
the bark in which the cork is deposited. It cracks and peels off at intervals in almost
all trees. In the birch and cherry it may at all times be seen hanging from the stem
in silvery shreds, and in other trees as rough broken patches. In the cork tree (Qnercus
suber] it remains firm until the tree has attained a certain age, after which it exfoliates
in the large masses in which it is brought to this country. It is probable that the
deposition of cork proceeds in all trees ; but in the cork tree it attains so great a thick*
ness as to become a highly important article of commerce.

The removal of the cork from the cork tree is not left to natural exfoliation ; but, when

THE BARK OF TREES.

the tree is sufficiently mature, incisions are made from the top to the bottom of the
stem, so that the cork may be more quickly removed. The sheets are then placed
upon the ground to flatten, and are at length cut up into convenient lengths for packing.
The tree will permit this process to be renewed during seven or eight successive years.
The cause of the exfoliation has not well been determined. It certainly does not
depend upon the growth of the tree, as though the increased size of the stem caused
the bark to rupture and thence to fall off; but it is said that a layer of tabular cells
are formed within it which cuts off its communication with the internal structure of
the stem, and thence it dies. No doubt can exist as to the fact of the constant destruc-
tion of the old bark and the formation of new structures, and it appears to arise either
from the death of the external layers only, or from the formation of cork on the inner-
most layer of the bark, which causes an arrest of the circulation, and at length the
death of the more external parts.

It is said that the bark of exogens is much more extensible than that of endogens ;
and that, as a consequence, the stems of the former exceed in diameter those of the
latter. But the fact just mentioned seems to prove that in fact the cellular part of the
bark of exogens possesses but little extensibility ; for, when the enlargement of the
trunk has proceeded but even to a moderate extent, the bark cracks off from a lack of
this power of extension. It is far more probable that the increasing size of the zone
of bark is less due to the extensibility of the old bark than to the formation of new cells
year by year as the stem enlarges, and in a layer at all times proportioned to the increasing
size of the stem in fact, that the old coat becomes too small, and rends, and a new one
is supplied of larger dimensions. It is quite clear that the external layers, after rupture,
either peel off, or the width of the rents increases as the tree grows larger.

The Epiphlceum consists of several layers of thin flattened cells, usually without
colour.

Thirdly, the Mesophlaum is a thin layer of green cells lining the epiphlseum, and, in
the cork tree, exfoliating with it. Its cells lie in a direction different from that of the
cells of the epiphlaeum, and sometimes contain cellular secretions.

The vascular part of the bark is called the liber, from its offering a smooth enduring
structure, which was formerly used as paper (liber a book). It consists of several

layers of small interlaced bundles of woody fibre,
connected together by loose cellular tissue. In some
trees, as the lace bark tree (Lagetta lintearia, Fig.
132), it resembles a textile fabric, and may be ob-
tained from the tree in sheets of large size. The
woody fibre of the liber has always the peculiarity
of being very strong, and of lying in small bundles,
and has been used as cordage by most nations. It
is still employed in Russia in the manufacture of
mats, and in many parts of the world for whip-
lashes. It is not equally smooth on both aspects ;
since, on its outer side, it has cellular connexion
with the mesophlaeuin, but on its inner surface it
is opposed to the smooth wood, or is covered by
the semi-fluid cambium. Its mesh-work character

Fig. 132. Bark of the Lace Tree of
Jamaica, composed of fine and
loosely arranged bundles of woody
fibre. Natural size.

permits the medullary rays to pass through it, and to keep up a circulation with the
cellular part of the bark. It is not subsequently converted into the wood of the tree,

THE WOOD.

Fig. 133. The branching
vessels of the bark along
which the fluids are con-
veyed.

as some have supposed, but is formed in the Spring season from the leares -with the
wood, and lies in successive layers -within the mesophlaeum.

The more immediate use of the hark is that of giving protection to the wood. If
bark did not exist there would be no cambium, and without cambium there could not
be any deposition of woody fibre ; and thus the presence of bark is necessary to tbe
growth of the tree. It is also essential to the life of the tree,
from its connexion with the cellular system, and with the
undeveloped leaf-buds.

The bark contains a large number of air vessels and vasa
propria, and not only conveys refuse matter from the leaves
to the soil, but is in almost all cases a depository of elaborated
secretions. This is well seen in the oak bark, yielding tan-
nin ; the cinchona bark, producing quinine ; and the fir-tree,
emitting turpentine. There are also many milk vessels ; but,
with the exception of the Nepenthes, there are no spiral vessels.
We have oftentimes found thick wall-cells, as in Fig. 40,
arranged in columns with great regularity.

Wood. We now proceed to the most important division
of the parts formed in exogenous stems viz., the Wood a
substance not merely giving stability and beauty to the tree,
but offering the greatest service to man. We find it occupying nearly the whole
body of the trunk, and arranged, as a rule, in a very regular manner in this class
of trees. On taking up any piece of wood, but more particularly the entire section
of a stem, we first notice a series of circles, which incraase in diameter, and are separated
by wider intervals as we approach the bark. In this manner the trunk is composed
of numerous zones inclosed within each other. Again, in almost all trees, we observe
the medullary rays before-mentioned passing in straight lines from the centre to the
circumference ; and as the circle of the stem at the bark is much larger than any
circle near to the centre, it follows that the medullary rays will be wider apart at
the bark than at the pith. On this view of the subject we may state that the stem is
composed of a series of wedge-shaped blocks, which have their edges meeting at the
centre. The combination of these two views gives the correct idea of the arrange-
ment of the wood viz., a series of wedges, each divided into segments of unequal
width by circular lines passing across them. From this description it must not be
supposed that these various portions are detached, or may be readily detached, from
each other ; for, although the medullary rays and the circular mode of deposition both
tend to a less difficult cleavage of the wood, they yet bind the parts very closely and
firmly to each other.

The explanation of the occurrence of distinct zones of wood is that each zone is the
produce of one year, and that in our climate, more so than in tropical countries, the
period of growth of wood ceases for many months between the seasons, and thus induces
a distinction in appearance between the last wood of a former and the first wood of the
succeeding year. This distinction is maintained throughout each year, and throughout
a long series of years.

The inclosure of zone within zone is owing to the mode in which the wood is pro-
duced, and the position in which it is deposited. Wood is formed by the leaves during
the growing season, and passes down towards the root between the bark and the wood
of the previous year (if any}, or in the position in which cambium is effused ; and, as th

80 THE WOOD.

leaves more or less surround the whole stem, the new layer at length completes a zone,
and perfectly encloses the -wood of all former years. This is the explanation of the
term exogenous, which is derived from two words signifying to grow outwardly, for
the stem increases in thickness by successive layers on the outer side of the previously-
formed wood. That this is the mode of growth has been abundantly proved by experi-
ment, and demonstrated by accidental discoveries. Thus, if a plate of metal be inserted
between the bark and wood, it will in progress of time become inclosed by the new wood
which has overlaid them. So in like manner, if letters be cut deeply through the bark
and into the wood, the spaces will not be filled up from the bottom, but may be seen
in subsequent years overlaid by new wood. A statement appeared in a daily paper,
during the past year, to the effect that in cutting down a tree a cat had been discovered
inclosed in the wood of the trunk. These facts prove that the wood is applied from
without. Again, if a branch be stripped of its leaves down to a certain point, it will
not grow above that point ; and so, in like manner, if branches be stripped from one side of
a tree, the tree will not grow on that side. If a circle of bark be removed from a
branch above and also below a leaf, it will be found that increase of size will occur
below, but not above that bud ; and so, likewise, whenever a ring of bark is removed
from a tree, the new woody fibre will not proceed from the lower but from the upper free
edge. Further, if a scion be engrafted upon a stock having wood of a different colour
from that of the scion, it will be found that the wood produced from the scion overlays
that of the stock. This may actually be seen in operation in the spring season, if a
leaf be exposed immediately below its base ; for then bundles will be seen to shoot
below the ring of bark or cuticle, and to divide into two sets, one of which proceeds to
the liber, and the other to the wood of the trunk.

These facts are undoubted, and the inferences seem to be indisputable ; but yet
various men of eminence have held contrary opinions. Thus, Linnaeus believed it to be
the produce of the pith, and Malpighi, that of the last year's wood ; whilst Du Hamel
affirmed that it was produced by neither, but solely from the cambium, which, according
to him, was secreted by the bark. It cannot be denied that the bark exercises an
influence in the formation of wood ; for if a zone of red bark be made to grow upon a
tree having white bark, all the wood appearing below this new bark will be red. But
this is not the result of any power in the bark to form wood, but simply that the wood,
as a part of the horizontal cellular system of a plant, has a controlling influence over
its secretions. These experiments, and others of a similar character, may be most
readily performed by any one of ordinary ingenuity. And what amusement could be
more instructive to our young friends of both sexes, and possibly through them to the
world at at large ?

If our readers will cursorily glance at the cut surface of any stem, they will at once
perceive another fact in relation to the zones of wood, viz., that whatever may be the
thickness of the zone for the year, it is rarely equal around the whole circumference of
the stem. This is no matter for wonder ; but, on the contrary, it is surprising that
there is any approach to regularity, seeing that the position of leaves upin the branches
seems to be an accidental rather than a circular or spiral one. The occurrence is
readily accounted for on the theory above propounded, and is due to the lesser abun-
dance of leaves on the branches of one side than on the other, or to the prevalence of
winds, or some other physical cause, acting in that direction in opposition to the
growing process.

SECTIONS OP EXOGENOUS STEMS.

Figs. 134, 135, 136, 137, 138 exhibit horizontal and perpendicular sections of an
exogenous stem, from the end of the first to the end of the fifth year. In each figure

Fig. 134. End of first year's growth

III" ! I , '
Fig. 135. End of second year's growth.

Ill

Fig. 136. End of third year's growth.

Fig. 137. End of fourth year's growth.

. ,

ii !

Fig. 138. End of fifth year's growth.

the pith occupies the
centre, and is the largest
at the end of the second
year; after which it pro-
gressively diminishes.
Immediately around it is
the medullary sheath.
The bark is on the outer
boundary ; and the woody
and pitted tissues occupy
the intervening spaces,
and increase at the rate of
one layer or zone per year. The medullary rays pass from the pith to the bark.

From the preceding remarks it will at once be inferred that a plant of one year's
growth has but one layer of wood ; and that that, therefon-, does not inclose wood, but
pith only. When the tree has reached the end of the seccnd season it will have two
layers ; and so on, successively, through any number of years. The above Figures
represent each a horizontal and vertical section of a steni at various periods ; and in
Fig. 138 it will be seen that the stem of a plant five years old exhibits a centra]
pith, five zones of wood, and the bark, besides the cambi/im in the spring season and
the medullary rays.

The age of trees has been inferred, when a section of the whole stem could be
examined, by counting the number of rings of wood whit, h have been deposited around
the pith. When only a part of the stem remained, and yet its original diameter was
known, the same end has been s ught by multiplying the width of one zone by one half
the diameter, or by counting; the number of zones from the pith to the bark, should so

IMMENSE GROWTH OF TREES.

much of the stem be found. In a large proportion of cases these modes will evoke
tolerably accurate results ; but there are several sources of fallacy to which we must
refer.

First, it is highly probable that in tropical climates the wood of more than one year
may produce but one zone ; for as there is but a short if any period of cessation of
growth, but very slight evidences of any line of demarcation can be detected. The
real age of trees may thus be underrated.

Secondly. It is highly probable that in some plants more than one zone of wood is
formed in the year; for such is evidently the case in the root of the Beta Vulgaris.
This would unduly increase the age of the tree.

Thirdly. When examining a fragment of a tree the observer should remember that
the zones are not of equal thickness throughout, and that it is quite possible that in
some years no wood whatever was formed in the fragment under examination. The
varying width of zones results from the age of the tree ;, so that it is less as the tree
advances in life, as also from the interruption to growth, which not unfrequently
continues on one side of a plant throughout a greater part of the growing season. This
may be readily observed by noticing a section of almost any stem; for then it will be
evident that the pith does not occupy the geometric centre of the plant. Dr. Lindley
gives the measurements of two sides of four stems, which he selected from East Indian
trees, which exemplify this fact clearly :

Real age or No.
of zones.

Total diameter.

Diam
Smaller side.

eter of
Larger side.

1st stem . ..

45 lines.

9 lines.

36 lines.

2d . . .

3d ...

4th . . .

23 ,,

" Suppose that a portion of the smaller side in the first example were examined, the
observer would find that each zone is 0*225 of a line deep, and as the whole diameter
of the stem is 45 lines, he would estimate the side he examined to be 22 '5 lines deep,
consequently he would arrive by calculation at the conclusion that as his plant was one
year growing 0'225 of a line, it would be a hundred years in growing 22*5 lines, while
in fact it has been only forty years."

Thus, whilst it is difficult to ascertain with great certainty the age of any tree when
a whole section can be obtained, the difficulty is vastly greater when only a fragment
can be examined.

The great size of the trunk of a tree is prima facie evidence of its antiquity ; and
judging from that fact alone we should be disposed to admit that the following remark-
able trees must be very aged :

The Chesnut pf Mount Etna (Castanea de Centi Cavalli) is 180 feet in circum-
ference.

A Plane tree in Turkey, 150 feet in circumference.

Some of the Brazilian Hymenaeas, 84 feet in circumference.

In respect of height, it is known that the Araucarias sometimes attain to the
height of more than 200 feet.

The Pinus Darglariana of Oregon is 193 feet high ; and the Pinus Lambertiana is
226 feet in height.

LONGEVITY OF TREES. 83

The real value of these enormous dimensions will be best felt if our readers would
make a circle in a field of 180 feet in circumference, and then measure a distance oi
70 yards to indicate the width and height of a tree.

There are several ancient oaks in England, through the remains of whose hollow
trunks coaches have been driven ; and in New Zealand it is said to be a common
txjcurrence to use decayed trees as stables.

The following list of ancient trees may be found in a French work, the " Teratologie
Vegetale," and their ages have been computed upon the principles now laid down.

List of old trees, according to Maguire and Tandon. There are known :

Palms of 200, 300 years.

Cereus 300

Chirodendron 327

Ulmus (Elm) 355

Cupressus (Cypress) 388

Hedera (Ivy) 448

Acer (Maple) 516

Larix (Larch) 263, 576

Castanea (Chesnut) 360, 626

Citrus (Orange) 400, 509, 640

Plantanus (Plane) 720

Cedrus (Cedar) 200, 800

Juglans (Walnut) 900

Tilia (Lime) 364, 530, 800, 825, 1076

Abies (Spruce) . 1200

Quercus (Oak) .... 600, 800, 860, 1000, 1600

Olea (Olive) 700, 1000, 2000

Taxus (Yew) .... 1214,1466,2588,2888

Schubertia 3000, 4000

Leguminosae 2052, 4104 ,,

Adansonia (Baobab) of Senegal 6000

Dracaena (Dragon' s Blood Tree) of Teneriffe . . 6000

When we remember that the two latter periods carry us back to the days of Adam,
and contrast them with the ordinary destructibility of vegetable growths, they appear to
be incredible, and we cannot but suspect that some elementary error has crept into the
computation.

Since the quantity of woody fibre produced depends mainly upon the number of
leaves upon the tree, and the number of leaves must bear some proportion to the size
of the tree, it might be inferred that the quantity of wood deposited would increase
with much regularity as the age of the tree advanced. This increase might be mani-
fested in two, or one of two ways viz., the increasing length of the zone and its
increasing width. It is very probable that an increase does take place in the annual
deposit, until the tree has attained its maximum of growth ; and it is quite clear that
so long as the tree enlarges, the circumference of each zone must increase likewise ;
but there is no evidence that the zone at the same time increases in thickness. This
militates against the oft-repeated attempt to determine the age of a tree from its
diameter ; and if there were no- other source of fallacy, it would suffice to remind our
readers that the growth of trees must depend upon the varying nature of the soil, the

CELLULAR STRUCTURE OF TREES.

changing seasons, and the prevalence of winds ; and that all these act with tenfold
greater effect upon a fidl grown than upon a very immature tree. It may therefore be
affirmed, that the zones of wood increase in length, and decrease in thickness, as the age
of the tree advances, and that both proceed from determinate causes, but that the
increase and decrease alike do not follow any rule of universal application.

Moreover the width of the zones of wood, in the same species of tree growing in
different positions, is not the same. Thus the Scotch Fir (Pinus sylvestris), growing
at various altitudes, produces rings of wood varying from 0'39 lines, to 10 times that
amount. That such must be the case we may readily infer from the fact, that in any
plantation trees of the same species, and planted at the same time, attain, within a few
years, to very different dimensions. This dissimilarity is far greater when we compare
trees of various species ; but yet, in reference to all wooded plants, it may be stated that
there is a general resemblance in the size, both in height and thickness, which plants
of the same species attain in the course of years.

Numerous efforts have been made to discover a relation between the height and the
thickness of trees ; but whilst there may be an approach to similarity in trees of the
same species, there is not a shadow of resemblance in wooded plants as a whole. Thus
it has been found, that of two species of Pine the difference was so great, that whilst
the relation was as 1 to 5 in one instance, it was as 1 to 120 in another.

Such speculations may tend to increase a spirit of inquiry, but hitherto they have
had no other good effect.

The foregoing description may suffice for exogenous stems which follow this usual
course of development, and therefore for the great majority of trees ; but it is readily
conceivable that a difference in figure may exist to a great extent, as in the cells of
cellular structure, considered at page 11.

Fig. 139.

Fig. 140.

Fig. 141.

Fig. 139, representing the section of a tree in which, from the irregular development of the stem,

there are no concentric zones of wood.
Figs. 140 and 140*, showing, in the section of a stem of a Bignonia, four internal deposits of bark, a,

by which the wood is divided into four wedges. The lines crossing the centre are well developed

medullary rays.
Fig. 141. The stem of a Clematis, in which the medullary rays are greatly thickened, a, the pith ;

b, the smaller ; and d, the larger wood bundles ; c, the large medullary rays ; e, the bark.

Thus, whenever the process of growth is so disturbed that it proceeds on one side,
whilst it is nearly arrested on the other, it is evident that the figure of the stem will

CELLULAR STRUCTURE OF TREES.

not be cylindrical, and that the layers of wood will not be in perfect zones. So also
when this disturbance is restricted to a portion only of one side, fhere will be no
growth at that part, and in process of time a depression in the stem will result, giving
it a furrowed appearance. At a still later period, assuming that the like causes exist,
this furrow will become deeper, but at the same time it will be narrower; for the woody
fibre, as it passes down on either side, will find little resistance in that direction, and
will push into the furrow and lessen its size. At the same time the bark will also
increase in thickness, and in process of time the original furrow will have disappeared.
A section of such a stem would show a triangular interval in the circumference
of the trunk, which would either be vacant or filled up with layers of bark. If,
whilst these changes are proceeding, others of a similar character were met with in
other parts of the circumference, the section, instead of exhibiting a circular outline,
would greatly resemble the figure of the stellate cell (page 11). These are the expla-
nations of a great variety of twining stems growing in hot climates, and which are
angular, or present a cruciate appearance on section.

An interesting modification, and one very nearly allied to the above, is that in which
the medullary rays increase in thickness so greatly as not only to be mere lines, giving
a grain to the wood, but large wedge-shaped blocks between alternate masses of wood.
This is not remarkable, when we remember that at every moment of growth there are
two processes going on, one the cellular or horizontal, and the other the woody or
vertical ; and it is no more a matter of surprise that nature should occasionally increase
the one at the expense of the other, than that she should rigidly adhere to the rule
which she has laid down ; for both the rule and the exception are alike wonderful and
inexplicable. Such exceptions, greatly varied, but yet for the most part originating in
the " Wood," or cellular structure of the stem, are by no me ins uncommon.

The general configuration of exo-
genous stems is conical, the circum-
ference being, for the most part, cir-
cular, and the base much larger than
the apex, or the free terminal part of
the stem. This necessarily results
from the remarks which we have
made on the production of wood ; for
it is manifest, that if the wood be a
product of the leaves, and the number
of leaves on the tree increases from
above downwards, the quantity of
wood deposited will be greater below
than above. The apparent exceptions
to this rule are in such fast-growing
trees as grow in the midst of a dense
wood, where the light reaches them

e d c d cd

Fig. 142, showing the component parts of a stem in

the fourth year of growth,
only at the top. bucn trees run up ot A, a part of a transverse section. B, a perpendicular

nearly even diameter, and without Bother h6 PartS f GaCh arranged accuratel y over
a branch, until more than two-thirds a, the pith; b, the surrounding medullary sheath;

c and d layers of wood and bothrenchym intermin-
gled. The open-work in A shows the position and
the extent of bothrenchym more clearly ; e, the bark

of their entire height has been at-
tained ; but from the point where

branches arise, the conical figure may readily be traced. The common asparagus

ENDOGENOUS STEMS.

plant is also said to be an exception to this rule. The circular figure of the
stem is due to the somewhat even distribution of the leaves around the trunk ; and this
will be the most perfect when the tree has grown apart from others, and where it is
freely exposed on all sides to the influence of light.

The wood of plants is not composed exclusively of woody tissue, but with that
structure is bothrenchym, or dotted tissue and ducts, in greater or less abundance. This,
as before mentioned at page 17, is more particularly the case in fast-growing plants.
The diagram on page 85, of an exogenous stem, shows how largely pitted tissue is
intermingled with the wood.

Fig. 143, representing a Palm forest, and some of the leading characters of endogenous growth.

Endogenous Stems. We now proceed to a description of stems which will be
less familiar to our readers, and which can usually be examined in museums, or as dried
plants only. These are almost peculiar to tropical regions, and are exclusively so if we
refer to wooded plants of considerable size. The giant representative of this class is
the Palm tree, with its wonderful utility and beauty.

The class is represented in this country, and in almost all cold climates, by plants of
lesser growth, and more particularly by the grasses ; yet, with the exception of the
direction of the veins of leaves, they afford but unsatisfactory indications of the peculiar
structure of the plant. The most ready illustration will be found in the common Cane
and Bamboo ; and these will suffice for a sufficient inquiry into this subject.

The term "endogenous" signifies to grow inwardly, and is explained by stating
that the bundles of wood sent down from the leaves do not range themselves in layers

THE CUTICLE OF ENDOGENOUS STEMS.

on the outer side of the previously-formed wood, but pass down in irregular masses
near to the centre of the stem. Such stems, like exogenous stems, are composed of a
woof and warp, each of which holds the same relation to the other in both great
divisions of trees, and they differ only in their relative proportions and mode of
arrangement. Thus the cellular or
horizontal warp is proportionally in-
creased in endogenous rather than in
exogenous stems; and this, together
with the arrangement of the woody
fibre into bundles, gives a more open
character to the section of the stem.

A section of an endogenous stem
(Fig. 144) exhibits the following struc-
tures: First, an external inclosing
layer or bark, x ; secondly, a series of
circular lines, which represent the cut
surfaces of vascular tissue, y; and
thirdly, the mesh- work intervening be-
tween the bundles, which is the cellu-
lar tissue or pith, z. "We shall consider
each of these separately,

Cuticle. The epidermis, cuticle,
or bark, of endogenous stems, differs
materially from the analogous structure
in exogenous plants. It cannot, in any
lormal instances, be separated from the stem, as may be readily seen by attempting to
peel a cane. It does not naturally crack and separate as does the bark of our forest
trees; but is hard, dense, smooth (usually), non-corrugated, inelastic, but slightly
extensible, and is a permanent unchanging structure. Thus, the diameter of such
stems is necessarily greatly restricted ; and it is in length only that endogenous plants
can be greatly developed. It does not consist of a series of layers, which may be
detached from each other, and distinguished by various names, but is simply formed of
one or two layers a mass of flattened cells, with bundles of woody fibre intermixed,
and connecting it with the internal parts of the stem. The non-extensibility of these
layers is not evident until the tree has attained to somewhat of its natural diameter ;
for the bamboo may appear at first as large as the finger only, and subsequently exceed
in circumference a man's thigh. Moreover, a few plants, as the Dracaena or dragon's
blood tree, referred to at page 1, has attained to a circumference of forty feet. Thus,
whilst it is true that the width of endogenous stems, as compared with their height, is
much less than in exogenous trees, we must admit that the cuticle is extensible, and
must infer that its further development is prevented by a degree of expansibility which
does not proceed beyond a certain point ; or that its further non-development is simply
a part of the general law which governs the growth of these plants. It is difficult to
agree with the common opinion, that the limited power of expansion, which the cuticle
is said to possess, is the cause of the limited diameter of the stem ; and it seems more
philosophical to assume, that it is only a part of these occurrences which accompany
the normal development of these structures.

That the size of the stem remains the same at all periods after its full development

d t fc *

Fig. 144, showing, by a horizontal and perpendicular

section, the structure of endogenous stems,
a, 2, cellular woof of the stem.
b d, bundles of vascular tissue,
y, their cut ends.
x, the so-called cuticle or bark.

ON VASCULAR STRUCTURE.

is quite evident from the fact that twining plants may encircle it for many years
without compressing it ; but this is begging the question ; for if the stem be fully
developed, as at first referred to, no further increase of the tree is expected. The truth
seems to be, that endogons cease to grow at their lower part, whilst growth proceeds
above ; and thereby the cuticle may have attained to a maximum of extension near to
the base, whilst it may be comparatively undeveloped above.

Schkiden explains the peculiarities of the cuticle of endogenous stems, as distin-
guished from that of exogenous ones, by employing the term " limited growth" to the
former, and "unlimited growth" to the latter; and explains them by stating, that in
the former, after a certain period, the production of the fast-growing thin walled- cells
of the cuticle ceases, and the partitions become thicker ; whilst in the latter, the cells
are continually reproduced throughout the whole period of growth of the plant. This
seems to be rather a statement of the facts than an explanation of them.

It is the fashion to state that endogens have no bark, since none is separable from
the wood, and that the cuticle is simply the hardened exposed cells of the stem, with
the ends of bundles of woody fibre intermixed. If analogies are truly founded upon
function, and not upon structure, we must admit that there is a cuticle or external
protective covering to endogenous stems.

Vascular Structure. This is a mixture of woody fibre and bothrenchym, with
the addition of spiral ducts or spiral vessels.

If we examine a transverse section of a cane, we do
not find a central pith, with wood arranged in layers
around it, but a surface marked by fourteen cut ends of
round bundles of vascular tissue, set in a cellular matrix.

f-oi// "K ] I >C V ; N' ^ a ^ so on ma ki n g a perpendicular section, we notice that

v^-. li/T^ /( /vxvfi fO *ke surface of the section presents a number of perpendicu-
lar defined lines, which may be torn out, and a series of
intervening connecting substances. The distinguishing
peculiarity of endogens is the arrangement of the woody
fibre.

The general direction of the woody fibre is clearly
from above downwards ; but it is highly probable that it
does not descend in straight lines, and that when the tree
has attained a tolerable height the wood does not descend
directly to the root. As the structure is not indigenous

145, showing the arciform to climes where scientific men abound, the observers have
arrangement of the bundles been few ; and as the subject is an intricate one, it has not.
of woody fibre m endogens . ,. ,.-,, - r i i -, i t

(as the Palm), as they pass as yet, been fully elucidated. Mohl is the best authority,
from the series of interfoliar and he affirms that $& bundles of fibres descend from the
organs at the head of the
stem, and their parallel leaves in arcs, which direct then- convexities towards the

sM^of The hark n tlie inner centre of the stem. Thus the fibre, in its descent, first

a ft, fully developed part of passes towards the centre, and thence towards the circum-

to d, 8t Strices of leaves, with ferer ice, until it reaches the bark, or nearly so, when it

their vascular bundles. passes down . in a more direct manner towards the root.

the'biS dl6S Pr C <iing lr m Each fibre will therefore somewhat represent a hedge-

/, the latest-formed leaves, hook with a long handle that is, have the form of an arc

After Schleiden. . , .. , ,

above, and a straight line below. The centre of each arc

will not correspond with the central point in the height of the stem, but will be distant

THE PITH OF ENDOGENOUS PLANTS. 89 .

from either end of the arc about one foot and a-half. It is not presumed that all the
fibres enter the bark, but that some curl and attach themselves to it, whilst others pass
to the roots. Thus the perpendicular section of a Palm would exhibit a series of arcs,
intersecting each other, and originating in points gradually ascending as the tree grew
in height. These arcs would proceed from every point of the circumference of the
stem, and present their convexities towards the centre. ,

Thus far, the best observers are agreed ; but the precise point of origin is still a
matter in dispute. That they proceed from foliaceous organs, as in exogens, is certain ;
but whether from the fully-developed leaf, or from undeveloped interfoliar organs, is
undetermined. The former is the opinion of Mohl, and the latter of Schleiden ; whilst
Mirbel occupies a midway position, and asserts that they proceed from an independent
part of the growing point, or Phyttophore. The successively ascending points of origin
of the arcs are explained on either of these theories ; for in endogens the foliaceous
organs, whether developed or undeveloped, are placed only on the top or head of the
stem, and are yearly supplanted by others rising from above them as the stem
elongates.

There is, however, a material difference of opinion as to the immediate direction
taken by the growing wood, according to the views above expressed. Thus, on Mohl's
theory, the woody bundles aro formed at the highest point viz. within the leaf itself,
and have but one direction, that from above downwards ; but on Mirbel' s theory, the
point of origin is below the leaf, and the bundles pass in two directions one upwards
into the leaf, and the other downwards into the stem. If we adopt the latter theory we
must admit that the oldest part of the wood is neither at the top nor at the bottom of
each bundle, but at an intermediate spot a point near to the upper extremity.

It is agreed by all observers, that there is no evident dissimilarity between an
exogenous and endogenous stem up to the end of the first year of growth ; for in both
cases there is a central pith and an external layer of wood, which has been divided
into two portions, one of which has applied itself to the bark, and become the liber ;
whilst the other is the true wood, which surrounds the centre. The distinction begins
in the following year, when the divisions of the bundles of woody fibre into liber and
wood does not again take place in endogens ; and, as in those plants, the whole wood
passes down into the bark, and near to it, the lower part of the stem, as in palms, is
much more solid and resisting than the upper part.

The uses of vascular tissue in endogens are the same as those of exogens, but the
proportion of saccharine juices which it contains is greater in the former than in the
latter. This is a beautiful arrangement for the convenience of those inhabiting hot
and often arid countries, where animal milk and water are but sparingly afforded. (See
page 24.)

Pith. The pith in endogens may be said to occupy the whole of the stem, and to
form the bed into which the woody fibres pass. If we deny the existence of bark in
endogens, we must affirm that the pith also forms the cuticle, having first had its
cells thickened to render it more resisting. On the section of a stem it will therefore
be found to intervene between the bundle of vascular tissue, as exhibited in Fig. 146,
and to form the very boundary to the stem itself. In the endogenous plants of our
climate, as the grasses, and in many similar fast-growing specimens of hot countries,
as the bamboo, the central pith is ruptured, and ultimately absorbed ; so that there is a
central vacuity, except at the nodes, where a partition of pith still continues.

The uses of pith are chiefly two : first, to supply a soft, elastic, and yielding struc-

THE ROOTS OF PLANTS.

ture, through which the vascular tissue may pass from the leaves towards the roots
and secondly, to contain starch, oftentimes of great purity and abundance, as in the

stem of the sago palm (Sagus

Rumphii),

The points in the external

characters of endogenous stems,

which are peculiar to these

structures, are the following :
First. As a rule the stem

does not give off branches, but

proceeds either singly or dicho-

tomously (divided into two)

from the base to the apex.

Fig. 146. Horizontal section of
the Sugar Cane (Saccharinum
officinale) showing the cellular
structure or pith at <, and the
intervening bundles of vascu-
lar tissue at c.

Fig. 147. A section of the
stem of the common Iteeu
(Phragmites], showing at
a the central vacuity, and
at b the solid stem, with
the bundles of woody
tissue.

Secondly. The leaves are
therefore found only at the
head of the stem, and surround
it by numerous insertions, ar-
ranged above each other in
a spiral manner. They are
usually of large size, and thus compensate for their paucity in numbers. When their duty
has been performed, they wither ai.cj aecay upon the stem, or ultimately fall from it,
leaving a mark called a cicatrix to radicate the points to which they were formerly
attached. The succession of leaves takes place from below upwards, and thereby a
palm of some years growth presents a series of cicatrices. As the age of the tree
cannot be determined by the number of the concentric circles of the wood, it is inferred
from the number of rows of cicatrices, which indicate the successive seasonal formation
of leaves.

Thirdly. From the above reasons, the stem is not conical, but cylindrical, and is tall
in proportion to its diameter. Not that it is cylindrical, as opposed to conical, to the
very apex of the plant, (for the very apex has not so large a diameter as the inferior
part,) but since the reduction in diameter is somewhat sudden, and is found only very
near to the terminal part of the stem, it is more truthful to state that the figure of the
stem is a truncated cylinder than a cone.

In all these respects the stems of endogens are very unlike the stems of exogens.
The Descending Axis or Root. Having now completed our account of stems,
it will be more convenient to state the little which may be necessary respecting roots,
before we proceed to a description of the numerous and complex structures which are
attached to stems.

We have already stated that the stem and root proceed in the seed from a central
spot termed the collum, and that they hence take opposed directions, the stem
ascending, the root or radicle descending. This direction of the root is almost uni-
versal ; and wherever it is once attained, no power short of the death of the plant can
prevent its progress.

As the root naturally seeks to bury itself in a medium much more dense than itself,
it is so formed that its extremity has but a very minute diameter, and at that extremity
it is composed of the most delicate structure. The vital process of growth enables it to
insinuate itself, without injury, between stones and other resisting substances. Thus
the root has naturally a conical figure, with its base opposed to the base of the stem,

THE ROOTS OF PLANTS

and the whole plant may be said to consist of two cones, attached by their bases. The
thicker part of the root is termed the cattdcx, the minute apex, the Jiirilla, and its
terminal point, the spongiola. Both of these parts, as has been proved by experi-
ments, have the power of elongating themselves, but more especially the part near to
the free extremity. Our readers may satisfy themselves of this fact by taking any fast-
growing root, as of a hyacinth growing in water, and tying a thread around the roots at
known intervals, and, after the lapse of a few weeks, ascertain, by admeasurement, the
total and relative elongation of the root and its parts. If a plant be selected, the root
of which grows in the ground, it will be found that the relative proportions of growth of
the upper, as contrasted with the lower portion, is infinitely less than in plants growing
in water. This is to enable the root to penetrate with less difficulty the resisting
medium. In this mode the roots of forest trees are enabled to penctra^ *he soil for
many yards from the base of the stem, so as to enable them to get the wnver and other
articles of food which may not be readily afforded at the base of the stem.

The tissues of wh. jh the roots are composed are nearly the same with those of the
stem, viz., woody fibre, ducts, and cellular tissue. The woody fibre does not penetrate
into the spongioles, but is restricted to the parts immediately above it, whilst ducts and
cellular tissue are met with exclusively in those organs. The reason of this arrange-
ment is that the spongiole is an organ of absorption as well as of growth, and by it all
the fluids which enter the plant are introduced ; it is, therefore, not restricted to one
point, as the apex of the
root, but is found on various
parts of it (as may be seen
on the side of the radish),
wherever absorption can be
effected ; and it is of the
greatest importance, in
transplanting trees, to avoid
the destruction of too many
of these delicate thread-like
organs. Some writers re-
strict the term spongiole to
the very extremity of the
delicate fibrilla, which is
somewhat tumefied ; and
there it is said to consist
of a mass of small cells.
This is probably the true
statement of the case, as
may be seen by placing a
thin section of the end of a
root of the radish under
the microscope ; and then
we must regard the ducts
to which it leads as organs
destined to convey fluids
from the spongiole to the caudex of the root. The spongioles have also the power to emit
from the root effete and deleterious substances. Thus it is said that trees (as a pear

Fig. 148. The PANDANVS, or SCREW PINK, emitting aerial root*
at a, b, e, d, and e, which ultimately reach the ground, and give
increased stability to the stem.

92 THE LEAVES OF PLANTS.

tree) -will not grow upon the spot where a tree of the same species recently grew ; and
that, not because the soil was exhausted, but that a poisonous excrementitious matter
had been deposited there by the roots of the former plant.

There are certain plants which emit their roots above the surface of the soil, as the
Pandanus or Screw Pine (Fig. 148), and the Mangrove tree. Such roots are termed
aerial roots; since, until they have sufficiently elongated to reach the earth, they remain
above the ground. Their natural tendency, however, is to bury themselves in the
ground, and they become eventually roots.

Roots vary greatly in figure, and therefore demand special names ; the most common
is the fibrous, as in the oak and forest trees, where the body of the
root is divided into many smaller, elongated, conical portions. If
there is but one conical elongation, the root is termed fusiform.
When the root seems to terminate suddenly at the body, it is termed
premorse, or bitten off ; if it be fleshy, and divided into several globose
parts, it is known as many-headed, or as tubercles in some of the
orchids.

It is often of importance to distinguish accurately between an
underground stem and a root; this is chiefly effected by negative
evidences. Thus a root has none of the appendages of the stem,
such as leaf buds, leaves, scales, scars, and stomata ; and in exogens
it has no pith. Some roots have the power of forming adventitious
buds, but the buds never proceed in a regular manner from fixed
points. So also with branches, when they occur ; they proceed not
Fig 149 A fleshy ^ rom ^ ea ^ buds, but i n an irregular way from any point of the surface,
fibrous root. By these various signs we infer that such enlarged parts of plants,
S.'Thefibrilftejwith as the potato, turnip, and radish, are true stems, although they
the terminal spon- aro situate under- ground, and that they give off the true fibrillse or

roots from their apices or sides.

Appendages of the Stem. Under the head of appendages of the stem or axis
we shall have to consider the respiratory and reproductive parts of plants, such as the
leaves, flowers, and fruit, with their subordinate structures, and shall take them in the
order in which they appear upon the stem.

Leaves. The leaf is the type of construction of all the appendages of the axis, no
matter how developed soever may be their external configuration. It is therefore not
only imperative to a right understanding of other organs that these should be well
studied, but a knowledge of the composition of the leaf is the readiest mode of becoming
acquainted with the structure of its prototypes. We will, therefore, invite our readers
to bear in mind that the immense variety in the figure of the leaf, and in the leaves
and other parts of the flower and fruit, does not imply any difference in structure, lut
that a knowledge of one is a knowledge of all.

The leaf is technically said to be " an expansion of the bark at the base of a leaf-
bud ;" but such a definition gives no idea of its structure. A more tangible definition
is, that it is a flattened and expanded stem ; for every structure, which enters into the
composition of the stem and none other, is present in the leaf. Thus there is cellular
and vascular tissue inclosed on each side by a cuticle.

The leaf is, for the most part, a flattened organ, having two surfaces, or paging a
border, a bore, and an apex, the whole of which constitutes the lamina or blade ; and
it is connected with the stem by a foot-stalk or petiole. The surface is

THE LEAVES OF PLANTS.

commonly marked by a number of ridges which are called veins, and which consist of
woody tissue, spiral vessels, and cellular tissue ; and they are retained in their position,
and the intervening spaces filled up, by cellular tissue. The tissues of the veins are
brought in closer proximity in the petiole, which is a small stem, and having passed
through it into the stem, one part enters the bark, whilst the other traverses the wood
&nd penetrates to the medullary sheath at the centre of the stem. Thus every leaf is
in direct communication with the stem, and not only so but it is a prolongation of the
very pith, spinal vessels, and wood of the stem. The similarity between tho leaf and
the stem may be carried yet further, for not only do the same structures enter into the
composition of both, but in both there is a double set of vessels, one of which conveys
the fluid from the root, and the other back again towards the root. The only difference
between a leaf and a stem is, that the parts of the stem are more widely distributed in
the leaf, and there is an increased quantity of cellular tissue to fit them for their pecu-
liar functions.

We have already, in a previous page, described the cuticle of leaves, with its appendages,
and may, therefore, at once proceed to consider the internal structure of these organs.

The veins of leaves are distributed on an uniform plan, and not as a matter of acci-
dent, and may be arranged under two heads viz., the venation of exogens and the
venation of endogens. The leaf of an exogen is said to be reticulated, and that of an
endogen straight or parallel veined.

The venation of an exogen, as an oak or the holly, consists of a central midrib and
a series of festoons, arranged on either side of it
(Fig. 150). The large branches proceeding from
either side of the midrib are termed primary veins
(2) ; and after they have proceeded for some
distance towards the edge of the leaf they form
a series of curves by which they communicate
with each other, and which are termed curved
veins (3). The curved veins in their turn be-
come trunks, from which other and lesser veins
are given off (4), which from their relative positions
are known as the external veins ; while others,
of a still smaller size, distributed to the mar-
gin of the leaf, are termed marginal veinlets (5).
Thus far all the veins have proceeded from one
source, and clearly belong to one system, being a
series of arches placed upon each other, and all
resting upon the midrib. But besides these veins
there are others, which may be said to belong to an
inner system. Thus the costal veins (6) are
small branches which proceed from the midrib,
at points intermediate to the primary veins ; whilst
the branches of the primary veins themselves are
termed proper veinlets (7), and their anastomoses

common veinlets (8). Such is Dr. Lindley's arrangement, and it is one which merits
approbation.

it. must not be supposed that these systems of veins can be traced in all leaves; for
in the leaves of mosses, and other plants of the lowest class, the-e are no veins ; and in

Fig. 150. representing the complete
venation of an exogenous leaf, as in
the ilex or holly.

1. The midrib.

2. The primary veins.

3. The curved veins.

4. The external veins.

5. The marginal veinlets.

6. The cortal veins.

7. The proper veinlets.

8. The common veinlets.

94 THE LEAVES OF PLAXTS.

certain thick fleshy leaves, as those of the aloe, the veins are altogether concealed.

The first are called veinless, and the last hidden veined.

The venation of endogeneoug plants offers a wide contrast to the foregoing, sine?
there are no reticulations, and the veins run in nearly parallel
lines (Fig. 151). Such leaves are found in grasses, in palms,
and in many exotics grown in hot-houses. They are termed
straight-veined, and their venation consists simply of a series of
primary veins running parallel with, and proceeding from, the
base of the midrih, and by a transverse arrangement of proper
veinlets. An endogenous plant may therefore be distinguished
from an exogenous one by the absence of all reticulation in the
venation of its leaf.

There is a kind of exogenous leaf, which closely resembles
the straight- veined or endogenous leaf viz., the ribbed, in
which three or more midribs spring from, or near to, the base of
the leaf; but it differs in having a reticulation of small veins

Fig. 151. The venation between the ribs. When the midribs proceed from the base, the
of an endogeneous ... . ... , r , ^ , .

leaf, showing its leaf is said to be three (or more) ribbed ; but when they originate
straight _vdns. a j^tle above the base the distinguishing term triple-ribbed is

2. The primary veins, given.

lets ThC proper Vein " There are other arrangements of veins, as the equal-veined of
ferns, the netted, the curve-veined, the radiating, and feather-
veined ; but they are not of sufficient importance to merit further notice.

Whatever may be the precise distribution of the veins, they all tend towards
the edge or border of the leaf, and do not there terminate, but are reflected back upon
themselves, so as to be accurately applied to the under surface of the one now described.
So perfectly is this effected that an observer could not detect the double distribution of
veining in any leaf attached to the tree, and it is only when the leaf is greatly decayed
that the two layers become separate. If such a leaf be handled, so that the veins on
the two surface be drawn asunder, a distinct division of the structure will be perceived.
This division may be accounted for in two ways : first, that there is such a process as
that just described ; secondly, that both sets are formed at the same time, and, from the
earliest moment, are connected together by their extremities ; and that as the leaf
increases in size both sets of vessels elongate equally at the same moment. It must
not be supposed that there is any substance intervening between the two sets of vessels,
for it is highly probable that the two sets form but one bundle.

The importance of clearly establishing the existence of a double set of vessels is,
that there is clearly a double current ; one by which the sap is carried to the leaf, and
the other removing it from that organ. The former occupies the upper, and the latter
the under surface of the leaf.

We have already intimated that the veins consist of bundles of woody fibre and
spiral vessels, with a prolongation of the cellular pith of the stem.

The cellular structure of the leaf is somewhat peculiar, and is admirably adapted to
the lung-like functions of that organ. It is divisible into two portions, a cuticular and
a parenchymatous (Fig. 152). We have already fully explained the structure of the
cuticle in leaves, and shall only further add, that the cuticular cells vary greatly in
size, figure, number of layers, thickness, and hardness ; but that as a rule there are two
layers of cuticular cells on each surface of a leaf. The parenchyma of the leaf consists

THE LEAVES OF PLANTS.

of several layers of somewhat large and thickened cells, which have the power ot

remaining distended, even when examined under the microscope a quality which, in

some instances, is assisted by the presence of a

spiral fibre within each cell (Fig. 44). These

cells also very freely commuiacate with each k '^-' -'- -^-'-l

other (Fig. 152). It may be fairly questioned

if this is not a peculiar structure, since it is

admitted that the cell-walls are not perfect,

and it is certain that they do not collapse when

cut open so readily as other cells.

The connexions of the parenchyma are the
cuticular cells above and below, and the veins
of the leaves which pass through it. It is also,
unlike all other cells, exposed to the direct ac-
tion of the atmosphere, since it receives air
through the stomata, which have their cham-
bers within its structure.

The functions of the parenchyma is to re-
ceive the juices from the upper layer of veins,
and, by the exposure of them to the atmosphere
and other influences, to elaborate them, and
thus to yield them up to the under or recumbent
set of vessels, to be returned to the stem of the
plant. It is therefore somewhat the ana-
logue of both the lungs and the stomach in

animals, for it performs the functions of both these organs. All the functions of res-
piration, which are attributed to the stomata, are fairly due to the parenchyma of
leaves ; for the former bear to the latter only the relation which the mouth and wind-
pipe do to the lungs. The parenchyma, in common with the cuticular cells, is usually
of a green colour, from the presence of starch and chlorophyle within the cells,

Forms of Leaves. The form of leaves is very varied,
but is permanent in the same species, and is conse-
quently the result of design. Except in a few instances
the leaf is never so far modified in form as that the
functions of respiration and digestion are interfered with,,
and therefore the precise neces-
sity for the infinite variations is
not clear, except as evidence of
that Creator's goodness which
cares for the beauty as well as the
utility of his works.

The shape or outline of the leaf
depends on, or is modified by, the
length and relative position of the
veins. When the midrib divides
into branches, and when all the Pip. 154. Leaf of Hy-
branches diverge in the same plane, drocot y le vul * aris -
the leaf is flat, and this may be called the normal state of leayes (Fig. 153) ; when

Kg. 152. A vertical section of the leaf of
the Euonymus japonicus, exhibiting the
cuticular andpurenchymatous structures.

a, the cuticular cells of the upper sur-
face.

b, the cuticular cells of the lower sur-
face, with stomata at c.

e, the lower open parenchyma, with the
air chambers of the stomata, at d.

Pig. 153. Elm Leaf.

9f>

THE LEAVES OF PLANTS.

Fig. 155.

the veins diverge in different planes, the leaf is orbiculai (round), as the leaf of the
common sheep-rot (Hydrocotyle vulgaris. Fig. 154). In succulent or fleshy leaves, such
as the leaf of the house-leek, sedum, several pinks, &c., the veins spread in different
planes, and the parenchyma is so much developed as to conceal the veins, which con-
sequently are neither prominent nor visible, as they are in the greater number of
leaves.

The leaf, when complete, consists of two parts (Fig. 155), a, the petiole, or leaf-
stalk ; $, the lamina or blade. The petiole connects the
leaf with the branch or stem, and is composed of the unex-
panded bundle of fibres, covered by the epidermis ; the ra-
mification of the nerves constitutes the skeleton, and the
veins and veinlets, with the cellular tissue and epidermis,
constitute the entire leaf. When the petiole is not present,
the leaf is termed sessile. Sessile leaves often partially or
entirely surround the stem, and in this case they are termed
semi-amplexical or amphxical (half embracing, or quite sur-
rounding the stem).

The most obvious division of leaves is into simple and com-
pound. In simple leaves the limb consists of one piece, either
quite entire, or variously indented, cleft or divided at the
margin. (See Fig. 155, an entire leaf; 154, a crenate; and
153, a toothed or incised leaf.) Compound leaves are com-
posed of one or more pieces, called leaflets, each of which is
jointed to the common petiole or rach, as it is termed when
the leaf is winged. (See Fig. 156, which represents a pinnate,
or winged leaf.)

Simple Leaves. The shape or contour of the leaf is regu-
lated or modified by the angle of divergence of the lateral or
secondary veins, and by their length. When the divergent
veins are but slightly distant, and extend from the base to the
apex, inclosing only a narrow slip of parenchyma, the leaf is

called linear. The leaves of grasses are familiar Fig. 156. a, the rach,
examples of this form. When the veins extend t Ve' compound leaf 6 ' 8 *
from end to end, and are rather more distant in the

middle of the leaf, the lanceolate form is produced. In these
two forms the veins usually diverge at
the base ; but in the second, viz. the lan-
ceolate form, the relative length of the
secondary veins and their wideness of
angle produce a lanceolate leaf (Fig.
157). When the secondary or branching
veins are nearly of equal length, both at
the base and apex, the leaf is elliptico-

Fit? 1 5S Fii? 1 59

leaf with branching nerve*; la * ceolate ( F %- 158). The oblong leaf
Fipr. 158. Eiliptico-lanceolate leaf. Fig. 159. differs from the latter merely in being
Oblong leaf. rather broader at the base and tip (Fig.

159). When the branching veins are nearly equal, the leaf, being obtuse at both ends,
is called a rounded leaf.

THE LEAVES OP PLANTS.

All these, and many other forms of simple leaves, depend upon the relative propor-
tions of development in the longitudinal and lateral directions ; for in every ease the
apex, or free end of the leaf, is first formed, and then the blade enlarges in both direc-
tions. As a rule, the growth proceeds more longitudinally than transversely ; and
thence, for the most part) leaves are longer than broad. But when it is equal in all
directions, the orbicular or rounded form of leaf results. Again, the lateral develop-
ment never proceeds equally from the base to the apex of the midrib, but is usually
greater at the former than the latter, thus constituting the ovate forms of leaves. In a few

instances, however, the contrary is observed, as
in Figs. 160, 161 ; and it obtains the prefix
ob as obovate or obcordate. When develop-
ment proceeds regularly in these two directions
the surface of the leaf is flat, and may be farmi-
liarly represented by the palm, or aspect of the
hand with the fingers outstretched; but when
between any two veins or fingers the transverse

development is uneven, a degree of puckerinsr
Fig. m-Obovate Fig. 161. -^cordate ^ ^ ag ^ ^ ^ Q holly fr

a few instances of tolerably even growth, the

resulting leaf is not flat, but somewhat tubular, as may be imperfectly shown by
contracting the hand so that the whole thumb and little finger shall approach eaoh
other.

The most frequent variation is the arrest of development at the margin of the leaf.
If the lateral development were complete, it is clear that the edge of the leaf would be
even or entire ; but in many instances it is incomplete, and thence a deficiency ensues

Fig. 162.

Fig. 164.

Fig. 165.

Figs. 166, 167.

Fig. 163.

Fig. 162. Serrate leaf.

Fig. 163. Doubly-serrate leaf.

Fig. 164. A pinnatifid leaf.

Fig. 165. A doubly-pinnatifid leaf.

Fig. 166, 167. Hastate and lyrate-shaped leaves.

which gires a tooth-like or crenate appearance to the edges (Fig. 162). Such a leaf is
termed serrated, toothed, or crenate. The extent of this deficiency varies much, and

VOL. II. J*_ ^

THE LEAVES OF PLANTS.

thence the figure necessarily changes. Thus, when it is much greater than that of a
serrate leaf, the leaf exhibits a series of lateral prolongations or lesser leaves, the
tttached end of which is yet distant from the midrib, and the whole is termed pmnatifd
(Fig. 164). In other instances the arrest of development is equally great at certain
points with the pinnatifid leaf, but is not so universal ; and thence a lyre-shaped or
halberd-head shape results, as in Figs. 166 and 167.

In all these examples the longitudinal system of development is perfect, and the
lateral deficiency is so arranged that the edge of the dentation is entire ; but in many
cases the latter is so modified that the dentations are themselves dentated or serrated.
Such leaves are known as doubly-serrated (Fig. 163), and doubly-pinnatifid (Fig. 165).
When the longitudinal system is modified, at the same time that the transverse develop-
ment is restricted, the leaf puts on a lobed character. Such is represented in Figures

Fig. 168. Fig. 169.

Fig. 168. An angular-lobed leaf.

Fig. 169. An orbicular-lobed crenate leaf.

Fig. 170. A palmate or deeply-divided lobed leaf.

Fig. 170.

168 and 169, in both of which the modification is hut slightly evident; but in others
the division of the lobes is so great that the line of separation passes nearly to the
petiole, as in the palmate leaf shown in Fig. 170, and quite to the petiole and primary
veins in the "Water Crowfoot (Ranumnlus aqwtilis).

It is not necessary that we should enter minutely into the mode of development of

every variety of leaf ; and it is probable that we
have alfeady given such examples as will enable
the reader to apply the principles now enunciated
to any other form which may present itself.
"We shall therefore only
name a few other forms
which are not unsusally
met with. The reniform
or kidney-shaped leaf is
represented in Fig. 172 ;
cordate or heart-shaped,
and sagittate or arrow-
shaped (Fig. 173).

Leaves are, for the most part, developed sym-
metricallythat is, each half closely resembles
the other ; but in some instances this rule is not
observed. Thus in the Begonia the leaf is mani-
festly unsymmetrical, having one side far less developed than the other ; and in some

Fip. 172. Reniform or
kidney-shaped leaf.

Fig. 173. Arrow-headed leaf of the
SAOITTARIA (Sagittce folia).

THE LEAVES OF PLANTS.

of our ordinary trees the transverse development commences on one side whilst it is
absent on the other. Such is shown in the elm leaf, Fig. 153.

Compound Leaves have already been defined to consist of several pieces connected
together at one extremity by the petiole, the whole of which taken together constitutes
the leaf. There is also another explanation of the terra, to which we shall refer pre-
sently. Compound leaves, then, are lobed or pinnatifid leaves, with the divisions
carried down to the midrib or petiole. In their first development they appear as sim-
ple leaves only; and in their subsequent progress may still be regarded as simple
leaves with extreme subdivision. This may be at once appreciated if Fig. 164 be con-
trasted with Fig. 174 ; or Fig. 170 with 17-5 ; or Fig. 168 with the Strawberry

Fig. 174. Fig. 175.

Fig. 174. A leaf of the GLUDITSIA (one of the Acacias), showing pinnate leaves becoming bipinnate,

and clearly exhibiting the mode in which many leaves are formed from one simple leaf.
Fig. 175. A pedate compound leaf of the HORSB CHESTNUT (Fagiis castanea).

leaf, Fig. 176 ; in all of which the reader cannot fail to observe that this mode of
division of leaves into simple and compound is purely artificial. The divisions of

Fig. 176. Fig. 177;

Fig. 176. A STRAWBTSRRY leaf, divided into three leaflets.
Fig. 177. Opposite pinnate leaves, with terminal leaflet.
Fig. 178. An interruptedly pinnate leaf.

Fig. 178.

a compound leaf are termed leaflets ; and, for the most part, each leaflet is of smaller

100 THE LEAVES OF PLANTS.

size, both longitudinally and transversely, than simple leaves. They are subject to
great variety of forma ; and in their development are guided by similar laws to those
already explained in respect of simple leaves.

The most common form of compound leaf is the pinnate (Fig. 180), in which there
are a series of small leaves arranged on each side of the midrib. When they are in
pairs on opposite sides of the midrib, they are said to be opposite; and when single
they are termed alternate. In many instances the leaf is terminated by an odd leaflet
(Fig. 177), and the branch is said to be determinate; when otherwise, the development
of the leaflet has been arrested ; and if no flower exist at the end of the branch, it is
called indeterminate. An intermediate condition is found in such leaves as have small
foliaceous organs attached to the midrib between the leaflets ; and then the leaf is
termed interruptedly pinnate (Fig. 178). It is understood that the normal arrangement
of the leaflets is alternate, as may be inferred from a consideration of Fig. 150 ; for it
is there seen that, although each side is symmetrical, the primary veins (which would
form the midribs of the leaflets of a compound leaf) do not leave the midrib at points
directly opposite to each other. This is also deduced from the observation, that at the
formation of the first leaf at the first node (see page 58), there is no opposite leaf, but
that one is subsequently formed at the next node ; and hence it is inferred that when-
ever leaves are placed opposite to each other, as seems to be the rule in the development
of the leaflets of a compound pinnate leaf, there has been the suppression of an inter-
vening leaf and node. This suppression is carried to a yet greater extent in the arrange-
ment of leaves in whorls (Fig. 179) ; for then not only are there two opposite leaves,

Fig. 179. Fig. 180.

Fig. 179. A whorl of leaves surrounding the stem.

Fig. 180. Representing at a the pinnate, and at b the hipinnate arrangement of leaves.

but the number is increased to four, six, or more. In such instances there has been
an absence of as many nodes as there are leaves, except one. "We may also explain the
formation of leaves in whorls on the same principles that we have applied to pinnate
leaves, viz., that they are all the produce of a divided simple orbicular leaf, as in Fig.
154, in which each leaf incloses one primary vein, whilst a pinnate leaf is in like
manner the product of the division of such a leaf as delineated in Figs. 157 and 158.
This arrangement of leaves into alternate, opposite, and whorled, is also applicable to
leaves, of whatever kind, arranged around the whole branch or tree. In many instances,
and especially in the Umbellifera, the pinnae of the pinnate leaf are themselves sub-
divided, and then the leaf is termed bipinnate (Fig. 180), and is analogous to the
doubly-pinnatifid leaf in Fig. 165.

THE LEAVES OF PLANTS.

101

In other instances the leaflets are not arranged in a pinnate manner, but form o
kind of tuft, as in Figs. 175 and 176 ; but even in Such cases there is no lifnculty in
tracing an analogy between them and the whorled form of leaves shown in Fig. 179.

"We intimated at the head of this section that there is another form of compound
leaf besides that now described, and it is one which is based upon distinct anatomical
characters. It is such leaves as are connected with
the petiole by means of an articulation or aa im-
moveable joint. If the leaf of an apple or -an oak
tree be examined, it will be seen that the midrib
passes uninterruptedly down into the petiole ; but
the leaf of an orange presents a transverse line with
a slight swelling on either side of it (Fig. 181 a), and
at this point the blade of the leaf may be somewhat
readily broken from the petiole. There is no arrest of
circulation at this place, although the separation is
easily effected, for the vessels pass uninterruptedly
from the petiole to the midrib. It is thus not easy
to show how or why such an anatomical peculiarity
should exist ; for the common opinion, that it is the
terminal leaflet of a compound leaf with the lateral
leaflets undeveloped, does not much help us. It is
also found in the common berberry (Herberts vul-
garis), and in a few other plants.

We have already stated that a leaf without a
petiole is termed sessile, or sitting, but when it en-
tirely surrounds the stem it fs known as perfoliate (Fig. 182), and when it runs down
the stem, as in certain
thistles, it is called decur-
rent (Fig. 183).

The petiole, or foot-
stalk of the leaf, is the
assemblage of the veins
of the leaf which con-
ducts the juices to and
from the stem. As it
contains all the vessels
of the leaf it must pos-
sess two sets of vessels, one devoted to the conveyance of fluids to, and the other
from, the leaf. There are also spiral vessels and so much cellular tissue and
cuticle as may connect and inclose the vessels in the most compact forms. The figure
of the petiole is rounded ; but in many instances the upper surface has a channel, and
thence is called gutter-shaped. In other cases it is perfectly flat, or has processes on its
sides which give it the appearance of winged ; or it is rigid, twisted, or hooked. The
grasses and the Ranunculacese have a sheathing petiole, or one which passes down the
stem, and is so large as nearly to embrace it. It has at its point of connexion with
the blade a little organ found universally in grasses, called the ligulu (Fig. 184 a). The
petioles of the leaflets of a compound leaf are termed petiolules.

The distal extremity of the petiole is the part first formed in the bud ; fcnd when at

Fig 181. The compound leaf of the
orange, with the articulation re-
presented at a.

Fig. 182. Aper-
foliate leaf.

Fig. 183. A decurrent leaf, with the midrib adhe-
rent to the sides of the stem.

102

THE LEAVES OP PLANTS.

ligula.

b, sheathing.

c, ligula.

length the whole is perfected it may be so closely connected with the stem that it does
not break off when the leaf has decayed, but hangs with the remains
of the leaf until the following season. A stem thus covered is said
to be induviate ; but in a majority of cases the petiole falls from the
stem, and leaves a mark which is known as the cicatricide. The
angle between the point of insertion of the petiole and the stem ia
termed the axile or axilla, and is the normal position of the leaf-bud
and the flower.

Petioles have several important modifications. Thus in certain
so-called leafless plants, as the acacias, they assume the function of
leaves, and are termed phyllodes; but that they are veritable petioles
is proved by the fact that they bear leaflets at the earliest stage of
their development, and have parallel veins, although occurring in
of a grass, with exogenous plants. Such are the petioles in the Dioncea muscipula or
il fl ^petiole and Venus' s fly-trap (Fig. 1), in which plant they are expanded laterally,
and resemble the true leaves. This modification is due to an unu-
sual development laterally ; but there is another in which it proceeds
solely in the longitudinal direction. Such are tendrils, or spiral -spring-
looking organs, formed sometimes at

the free ends of leaves, as in the pea,

and at others at the side of the petiole

itself, which twist around any fixed

body to seek support for the climbing

plant. (See Fig. 185.)

There is yet a still more curioua

modification of development, that in

which the petiole enlarges, not only

longitudinally and transversely but

within itself, by the separation of its

vessels and the increased deposition

of connecting cellular substances.

Thus the petiole becomes a tube,

closed at the end by which it is at-
tached to the stem, and open at the

other which is opposed to the blade of

the leaf. This is the explanation of

the formation of the interesting organs

known as pitchers (Fig. 185*, p. 103)

the pitchers themselves being the peti-
oles, and the moveablo lid which closes

them being the true leaf. These

pitchers have a further interest in

the functions assigned to them of

containing a watery fluid, and in the

unique fact of the secretions of this

fluid by certain glands formed within

them at their base. In certain plants Fig * 185 The tendril > or elongated petiole or midrib.

they are true fly-traps, and thus become direct organs of nutrition to the plant.

THE LEAVES OF PLANTS.

103

Stipules are leaf-like organs occurring in pairs at th
petiole with the stem (Fig. 184*).
They are formed at the very ear-
liest appearance of the leaf, and
then are seen as two small tu-
mours, continuous with the leaf-
like expansion ; and since they
grow more rapidly than the loaf
itself, they at length become one
of its protective coverings. They

point of connexion of the

n. ie^< ;f Q f;,i M Fi S- 185*. Exhibiting pitchers of various plants produced

Fig.184*. A pairof stipules, f modified petioles, a, pitcher of sarracenia. b, pitcker

b, attached to a stem a, at of nepentes . pitcher O f cephalotus.

the base of the petiole d.

usually assume all the external characters and internal anatomy of leaves (except in size
and position) , and, no doubt, perform the functions of those organs. In certain pod-bearing
plants, as the sweet pea (lathyrus), they cannot be distinguished from leaves ; and, although
they appear as distinct organs in certain roses, they sometimes subsequently become true
leaves. la the polygonums and rhubarbs they do not assume this leaf-like character, but
appear simply as a membraneous, almost colourless, sheath, which surrounds the base of
the petiole and the stem, and is known as
an ochrea (Fig. 186). When they are
found at the base of the petiole of a pin-
nate leaflet, they are distinguished from
the stipules of the whole leaf by the
term stipels. The stipel differs from the
stipule in being developed after its leaf,
and in proceeding in its growth very
slowly. It is occasionally difficult to
distinguish the stipule from certain mem-
braneous parts formed at the base of the Fi &- 186.-Showing the ochrea, a, or sheath, sur-
,....., rounding the stem in the polygonum, and which

petiole of the common crowfoot and um- is a modified stipule.

bellifers ; and in most monocotyledonous or endogenous plants, they are not met with.

We have now completed our account of the fully developed leaf, with its lamina,
petiole, and stipules, without having as yet discussed the constitution of the embryo
leaf or leaf-bud, because, although the leaf is developed from the bud, and the bud is the
first to be formed, yet in the earliest development of a plant the first leaf is produced
without a bud, and passes through its course of development before a leaf-bud appears.

The leaf-bud is an imbricated or scaly coniform organ, placed in the axis of a leaf,
and is a rudimentary leaf or branch formed as the growing season is about to close.

104

THE LEAVES OF PLANTS.

En it, therefore, we rather find the place and the nidus in which the leaf will be

formed in the coming Spring than the parts of a leaf in a rudimentary condition.
There are only two parts which need attention the central
growing point and the imbricated scales (Fig. 187).

The growing point is composed of cellular tissue, pos-
sessing special powers of vitality and growth, and connected
with the horizontal system, or pith of the stem. There are
no vascular structures within the point itself, but spiral
vessels and woody fibre approach near to its base (Fig. 105 a).
It has a highly important function to perform, for not only
is it the point from which all the future leaves must be
developed, but it is probably the means whereby the circu-
lation of the sap of plants is again effected after the quietude
of the previous winter. To what anatomical part of the
growing plant this " pumping " power is to be attributed is
unknown, find the vital principle which excites it to action
has not' been discovered ; so that we must at present regard
this property simply as being a part of its constitution, and
of that of the plant as a whole. This growing point has a
certain analogy with the embryo in the seed; inasmuch as both
tend to growth and reproduction ; but they differ inasmuch that
the leaf-bud needs no fertilization for its development, and
propagates the individual as well as the species, whilst the
embryo imperatively needs fertilization, and continues the
species, not the individual. There is also a resemblance be-

tween leaf-buds and bulbs, page 71.

The imbricated scales (Fig. 187 ), are called tegmenta or coverings, since their

duty is to protect the delicate growing point.

They are foliaceous organs, and are con-

sidered to be identical with stipels. The

outer ones are usually harder and of ruder

texture than the inner ones or those more

immediately surrounding the growing point ;

and in cold climates a further protection is

afforded by a thick downy covering, as in

willows, whilst the scales are thinner and

smoother in plants growing in tropical

regions. All the scales, at least in many

plants, are ultimately developed into

leaves.

The normal position of a leaf-bud is in

the axil of a developed leaf ; but, according to

the opinion of certain physiologists, the sap

Fig. 187. The leaf bud,
with its imbricated
scales, &, pointed extre-
mity and cicatrix of old
leaves, a. The growing
point is inclosed and
hidden by the scales.

18?. The leaf O f the Bryophyllum cagci.
num, in which leaves are developed at its bor-
ders.

has the power of producing buds in any

*, & . . , J

position. It is well known that they have

been produced upon the stems of plants and

upon the leaves of the Bryophyllum (Fig. 188) ; and the fleshy parts of most plants, aa

of the bulb of the Hyacinth, may, by care, be compelled to produce buds, and to repro-

ORGANS OF REPRODUCTION INFLORESCENCE.

105

duce the plant. Still such instances must be regarded as exceptional and irregular ;
and hence the buds so formed are termed adventitious.

ORGANS OF REPRODUCTION.

The foregoing descriptions have referred to those parts of a plant which are con-
cerned in maintaining its own vitality and increasing its development, and may
therefore be termed personal ; but there are other parts which have for their functions
the production of new individuals, and may thence be called relative. Such are the
organs of fructification, and they are known generally as flowers, seeds, and fruit. We
shall consider these in their order.

The Flower is in part a reproductive organ, with certain protective coverings. It
consists of various parts, as the bract, calyx, corolla, stamens, and pistils, in their order,
proceeding from without inwards.

The Inflorescence. A number of terms have been devised to enable us readily
to designate the appearance which the whole arrangement of flowers presents upon the
flower stalk, and it will be convenient to place them here before we enter upon the
consideration of the parts of each flower. Such an arrangement of flowers is commonly
termed the inflorescence.

The flowers are immediately supported upon the stem in one of two ways ; either
by a more or less elongated branch, or foot stalk, termed the peduncle, or by a flattened
more or less fleshy organ, as in the Strawberry, known as the receptacle. The peduncle
differs in no essential respect from the foot stalk of a leaf, its variation being merely
that of size and form to enable it to support the flowers. When it supplies the place
of a stem, as in the Cowslip (Primula], it is called a scape ; and when it is elongated,
and passes in a straight line throughout the inflorescence, it is called an axis, or rachis,
as in Grasses, Fig. 184 a. In many instances, as in the Vmbelliferce (the Parsley), it
is divided into a number of lesser peduncles, each one still supporting many little
flowers, and the divisions are termed pedicels.

The receptacle is very commonly met with, and more particularly
in the most numerous class of plants, the Compositae ; but it is there
not fleshy, and is sometimes distinguished from the fleshy receptacle
of such plants as the Strawberry by the term thalamus. The juicy
part of the Strawberry is the receptacle, as may be observed by
noticing the position of the little seeds which are placed upon its
outer surface. The recep-
tacle is the terminal grow-
ing point of the stem,
and is closely analogous
to the flower head of the
Arum, Fig. 192.

The arrangement of the
flowers upon the foot stalk
or receptacle is primarily

divisible into two classes Fig. 189. The Catkins of the Willow, shoeing
viz.. such as have n a multitude of flowers sessile upon a common

' rachis.
other intervening foot

stalk, and then are called sessile or setting, and such as are stalked. The examples of
sessile inflorescence are the Spike, Locusta, Spadix, Catkin, Capitulum, and Gflomerulu>

Fig. 190.-The
Spike.

106

THE INFLORESCENCE.

The spike (Fig, 190) is represented by the Plantago, and the locusta by the common
Grass ; and they differ from each other, chiefly in that the former has the envelopes
of the flower distinct from each other, whilst in the latter the bracts foim the sole covering.

Fig. 192.

Fig. 193.

Fig. 192. The inflorescence of the Arum, a, the spadix inclosed by the spat'ie; 6, the fleshy rachis,
or spadix denuded of flowers ; c, the spadix covered with sessile flowers.

Fig. 193. A Capitulum in the Composite, o, florets of the ray ; b, florets of the disk; c, floret of
the ray detached; d, floret of the disk detached.

The catkin, as in the "Willow, BO far resembles the locusta, that the coverings are not
distinct from each other ; but it differs inasmuch that the rachis with the flowers falls
in a single piece after fructification, whilst the rachis of the locusta is permanent.
The Spadix, as in the common Arum, is an inflorescence with a fleshy rachis, to which
the flowers are closely attached, and inclosed in the modified bract called a spathe,
Fig. 192. The Capitulum is a head of flowers sessile upon a receptacle, page 105 ; and in
the Compositae the flowers are divided into two classes, \hsflorets of the ray (Fig. 193 a),
which are usually ligulate or strap-shaped, and the florets of the disk, or centre, which
are commonly smaller, Fig. 193 b and d. The Gtomendw consists of a series of heads
in a common involucre.

The second division, or those modes of inflorescence in which the flowers are each
supported by a pedicle or stalk, is an extensive field, and comprehends the most beautiful
flowering plants. It is divided into the Raceme, Fascicle, Corymb, Cyme, Panicle, and
Umbel.

The Raceme is the simplest form, and consists of a series of stalked flowers arranged
on a common peduncle (Fig. 194), the pedicels being of nearly equal length. When
the lower pedicels are so much larger than the upper that the flowers are supported at
nearly an equal height, so as to form a kind of head, the terms Fascicle and Corymb are
applied, the former, as in the Sweet "William (Dianthus), when the expansion of tho
flower is from within outwards ; and the latter when from without inwards. Tho
remaining varieties of inflorescence are somewhat more complicated, since the stalks 01
pedicels are divided, and bear many flowers instead of one only. Thus the Panicle is a

THE IKFLOKESCENCE.

107

raceme, each pedicel of which bears many flowers ; but where the rachis itself divides,
and no longer exists as an axis, the panicle is termed deliquescent. This latter form
gives rise to another variety the Cyme (Fig. 198), as in the Elder (Sa/nbucus nigr)

Fig. 195. Fascicle.

Fig. 194. The Raceme,
its single stalked flowers.

Fig. 196. Corymb.

Fig. 197. Panicle.

which consists of a series of deliquescent panicles that have become short and corym-
bose, with their central foot-stalks meeting at a common centre. The last form is the
Umbel, and is divided into two classes, the Simple and the Compound (Fig. 199). The
Simple Umbel consists of a number of corymbose branches, meeting at a common point,
as in the Cyme, and differs from the Cyme only in that the branches are corymbs and
not panicles. The Compound Umbel is distinguished from the Simple Umbel by the
division of the pedicels, so that they divide and bear other Umbels. The whole head of
Umbels is then called an universal umbel.

Such is a written description of this somewhat complex and difficult subject ; but
!n order to a ready familiarity with the various kinds of inflorescence, it will be
necessary to select the illustrations, and carefully study them with the descriptions,

108 THE INFLORESCENCE.

end after a little attention it will be found that the eye will intuitively, as it were,
recognise the leading forms. "We now proceed to consider the several parts of which a
flower is composed.

Fig. 198. The Cyme. Fig. 199. The Umbel.

The Bract is the outermost envelope, and closely resembles a foliaceous organ, and
bears the like relation to the flower that stipules do to the leaf. Its colour is more or
less green, and as it oftentimes bears much resemblance to a leaf, it is not always
readily distinguished from those organs. The rule adopted in making the diagnosis is,
that all organs, of whatever size, form, and colour, which intervene between the true
leaves below, and the flower above, must be bracts. This definition is too expansive to
render the determination of this question easy in every case, and therefore much
attention must be given by the botanist to each particular instance of difficulty.
Whenever the last leaf on the one hand, and the Calyx (to be mentioned presently) on
the other, can be clearly determined, then whatever intervenes must be of the nature of
bracts ; but whilst it is to be distinguished from leaves only by its lesser size and
higher position, and from the Calyx by its foliaceous character and lower position, there
must be great difficulty in determining its nature in many instances. In some plants it is
necessary to know the number of the divisions of the Calyx, and then to regard all
parts external to these, even if almost identical in colour and structure, as bracts.

So long as they resemble leaves it is not needful to attach to them any more parti-
cular name than that of bracts ; but when they are sensibly modified, it is convenient
to give them other designations. Thus in grasses they supplant all other coverings of
the flower, and are known as Glumes (Fig. 200).

The arrangement of the parts in the flower of the grass is so peculiar as to present
much difficulty to the botanist, and consequently various designations have been given to
the parts or organs. The three parts which constitute the coverings of flowers are bracts,
calyx, and corolla ; but, in this great class of plants, either they do not exist, or they are
incapable of separate definition. On reference to Fig. 200, it will be observed that
there are a series of scales or valves connected by their bases to the common stalk
on which they are supported, and having their apices free and oftentimes prolonged
into beards or bristles. The outer ones, b 1, are large and empty, and are suitably termed
Glumes or Gluma exterior. "Within these are a series of similar but smaller, scales^ attached

THE INFLORESCENCE.

109

in like manner on either side, and opposite to each other, b 2, and which differ froia
the outer ones in that they hear
the organs of fructification, and
each one, in fact, is a separate
flower. These have heen known
as the Gluma interior, or more
recently as the/wfesor chaff. With-
in each of these is a third structure
consisting of two minute and some-
what fleshy scales, d, to which
the term glumetta or squamul has
been given. Of these thiee struc-
tures it is prohable that the first
>r the external glumes have the
greatest analogy to bracts.

The Cupule or cup, as in the
hazel-nut (Corylus), and acorn
(Quercus), is another instance in
which the bracts constitute the
covering of the flower.

The Spathe is a large bract
coloured on its inner side, as in
the common Arum, and in palms,
and in the numerous plants ar-
ranged with them. In this in-

stance there is much evidence

Fig. 200. The arrangement of the flowers in Grasses.

that the inner coverings of the a. A series of flowers arranged on a rachis or stalk.

flnwpr p-n'<!t hut orA indJaQnliihlir b ' A smaller portion magnified,
flower exist, but are mdissolubly ^ The empty external glume .

Connected with the bract. 2, The internal glume with the organs of fructification.

In the amt^tt^ or compound
flowers, as the rosemary, there are
many rows of bracts around each head of flowers on its external surface. This
is called the common involucre ; but besides these there are other bracts placed upon the
head between the little florets, and from their resemblance to chaff they are called palece.
In the sedge tribe (carex) each floret has two bracts adherent at the edges named
urccolus, or perigynium.

The term involucre is employed whenever a series of bracts surrounds a number of
flowers. The word universal is also added in the umbelliferous plants, as the carraway
seed (Carum Carui), to distinguish the common involucre of the whole head of flowers,
whilst the term partial designates the involucre of each little division of the flowers
(umkelltttet).

Perianth (Fig. 201) is a term employed to designate such flowers as have the two
next coverings, the calyx and corolla, combined. Such is the flower of the tulip and
the orchis. In many instances the inner divisions of the perianth are more gaudily
coloured than the outer ones, thus indicating the separation into corolla and calyx
which naturally occurs, and it is customary to describe the three outer leaves of the
perianth as a calyx, and the three inner as a corolla.

The Calyx is that covering of the flower which externally is enclosed by the bracts,

110

THE INFLORESCENCE.

and internally lies in apposition to the corolla. Aa the bract is usually situate at a
distance from the flower, the calyx is in fact the external envelope (Fig. 202). In colour

Fig. 201. Fig. 202.

Fig. 201. The Perianth.
Fig. 202. -Showing the calyx, o, surrounding the corolla, 6, and forming the external covering.

and general texture it resembles a foliaceous organ, and thus may usually be dis-
tinguished from the corolla. When any difficulty occurs in determining the nature of the
coverings of flowers, it is customary to regard the external series as a calyx, whatever
may be its appearance, and thus no flower can be without a calyx (except such as are
composed of bracts only) ; whilst many are met with without a corolla. The calyx is
evidently subservient to the corolla ; for, although it exceeds the latter in size up to the
period of the unfolding of the flower, it usually becomes relatively smaller by reason of
the growth of the corolla, and, in many instances, in the mature state of the flower, bears
no proportion to the corolla in size. The calyx is commonly continuous with the pedun-
cle, and is permanent ; but in many instances it is deciduous, and falls away on the
opening of the flower, or immediately afterwards, as in the poppy and the Cruciferce, or
pod-bearing plants. When the enlargement of the inner parts of the flower causes the
calyx to fall, it usually separates from the peduncle in one piece, and is called op&rculate^
except in falling it be ruptured, when it is termed catyptrate.

The calyx is originally formed of several distinct pieces, which are termed sepals ; and
when, in its after development, these adhere to each other by their sides, and become but
one tube, it is termed mono-sepalous ; but when they still remain distinct, each part is
known as a sepal, and the whole calyx is termed poly-sepalous. The sepals have all the
properties and analogies of common leaves, but have the superadded function of protect-
ing the essential parts of the flower. There is, however, one class of plants in which
the calyx has exceptional characters, viz., the Composite, or compound flowers.

THE INFLORESCENCE.

Ill

The flowers in this class are arranged on a capitttlum, and are very numerous upon one
common receptacle. Each floret is perfect, and therefore has a separate calyx, either rudi-
mentary or developed; which, on account of its membranous character, is termed pappm.
When its divisions are hroad, it is called paleaceous, or chaffy. The terms pilose (velvety),
plumose (feathery), and setee (bristles), express various conditions under which it appears
in its connexion with the ovaiy.

The position of the calyx is described in reference to that of the central organ of
reproduction, the ovary, and is called superior or inferior, as it appears to arise above
or below that organ. But in truth it is simply a question of appearance, for since the
ovary is the central and final point in the development of the plant, all other organs must
be arranged around and therefore below it (Fig. 203). The calyx is consequently
always inferior ; but whenever it adheres to the ovary, or the parts surrounding the

con

err.

Fig. 203. Fig. 204.

Fig. 203. Representing the relative positions of the parts of a flower, and showing that the calyx,

corolla, and stamens must be below the pistil.
Fig. 204. Showing a condition of flower in which the calyx, corolla, and stamens are said to be

superior because they adhere to the side of the pistil or ovary.

ovary, so that it appears as a separate organ only at a point above that organ, it is, in
indefinite language, said to be superior. Pappus is a superior calyx, since it is closely
attached to the ovary. The form of the calyx is a material incident in the description of
a plant (Fig. 205), and many
terms have been invented to
express it beyond those which
indicate the number of its
sepals, and its permanency or
otherwise upon the peduncle.
Moreover the form and size
of each sepal, and the charac-
ter of its margin, are always
referred to ; and the calyx is
said to be regular or irregular,
according to the uniformity
or otherwise of its divisions.
As a rule, the number of
sepals has a relation to the
number of the divisions of the
corolla ; so that if there be five of one there will probably be five of the other.

Fig. 205. Different forma of calyx, a, tnbnlaT; J, Inflated ;
c, flattened ; all being monosepalous, and the two formei
having a dentated margin.

112

THE INFLORESCENCE.

The Corolla. The arrangement of tho various parts of the plant upon the stem ia
agreeable to a definite course in obedience to a known law, as already intimated,
commencing with that of leaves and ending with the ovary. It has also been stated
that each foliaceous organ is normally formed separately and not in pairs, or in greater
numbers, and as the parts are not produced on the same plane or in right lines, but at
different heights and in a spiral manner, each one appears to be alternate to the other.
"When the parts are widely separated this is readily apparent, but when they are brought
close together, the observer is disposed to doubt the fact. Yet in such instances they
are never so closely arranged that they occupy, or appear to occupy, the same spot, but
are placed more or less side by side, and by multiplication ultimately encircle the stem,
and are said to be in whorls. Such whorls of leaves oftentimes seem to be on
the same horizontal plane ; but if such be really the case, it is an exception to the
established rule. Thus it will be evident that the whorls of leaves taken collectively,
cannot be on the same plane, but must be relatively above and below it ; and also that
each member of the whorl will be alternate with a corresponding member of the whorl
above and below it. Such is the rule, liable to many exceptions ; and when, as excep-
tional cases, leaves are found opposite or in whorls and not alternate, it is assumed

that an intermediate leaf, or set of leaves, has
been suppressed, or that the opposite or
whorled leaves have each really split into
two, and thus doubled the original number.
This is a difficult subject for investigation,
but it is highly probable that the former
theory is correct. From this statement the
reader will infer, that if the development of
the tree begins with the formation of leaves,
and ends with the production of fruit, the

leaves and * P 8 * 8 between them and *

flower, showing that the members of each fruit must be situated below the fruit. Thus
whorl are alternate with those of inner and -i v_ a _f a nvA rJa,,^ a ^ n ^^ f>iP lan-o-pa tTio
outer whorls, a represents the whorl of the tne bracts aie P laced above the leaves, tne
calyx, 6 the whorl of the corolla, c the whorl calyx above the bracts, the corolla above
pLr r ov a f ry he8tamenS ' "^ * ** "^ the calyx, the stamens above the corolla ; and

finally, we arrive at the pistil or centre organ

of the whorle. The relatively external and alternate position of the various parts of
the flower are well exhibited in the outline sketches in Fig. 206.

A knowledge of this fact is a fundamental one in botany, and enables us, at this
point of our subject, to include all the parts within the term corolla which lie between
the stamen internally and calyx externally (Fig 203.) ; and, moreover, whenever the
calyx and corolla are not very distinct from each other, the inner whorls of leaves are
thus appropriated to the corolla.

The corolla, then, is distinguished from the calyx by its normally superior and
alternate position ; but it has a further characteristic in being unusually gaily coloured.
It is that part to which the term flower is commonly restricted in ordinary
language, and is longer and larger than any other part. It is almost invariably
caducous, and falls very soon after the impregnation of the inclosed organs When it ,
consists of one piece, it is termed mono-petalous ; and when divided into several pieces,
its divisions are known as petals ; and the corolla is tri-petalous or poly-pet zlous, accord-
Ing to the number of its petals. The number of petals is very variable ; and whilst it

THB INFLORESCENCE.

113

remains tolei-ably fixed in the same species, so long as it retains its wild condition, it is
apt to vary greatly when the same plant is cultivated. Thus, if we take the rose as an
illustration, we find that its normal number of petals is five, as in the hedge rose ; but,
when cultivated, the number vastly increases, until a " perfect " rose, in horticultural

Fig. 207. A perfect E,ose, having nearly the whole of its stamens converted into petnls.

language, should present to view nothing but petals (Fig. 207). Whence, then, has
the rose obtained its additional petals ? Not from new formations, since that would be
in opposition to the established law of development, but from a modification of other
organs which were originally formed for another purpose. This applies not only to the
corolla, but to every part of the flower ; and, as a further rule, it may be remarked,
that the parts so modified are usually, if not invariably, those which are naturally
placed higher on the stem than those into which they become transformed. Therefore
the petals are not produced from sepals, and sepals from bracts ; but, on the contrary,
the bract may assume the place of calyx, and the calyx that of corolla. The newly-
formed petals are thence the product of transformed stamens, or the parts of- fructifica'

VOL. II. 7

THE INFLORESCENCE.

Fig. 208, representing the coBrersion of stamens
into petals, in the Wafer-lily (Nymplnva alba).

Hon which lie immediately within the corolla. In thjs mode the number of stamen,
diminishes in proportion as that of the petals increases ; and this transformation may
readily be traced in any garden rose. The gradual conversion of the one into the othei
is well exhibited in Fig. 208.

It thus becomes evident that the
number of the petals can seldom be em-
ployed with certainty as a distinctive
mark in the classification of plants. But
yet it is not without its value in such
plants as retain their natural habits ; and
the more so when it is known that any
increase is usually that of a multiple of
the original number, as that five petals
become ten or fifteen.

In respect of position, the corolla naturally places itself below the ovary (Fig. 208) ;
but whenever it is so attached to the side of the ovary, so that it separates itself only
when above that organ, the relative terms of superior and inferior are still employed.
Thus all corollas are said to be either superior or inferior.

As a petal is the analogue of the leaf, it is probable that it will have similar parts ;
and thus we describe the expanded part as the lamina y and the contracted part by which
it is inserted as the unguis, or claw. In many instances, as in the rose, there is no unguia,
just as many leaves are destitute of petioles; whilst in many others the claw is seve-
ral times the length of the lamina, as in the pink, and the petal is termed unguiculate.
The short claw of the petal of the Crowfoot (Ranunculus) has on its inner surface a
small gland which secretes honey, and is a true nectarium (page 69), but which may
probably be a modified stamen.

The forms of the corolla are extremely numerous, as is familiar to every one, and
require special designations. If we first examine a monopetalous corolla we find three
parts, which, by their variations, give variety of
form. First, there is the expanded portion, which
consists of a series of laminae, connected at their
margins, and which has its free border more or
less indented or divided in such
a manner that the divisions are
regular or irregular (Fig. 210) ;
secondly, the tube, constituted
of the united edges of the claws ;
and, thirdly, the point at which
the tube is inserted, or expands
into the expanded laminae, which
is termed the/aw^; or throat. In
a few instances, other parts enter
into the formation of a corolla,
as the corona or cup observed

around the throat of the Narcissus (Fig. 209), and the true Nectaria,
Fig. 209 The corona, or honey spots, so well known to the honey-bee. A campanulate, or
SroIidj rCi86 ic bell-shaped corolla (Fig. 210 a), as in the Campanula, has little
tluoat. or no tube ; and BO in like manner with the flattened rotate cr

Fig. 210. , a regular, and b, an
irregular corolla.

THE INFLORESCENCE.

115

Fig. 212 . Hypocrate-
riform corolla, a,
daliate.

wtieel-shapcd corolla. The tube is greatly elongated at the upper part in the Injpocratt
form or salvor-shaped corolla (Fig. 212) ; whilst the injundibuliform, or funnel-shaped
corolla, differs from the latter chiefly in having the tube expanded at its upper part.
There is yet another form of m< nopelatous corolla, called the labiate, and which offers
the greatest resemblance to the
inftindihuliform variety. Its dis-
tinctive mark is the division of
the expanded part into two por-
tions, which in some degree re-
semble lips (Fig. 210 b], and are so
placed that one is called the lower
and the other the upper lip. When
they are widely separated, as in
the dead nettle, the corolla is said
to be ringent (Fig. 211), or grin-
ning ; and when the upper lip is
hollowed and expanded, as in the Monkshood, it is called
galeate, or helmet-shaped. When, on the other hand,
the lips are pressed closely together, as in the Snap-
Fig. 211. Ringent corolla. dragon, the corolla is said to be personate. These ar
fanciful terms, but yet in many instances give a
familiar idea of the forms to be represented.

The forms of a polypetalous corolla are perhaps less varied than those now
described, and, for the most part, will readily suggest the names by which they are
designated. Such, for example, is the cruciate corolla, which is divided into four parts
like a Maltese cross, and having six stamens, four of which are long and two short.
There is, however, one very marked variety, which offers some complexity, vit.,
that of the Pea, and many other plants, called the papilionaceous or butterfly- winged
corolla (Fig. 213). Such a corolla has also five divisions or petals, four of which are
arranged in pairs, and one separately. The pairs form the earina, or keel, a, and im-
mediately inclose the sexual organs ; the alee, or wings,
b, which lie on either side of the earina; and, lastly,
the large vexillum, or standard, c. The two former names
are not inappropriate ; but the latter one might have
been well exchanged for some term designating a sail.

The anatomical structure of the corolla differs in no
essential respect from that of leaves. There is, however,
a greater delicacy of organization, and variation in the
relative proportion of parts. Thus, whilst there are
stomata as in leaves, they are fewer, and are accom-
panied by a smaller quantity of the parenchyma. The
veins of the corolla contain a larger proportion of spiral
vessels, and less of woody fibre, than is found in leaves.
The colours, even the pearl white met with in the corolla,
are due to a colouring matter termed chromule (page 53), placed within each individual
cell ; and so carefully is this distributed, that adjoining cells may vary considerably
in colour. The function of the corolla is that of leaves, with the superadded one of
protecting the organs of fructification.

Fijr.213. Papilionaceous form
of corolla.
, the earina or keel

b, the alse or wings.

c, the vexillum or standard.

THE STAMENS.

The Stamens. We now enter upon the description of the essential parts of the
flower viz., the sexual organs, cr those parts concerned in the process of reproduction.
All the organs which have hitherto heen described are accidental, and not essential,
since many plants are met with without them, and since their sole duty is to minister
to the wants of these central and ultimate objects of vegetable organization. No plant
exists which has not organs of reproduction of a higher or a lower grade of organiza-
tion ; whilst many are wanting in every other accessory structure.

The stamens are placed within the corolla, and immediately surround the central
point or pistil, and are regarded as the male organs
of reproduction. When longer than the corolla, they
are said to be exserted (Fig. 215) ; and when shorter,
they are included (Fig. 214). Their number is very
variable, from one to fifty, and even more ; and from
the causes already mentioned (page 112), it is not
permanent in the same plant, or the same class of
plants. It is, however, commonly the same as the
' petals and sepals ; or, if it vary, it is a multiple of
that number (Fig. 215). They may constitute one
whorl only, which will consist of an equal or double
number of the petals, and if of the same number, they
will be alternate with them ; or there may be several
whorls, all of which lie nearer and nearer to the
pistil, and follow the same law as the outer whorl.
It is not an unusual occurrence to find the stamens
placed opposite to, and not alternate with, the petals,
or with an inner whorl of themselves ; but this is an
abnormal condition, and arises from the suppression of alternate individuals or whorls.
This may be readily understood by reference to Fig. 206, in which the stamens are
double the number of the petals ;
so that each alternate stamen in
the whorl will be alternate with,
and each other stamen opposite
to, the petal. If, therefore, these
stamens be removed, or placed
in an inner whorl, which are
opposite to the petals, the sta-
mens will then be alternate with *"te-216. Shonringaplan

of a double row of sta-

the petals ; and thus the normal mens, c, arranged al-
ii*. 21S.-With double the number number and position of the parts ^ tely * ith . * he -
of exserted stamens to the petals. c ,, a selves, and with the

oi tne nower be produced. J3ut petals, b, and sepals, .

if, on the other hand, the euppressed stamens are the alternate and not the opposite
ones, the flower will become more abnormal by the alteration.

The stamens are also necessarily placed on a plane lower than that of the pistil or
ovary, and, therefore, must be inferior, as represented in Fig. 203. But not ^infrequently
they are said to be superior, from the attachment which they contract with the sides of
the ovary (Fig. 204). Three Greek terms have been devised to express this apparent
relation in position between the stamens and the pistil viz., Hypogynous, as in the
Poppy, when normally placed below the ovary (Fig, 225) ; Epigynous, when growing

Fig. 214.

a, the central pistil.

b, the stamens included.
e, the corolla.

d, the calyx.

THE STAME> T S.

117

upon the ovary (Fig. 218) ; and Perigynous when placed around it (Fig. 217), and
attached to the calyx or corolla, as in the Rose all of which terms, although inaccu-
rate, are in constant use.

Fig. 218.

Fig. 219.

Fig. 217.

Fig. 217. Perigynous stamens.
Fig. 218. Epigynous stamens.
Fig. 219. Monodelphous stamens of the Mallow ; a, forming a tube ; 6, pistils.

The point of insertion of the stamens is into the peduncle, at its terminal point ;
but sometimes they contract adhesions with themselves, which give such plants a
distinctive peculiarity. Thus of ten stamens in the Pea tribe of plants, nine are united

together, and constitute a bundle, to the exclusion
of the tenth (Fig. 221 a). In the Geranium and the
Mallows the whole
are united into one
body (Figure 219);
whilst in the Hy-
pericum (Fig. 220)
there are three, four,
or more bundles. These conditions are
expressed by Greek words, which signify
the number of bundles or brotherhoods.

Thus the Geranium is Monodelphous (one brotherhood), the Pea Diadel-
phous (two brotherhoods), and the Hypericum Triadelphous or Polydel-
phous (three or many brotherhoods). This union of the anthers refers to
their lower parts, and is sometimes so close as to have received the name of
columna, or gymnostemium, as in Orchids ; but there is another which has
exclusive reference to the upper vis., such as is met with in the Compositse.
Like that great class, the number of stamens in each floret is usually five ;
and they are so connected together at the top as to form a tube, through
which the pistil passes (Fig. 222). Such a condition is termed Syngenesia
(to grow together). Again, there are differences in size as well as position,
both accidental and essential. The accidental are such as have shorter ones, F jg > 2227
from an uneven development within the period of growth, either from Syngenesia.
original tardiness of appearance, or from some subsequent hindrance to mens united"
growth. This may be well seen in the Poppy, in which thu great number . ^> tne P^ s ~
of stamens offers a facility for this kind of investigation. In the oxalig, also, thro' them 1 . 8 "

Fig. 220. Poly-
delphous stamens.

Fig. 221. Diadel-
phous stamens.

118

THE STAMENS.

Fig. 223. Fig. 224.

Fig. 223. Dydynamous stamens.
Fig. 224. Tetradynamous sta-
mens.

it is not unusual to find one-half of the stamens shorter than the other. The essential
differences in size are such as are permanent in the
same species ; and of these there are two examples.
Many flowers with a bilabiate corolla, as the Foxglove
and Mint, have two long and two short stamens;
whence they are called Didynamous (Fig. 2 2 3). The
cruciate corolla, as in the Turnip and Radish,
has usually four long and two short stamens; and
to them the term Tetradynamous (Fig. 224) is aptly
applied.

The number and arrangement of the stamens was a
chief element in the classification of Plants by Lin-
naeus ; and of the twenty-four classes arranged by
him we- have now referred to five. Eleven others
vary simply according to the number of stamens,
from one upwards, and are named from Greek words having that signification. Thus
Monandria signifies one stamen ;
Diandria, two stamens ; and so on to
Dodecandria, which represents twelve
or more stamens up to twenty.

Two others viz. Icosandria and
Polyandria have an indefinite number
of stamens, which in the former are
perigynous, and in the latter hypogy-
nous (Fig. 225). Thus no fewer than
eighteen out of twenty-four classes
are arranged according to the number,
length, and place of insertion of the
stamens.

"We have hitherto regarded the
stamen as a whole, but it is naturally
divisible into three parts, each of

which has special functions and analogies. These are the filament, anther, and its

contained pollen, the first of which may be
entirely absent.

The filament is, as its name implies, a
thread-like organ, attached by its base to the
peduncle, and by its apex to the anther, and
a, lily ; is simply a pillar on which to rest the
;oe; d, be; erry; , latter> and a conduit through which vessels
and fluids pass for the nourishment and
growth of the pollen and its case the anther. It is the analogue of the petiole
of the leaf, and like it consists of a bundle of vascular tissue, enveloped in cells,
and a delicate cuticle. Its figure is seldom quite cylindrical, but more com-
monly tapers towards the top, when it is said to be awl-sbaped. In a few in-
stances, as in the Meadow Rue, it is the thickest at the top; in others it is spiral, or is
bent like an elbow or knee (geniculate), or bifurcates into two branches. In some
instances it assumes a foliaceous form, and likewise in most sterile stamens. The

Fig. 225. The Poiyandrous flower of the Poppy.

Fig. 226. Different forms of stamens.
b, cluck weed ; c
ginger ; /, sage.

THE STAMENS. 119

outer whorl is the most subject to this modification, and also to the transformation into
petals. Its colour is usually white; but in the Evening Primrose and the Fuschia it is
gaily coloured.

The anther is essential only so far as it protects the pollen, which is the male essence
in the plant. It consists of a series of cells, which are attached to the top of the fila-
ment in three recognizable modes. First, when the base of the anther- case is connected
with the apex of the filament (innate, Fig. 229) ; secondly, when the union is at the
back of the anther (adnatc, Fig. 231) ; and, thirdly, when it is so slightly attached, as
in grasses, that it can swing freely in almost any direction (versatile), Fig. 237 B. This
and other facts will be better understood by a reference to the analogies of the anther ;
for as that organ is the modified lamina or blade of the leaf with its edges so folded that
it can inclose contents, it would evidently be expected that in its normal state it should
be attached to the filament or petiole by its base.

This view of its construction will also lead us to infer that there are two cells (one
on each side of the midrib), with two points of union viz., one behind, called the
midrib, or dorsal suture, and one in front, known as the newly-formed ventral suture.
There will also be one line of separation or division viz., that lying between the dorsal
and the ventral sutures, called the connective. Such, it is probable, is the normal type
of construction of the anther ; but in the extremely modified form in which the leaf
thus appears, it is no matter for wonder if the relations of parts should be found much
altered. Thus the connective is sometimes absent, and then the anther is one-celled ;
and, on the other hand, a new septum arises across each cell, and the organ becomes
four-celled ; and this latter, according to the investigations of Schleiden, is the more
common form of anther (Fig. 227).

Its actual construction is best seen at the period of its opening or dehiscence for the
expulsion of the pollen, and the precise mode of its rupture has been carefully investi-

Fig. 227. Fig. 228.

Fig. 227, representing a cross section of an Anther. A, the connective with the bundle of vessels at
a ; B, the halves of the Anther corresponding with the halves of the leaf; d t processes sub-
dividing each lateral half, so as to form four loculi or cells.

Fig. 228. Exhibiting the ordinary mode of dehiscence at a, by longitudinal fissure, leaving the cell
open, and some grains of pollen attached , and at 6, the opening by the rupture of the valve or
face of the Anther c, which then curves back, as in the Berberry.

gated. It is certain that the line of rupture runs longitudinally along the ventral
suture, and not transversely, except in a few instances, as in the Duck- weed (Lemna),
Fig. 226 b, and that the cells open by a separation of two portions or valves, which

120 THE STAMENS.

diverge more or less widely from each other, and thus give the appearance of a one-
celled organ. In many plants the cells are either unequal, or one only is developed, as
in the Sage (Fig. 226 /), Canna, and the Arrowroot plant ; or after the commencement
of the process of development the two cells become confluent, and produce a single cell.
As each cell will have a separate line of dehiscence or fissure, a two-celled anther
will have two fissures, and a four-celled four fissures, and the latter is probably of
common occurrence. But besides the number of fissures, there are other points of dis-
agreement with the general law. Thus in a few instances the pollen is emitted not by
a fissure, but by small holes, or perforations ; or the fissure does not occupy the whole
length of the cell ; or the cells burst first into each other, and then have a common dehi-
scence ; or a large portion of the whole face of the anther comes away in a piece (Fig.
228 /;). But however much so minute a matter may vary, it is of importance to bear in
mind that it proceeds on a fixed plan, and that its whole organization has a known
correspondence with it.

"When the line of dehiscence is towards the petals, the anther is said to be extrorsa,
and when inwards towards the pistil, it is called introrsce. The lining membrane of the
cells is called Endothecium, and usually consists of fibro-cellular tissue, whilst the pollen
occupies the position of the normal parenchyma.

The Pollen. The parts of the stamen already described seem to include in their
analogies the whole leaf; for the filament represented the petiole, and the anther the
lamina, with the parenchym in which the pollen is deposited. But yet there is another
and the most essential part of the stamen as yet undescribed, and one which has also
its analogies in the leaf itself. This substance is known as the pollen, and is the imme-
diate source of fructification. It is a powdery substance of various colours, but more
commonly colourless, as may be noticed upon any fully-developed flower. It is
that material which is shaken like dust from the flower, and which is not un-
frequently adherent to the nose when that organ is searching out the sweet odours of
flowers.

Its normal position is the anther case, where it remains until it has arrived at a
stage of maturity fitted for the performance of its functions,
when it is emitted by the dehiscence or sudden rupture of the
anther, or pollen case, and is ultimately deposited upon the free
end of the pistil. The quantity of small grains of pollen upon
a single stamen is immense infinitely greater than is needful for
the fertilization of the pistil ; but that is a wise arrangement to
insure fructification, despite the influence of winds, the sterility
of some of the stamens, and the irregularly-placed pistil. If our
readers will examine any half-dozen plants, which may be near
to them, in full bloom, and notice the relative height of the
pistils and stamens, they will wonder not why so great a waste
of pollen has been provided by nature, but that the fertilization
exhibiting pollen should be effected with so much certainty. The improbability of
this occurrence is of course greater where the male and female
parts do not exist in the same flower ; yet not only does it pro-
ceed regularly where there are separate flowers for nvdes and others for females, but
in our large forest trees, in which one tree has male flowers only, and another
only female flowers. In such cases the pollen is carried by the wind that very \
influence which at first sight seemed more likely to cause an entire waste of the I
_ J

THE STAMENS.

121

fertilizing material ; but in other instances, as in the Bee Orchis (Fig. 2uO), it is pro-
bable that insects and birds are the means of con-
veying the pollen to the pistil.

Before we describe the influence of the pollen, it
is needful to refer to the anatomical characters of
that substance. The pollen appears to the naked eye,
or with a lens of low power, to consist of a number
of particles or granules, of various sizes and figures,
which are technically termed cells. The more com-
mon figure (as is the case in all cells which lie loose),
is spherical, or ovoid ; but the most diverse forms have
been noticed. Thus they are square in the Bladder
(Senna), and tri-
angular in the
evening primrose
(Fig. 233). In
various com-
pound flowers
they are many-
sided ; in other
plants they are
twisted; and in
Dill they are cy-
lindrical. Such,
however, are ex-
ceptional cases ;
and whether they

Fig. 230.-An Orchis, with its gy- may be attributed
nandrous flower.

to pressure as in

the cells of cellular tissue, is not known.

When examined with high magnifying powers, as with the eighth of an inch ob-
ject glass, they are found not to be simple cells, but cells having a cell- wall divisible
into two or three layers, and inclosing a turbid-looking fluid, termed fovilla. The ex-
ternal layer of the cell-wall is usually itself composed of cells, and is called the extine ;
whilst the inner one is of greater delicacy and extensibility, and known as the inline.
In some instances, as in the Yew, there is a third membrane between these two, and
named the exintine, whilst in the Evening Primrose a fourth has been described as the
intexine. It is probable that all pollen cells have the two former ; but it is not indubi-
table at present that the two latter are at all commonly found.

Thefovilla usually consists of two portions, which are in constant motion, as may
be seen in the garden plant, Clarlcia pulchella, one of which is larger and more oblong
than the other ; and as it differs from all other vegetable structures, it is presumed to
be the fructifying substance.

Such is the structure of the pollen before it is applied to the stigma ; but after it
has commenced its fructifying function it exhibits characters unseen before. Thus,
immediately it has fallen upon the soft viscid tissue of the pistil, it begins to emit one
or more minute processes, which traverse the length of the pistil, and are called pollen
tubes (Figs. 232.233). These tubes terminate in the placenta, and thus constitute a medium

Fig. 231. Exhibiting adnate stamens
and a pistil elevated much above the
stamens.

122

THE STAMENS.

of communication between the pollen upon the surface of the pistil and the young
embryo. It is presumed that some undetected material is con-
veyed through the tube, which is the immediate source of ferti-
lization ; and it has been observed that the flower has begun to
fade immediately after this occurrence, as though the function of
that organ hau then ceased.

How swnute and wonderful are the structures and their
functions found in vegetables ! equally so with anything known
in the animal creation. Thus all the parts of a plant, external
to the stamen, are created in perfect subserviency to the func-
tions of that organ ; and of the stamen itself, how small a portion
seems to be essential. The filament supports the anther, the
anther incloses the pollen, the cell- walls of the pollen inclose a
little matter, and it is only a part
of that ultimate production which
is essential to the function for
which the' plant was chiefly
created !

Before leaving this part of our
subject we must refer to a sub-
stance lying between the true
stamen and the pistil, and which
is considered to consist of unde-
veloped stamens. It is known
as the disk (Fig. 241 <?), and
appears under various forms, according to the so-called superior and inferior positions
of the ovary. In the Compositse and Umbelliferae, with their inferior ovary, the disk
is a fleshy body, placed upon it, and oftentimes assumes a scaly appearance. In
others, as the Dead-nettle and other labiate plants, it is found beneath the ovary, and
has some resemblance to glands. As it is a mass of undeveloped stamens, its position
will always be below the ovary, although it may adhere to that organ, and seem to be
perigynous or epigynous.

HIT. 232. Pollen tubes,
passing fajmtte pol-

conducting tissue in

Fig. 253. Pollen tubes in the
CEnothera bienn-is.

Fig. 234. Grains of Pollen ; a, Fuschia ; b, Scirpus romanus ; e, Sal via; d, Armeria fasiculata ;

e, Acacia.

The Pistil. The pistil is the female part of the flower, and the central point
around which all the organs placed upon a branch are arranged. It is usually
a complex organ, and oftentimes compounded of many leaves. It is readily distin-
guished by its central position, and the dissimilarity between it and the stamens in
height and form, and more particularly by the absence of an anther at its apex. Occa-
sionally it puts on a foliaceous appearance, as in Fig. 235.

THE P13TIL.

123

In a majority of instances it is alone ; but not unfrequently there are several pistils
so ad to constitute one or more whorls. When only one exists, it is termed Monogynia^
from two Greek words signifying one
female. Digynia will signify two pistils,
and so on (as was explained with regard
to the stamens), until we arrive at Do-
decagynia, which represent about twelve
pistils. In this mode eleven orders are
added to the classes referred to at
page 118; and to these one other is
appended viz. Polygynia, which sig-
nifies an indefinite number of pistils.
The number of pistils, as well as of
stamens, forms an essential element in
the Linnaean classification, and is so
employed that a plant with one stamen
and one pistil would be arranged in the
class Monandria, and order Monogynia.

The pistil, like the stamen, is divisi-
ble into three parts, each of which, as
well as the whole, being a modification
of the parts of a leaf. They are, first,
the free end or apex, called the stigma
(Fig. 236 d] ; second, the dilated base, or ovary (b) ; and, third, the intermediate struc-
ture, or style (c).

The stiff ma is one of the few external parts met with in vegetables, which are not

Fig. 235, showing a Pistil with recurved ends, and
having a leafy character.

Fig. 236.

Fig. 237.

Fig. 238.

Fig. 236. The pistil in section, showing its turgid stigma, d ; the style, with the conducting tissue, ci

ovary, b ; peduncle, a.

Fig. 237. A, a pistil with notched stigma; B, versatile stamens.
Fig. 233. Stigmas with collecting hairs.

covered with cuticle, at least in the vast majority of instances. Its surface ia usually

124 THE PISTIL.

turgid, and covered -with a viscid tenacious fluid. It is either simple or divided
into two or more parts, and when divided the divisions for the most part arrange them-
selves in a whorl. The simple form has also usually a notch in the side (Fig. 237, A),
indicating the normal division of even a simple stigma into two parts (see page 126). The
anatomical character of the stigma exhibits a series of cells of various sizes, bounded on
the sides by another series, which are the cuticular cells. It is in direct connexion with,
and in fact is formed by the conducting tissue, to be described with the style, and through
which the pollen tubes pass (Fig. 232). The function of the stigma is that of collecting
the granules of pollen upon its surface, and conveying the emitted pollen tubes to the
style. It is oftentimes assisted in the collection of the pollen by hairs which surround
the style, and which, by the movement of the air, are enabled to sweep the pollen out of
the ruptured anther (Fig. 238). Whether it exercises any influence upon the pollen, so
as to cause it to emit its pollen tube, or whether the property of emission is exclusively
that of the pollen i; not known. The part of a leaf with which it corresponds is the
very apex of the midrib ; and as the leaf is folded inwards on each side of the midrib in
order to form the pistil, it is manifest that the stigma will be formed by the two surfaces
folded together, and thus be double and lateral (not absolutely terminal) . It is present
in all fertile plants, except in such trees as the Fir tribe, in which the seeds are naked
(Fig. 249), and is stalked when situate at the end of the style, and sessile when the style
is absent, as in the Poppy.

Style. This resembles the filament of the anther ; and as its function is that of sus-
taining the stigma at a convenient distance from the ovary for the reception of the
pollen, it may be entirely absent. It varies in form, being flattened and leaf-like in
the iris, very thick and sometimes angular in other instances, whilst its most usual
character is that of a thread-like or tapering process. It is almost always colourless.

The anatomy of the style is somewhat peculiar, since it not only has bundles <)f
vascular tissue inclosed by a cuticle, as in the filament and the petiole, but there is a
superadded structure called the conducting tissue (Fig. 232). This tissue is of cellular
character, with the cells loosely arranged, and probably is a prolongation of the placenta
(page 126). It is connected above with the stigma, and below with the ovary, either
at its highest point, as is usual, or at its side, and varies much in quantity. It is
analogous to the elongated midrib of the leaf.

The Ovary. This is the expanded base of the pistil, and is destined to contain the
seed, and to become the fruit. It is therefore a most essential part of the organs of
reproduction, and is the seat of the latest developments of the plant. It is a hollow
organ, consisting of a single cell, or divided into two or more compartments, in each of
which one or more ovules or seeds are normally found. The ovules are attached to the
ovary by the intervention of a small mass of cellular tissue, called (from its analogue in
animals) the placenta, and not unusually have an intervening thread of tissue named
the funis.

The form of the ovary is usually spherical or conical, but sometimes it is flattened
and angular. The size varies very much. It is usually sessile, or sitting upon the
end of the peduncle ; but in a few instances, as in the Passion flower, it is supported on
a long stalk.

The analogue of the ovary is the lower expanded portion of the leaf, or, more pro-
perly speaking, the whole of the lamina except the terminal extremity of the elongated
midrib. This is the type of the construction of the ovary ; and one which enables ua
to determine the conformation of the ovary with considerable accuracy. "We shall now

THE PISTIL.

125

direct attention to this interesting but difficult subject ; and in doing so shall conb.de
the pistil as a whole.

If we take up any oval sharp-pointed leaf, such as that of the Poplar, and fold its
edges together, so as to inclose the upper surface,
we shall have the mode of construction of the
ovary. It will then present an internal cavity
without any partitions, bounded on each side by
a plate or valve, which is the half of the lamina
on each side of the midrib. There will also be
two lines of union, or sutures, one on the back
formed by the midrib, which in the leaf naturally
unites the two sides of the lamina, and the other
in front, formed by the union of the edges of
the leaf. The former line of union is called the
dorsal, and the latter the ventral suture. Each
ovary will thus have an expanded base and a
narrower apex, with a single cavity, two lateral
pieces or valves, and a dorsal and a ventral

suture lying between them. Such an ovary

* c and d represent u single and double car-
is termed simple ; and as it develops the placenta

pel, with a and b to illustrate the mode
of construction out of a leaf. The lower
expanded portion is the ovary, and the
free upper end the stigma. There are
two carpels ; they face each other at d
and b. e, the ventral suture ; /, the
dorsal suture.

upon the inner edge of the ventral suture, the

placenta will be partly attached to one side and

partly to the other, and thus be double. So, in

like manner, with the stigma above mentioned ;

it is situate at the extremity of the midrib, on the ventral suture, and will be formed

by both sides, and consequently be double. The style, when it exists, will have, on its

dorsal aspect, the vascular structures belonging to the midrib ; and on its anterior or

ventral part, the new tissue described as the conducting tissue (Fig. 228), which will

either be a mass of placentas or a prolonged placenta. Thus the stigma, conducting

tissue and placentae, occupy the ventral suture ; whilst the vascular tissues are formed

at the dorsal suture.

This description will apply equally to an ovary, which consists of many such leaves,
so far as each separate leaf or carpel, as it is then termed, is concerned, provided the
development of each part proceeds normally. But something further must be said in
reference to the arrangement of the leaves or carpels.

If the various carpels are so situated that they are not connected with each other,
the ovary is called Apocarpus (Fig. 240) ; but if, as is usually the ease, they are closely
and indissolubly associated, the ovary is said to be Syncarpous (Fig. 241). "When only
two carpels are formed they may be placed side by side, that is, with their ventral
sutures having the same direction ; or facing each other, when the same sutures will
regard each other (Fig. 239). If three or more carpels are formed, they will, in obedience
to a general law, be placed in a whorl, and consequently have all their dorsal sutures
directed outwards, and their ventral sutures directed inwards, or towards a common
centre. As the carpels will thus be placed side by side, there will be spaces, however
small, between them ; and thus there will be alternately a carpel and a space (Fig. 243).
The space will be bounded by a carpel on either hand, and may therefore be said to
have double walls. The space and the boundary walls are together called the dissepi-
mentt, or septa ; and when the carpels are united into one mass, the whole may bo

126

THE PISTIL.

regarded as one cavity, divided into several compartments by these septa, as in
the Orange, which exhibits an ovarium of ten carpels. These compartments are
called cells ; and an ovary made up of many carpels is said to have so many cells, as,
for example, a four-celled ovarium (Fig. 242) . But it often-
times happens that the septum becomes imperfect, and thus
reduces the number of cells or compartments ; and should
this be the case with all the septa, a many-celled might
be reduced to a one-celled ovarium, as in the Poppy. So
far, then, a compound ovary consists of a whorl of carpels
and a number of cells and r-spta. Its style will also be
compounded of the midribs o' so many leaves, and have an
equal number of bundles of vascular tissue and lines of
conducting tissue. The stigma will be compound, and

Fig. 240. Fig. 241.

Fig. 240. Apocarpus ovary, in which each pistil is separate. A, situate within the rows of stamens

on the flower ; B, detached
Fig. 241. A pyncarpous ovary, or an ovary in which the carpels are indissolubly united, o, ova-

rium ; b, limb of the calyx, united to the side of the ovary ; c, the disk surmounting the ovary ;

d, placentae ; e, ovules ; /, style ; g t stigma ; i, peduncle.

represent the same number of leaves, or double the number should each half of the
stigma of each be separate ; or it may be that the styles and stigma of each carpel
remain distinct, and then there will be as many pistils as there are carpels. This
is an arrangement of the ovary found very frequently; but in the
Ranunculus or Crowfoot, the Strawberry, and many others ^Fig. 240),
the ovarium is still more complicated. The further complication is
due to the presence of two or more whorls of carpels instead of a single
whorl. We will consider an ovarium of two whorls only, since, if that
be understood, the reader will readijy comprehend the arrangement of
any number of whorls. When two whorls exist, one will be within the
other ; and thus the dorsal sutures of the inner will be opposed to the ventral sutures
of the outer whorl ; and in obedience to the law mentioned at page 116, the members
of the inner whorl will be alternate with, and not opposite to, the members of the
outer whorl. Thus a member of the inner whorl will be immediately in front of
the septum, or line of dehiscence, of two members of the outer whorl. This will also
apply to the styles and stigmas of the inner as opposed to those of the outer whorl.

Eeference is frequently made to two circumstances connected with the arrangement
of the carpels t'tz., the position of the placenta and dissepiments relatively to the
stigma and other parts. As the placenta and stigma are both formed on the inner side
of the ventral suture (Fig. 244, c), the position of one may be determined by that of

Fig. 242.-A
four-celled
ovarium.

THE PISTIL.

127

Uie other ; and should the edges of the ventral suture be open at the point of develop-
ment of the placenta (Fig. 239), and closed at that of the stigma, there will be two

Fig. 243. Fig. 244.

Fig. 243. Showing two rows of carpels, one within the other.
e n.dicates the dorsal and d the ventral suture ; -whilst dis and the bracket mark the position and

composition of the dissepiment or septum. The dorsal suture, e, of the inner whorl is opposed

to the dissepiment of the outer whorl.
Fig. 244. Representing the alternate position of the dissepiments, or septa, with the placentae ami

carpels in an ovary with three carpels, a ; 6, is the dissepiment, or the interval between the

carpel and its boundary walls ; c, represents the ovules and placenta at the angle of the carpels,

and separated from each other by the dissepiments.

placentae to each carpel, and the latter will have a placenta on either hand. So, also,
should the stigma be double whilst the placenta is single, the two stigmas will be on
either hand of the placenta.

As the dissepiments consist of the interval between the carpels, as well as of the
walls which bound it, and, in fact, lie between the carpels, they will be alternate with
the stigma, placenta, and carpels (Fig. 243). They will also be perpendicular or
longitudinal from the base to the apex of the leaf, and will be equal in number to the
carpels, at least when more than two carpels are present, and one carpel cannot have a
dissepiment.

Various irregularities occur in the development, or subsequent growth, of the parts
of an ovary, and especially in reference to the placentae and septa. Thus, when the
placentae are not developed on the inner surface of the ventral suture, but upon the
outer surface that is to say, on the part looking into the space between the carpels
the septa and placentae will be opposite to and not alternate with each other ; and then
the placentae will be alternate with the stigma. Again, in many cases, as in the Poppy,
the Lychnis, and the Violet, the septa are imperfect, and do not extend from the dorsal
to the ventral suture. In the Lychnis the portion to which the placentae are attached
at the ventral suture remains, whilst the remainder is altogether removed \ and thus the
placentae, with a small portion of the septa, remain isolated at the centre of the ovary,
and are termed " free central placentae " (Fig. 245). In other instances the central
part, or the ventral suture alone, is reuv /ed ; and then the placentae are situated on the

;

128

THE PISTIL.

sides of the septa, and are called lateral placentae (Fig. 246). In others still, the
whole dissepiment is removed, and the placentae are placed near to the dorsal suture
(Fig. 247).

Fig. 245.

Fig. 246.

Fig. 247.

Fig. 245. Representing an ovarium with free central placentae.

Fig. 246. Lateral placentae in the POPPY ; the centre being vacant.

Fig. 247. Lateral placentae placed very near to the dorsal suture, as in the VIOLET.

The source of the placenta is still a matter of doubt ; but it is either the termination
of the growing point, as Schleiden affirms, or it is a modification of the cells of the leaf
at the ventral suture. As the position of the placenta is the centre of the very extreme
end of the branch, and as it is the point of attachment and growth of the ultimate
organ of reproduction in plants, it is probable that Schleiden' s theory is both more
correct and more philosophical than that which has been more universally received.

Before leaving this part of our subject we should state that the pistil is rarely, if
ever, transformed ; but occasionally it is itself a transformed stamen, as in the Horse-
radish (Cochkaria armoracid), and the House-leek (Sempervivum tectorum).

The Ovule. Having now described the house provided by nature for the seed,
or embryo plant, we proceed to consider the organs for the protection and growth of
which it was designed.

The ovule is the unripe seed, and consequently is the product of the organs of
reproduction in the plant. It resembles a leaf-bud in its function, and also in ita
structure, in so far that it has a central growing point and protective coverings ; and
in many instances, as the Mignionette and other plants, it has directly produced leaves,
without the intervention of a leaf-bud.

The nucleus is the central growing point (Fig. 250, g), and consists of a mass of
cells, having the chemical constitution of albumen ; within it is a cavity containing
fluid called the amniotic sac and fluid (Fig. 250, A). It is formed at the earliest mo-

Orthotropal. Campy lotropal. Anatropal. Amphitropal. Semianitropa

Fig. 248. Representing the relation -which the base and apex of the nucleus bear to the hilum

and foramen in the normal and abnormal conditions
The dot represents the foramen, the * the chalaza ; the outline is the primine, and the opening

into it is the hilum at which the vessels enter.

mcnt of the development of the ovule, and subsequently is inclosed in two coverings or
sacs, open at the top, the outer one of which is called primine (Fig. 250, c), and the

THE PISTIL.

129

inner one secundim (Fig. 250 c*). The secundine is very delicate, and is larger than
the primine, and usually protrudes through the opening, or foramen (Fig 250 0J, and
can be examined only at the earliest period.

It has already been stated that the ovule is connected with the ovary by means of
a placenta, and a delicate cord, termed the umbilical
cord (Fig, 250 a) ; and this is universal, except in such
plants as have naked seeds, or seeds and ovules deve-
loped without ovaries (Fig. 249). Such are the Coniferoe
and Cycads, whilst the Mignionette has the seeds par-
tially naked. When it grows from the base, or near
to the base, of the ovary, it is called erect and ascending,
respectively ; and when suspended from the top, or near
to the top, is termed pendulous and suspended, respectively.
The relative position of the nucleus, coverings, foramen,

and funis, is variable, and

is important, since it enters

into the classification of

plants. In the normal

position the base of the

nucleus is next to the pla-
centa, and is marked by a

hilum on the coverings at

which the vessels enter,

whilst its apex is directed

to the foramen. Such an

ovule is termed orthotropal

(Fig. 248 a). When this arrangement is changed only
so far that the foramen is curved down so as to approach
the hilum, the expression campylotropal is employed
(Fig. 248 b]. In other cases the nucleus changes its
position : so that its poles are reversed, and its base is
removed from the hilum to the point most distant from

it, whilst the foramen with the apex of the nucleus is brought near to the hilum.
This change is called anatropal (Fig. 248 c), as in the Apple, Almond, and Cucumber.
The terms amp hi tr opal and semi anatropal (Fig. 248 d and t), indicate that the two ends
of the nucleus are transverse with respect to the hilum.

Whenever the nucleus has its base removed from its normal position at the hilum,
it is in danger of dying from want of nourishment, since thus it is separated from the
placenta and umbilical cord (Fig. 248 c), the source of its nutriment ; but this is
averted by the formation of a bundle of vessels called a rap he (Fig. 248 e), occupying
the ventral suture of the ovary, and passing from the hilum to the base of the nucleus,
where it distributes itself in a star-like form, termed chalaza. The chalaza, therefore,
cannot exist apart from the hilum without a raphe", and both are absent so long as
the base of the nucleus is in apposition to the hilum in the membranes.

FRUIT.

When the ovary and its contents, of which we have now treated, have arrived at
maturity, they are named fruit, and that quite independent of any edible qualify wLicli

\OL. II. K

Fig. 249. Representing a cone,
between the scales of which
the seeds lie naked.

Fig. 250. Exhibiting the va.
rious parts of an ovule.

a, the placenta, with its vas-
cular cord leading into

e, the raph, which expands
at/, at the base of the nucleus,
and forms the chalaza.

c, the priniine, with its fo-
ramen or exostouie, b.

c*, the secundine, with its
foramen or endostome, bx.

d, the nucleus, with its apex
g, and amniotic sac, h.

THE FRUIT.

they may or may not possess. At this stage the ovule has matured into a seed, and the
ovariuiu either remains still as a mere containing vessel, or certain parts of it have
become fitted to sustain the life of the seed during the earlier periods of its germination.
It is to the latter form, as the Apple, that the term fruit is popularly applied ; but, in
botanical language, the term still comprehends the ovariuni with its contents, whatever
may be the nature of either.

Fruit, then, consists of various parts viz., the ovary and its contents ; but in many
instances there are additions to it, in the form of the remains of some or all of the other
parts of the flower. Thus, in the Strawberry and Apple, the calyx remains, and is

converted into a succulent substance, or the part of
these fruits which is eaten ; and in the latter the
corolla also remains. The Pine Apple is composed
of all the parts entering into the composition of the
ovary viz., bracts, calyx, corolla, and ovary. The
Orange (Figs. 181 and 19) is an ovary containing
the seeds, and a succulent mass, in which the re-
freshing juice is placed. On the upper part of this
ovary, and at the centre, will be found a circular
spot, at which the pistil was formerly attached to
the ovarium, and traces of the like attachment may
be found upon most fruits ; but in certain large
classes, as the Labiata and Rosaceae the style passes
from the side, and not from the centre of the su-
perior aspect of the ovary. In a few instances only

251.- in,- strawberry, consisting i s the ovarium absent; viz., in the case of the naked
seeds of the Conifer* and Cycads (Fig. 249), and in

one or two others, in which the ovarium is ruptured, and the seeds escape long before
the maturity of the fruit ; but when the fruit has been formed, the term ovarium is no
longer applied.

The structure of the fruit is precisely that of the ovarium, except in the instances
in which the maturation of the organ has caused certain malformations ; and although
the former is undoubtedly the rule, the latter occurs so frequently that an examination
of the parts is at all times necessary. Thus, on the one hand, the number of carpels
seems to be lessened, as in the three-celled ovarium of the Cocoa-nut (Cocos nuiifera], in
which but one cell and one seed remain in the fruit. Such is also the case in the
common Hazel-nut, except that the absorption has progressed a step further, and
has left but one cell and one seed out of three carpels and six ovules. In a few other
cases the number of cells is at least apparently increased, since new partitions are placed
across the ovarium, in order to separate the seeds from each other.

The fruit, like the ovary, is also said to be superior or inferior, and for the same
reasons viz., the adherence of the envelopes of the flowers in the latter and not in the
former. It is divisible into two distinct parts the/seed and the pericarp.

The Pericarp is composed of three parts or layers, one within the other viz., the Epi-
carp (a) or external layer ; the Endocarp (b] or internal layer ; and the Sarcocarp (c) or fleshy
substance lying between them (Fig. 259). Thus, in the Apple the outer skin is the
epicarp, the juicy part of the fruit the sarcocarp, and the tough thick wall-celled cover-
ing to the seeds (Fig. 36) is the endocarp. The same relation is found in stone fruit ;
and the stony covering of the seed is the endocarp. The epicarp is less subject to

CLASSIFICATION OP FRUITS.

131

variation than the other structures; but the sarcocarp and endocarp assume every
possible variety of form and consistence.

We have not hitherto referred to the mode of opening of the ovarium, since it is not
until that organ has attained its maturity that it becomes necessary to make provision

Fig. 252. Representing the ordinary modes of dehiscence of fruit, a, Septicidal, or between the
carpels ; b, septifragal or by the backs of the carpels ; c, loculicidal, or through the dorsal suture.

for the emission of the seed. This occurs in the fruit, and is a matter of much interest.
From the construction of the ovary it may be assumed that the normal mode of rupture
of the fruit would be between the carpels ; and such a mode of dehiscence, as it is termed,
is said to be septtcidal (Fig. 252 ). When the whole back of the carpel comes away
from the septa and the ventral sutures, the dehiscence is called septifragal (Fig. 252 6) ;
and when the septa remain perfect, whilst the ventral sutures become detached
from each, and the dehiscence proceeds through the dorsal sutures of each carpel, it is
termed loculicidal (Fig. 252 c). The pieces into which the fruit is thus broken, are
termed valves ; and in the first mode (dehiscence), each valve consists of an entire
carpel, whilst in the two latter it is formed by parts of two adjoining carpels. When
the fruit is simple, that is, composed of but one carpel, as in the Pea (I'isum, Fig. 260),
the dehiscence is through sutures, and is called sutural, and there are no dissepiments.

In the Scarlet Pimpernel (Anagallis) there is another mode of dehiscence, one in
which the upper part of the capsule or ovary is detached ; and, as the line of separation
is horizontal and not perpendicular, the term circwnscissile has been employed.

Classification of Fruits. The great variety which exists in the external
appearance and anatomical characters of fruit, renders it necessary to devise terms
which may serve easily to distinguish one kind from another ; and as the number of
such terms is very considerable, it has, at all times, been customary to classify them
according to their relationships. This has been effected by various writers, with
different degrees of success ; and, as we cannot devote much space to a consideration of
this question, we think it will be most useful to transcribe the newest, and perhaps the
most comprehensive, system, that of Professor Lindley.

CLASS I. Fruit simple. APOCARPI.
One or two-seeded :

Membranous UTRICULUS.

Dry and bony ACH^ENIUM.

Fleshy externally, bony internally . . . DKTJPA.
Many-seeded :
Dehiscent :

One-valved FOLLICTJLUS.

Two-valved LEGUMEX

Indehiscent . : LO.MEXTUM,

132 CLASSIFICATION OP FRUITS.

CLASS II. Fruit aggregate. AGGREGATI.
Ovaria elevated above the calyx :
Pericarpia distinct
Pericarpia cohering into a solid mass . . ,, SYNCABPIUM.
Ovaria inclosed within the fleshy tube of the calyx . CYNARRHODUM,
CLASS III. Fruit compound. SYNCARPI.
Sect. I. Superior :

A. Pericarpium dry externally .

Indehiscent :

One-celled CARYOPSIS.

Many-celled :

Dry internally :

Apterous . . . . - . CARCERTJLTJS.

"Winged SAMARA.

Pulpy internally .... AMPHISARCA.
Dehiscent .

By a transverse suture .... PYXIDIUM,

By elastic cocci REGMA.

By a longitudinal suture .... CONCEPTACULUM,
By valves :

Placenta opposite the lobes of the
stigma :

Linear SILIQTTA.

Roundish SILICULA.

Placentae alternate with the lobes of

the stigma :

Valves separating from the replum CERATIUM.
Replum none .... CAPSULA.

B. Pericarpium fleshy :

Indehiscent :

Sarcocarpium separable .... HESPERIDIUM.

Sarcocarpium inseparable . . . NUCTJLANIUM.

Dehiscent TRYMA.

Sect. 2. Inferior :

A. Pericarpium dry :

Indehiscent :

Cells two or more CREMOCARPIFM.

Cell one :

Surrounded by cupulate involucrum . GLANS.
Destitute of a cupula . . . CYPSELA.
Dehiscent or rupturing DIPLOTEGIA.

B. Pericarpium fleshy :

Epicarpium hard :

Seeds parietal PEPO.

Seeds not parietal BALAUSTA.

Epicarpium soft :

Cells obliterated, or unilocular . . . BACCA.

Cells distinct POMUM.

CLASS IV. Collective fruits. ANTHOCARPI.
Single :

Perianthum indurated, dry ..... DICLESITJM.

Perianthum fleshy . SPHALEROCAR-

Aggregate : PITTM.

Hollow ..,,,.,.. SYCONUS.
Convex :

An indurated amentum . . , . . STROBILUS.
A succulent spike ...... SOKOSIS,

VARIOUS KINDS OF FRUIT.

The most common kinds of fruit axe the Pomunt (Fig. 256), or Apple ; Drupa, or

Fig. 253.

Tig. 261.

Fig. 260.

Fie. 253. Siliqua. 'Fig. 254. Capsule. Fig. 255. Siliqua, with valves separate.

Figs. 256 and 50. The Pomum. Fig. 257. Strobilus. Fig. 258. Drupe.

Fig. 260. Legume. Fig. 261. Glans.

Drupe, as the Plum (Fig. 258) ; Strobilus, as the Pine Apple (Fig. 257) ; Glans, as the

134

THE SEED.

Fig. 262. Seed,
a, cotyledons ; b, embryo.

Acorn (Fig. 261) ; Legumen or Legume, as in the Pea (Fig. 260) ; Siliqua, or pod, as
in the Mustard (Fig. 255), and which differs from the Legumen chiefly in the longi-
tudinal false dissepiment at a being present in the former, and dividing the cavity into
parts ; Capsule, as in the Larkspur (Delphinum] or Poppy (Fig. 254) ; and acca, or two
berry, as Currant.

The Seed. The seed is the mature ovule, and in its internal anatomy maintains
a great resemblance to that body. The pro-
cess of growth and development has, how-
ever, induced certain modifications which it
it needful to understand, and the more so
that the characters of the seed have of late
years become of great importance in the
description and classification of plants. Like
the ovule it consists, in general terms, of
a growing point, and contains membranes.
The term embryo is expressive of the former
(Fig. 262 ), and testa, in a general sense, of
the latter.

The testa, or coverings of the seed, are divisible into three or more layers viz. the
outer one, or primine ; the inner one, or secundine ; and the third coat, or tercine. The
detection of these three coats is oftentimes a matter of difficulty ; but our readers who
have tolerably good microscopes, and who have attained to a certain degree of delicacy
of manipulation, need not fear to enter upon it. It will be needful to examine a seed
in its fresh state, and to seek the separation of its coats by immersion in water for some
hours, and subsequently by the aid of the needles.

The outer integument is commonly smooth, somewhat dense, and resisting ; but it
may assume every variety of character. The most interesting departure from the
established rule is in the instance of the Cotton seed (Gossypium], Sage (Salvia, Fig.
263), and the Collomia grandiflora, in which a large number of
shrivelled hairs are attached to this membrane. There is no
difficulty in seeing them in the Cotton plant under every condi-
tion ; but in the latter examples they are inappreciable to the
naked eye, until they have been immersed for an instant in
water, when they start out, and give a fringed character to the
seed. The hair in this case contains a spiral fibre (Fig. 263),
which is the cause of its elasticity (pages 14 and 66). In other
instances it is largely developed and fleshy. The inner membrane
is placed immediately within the outer integument, and itself
incloses the most external or third coat. This latter envelope
is in immediate proximity to the nucleus or embryo, and is diag.
nosed from its inclosing covering simply by the non-perforation
of its apex.

These various membranes are seldom distinct in the seed, and consequently it is
customary to speak of the testa of the seed rather than of the primine, or any other
specific part of the covering.

The Nucleus. This is the growing point already referred to at page 129, as the
nucleus of the ovule, and now consists of two distinct parts, the true growing point,
or embryo, which, in the futiire germination, elongates upwards and downwards to

Fig. 263. Fibres of

THE NUCLEUS. 135

form the new plant ; and, in most instances, one or more masses of albumen destined to
supply food to the newly forming plant.

The direction of the embryo in the seed varies as greatly as that of the nucleus in
the ovule, and is always determined by similar means viz., the position of the chalaza,
micropyle, and raphe. The terms employed to designate this relation are similar to,
but not identical with, those given at page 128 in reference to the ovule. Thus antitropal
in the seed corresponds with orthotropal in the ovule, the sacs of the ovule not being
inverted, but the embryo inverted with respect to the seed, as in the Stinging Nettles.
Orthotropal in the seed, as in the Apple, is the anatropal of the ovule ; amphitropal in
the seed, that of camphylotropal in the ovules, as in the Mignonette, and have both
apex and radicle next to the hilum ; and last, heterotropal in the seed, is the amphi-
tropal or semi-anatropal of the ovule, and they lie across the seed. In the antitropal
and amphitropal forms there will be neither raphe nor chalaza; whilst in the ortho-
tropal and heterotropal varieties both these parts will be present.

The above is indicative of the relation which the embryo bears to other parts of the
seed ; but there is also a relation which the whole seed has to the fruit of which it
forms a part. The seed is termed ascending, when the direction of its apex is that of
the apex of the fruit ; descending, when the contrary, or towards the base of the
fruit ; centrifugal, if towards the sides ; and centripetal, when towards the axis of the
fruit.

The albumen varies greatly in quantity, as may be seen by contrasting the split Pea
with the white of the Cocoa-nut. It also offers great diversity in solidity, from a mass
of jelly-like consistence, to the hardest ivory, as in the Ivory Nut (Fig. 38) in its dried
state. It is not present in all seeds, and in many is so minute in quantity that the
microscope alone can detect it. Wherever it exists, it immediately surrounds the
growing point. Its structure is cellular, as shown in Figs. 37, 38, 39, and others,
as may be readily proved, by placing a very thin portion of a green pea under the
microscope. When it is met with in the embryo sac (page 129) it is called Endosperm
(within the seed) ; and when it constitutes the nucleus it is known as the Perisperm
(around the seed). Sometimes it is placed near to the chalaza ; but it never occupies
the position of the membranes. In Dicotyledonous plants, as the Pea,
the seed readily separates into two halves, which proves that the mass
is divisible into two lateral and symmetrical portions, termed Cotyledons,
or seed-leaves (Fig. 262). In Monocotyledonous plants, as the Palms, the
albumen cannot be divided into parts, and hence the terms Monocoty-
ledon, or one seed-leaf (Fig. 264) ; and in certain plants it is so reduced
in quantity that the seed is termed Acotyledonous, or a seed without coty-
ledons. These terms are of great moment, and of constant employment,
since the two former correspond to the exogenous and endogenous divi-

FiR. 264. The 8 i ons o f plants referred to at page 81, et sea. All flowering exogens, or
Monocotvledo-

nous seed of nearly so, are Dicotyledons ; all endogens, or nearly so, Monocotyledons ;
the Grass after and all fl owe rless plants, Acotyledons. The arrangement of the parts
germination . T_ i

has begun. in the embryo varies in the classes just mentioned, as might be

C ' ^imnule 1 '' ex P ec * e ^> when in germination one puts forth no seed leaves, another
r, radicle. only one, and a third two. The direction of the Cotyledons is usually
straight ; when two or more exist, they are placed face to face. They are said to be
incumbent when they are folded with their back upon the radicle, but accumbent when
their edges occupy that position.

136 COTYLEDONCUS PLANTS.

The seed of a Dicotyledon, as the Pea or Apple, presents the following parts (Fig.
265) : two Cotyledons, or seed-leaves, a, at the upper part, within the base of which ia
a minute point, destined to become the stem, named the plumule, b;
and at the bottom of the seed is the radicle, c, having dimensions
larger than those of the plumule, and separated from the Cotyle-
dons by an unseen line, the caulicule. Sometimes the Cotyledons
are absent, or cohere into one mass, or divide into a greater num-
ber, as four in the Cruciferse, and double that number in some of
the Coniferae.

An approach to the condition of a Monocotyledenous seed, is
seen in such Dicotyledons as have great inequality in the size of
the Cotyledons ; so that one of them is scarcely perceptible. In
this class (Monocotyledons, represented in this country by the . ^~^

Grasses), there is no such distinction of parts as that now referred the Garden Bean,
to ; but the lower part of the seed emits a number of radicles ^[k^radicle lu "
(Fig. 264 r), whilst from the upper part the thread-like green
plumule, p, is emitted. Thus the growing points are sheathed by the embryo, which
remains within the testa throughout the process of germination. There are many
exceptions to this description; but they do not materially invalidate the rule now
given. Monocotyledonous plants are as exclusively endogenous (p. 86) as dicotyledo-
nous are exogenous in their general structure.

There are certain plants in which distinct Cotyledons have not been discovered, and
hence have been termed Acotyledons ; but this would not be a correct mark of distinction
for the members of the two classes now described, since it is probable that there
are parts analogous to Cotyledons. The true diagnostic is, that in these plants the
germination does not proceed from fixed points, as the plumule and radicle, but
indifferently from any part of the surface of the seed. This is the condition of the
embryo in the great class of plants to which we shall presently refer viz., the flower-
less plants.

There are yet one or two points to which reference must be made, before we conclude
this account of the seed. The Amnios (Fig. 250) is a fleshy bag surrounding the embryo
in many seeds, and consequently lying within the innermost integument. It has also
been termed the Vitellus, or Yolk-bag, and it probably performs an analogous office in
the sustentation of the embryo.

"We have already referred to the hiluni and other vascular parts of the ovule and
seed, and need here only to state that the hilum is the umbilicus, or the spot at which
the vessels from the placenta enter the seed. In many plants it can scarcely be seen,
whilst in others it is of a dark colour, or is very large, as the Pea, Bean, and Horse-
chestnut. The micropyle, or foramen, is the opening in the seed to which the radhle
is always directed, and may be at the end of the seed opposite to the hilum, or the two
may be close together, as in the Pea ; or it may occupy other positions, as shown at page
128, in reference to the ovule. Its position determines that of the radicle, and conse-
quently is of importance. The chalaza and raphe have precisely the same indications
in the seed as in th" ovule ; but the latter is always distinctive of the face of the seed
when the figure of that organ does not render the determination of that question easy
The placenta is the cellular expansion by which the seed is attached to the ovary,
and brought into direct connexion with the sexual organs of the plant through its pro-
longation the conducting tissue of the style.

THE ARIL OF THE NUTMEG.

1ST

The fonts, or umbilical cord, when it exists, connects the hilum of the seed with
the placenta, and conveys the vessels to the ovule and seed.

The aril is known familiarly to our readers by the spice
called mace, which is the aril of the nutmeg, as may be
determined by an examination of the preserved fruit. It
presents a great variety of forms and characters in various
plants, and oftentimes it is difficult to distinguish it from other
structures ; but here, as in the case of bracts, negative evidence
is of value, and supplies us with the expression, " that every-
thing proceeding from the placenta, except the seed, must be an
aril," It is not of large size, except in fully developed seeds.
It is closely applied to the outer integument both of the seed
and ovule, and in its analogies has been regarded as an ovulary
leaf. Arils are divided into two classes viz., true and false
arils, the distinguishing mark being, that in the former the
micropyle or exostome either is covered, or would be covered,
by the aril, if it were sufficiently extended; whilst in the
latter the micropyle is at all times free. It is probable that the aril of the nutmeg
belongs to the latter class.

Fig. 265. Aril of
Nutmeg.

138 FLOWERLESS PLANTS FERNS.

FLOWERLZSS PLANTS.

There yet remains, before we conclude this first division of our subject viz., the
structure of plants to mention a few special modifications of those organs now
described as they are found in the flowerless plants ; and in doing so we beg our
readeis to bear in mind, that they are not new structures but modifications of those
belonging to flowering plants. There is, however, the most marked line of demarcation
between flowering and flowerless plants, both in their minute composition and their
external configuration ; and we might almost venture to affirm, that we have here an
exception to the rule, that nature ascends and descends by imperceptible degrees. There
is, however, no new element in structure, in this lower division, than has already been
described in reference to the flowering plants ; so that the existing diversity is due to
the number and arrangement of these elements in the general fabric.

It is customary to consider flowerless plants as more lowly organized than those
which bear flowers, although it is through them that the vegetable kingdom approaches
the animal. This seems paradoxical, seeing that the animal kingdom is manifestly of
a higher grade than that of vegetables ; and proves that, from the highest members of
the animal kingdom, we do not pass through the lowest to the highest vegetables (as
would be the case were the views commonly received properly carried out), and thence
to the lowest plant, but that the well-defined members of both kingdoms are wide as
the poles asunder, whilst the lowest members are so intimately associated, that it is yet
undecided whether they belong to the animal or the vegetable kingdoms.

There is reason, however, in considering the flowerless plants as the lowest members
of the class, since their organization is more simple. Precisely so, also* in respect of
animals ; and thus the two kingdoms may be likened, not to one cone with an artificial
line drawn across it at some undefined point, but to two cones with their apices con-
nected, and their expanded part, or base, at either extremity.

The great point of dissimilarity is that connected with the organs of reproduction ;
and the question of sexes, and their product, has ever been, as it now is, the bone of
contention. That every member of the whole is endowed with the faculty of repro-
duction is perfectly evident ; but the precise mode in which it operates, and even the
immediate seat of its operation, is shrouded in mystery. This, however, is only the
counterpart of the condition of the lowest animals ; and therefore the one is no more
matter for wonder than the other. In both kingdoms the lowest examples have abun-
dant power of reproduction ; but the distinction of sexes is not evident. When, there-
fore, we affirm that there is nothing new in the class of flowerless plants, we mean that
every part of the structure has its analogue in the higher division of the vegetable
kingdom.

The flowerless plants are numerous and very varied, and comprehend chiefly the
Ferns, Club-mosses, and other kinds of Mosses, Lichens, Mushrooms, and Sea-weeds.

Ferns. This extensive class of plants is known in this country only by herbaceous
varieties, or such as have their stem or root in the ground, and present to view a series
of leaves only (Fig. 266). But in hotter climes the stem is above ground, and often
attains the height of fifty or sixty feet, and a diameter larger than a man's thigh (Fig.
270). The following are their chief anatomical peculiarities :

The leaves are termed fronds, and they bear the organs of fructification in little
cups or receptacles on their edges, or on their under surface (Fig. 267). These exhibit

THE FBRNS.

139

little masses of granules, of defined forms, termed aori, and consist of a containing organ
called sporangia, theca, or capsules, surrounded by a ring (gyrus, or annulus], and a

Fig. 267.

Fig. 266.

Fi?. 266. A Fern, Polypodium Vulgare, as it grows in our climate.
Fig. 267. Fructification in the Polypodium.
Fig. 268. Sori emitting spores.

number of contained cells, termed spores or sporules, from which new plants are directly
produced. Thus the organs of fructification may be likened to the ovary with its con-
tained seeds, and doubtless this is their true analogy ; but to the naked eye they have
a greater semblance to the anther with their contained
cellular specks of pollen; and this latter idea is further
strengthened by the fact that the spores, as well as the
pollen, are produced on and from the cells of leaves. The
sporangia burst with elasticity ; but this property is pos-
sessed alike by both anther and ovary. There can be
no reasonable doubt but that they are the female organs
or ovaries, with the spores or seeds.

There is much difliculty in determining what are the
male organs, if any, existing in Ferns. Some have
referred them to the articulated hairs which are found sur-
Fir. 269.-The fructification of rounding the sporangia; and others again have imagined
the Ophioglossum Vul^atum, that the layer of epidermis which covers the sporangia in
showing the transverse i lits, a. ^^ ^^ ^^ indusiuni) may be connected with that

function. Nothing certain, however, is known.

140

THE TREE FELJST.

There are no sporangia in that division of Ferns known as the adders' tongues ; hut
the whole leaf is rolled up on either side of the midrib^ and becomes a containing organ*
At maturity the leaf opens by transverse valves, and emits the spores (Fig. 268).

The foot-stalk of the frond is called the stipes, and consists of bundles or plates of
hard woody fibre and scalariform vessels, connected together by cellular tissue, which
pass down into the stem within the bark, and appear to form a part of the zones of wood.
The arrangement of the parts in the stein of the Tree Fern is very peculiar ; and
although it has no close resemblance to either the exogenous or the endogenous arrange-
ment, it seems to be more closely allied to the latter. Thus the rind or bark consists
of one or two layers only of cellular tissue, and is marked by the cicatrices of leaves or
fronds, arranged somewhat irregularly, and at considerable distances below, but
regularly and closely near the apex of the tree, showing that its leaves are produced at
the head only, and in successive clusters. Again, a large portion of the transverse
section of the trunk is seen to consist of cellular tissue ; and through this the wood

passes. The points of resem-
blance to exogens are, that its
centre is occupied by a mass
of scalariform (Fig. 71) and
large spiral vessels, which in
some degree may represent
the medullary sheath ; and
the wood is arranged in cir-
cles, but only near to the bark,
and the circles have a wavy
outline. These pass up into
the fronds, or rather are sent
down from the fronds; and
as the fronds surround the
stem, the bundles sent down
from them lie side by side,
until they form a circle.
There are, moreover, lines of
communication between the
medullary cellular tissue and
the bark, which are the ana-
logues of the medullary rays.
There is a peculiarity in
the growth of the Tree Fern
viz., that the interval be-
tween the cicatrices enlarges
as the size of the tree in-
creases, showing that the
stem of the tree increases in height, not only at the apex for the time being, but after-
wards in the body of the trunk (Fig. 270).

^ As there is no definite growing point in the sporule, its germination must differ
widely from the exogenous and endogenous forms of plants. The sporule, after extrusion
from the sporangia, bursts its envelope, and emits a leafy expansion from its centre*
which sub?equently forms a bud, and from thence a plant.

Fig. 270. Tree Fern, forty feet high, growing in the moist
climates of small tropical islands.

THE GERMINAL FROND.

141

This subject has been discussed with much judgment by an eminent English
botanist, Mr. Henfrey, who has given
the following account in the Gardener't
Magazine for 1851, p. 23 :

" The germinal frond must be taken
very young, while yet not more than
one-eighth of an inch in diameter, and
before any sign of the first leaf appears

Fig. 271. Fig. 272.

Fig. 273.

Fig. 274.

Fig. 275.

Figs. 271, 272, 273, 274, 275. Successive stages of development from the spore (Fig. 271). In Fig.
275 are seen two of the antheridia.

rising from its upper surface. The little frond will then be found in the shape of a rounded

Fig, 277.

Fig. 278.

qoo*

Fig, 276.

Fig. 279.

Fig. 276. A germinal fropd (it is a simple cellular plate like the leaf of a Moss) : a are two ovules ;
b a number of antheridia ; c root fibrils.

Fig. 277. A more highly magnified view of a piece of the frond with two antheridia, one con-
taining the vesicles (b), the other burst (d).

Fig. 278. Side view of b in the last figure.

Fig. 279. The same bursting tp discharge the vesicles, which again discharge the spiral filaments e.

or heart-shaped disk, formed of delicate green cells (Fig. 276) ; a single layer, except in

142

CLUB MOSSES.

the middle, having been gradually developed into this form through the stages
represented in the annexed figures (Figs. 271 275). To see the peculiar organs,
the disk-like cellular plate must be carefully laid face downwards upon a slip of glass, and
washed clean, gently removing the grains of soil, with a camel-hair pencil, from among
the rootlets. When placed under the microscope, a number of projecting cells (Fig.
276 b] are generally found scattered about the frond. These are seen to be again filled
with minute vesicles (Figs. 277 and 278), which escape by the bursting of the protrud-
ing cell, either spontaneously or by slight pressure on the glass covering the object
(Fig. 279). As the vesicles emerge they burst also, and from them springs out a spiral
thread-like body, thickened at one end, and furnished with cilia, as represented in the
woodcut (Fig. 280). These, the so-called animalcules, swim about with great rapidity, !

Fig. 282.
agnitied.

Fig. 283.

Fig. 280.

Fig. 280. One of the sp
Fig. 281. Side view of an ovule.
Fig. 282. The summit of the same, seen from above.

Fig. 283. Side view of an ovule from Suminski, representing the embryo-cell at the bottom of
the cavity.

shooting forward, and continually whirling round on their own axes. To see them
clearly, their motion must be stopped by adding a little solution of iodine.

On the thickened part of the frond, near the notch, are to be found, in most cases,
not always, cellular structures of larger size, and more complicated (Fig. 281). They
consist of conical papillae, with cellular walls, containing a cavity in the centre, as
represented in the Figures 282 and 283.

In Club Mosses (Lycopodiutri), the containing reproductive organs are also called thecse,

Fig. 284. Fig. 285.

Fig. 284. The Lycopodium Aphodium, or Club Moss.

Fig. 285. A, full-grown plant of Marsilea pubescens; B, spore (opened), natural size; and C,
section of spore magnified, with the contained spores. .Both of the Olnaria globulifera.

URN MOSSES.

143

capsules, or sporocarpia, and, as a rule, are filled with sporules (or pollen) in the form
powder like granules, when they are called
antheridia; or they contain several rounded
fleshy bodies analogous to buds, much larger
than sporules, and named Oophoridia. In
Marsilea the organ of fructification is a modi-
fied leaf, and consists of two valves. The
fructification is immediately placed upon a
number of spikes, covered by ovules and
anthers, attached at first to the modified leaf
by a mucilaginous ring. The Split Mosses
and the Urn Mosses have organs of fructifi-
cation placed at the summit of their branches.
These are called Antheridia, and have an
elongated flattened form ; and, on being
ruptured, emit a multitude of spiral threads,
with an enlarged extremity, sometimes curled, and at others straight in their figure.

These are said to be abortive Antheridia by certain writers ; but there is no doubt,
from their configuration and rapid motion, that they are true Phytozoa, or organs of
reproduction.

This organ in the UrnMosses, as the Funaria hygrometrica (Fig. 288), is somewhat more

Fig. 286. The Antheridium (a) of the Polytri-
chum Commune, emitting at b a. number of
coiled fibres, c d, with an enlarged free end,

Rg. 287.

Fig. 288.

Fig. 287. The Hypnum Castrensis, or Feather Moss, with its organ of fructification, situate at the

top of a long seta or stalk, A.
Fig. 288. A. The urns (w) of the Funaria Hygrometrica, supported on setae (s}, and covered by

calyptra (c). B. s, the seta ; c, the calyptra ; u, the urn ; and o, the operculum of the

encalyptra.

complicated, and possesses parts which are most sensitive to the presence of moisture ; so
Tiuch so, that the observer breathing upon them causes them at once to contract. It 19

144

LIVERWORTS AND SCALE MOSSES.

known as the sporangium or theca, and its contents are called sporules ; but besides these,
there are several bodies called prosphyses, enveloped in a membrane which subsequently
bursts, and is curved to form the calyptra. The calyptra is termed dimidiate when the
sporangium bursts on its side, and milriform when the membrane is detached at its base.
The sporangium is covered by a lid or operculum, and incloses a multitude of sporulea
surrounding the central axis, or columnella, and oftentimes inclosed in several cells,
with their septa attached to the columnella. The whole rests upon an elevated stalk, or
seta. It is lined and also inclosed by two membranes the inner and outer peristomin
which have a toothed edge ; and by closing the orifice, especially when moistened, as
by the breath, constitute the tympanum. It is bounded above by an elastic external
ring, or annuls.

Whether any, and what part of the above organs can be appropriated to the
sexes, is a subject of much dispute ; but it is highly probable that the sporules are
the analogues of the pollen in flowering plants, and it has been ascertained that they emit
tubes very similar to pollen tubes.

7 There is an arrangement of the internal parts

of the organs of fructification in the Horse-tails

which greatly resembles that described in the

Lycopodium viz., a spiral

fibre moving with great

rapidity, and influenced, as

in the Funaria, by mois-

ture. There are usually

* or ore suet fibres

having an enlargement at

their free ends, and connected to a central organ, around which
they wrap themselves spirally (Fig. 289). On the application of
moisture they instantly wrap themselves around the spore, b, but
on it its withdrawal they relax their hold, a. These structures are
contained with cases or sporangia, which are arrarged around
the apex of the stem in the form of a cone (Fig. 290). It is
probable that the elaters represent the male, amd the spores the
female parts of the sexual organs.

In Liverworts, as Marchantia polymorpha, the foliaceous organ
is termed thatttis or frond indifferently, and is a flat lobed organ,
lying flat upon the ground. Its reproductive organs are three in
number . 1st., little green bodies, or buds, placed in cups (Cys-
tulae) on the upper surface of the frond, believed to be a vivi-
parous apparatus ; 2nd., sporangia, or female parts, placed beneath.
calyptra, or a stalked receptacle ; and 3rd., oblong bodies, or
anthers, found in other sporangia on the upper surface of the
frond. These last resemble the spiral fibres of the Chara vul-
gar is (Fig. 291).

The Scale Mosses (Jungermannia) have a pericladium arising amongst the leaves,
from which a seta proceeds, and bears a valvular brown case, or sporangium, containing
a number of spiral fibres (Fig. 295), which are highly hygometric, and are intermixed
with sporules, or female organs. There is also a calyptra or the ruptured membranous
bag (Ej)igonium}.

290. The Equise-
turn, or Horse -tail,
with fructification.

LICHENS.

145

None of the members of the various kinds of Mosses now described have any vascu-

Fig. 291.

Fi-. 292.

Fig. 291. a, Phytozoa, or male parts, in situ within the cells; b, the same, detached from the ce.l-
wall in the chara.

Fig. 292. Marchantia Polymorpha, or Liverwort, with its broad frond, A, and organs of fructifica-
tion, B.

lar tissue, but are wholly composed of cellular tissue of various forms.

Lichens. This important class of plants are more particularly found in regions
so far north that more highly and more delicately formed plants cannot exist ; as in the
instance of the Iceland Moss (Cetraria Islandlcct), so useful to the reindeer in its native
regions, and employed as a medicinal agent in this country. It consists of a lobed leaf,
called Jrond, thallus, or blatemas, of various forms and degrees of consistence, and which

Fig. 293.

Fig. 294.

Fig. 295.

Fig. 296.

Fig. 293. Lichen growing upon a piece of rotten wood.

Fig. 294. The fructification of the Jungermannia. A, very young spor<

calyptra ; B, the same, quite developed, with the hyulina rpe and bursting, and presenting

view the inclosed spores.

Fig. 295. Spiral fibres or elaters of the Jungermannia (Scale Moss.) f .. *v an A nf

Fig- 296,-Acrostalagmus Cinnabarinus, very highly magnified, with the fructification at the end of

the filaments.

differs from the like organ in all higher members of the vegetable kingdom, in the
fact that not merelv a part but the whole of its intra-cuticular substance is devoted to

VOL. II.

146

LICHENS AND FUNGI.

the functions of reproduction. The upper cuticle is pierced by two forms of fructifying
organs viz., soredia, or masses of powdery bodies, scattered over the surface and

Fig. 298.

Fig. 299.

Fig. 297.

Fig. 296.* Section of the shield in a Parmelia, showing the position of the spores.
Fig. 297. Magnified representation of the cellular structures of Sea-weeds. (Algae.)

8. The Fucus Vesiculosus, or Bladder-wrack.
Fig. 299. Promelia Perforata : Lichen, with projecting shields.

shields (Scutella, Fig. 299, A), surrounded by a rim, and containing asci, or tubes filled
with sporules.

Fungi, or Mushrooms. This is a most extensive family of plants, and assumes
forms infinitely more diverse than is represented by the members to which the name is

ALGJ3, OB SEA-WEEDS.

147

popularly applied. The most common, and at the same time the least noticeable,
forms are the minute substances which appear in and upon decomposing fluids, and as
vegetable parasites upon many living plants and animals (Fig. 300). All alike, how-
ever, consist exclusively of cellular tissue, but differ greatly'in its arrangement, and
especially in the nature of their reproductive organs. In the minute bodies just

Fig. 300.

Fig. 301.

Fig. 300. The conformation of the common Mushroom (Agaricus campestris). A. a, the pilous ;
b, the lamella, covered by the hymenium ; c, the stripe ; d, the mycelium. B. a portion of the
hymenium, with basidia in four different stages of formation. C. a perfectly developed spore
in one of the processes of the upper part of a basidium.

Fig. 301. Mucor Mucedo, showing the asci, A, and the sporidiae, B.

mentioned, the organ of fructification is simply one enlarged cell, containing the
gporules or spores ; but in the common Mushroom there are true sporidia contained in
asci or sporule cases, and in a few there are moveable spiral fibres or elaters. The
former division of fungi is the most interesting and accessible ; so that we would urge
our readers, possessed of some microscopic knowledge, to examine the various forms of
mould so universally distributed. No preparation or subdivision of the substance is
necessary, except that of placing a very small portion of it in a little water.

Algae, or Sea-weeds. This is the last one of the Fungi, the lowest forms of
vegetable life and growth, and is the boundary line of, or rather the neutral territory
between, the animal and vegetable kingdoms. The members of this class are univer-
sally distributed, and are all different, from the string of cells found in a drop of
stagnant water to the beautifully varied and large sea-weeds familiar to many of
our readers (Fig. 297). It is a class, however, which is best represented in the
southern or tropical seas; for there, not only is there greater variety of appearance, but
the masses in which they abound almost exceed belief. Moreover, in such, as also in
many representations on our own shore, it seems almost impossible to deny the animal
characters with which many observers have invested them. Nothing can so much
relieve the monotony of a sea-side residence as to fix a microscope on the sands, and
examine these beautiful objects, fresh from the salt water.

As in other families, the reproductive parts, for the most part, are called spores, and
are found in the ordinary cells of the plant, as in Fig. 297, or are gathered together
into sporangia, or spore-cases, of various kinds. "We cannot enter into the dispute as
to the sexuality of these as of other members of the class of flowerless plants, but

148

.THE SEXUAL ORGANS OF FLOWERLESS PLANTS.

would remark that a kind of conjugation has heen noticed in the Confervse, or lowest
members of the class (Fig. 302), from which the spores are believed to result. These
spores are endowed with the faculty of motion within the cell, and more particularly
soon after their extrusion, as mentioned at page 4, Fig. 2.
In closing this account of the structure in flowerless
plants, we would remark that a great multitude of terms
have been invented to describe certain minute peculiarities
in reference to the seeds or sporules, and the cases or
ovaries in which they were developed ; but as they would
occupy much space, and be tedious to readers of all classes,
we omit further mention of them. In reference to the
sexual organs of the whole class, it must still be admitted
that the whole question is mb judice, and that we can
only affirm that, whilst such plants reproduce themselves
with the most astonishing rapidity (a rapidity which seems
to be in the inverse ratio of their organization), distinct
sdxes either do not exist, or are possessed of forms as yet
unrecognised. Lastly, cellular tissue, and that alone, is
the form of organization of all except the highest divi-
sions ; but the cells are very varied in figure, size, and
arrangement, and are commonly coloured green or red, as
in the Confervas and Sea- weeds ; or are resplendently
coloured, as in many Fungi. They are not the less beau-
tiful and interesting because their structure has a simple
basis ; but, on the contrary, evidence, in a remarkable degree, the power and wisdom of
the Creator in the infinitely varied and beautiful arrangements cf so simple an object.

Fig. 302. Confervas, with
spores lying within cells,
which have undergone the
process of conjugation, at 1 .

CLASSIFICATION OF PLANTS. 149

SYSTEMATIC BOTANY, OR THE CLASSIFICATION OF PLANTS.

HAVING, in the preceding pages, described all the parts and organs which enter into
the composition of individual plants, we are prepared to take a wider view, and deter-
mine the mode by which masses of plants may be grouped together. This is termed
Classification.

This department of botanical science is vastly more extensive than that which
treats of the structure of plants ; so that it is not possible, in a treatise like the present,
to consider the subject in any lengthened detail. We therefore purpose, after offering
some introductory remarks, to consider the Linnsean and the natural systems of classifi-
cation, and to name the most common or important plants which have been arranged
under each head.

The necessity for a- classification of plants must have been felt at all periods, even
in the Grecian and Roman eras, when the total number of known species did not exceed
1,000 ; but since, at the present day, upwards of 100,000 species have been named and
described, the necessity has become absolute. The only question on which botanists
have been at issue refers to the principles on which that classification should be
founded. In the first place it is imperative that each plant should have a distinctive
appellation, or any description of it would be in vain. Then, again, since 100,000
distinct names, assuming for a moment that so many could have been invented, could
not have been borne in mind by any person, the next step in the process would be to
ascertain if any of this number could be grouped together under one name, but yet
having a special term to indicate its individuality.

The success of this inquiry would, of course, depend upon the existence or other-
wise of any anatomical characters which would at a glance be found common to both.
Such resemblances were soon discovered ; and the term Rose, for instance, was found to
suffice for very many species, with the addition of white, red, &c., to mark their indi-
viduality. Thus the term Rose denoted a genus, and white the species ; and in this mode
the number was reduced within reasonable proportions.

But this first was not the last step, for it was ascertained that on some one point, or
on many points, the genera resembled each other; and thus the term Icosandria, for
example, was devised, which should comprehend the Rose, and the Apple, and the
Strawberry, and others having these characters in common. This then gave rise to a
system of classes and orders, the term Icosandria representing one of the classes. The
orders were subdivisions of the classes, and referred to certain minutiae in which all the
members of the orders did not agree. Thus the nameless plant became at length the
Rosa Alba, of the class Icosandria, and order Polygamia.

This is precisely the plan adopted in the classification of animals. Thus the Cow is
the Bos taurus of the class Mammalia and order Ruminantia. It is not, however, a
perfect plan; and as tne number of objects to be included have continually increased,
it has been found necessary to invent a more general term as that of family which
shall comprehend a number of classes. Reversing, then, the order of classification which
has already been given, we may first refer a plant to a f amity ; next to a class and
order; and then find its generic and specific names.

The term variety has also been introduced to indicate the existence of ?ome trifling
change in a species ; and although the boundary between a species and a variety is not
capable of nice def nition, yet it may be stated that a variety does not so reproduce

150 CLASSIFICATION OP PLANTS,

itself by seed as that its own form shall result, but so that a return to its original
species shall inevitably follow. There are also Hybrids in plants as in animals, and
resulting from the operation of the same law viz., the admixture of the sexes, not of the
same, but of different species of one genus.

The first point will probably depend upon one or two features only ; but the last
will require a knowledge of every part of the plant. Thus, whilst the multitude of
names which have no necessary significance tends to confuse and weary the mind, the
various steps of that classification render the task the lighter, and indeed infuse a deep
interest into the study. It is a mark of unbounded knowledge, on the part of the
Creator, to have made so great a multitude of varied objects ; but it is not the less so
that He has made many of them on a common plan, and has given to us the capability
of unfolding His designs. It is no mark of our mental capability to have found or seen
a plant ; but it is not a little flattering to us to have discovered or perceived the principle
on which the plant was constructed ; and this is the central point of interest to the
philosopher.

But the school-boy is not without his gratification. To point out the flower, the
name of which we know, and to gather that to-day which long ago we first discovered, and
discovered in the company of some one whose society we cherished, may yield pleasure to
any one. Thus we would offer encouragement to the young botanist, by the assurance
that the road is not so hilly as it appears to be, and that it is rendered shorter by the
snatches of pleasure which fall to the lot of the anxious traveller.

There have been, and still are, various modes of classification ; and since all depend
upon the selection of certain parts of plants as their basis, it cannot surprise us that
they should be held in various degrees of estimation.

A prime consideration, in the selection of distinguishing characters, is, that those
characters shall be constant, and not greatly influenced by accidental circumstances.
Such a condition, if it exist at all, can only belong to those parts which are essential to
plants. These essential parts are connected with the function of reproduction, and have
been referred to in every system of classification ; but as nature does not slavishly follow
the path which she herself has marked out, we meet with occasional variety even here.
The flower would naturally attract attention ; and in the earlier attempts at classifica-
tion, its permanent parts, the stamen and pistils, were exclusively selected. This was
called the sexual system ; and was first pointed out by our renowned countryman, Grew,
in the seventeeth century, and a century later was perfected by Linnaeus.

This one prime principle of constancy, then, was that upon which the Linnsean
system was founded, and to which it still owes its continued existence. The system is,
moreover, very simple in its arrangement, and therefore has been at all times in favour
with beginners, and with all those who have not cared to drink deeply of the Pierian
spring ; and, in spite of its insufficiency, it will doubtless be handed down to succeeding
generations.

A perfect classification, however, demands more than mere constancy; and it is in
these further requirements that the Linnaean system has been found wanting. It is
necessary that no violence be offered to that uniformity of organization which is well
known to exist in the vegetable kingdom, so that plants evidently widely dissimilar
shall not be grouped together. Again, since all plants have qualities which are bene-
ficial or prejudicial to the health of man or animals, and since these qualities are known
to be associated with certain similarities of organization, it is demanded that plants of
greatly dissimilar properties shall not be classified together. These two last require-

THE LIXX^AN SYSTEM. 151

ments clearly call for a more extensive knowledge of the anatomy of plants than that
upon which the sexual system was founded, and should more nearly approach to a
natural association of these products of creation. Systems have been founded which
are intended to answer to all the three above-mentioned requirements, and have been
termed natural system, in opposition to that of Linnseus, which, from its narrow basis,
was known as the artificial system. It is evident, however, that the natural systems
are the more desirable, and they are rapidly superseding the Linnaean arrangement ; but
as we are addressing ourselves to an extended circle of readers, we deem it a duty, first, to
make them acquainted with the latter, and then to give them an insight into the former.

LINNAEAN SYSTEM.

The Linnaean system is based upon the existence of sexual organs, and is varied
according to the number and position of each division of these organs. In consists of
classes and orders; the former associated chiefly with the stamens, and the latter
with the pistils.

There are 24 classes, of which 23 belong to flowering and one to flowerless plants.
A reference to the annexed plan will show that the first eleven classes are named
according to the number of the stamens viz., from 1 to 12 stamens ; the last, however,
admitting also of more than 12 stamens. The 12th and 13th classes have an indefinite
number of stamens ; but in the former (Icosandria) they are all attached to the calyx,
whilst in the latter they remain free from their origin in the receptacle. This difference
appears to be a trifling one, but it is constant, and in practice, moreover, is well denned.
The 14th and 15th classes depend upon the number and relative length of the stamens?
there being two long and two short stamens in the former, Didynamia, and four long
and two short ones in the latter, Tetradynamia. In the 16th, 17th, and 18th classes, the
stamens are associated into bundles ; one bundle in Monodelphia, two in Diadelphia, and
three or more in Polydelphia. In the 19th class the stamens are also united into one
bundle, Syngenesia; but they thus form a tube through which the pistil passes. The
class termed Ggnandria, indicates that the stamen and pistils are united together.
The 21st, 22d, and 23d classes, comprehend plants in which the male and female parts
are not met with together in the same flower. Thus in Moncecia separate male and
female flowers are found on the same plant, whilst in Dicecia one plant is entirely male
and another exclusively female ; and in Polygamia both bi-sexual and uni-sexual flowers
grow on the same tree. The 24th and last class embraces an heterogeneous assemblage
of low organized plants, having this one property in common, that their sexual organs
are concealed, whence the term Cryptogamia.

The foregoing 24 classes are divided into numerous orders. The orders of the first
13 classes are based upon the number of the pistils, which vary from one, Monogynia,
to twelve, Lodecagynia, and more than twelve, Polygynia ; whilst the 16th, 17th, 18th,
20th, 21st, and 22d classes are subdivided into orders according to the number of their
stamens. The nature of the ovary determines the orders in the 14th and 15th classes.
The 23d class, or that termed Polygamia, has but one order, and that depends upon the
fact that certain of the flowers on the same plant are bi-sexual, whilst others are uni-
sexual. The 19th class, or Syngenesia, has orders depending upon the forms and
fertility of the florets ; and the last one, Cryptogamia, is subdivided according to the
families of which it is composed.

The following tables contain a complete summary of the Linnsean plan of classi-
fication. The reader will understand that the table reads across the two pages.

152

THE LINN2EAN CLASSIFICATION.

COMPLETE SCHEME OF THE LINN^AN CLASSIFICATION. @-

CLASSES.

NAMES.

DESCRIPTIONS.

1. Mon-andria (/u

ovo?, one ; av&pot, male) .

1 Stamen.

2. Di-andria (3<r,
3. Tri-andria

two)

3 do. .

* *

4. Tetr-andria

4 do. .

5. Pent-andria

5 do. .

6. Jlex-andria

6 do. .

7. Hept-andria

7 do. .

8. Oct-andria

8 do. .

9 do. .

10. De-candria

10 do. .

11 Dode-candria

191 or mnrp StATnpns .

12 Icos-andria

13. Poly-andria (iro\vt, many)

20 do. do. Receptacle .

14. Didy-namia

4 do. 2 lo

ncr. 2 short J

15. Tetra-dynamia

.... ft rtft. 4 rln 2 fin.

16. Mono-delphia (/
hood)

io>/or,one; 6e\(pot, brother-

| Filaments united into 1 set .

17. Dia-delphia (<5tt

two)

18 Poly-delphia

, i/vTuy

do. do. 3 01

more seta

19. Syn-genesia (aw, together ; yeve'tw
20. Gy-nandria (iwt\, woman)

birth)

Anthers united .

Stamens attached to the Pistil ....

21. Mon-oacia (OIKOS, house) ....

( Flowers with Males only ; others with Females (
) only on the same tree . . . . )

22. Di-03cia

) Flowers with Males only ;
) on different trees

others with Females (

23. Poly-gamia (70^09, marriage) .

{Unisexual and bisexual flowers on same and on j
different trees

24. Cryptogamia (KPUTTTW, to conceal) .

The flowers not evident

The simplicity of the system will be

better observed on reference to the following

plan, adopted from the

" Encyclopedic des

Connaissances utiles :"

TABULAR VIEW OF THE CLASSES OP THE LINN^EAN SEXUAL SYSTEM.

CLASSES.

/ 1. Monandria.

2. Diandria.

3. Triandria.

Number of stamens.

4. Tetrandria.
5. Pentandria.

'P<

6. Hexandria.

J-

7. Heptandria.

-2

8. Oetandria.

Free.

(

9. Enneandria.

10. Decandria.

11. Dodecandria.

1
*

Number and insertion.

[12. Icosandria.
US. Polyandria.

{3
&
i

Proportionate size.

14. Didynamia.
15. Tetradynamia.

By their filaments.

16. Monadelphia.
17. Diadelphia.

umtea.
> By their anthers.
Stamens placed upon the pistils.

18. Polyadelphia.
19. Syngenesia.
20. Gynandria.

Flowers of one sex only.

21. Monuecia.
22. Dioecia.

Sexual organs hidden.

23. Polygamia.
24. Cryptogamia.

As we propose to give, in very brief detail, both the Linnsean and the Natural

systems, and shall therefore have to travel twice over the same ground, it will be more

THE

CLASSIFICATION.

153

COMPLETE SCHEME OF THE LINKS AN CLASSIFICATION.

ORDERS.

NAMES.

Monogynia Digynia ( yvvn , a woman)

Do. do. Trignia ....

Do. do. do

Do. do. Tetragynia

Mono, Di, Tri, Tetra, Penta, and Polygyni/v

Do.
Do.
Do.
Do.
Do.
Do.
Do.
Do.

do. do.
do. do.
do. do.

do.

do.
do.

do.
do.
do.
do.

do. do.
do. do.

do.
do.

do.
Heptagynia

Hexagynia

do.

Decagynia .
Dodecagynia
Polygynia .
do.

Gymnospermia (fv/j.vos, naked ; o-rrep/ia, seed) .

Angiospermia (a-p-ov, a vessel)

Siliculosa, small pod ; Sihquosa, large pod.

Triandria, Pent., Hex., Kept., Oct., Dec., Dodec., and Polyandria.

Do. do. do. do.

Do. do.

Polygamia aequalis, Superflua, Necessaria, Segregata.
Monandria, Diandria, Hexandria.
Monandria, Di., Tri., Tetra., Pent., Hex., Oct., Icos., Poly., and

Monodelphia.

Monandria, Tri, Tetra, Pent., Hex., Oct., Enne., Dec., Dodec.,
Icos., Poly., Monodelphia.

Moncecia, Dicecia.

Filicels, Lycopods, Muscals, Lichenals, Fungals, Algals.

DESCRIPTIONS.

and 2 Pistils.
, 2, 3 do.

, 2, 4 do.

, 2, 3, 4, 5, and many Pistila.

, 2, 3 do.

, 2, 4, and 7 do.

, 2, 3, 4 do.

1, 3, 6, do.

1, 2, 3, 5, and 10 do.
1, 2, 3, 4, 5, 6, and 12 do.
1. 2, 5 do.

1, 2, 3, 4, 5 do.

Naked seeds.
Seeds inclosed in a vessel.

convenient to our readers, if we illustrate the Linnaean system from the English flora
exclusively, and the Natural system from the foreign plants.

CLASS I. MONANDRIA,

This is distinguished by having but one stamen, and is subdivided into two orders,
Monogynia (one pistil), and Digynia (two pistils). It contains but few-
English plants viz., five genera and fourteen species and
these remarkable neither for beauty nor utility. Four
genera viz., Salicornia, Hippuris or Mare's-tail (growing
jpi ditches), Zostera, and Chara, commonly known as
Stonewort or "Water Horse-tail have but one pistil >
whilst the Callitriche, or Starwort, is the only genus
having two pistils. The Chara offers the most numerous
species (six), and is, perhaps, the least uninteresting of all
the genera. It is found in ditches both of fresh and
salt water. The organization of members of this class is
of a low grade.

CLASS II. DIANDRIA.

This class has two stamens and two orders viz., Monogynia and Digynia. It con-
tains several plants of interest in the eleven genera, and thirty-nine species of which
it is composed. Under the order Monogynia we find the well-known Privet (Ligus-
trum) ; the Fraxinus, or common Ashtree ; the prolific, and almost ubiquitous weed
Veronica, with its nineteen species ; the Pinguicula, found in bogs ; Utricularia ;

154

TRIANDRIA.

Lycopus, or Cat-mint ; Salvia, or Sage; Circaea, or the Enchanter's Night-shade, found

in country parks and under field-hedges ; the Lemna

or Duckweed, covering every stagnant pool; and the

Cladium. The first eight genera have inferior mono-

petalous flowers, whilst the Circsea has a superior flower,

and the two last are destitute of flowers.

The most agreeable member of this class is the An
thoranthum odoratum, a sweet scented meadow-grass,
which possesses two pistils ; and, as it has but two
stamens, is cut off from the great family of grasses, to Fig. 305.

which it clearly belongs. Diandria Diandria

Digynia. Monogynia.

CLASS III. TBIANDRIA.

This is a most extensive and invaluable class of plants, comprising all our British
grasses except one, including the various cereals, as wheat and oats, so necessary to
man. The members of this class are the means of sustaining the life of man, and of
almost all animals, and are the. most widely distributed, and the most abundant of all
plants.

There are forty-eight genera, and one hundred and sixty-five species, arranged in
three orders, Monogynia, Digynia, and Trigynia.

The order Monogynia contains twelve genera, of which
five have superior flowers, and contain medicinal or poison-
ous plants, as the Valeriana, Crocus, and Iris. Six others
have superior flowers, and comprehend many of the com-
mon rushes ; and one is a true grass, the Nardus stricta.
The order Digynia is remarkable for its natural assemblage
of grasses ; twenty-eight of which have chaffy flowers in
panicles, arranged in bracts containing one, two, or three
flowers. Five others amongst which are the Wheat,
(Triticum), and Barley (Sordeum) have a spiked inflores-
cence. Of all these genera, only one is known to possess
poisonous properties viz., the Loliwn temulentum, or
Bearded Darnel. The Festuca ovina and Duriuscula are
the most common grasses.

This is a class of plants offering great difficulty
to the young botanist, on account of the apparent
resemblance of many genera, and the absence of
the calyx and corolla of other plants. But this
difficulty is not unconquerable ; and when it has
been surmounted the pleasure attending the
acquired knowledge is very great. The characters
of this inflorescence have been discussed at pages
108 and 109.

The third order, Trigynia, has nothing in com-
mon with the last order unless we except the
- 307. number of stamens, and this tends to show the

Triandria
Digynia.

Fig. 306.

Triandria
Monogynia.

Triandria Trygynia.

great defect in the Linnaean system. It contains

but three genera Montia, Polycarpon, and Holosteum.

TETRAXDRIA AXD PENTASTDRIA.

155

Fig. 308.
TetrandiaTetragynia. Tetrandia Digynia.

CLASS IV TETEANDRIA.

The flowers in this class have four stamens, and one, two, or four pistils Mono-
gynia, Digynia, and Tetragynia. It is not an extensive class, having only twenty-two
genera and sixty-five species ; and of these the large majority are valueless weeds.

The order Monogynia is
the largest, and contains
fifteen genera, four of which
have no petals viz., Al-
chemilla, or Lady's-mantle ;
Sanguisorba, Isnarda, and
Parietaria ; whilst nine are
monopetalous, and two are
polypatalous, with four
petals. There are seven
genera, possessing four pis- Fig. 309.

tils, and amongst them the Holly, Hex, Lime-tree, Tilia, and Pond Tetrandria Monogynia.
weed Potamogeton. A few plants are supposed to possess medicinal properties, as the
Rubia, or Madder ; Galium, or Bed-straw ; and Sanguisorba officinalis, or Great Burnet.
The Dipsacus Fullonum, or Fuller's teazel, the hairs of which (Fig. 113) are so useful
to clothworkers, belongs to this class. Several other members possess a certain
degree of beauty as the Scabiosa and the Ilex, which is the cheering emblem in our
Christmas festivities. The most numerous plants, under this head, are the Plantago,
or Plantain, with its spike of sessile flowers, the Alchemilla, and the Potamogeton.

CLASS V. PENTANDRIA.

This is a most important, numerous, and varied class of plants, and has ninety-four
genera and two hundred and ten species. The plants have five stamens, and one, two,
three, four, five, six, or an indefinite number of pistils (Polygynia). It is not possible
to give any one expression which shall represent this class as a whole ; but there are
many of its members which may be arranged together both in structure and properties ;
so that the class is a compound of several bodies or classes of plants.

The order Monogynia is very extensive, comprehending no fewer than forty genera.
Thirty-one of these have monopetalous corollas ; six are polypetalous of five petals, and
three are apetalous. Ten genera are closely associated together, as
shown by having inferior monopetalous flowers with two or
four naked (so-called) seeds, and a covering of rough hairs over
the plant. Such are Symphytum or Comfrey, Echium, Borago,
Anchusa, or Alkanet-root, Cynoglossum, and the sentimental Myo-
sotis or Forget-me-not. This is a compact and well-defined body
of plants. Fifteen other genera are distinguished from the above,
by having the seeds more manifestly inclosed in a seed vessel;
and amongst these are the beautiful Primula or Primrose, and
Cowslip, Menyanthes or Bog-bean, Anagallis, Convolvulus, Polemonium or Jacob' s-
ladder, Vinca or Periwinkle, and Verbascum ; as also the poisonous Atropa, Belladonna
or Deadly Night-shade, the Hyoscyamus and the Solanum Tuberosum, with its poi-
sonous berries and edile subterranean stem, known as the Potato.

The six genera, with superior monopetalous flowers, are of mixed characters, and

Monogynia.

156

PENTANDBIA.

three of them axe well known viz., the Lonicera or Honeysuckle, Campanula or Bell
flower, and Lobelia.

Of the six genera with polypetalous flowers, four have them inferior, as the Yiola
or Violet, and Rhamnus or Buckthorn ; whilst two are superior viz., the delicious
Ribes or Currants and Gooseberries, and the Hedera Helix or common Ivy.

The order Digynia is also very extensive and important, since there are thirty-
six genera belonging to it, many of which possess valuable medicinal properties. Two
of these are monopetalous viz., the Gentiana and the Cuscuta ; and four apetalous,
the Beta maritima, Chenopodium, Salsola, Ulmus or Elm-tree, and Herniaria. The

Fig 311.
Pentandria Digynia.

Fig:. 312.
Pentandria Trygynia.

Fig. 313.
The Drosera, or Sundew.

greater number are, however, distinguished by the umbelliferous mode of inflorescence,
and constitute a naturally associated division. All have five superior petals and two
seeds, but differ amongst themselves as to the presence and arrangement of bracts.
Amongst this numerous and highly-important class of plants we may mention the Carum
carui or Caraway seed, Meum Faeniculum or Fennel with its aromatic oil contained
in the vitta3 of the seeds, the Daucus Carota or Carrot, Heracleum or Cow-parsnep,
Pastinaca Sativa or common Parsnep, Bunium Flexiosum or Earth-nut, sought after
by boys and animals, and the Apium graveolens or Wild-celery; the stately
Angelica, the poisonous Conium Maculatum or Hemlock, Cicuta Virosa or Water
Hemlock, Sium or Water Parsnep, the bitter Gentiana, and the Hydrocotyle with

HEXANDRIA. 157

its peltate leaf. The various genera of Parsley and Parsnep exceed any other in.
number ; and nearly the whole of this large subdivision may be naturally arranged
together.

In the order Trigynia are two genera with superior flowers, which are well known :
the Sambucus Niger, or Elder, with the inflorescence called a cyme, and the elegant
Viburnum or Lilac ; and also three others of less notoriety, which have inferior flowers.
The orders Tetragynia and Hexagynia have each one genus known well to botanists,
and growing on boggy ground viz., Parnassia in
the former, and Drosera or Sundew in the latter.
The Drosera is remarkable as being the only
English plant which exhibits sensibility to touch
in a marked degree. It possesses a number of
remarkable glands upon the surface of its leaves
Pe n tandria Fig<31 pentandria (page 70), which emit a tenaceous fluid by which
Pentagynia. Tetragynia. fli es are caught, and which are subsequently appro-

priated as food for the plant.

The order Pentagynia possesses three genera, two of which are of interest t>tz., the
Statice or Thrift, with its cheerful head of flowers, and the Linum or Flax plant.

The last order, Polygynia, includes but one genus, and that of but little value the
Myosurus or Mouse-tail.

Our readers will now perceive how remarkable is the combination of plants brought
together by this class of the Linnsean arrangement, and how unfitting it is that so
many varied alliances should be enrolled under one head. It is also well to remember
that three weU denned natural classes may be formed out of many of its members, the
one with the umbelliferous inflorescence (VmbdUfera), another with a rough hairy
cuticle (Boraginacea), and a third with highly poisonous properties and sombre
aspect (Solanacea). It is a class remarkable both for the beauty and utility of its
members a utility embracing both medicinal and dietetic qualities.

CLASS VI. HEXANDRIA.

This class is characterized by having six stamens, and is divided into four orders
viz., Monogynia, Vigynia, Irigynia, and Polygynia ; and contains twenty-six genera
and eighty-five species.

It is remarkable as a class of flowering plants for the endogenous structu
members, as evinced by the straight veins of its leaves, and possesses many plants of
great beauty and a few of considerable utility.

The order Monogynia comprehends nineteen genera, or two thirds of the whole
class; and, with the exception of the Berberis or Berbery, with its compound leaves
(page 101), sensitive stamens and fruit capable of being used as an excellent picJ
the Peplis and the Frankenia, and a few others, have a perianth (Fig. 201), as a
covering of the flower, and a bulb for their underground stem. As examples of th<
class, we may mention the Galanthus nivalis or Snowdrop, or Narcissus Ormthogalum
or Star of Bethlehem, Hyacinthus, Scilla or Squill, and Tulipa, aU of which contain
starch in their bulbs, and have beautiful flowers. The Convallaria or Solomon's Seal
is an elegant member of this class. The Asparagus officinalis, and Album o
Garlick, are edible. The Acorus Calamus or Sweet Flag, emits an aromatic o
from its leaves and root, and is a grass not only used medicinally, but is much

158

HEPTAXDRIA.

employed in India as an artificial shade, when it is drawn into a frame, and water thrown
upon and air driven through it so as to produce a low temperature and an aromatic
odour.

The genera having the greatest number of species are the Juncus or Rush, and
the Luzula or Wood-rush, under which terms are comprehended most of the Rushes
growing in fresh and salt water in this country. They comprehend thirty-seven
genera.

The orders Digynia and Polygynia have but one genus Oxyria in the former, and
Alisma Plantago or the "Water Plaintan in the latter. In the order Trigynia we find
five genera, two of which are worthy of mention : the Colchicum Autumnale, with

Fig. 316.
Hexandria Polygynia.

Fig. 317.
Hexandria Trygynia.

Fig. 315.
Hexandria Monogynia.

Fig. 318.
Hexandria Digynia.

its beautiful flower and medicinal cormus, and the common Rumex or Dock, and
Rumex Acetosa and Acetosella, the common and the Sheep's Sorrel. The latter
class of plants have no corolla.

Thus, whilst a few of the members of this class are worthless weeds, many others
form the choicest parts of the coUections of the horticulturists, and have obtained more
attention in their cultivation and improvement than almost any other native plants.
They comprehend nearly all our native flowering endogenous plants.

CLASS VII. HEPTANDRIA.
This class possesses but one genus, the elegant European Chickweed Winter-green

OCTANJDEIA.

159

Trientalis Europea, which has seven stamens, and one pistil. Its calyx, corolla,

Fig. 320.
Heptandria Monogyma.

seed-vessel are each divided into seven parts, and well illustrate the law mentioned at
page 111.

CLASS VIII. OCTANDRIA.

The plants of this class have eight stamens, and are divided into four orders viz.,
Monogynia, Digynia^ Trigynia, and Tetragynia. These are, however, few in number ;
forming only thirteen genera and forty species. The general characteristic of the class
is rather that of beauty than of utility ; and yet it is far from being wanting in either.

Fig. 323.
Octandria Tetragynia.

Fig. 324.
Octandria Monogyma.

As instances of beauty, we may mention that in the first order there are the JEnothera
biennis, or Evening Primrose ; the Epilobium, or "Willow-herb ; and the gentle Erica 1
or Heath, than which nothing can be more lovely in their separate characters.

Amongst the genera which may be termed useful, we instance the Acer, or Sycamore

160

AND DECANDRIA.

and Maple; Vaccinium Vitis-idsea, or Cowberry ; Vaccinium oxycoccus, or Cranberry ,
Vaccinium myrtillus, or Bilberry, with Daphne Mezereum, or Mezereum, and Poly-
gonium, both of which possess valuable medicinal properties. The last-named plant
belongs to the order Trigynia ; and three others, Adoxa, Paris, and Elatine are ranged
under the order Tetragynia. The Epilobium is the most abundant and fruitful in species ?
having nine, which inhabit either dry or moist localities. It is probable that the whole
class must be regarded as possessed of irritating properties.

CLASS IX. ENNEANDRIA.

This class, like Heptandria, contains but one
genus and one species, the beautiful Butomus
Umbellata, or flowering Rush, growing in ditches
and the borders of stagnant waters. It has six
pistils ; and, consequently, the sole order in the

class Enneandria is Hexagynia.

Fig. 325. Enneandria Hexagynia.

CLASS X. DECANDRIA.

This is a well-defined class of plants, the members of which are, for the most part,
fitly associated together. They have ten stamens, and two, three, or five pistils,
and consist of twenty-one genera and one hundred and seven species. A few are
beautiful ; but the majority are weeds, though not without a certain degree of interest,
since they enliven by their small and modest flowers our mossy banks and waste places.

The order Monogynia has five genera, two with polypetalous flowers Monotropa

Fig. 326.
Decandria Monogynia.

Fig. 327. Fig. 328. Fig. 329.

Decandria Digynia. Decandria Pentagynia. Decandria Trygynia

and Pyrola, or Winter-green and three with only one petal, as the Arbutus or Bear-
berry. There are five genera in the order Digynia viz., Scleranthus, Chrysosplenium,
Saxifraga or Saxifrage, Saponaria, and Dianthus or Pink ; whilst the order Trigynia
has the Arenaria or Sandwort, Stellaria or Stitchwort, Silene or Catch-fly, and Cherleria
all weeds. The fourth order, or that called Pentagynia, has seven genera the
Lychnis; Cerastium, or Mouse-ear Chickweed; Sedum, or Stone-crop; Cotyledon;
Oxalis Acetosella, or Wood-sorrel ; Agrostemma ; and Spergula. The Dianthus,
Saxifraga, Lychnis, and Oxalis are doubtless the most beautiful ; whilst the Pyrola and
Arbutus exhibit certain feeble medicinal qualities. The class is somewhat remarkable
for the number of species in proportion to that of the genera.

THE GLASSES DODECANDRIA AND ICOSANDRIA.

161

CLASS XI. DODECANDRIA.

Hitherto the classes have succeeded each other by the addition of one stamen ; but
this addition is of two, there being no English plant with eleven stamens. The order
contains but five genera and eight species (each plant having twelve stamens), sub-
divided into five classes viz., Monogynia, Digynia, Trigynia, Tetragynia, and Dodeca-
gynia, (twelve pistils). The genus and species Sempervivum tectorum, wr House-

. 330.
Dodecandria Tetragynia.

Fig. 331.
Dodecandria Trigyma.

Fig. 332.
Dodecandria Digynia.

leek, is the best known, and belongs to the order Dodecagynia ; after which may be
placed the Agrimonia Eupatoria or Agrimony (Digynia), and then Reseda (Trigynia),
and Asarum and Lythrum (Monogynia). The Agrimonia is presumed to possess slight

Fig. 333. Dodecandria Monogynia.

Fig. 334. Dodecandria Polygynia.

medicinal properties ; but the whole class is deficient, not only in number, but ia
beauty and utility.

CLASS XII. ICOSANDKIA.

This is a most interesting class of plants, second, if at all, only to Triandria ; and is
one of those which chances to be well comprised in the Linnsean system. It contains
twelve genera and sixty-seven species ; and, with the exception of the Pyrus Aucuparia,
or Mountain Ash, is either edible or harmless. It is dis-
tinguished less by the number than the position of the
stamens for there are an indefinite number of stamens
but they are attached to the calyx (Epigynous, Fig. 218
and so distinctive is that arrangement, that a member o
the class is instantly recognized.

It is divided into three orders Monogynia, Pentagy-
nia, and Polygynia. Prunus, or the Cherry and Black-
thorn, is the only occupant of the first order ; whilst three
delicious plants Mespilus or Hawthorn and Modiar,
Fynis (Pear, Apple, and Crab), and Spiraea or Meadow-sweet have from two to nv

VOL. II. '*?

Fig. 335. An losandrous
flower.

162

THE CLASS POLYANDRIA.

Btamens, and are arranged in the order Pentagynia. The third order has more than five
pistils, and is termed indefinitely Polygynia ; and in it are found the Rosa or Hose,
Rubus or Bramble and Blackberry, Fragaria or Strawberry, Geum, Dry as, Tormeu-
tilla, Potentilla, and Comarum.

It is thus evident that this class comprehends nearly all our edible juicy fruits,
besides the beautiful flowers which precede them, and such others as the Rose. It is a
class of plants most readily diagnosed, in whatever part of the world they may be found,
and, moreover, are, with few exceptions, healthful as food. A slight medicinal astrin-
gent influence is attributable to the Tannin, which is present in small quantities in
such plants as the Potentilla, Tormentilla, and the Rose ; and it is not improbable that,

Fig. 336.
Icosandria Polygynia.

Fig. 337.
Icosandria Monogynia.

in a slight degree, it pervades the whole. This class of plants is, however, of greater
use to the horticulturist than to the physician; for none are more susceptible of
improvement from culture and admixture of species than the beautiful Rose (Fig. 207),
the Strawberry, Apple, and ether juicy fruits.

CLASS XIII. POLYANDRIA.

This class differs, in a remarkable degree, from the preceding, especially in the
powerful medicinal qualities with which its members are endowed. In this respect it
resembles only a part of the heterogeneous class Pentandria, and with that division of
plants furnishes many poisonous narcotic and tarcotico-acrid substances. It has nearly
double the number of genera, and yet fewer species than those possessed by Icosandria
viz., twenty-two genera, and fifty-five species. It is determined by the presence of
numerous but an indefinite number of stamens, similar to the class Icosandria ; but the
two classes present some difference, the former having the stamens inserted beneath
the ovary, and therefore hypogynous (Fig. 225), as in the Poppy. It is divided into
three orders, named Monogynia, Pentagynia, and Polygynia.

The order Monogynia contains eight plants, of which four
(viz., thePapaveror Poppy, Chelidonium, Glaucium or Horned
- 'PPy an( J Actaea) have only four petals ; whilst two (the
Kelianthemum) or Rock Rose, and Tilia Europsea (or the Lime
Tree), have five ; and two others, which are water plants (the
Nymphaea A1W or the White Water Lily, and the Nuphar
L^tea and Putnila or the YeUow "Water Lily), have an indefi-
nite number of petals. The above distinctions are, however,
somewhat illusory ; since no plants more than these now men-
tioned uave the power of multiplying their petals by cultivation at the expense of the

Fig. 33S.-Polyandrta
Monogyida.

THE CLASS DIDYNAMIA. 162

stamens (page 114) ; but they are of value, inasmuch as the number is either the
original one, or some multiple of it.

The order Fentagynia contains five genera of beautiful plants, which have from two

Fig. 339. Fig. 340. Fig. 341.

Polyandria Monogynia. Polyandria Pentagynia. Polyandria Polygynia.

to six pistils, and includes the splendid Paeonia or Paeony, Delphinum or Larkspur,
Aconitum or Monkshood, Aquilegia or Columbine, and the Stratiotes.

There are nine genera in the order Polygynia, each of which have an indefinite
number of pistils ; and many of these are remarkable for their sombre beauty. Thus
there are the Clematis, Anemone, Hell chorus or Hellebore, Adonis, Ranunculus or
Crowfoot, Thalictrum or Meadow-rue, Caltha Palustris or Marsh Marigold, Trollius,
and Ficaria.

This class is therefore remarkable for its powerful medicinal or poisonous properties
properties which pervade the class as a whole and for its flowers, of a deep colour
and sombre beauty. Amongst the former we may mention the Papaver, which supplies
so vast a quantity of Opium (page 51), Helleborus Niger or Black Hellebore, and
Aconitum, all of which still supply medicinal preparations ; whilst the Chelidonium,
Delphinum, Ficaria, Ranunculus, and several others, are known to be poisonous. The
Tilia affords a delicious scent when in bloom ; whilst the flower of the jSympha?a
Alba, Pseonia, Helianthemum, Delphinum, Aquilegia, Anemone, and Adonis, may well
take rank amongst the most favourite productions of our gardens and ponds. The
Nymphsea is also remarkable as yielding beautiful stellate cells (page 11) ; whilst the
Papaver and Chelidonium possess a large quantity of laticiferous tissue (page 29) and
milky juices. The Ranunculus is the only plant bearing a true nectarium on the
claw of its petal (page 69).

CLASS XIV. DIDTNAMIA.

"We have now passed in review all the classes which are founded simply upon the
number of stamens and their position, and proceed to those which are based on
more complex phenomena. The one now under consideration has only one other
element added to that of number viz., the relative length of the stamens, not as an
accidental but an essential fact. The class Didynamia is characterized by having two
long and two short stamens (Fig. 223), and is divided into two orders viz., Gym-
nospermia, in which the seeds do not exceed four in number, and appear to be, but
really are not, naked at the base of the flower ; and Angiospermia, having the seeds in

1C4

THE CLASSES DIDYNAMIA AND TETKADYNAMIA.

Fig. 342.

Fier. 342. Didynamia Angiospermia.
Fig. 343. Didynamia Gymnospermia.

a manifest capsule. It is requisite to remark, that when Linnaeus founded his classi-
fication, the seeds in the order Gymnospermia were believed to be naked ; but more

recent investigation has shown that they were
inclosed in a flattened two or four-celled
ovarium. This, therefore, is an incorrect
division of the class ; but it has its value,
since the seeds, as they lie at the bottom of
the ovarium, seem to be naked.

$'JTVJ _Jlf1ll!IIIM^F There is a further general characteristic

$ \ '^^^Jlllk*'^^' ^ *kis C ^ ass v * z "> *^ e l^iate or bilabiate

corolla (page 115), which is found in the
major part of its members.

There are thirty -four genera, and eighty-
five species, in the class Didynamia, and
of these twenty genera are arranged in the order Gymnospermia. The calyx is two-
lipped in six genera viz., the Origanum or Marjoram, Thymus or Thyme, Prunella,
Scutellaria, Melittis, and Clinopodium ; but it is nearly regular, and divided into five
segments in the major part of the order, as the Mentha (Peppermint, Spearmint,
Bergamot-mint, Pennyroyal, &c.), Nepeta or Catmint, Marrubrium or Horehound,
Betonica or Wood Betany, Leonurus, Glecoma or Ground Ivy, Lamium or Dead
Nettle, Galeopsis, Teucrium or Wood Sage, and others. Nearly the whole of the
members of this order are common way-side and water-side plants ; but they possess
valuable medicinal properties, as in the essential oils found in little reservoirs of the
leaves of the Mentha, Origanum, and Thymus ; and a bitter principle, which is well
known to herbalist housewives, residing in the Marrubium, Betonica, and others. It is
probable that no member is decidedly poisonous.

The order Angiospermia differs not only in having an evident capsule, but in the
possession of poisonous qualities, at least in several of its members, and is an instance
in which plants of diverse affinities have been improperly arranged together under the
same head, simply because one point in their organization seemed to indicate a resem-
blance.

The number of sepals is again a mark of distinction. Thus the genus Orobanche
has but two sepals, whilst the Euphrasia or Eye-bright, Rhinanthus or Fellow Eattle,
Lathraea, Bartsia, and Melampyrum, have four segments of the Calyx, and eight have
the Calyx five-cleft. The last division contains the most important members of the
order, and of these the Digitalis, or Foxglove, takes precedence. That plant yields a
product from its leaves which is of great value in medicine, and which on many occa-
sions has inadvertently produced death. There are also the Scrophularia or Figwort,
common in ditches and on banks, Antirrhinum or Snapdragon, Linaria or Toad Flax,
Pedicularis or Lousewort, and the modest Linnsea Borealis, named after the great
founder of this system.

None of the members of this order possess the aromatic properties mentioned in the
preceding order ; but there are several which add much to the gaiety of our fields and
shady lanes. In neither order are there any plants which afford nutriment to man.

CLASS XV. TETRADTNAMIA.

This class resembles the last, inasmuch as it has stamens of different lengths ; but it
differs in having four of them long and two short (Fig. 344). The two short ones are

THE CLASS MONODELPHIA.

1C5

placed at the sides of the others, and the whole are inclosed in a flower, whicn nas
invariably four petals, arranged in the form of a Maltese cross, and hence termed
Cruciate (Fig. 344). Upon the whole it is a well-defined and arranged class, and
may be readily distinguished by the construction of the flower and the pod-like seed
vessel which its members possess. It is divided into two orders by somewhat indefinite
boundaries viz., Siliculosa, signifying a short pod (Fig. 345) ; and Siliquosa, indicating
a long pod (Fig. 346). There are twenty-eight genera and sixty-eight species in the
whole class.

The order Siliculosa is again subdivided into such members as have the pod entire
at the top, and others in which the pod is there notched. The former comprehends ten
genera, amongst which are the Cochlearia Armoracia or Horse-radish, with other
species of tre same genus, Crambe Maritima or Seakale, Cakile or Sea Rocket, and
Subularia or Awl-wort ; whilst in the latter there are Thlaspi or Shepherd' s-purse,
or Candy-tuft, and Lepidum or Pepper- wort.

Fig. 344. Tctradynamia. Fig. 345. Siliculosa. Fig. 346. Siliquosa.

The second order, Siliquosa, contains fourteen genera, and amongst them are plants
of greater interest. Thus there is the Brassica (Cabbage, Rape, Turnip, Navew, and
Seakale), Sinapis or Mustard, Raphanus or Radish, Nasturtium Oflicinale or Water-
cress, Barbarea or Winter Cress, Arabis or Wall and Rock Cress, all of which are
useful edible plants ; Cardamine or Ladies' Smock, and other species, Matthiola or
Stock, and Cheiranthus or Wall-flower, which are favourite indigenous flowers.

The class Tetradynamia is therefore ranked amongst the most useful of our vege-
table productions, since it supplies much of the green vegetable food used "by man, as
well as condiments and aromatic perfumes. The nutritive properties of the Brassica or
Cabbage are computed as 1 to 16 of Horse Beans, Lentils, Peas, and Haricots; 1 to 8
of Wheat and Oats ; 2 to 1 of Turnips, and of equal proportions to Carrots and old
Potatoes ; and is chiefly due to the relative quantities of starch contained within their
cells (page 32).

CLASS XVI. MONODELPHIA.

This and the succeeding classes are founded upon another feature in connection

Fig. 348.
Monodelphia Polyandria.

Fig. 347.
Monodelphia Pentandria.

with the stamens viz., the adherence of their filaments, so as to produce one, two, or

Fig. 349.
Monodelphia Deeanclria.

1C6 THE CLASS DIA1>ELPHIA.

more sets. In the small class, now under consideration, the filaments are united together
into one bundle, which may consist of five stamens, as in Erodium or Stork's bill ; of
two stamens, as in the allied genus Geranium ; or of an indefinite number of stamens,
as the Malva or Mallow (Fig. 219), Althaea or Marsh Mallow, and Lavatera or Tree
Mallow. These four genera constitute the whole class, and are subdivided into the follow-
ing orders as above intimated Pentandria, Decandria, and Polyandria. None of them
are either edible or poisonous ; but the Malva and Althaea have been employed in
domestic medicine on account of the mucilaginous juices which they yield. The
indigenous Geranium, or Crane's bill, offers thirteen species ; but, whilst they are
interesting wayside herbs, they are infinitely inferior in beauty to the cultivated flowers
which more commonly bear that name. The whole class consists of five genera and
twenty-two species.

CLASS XVII. DIADELPHIA.

This is a class of very great importance, and is fitly associated with the Icosandria*
Triandria, and Tetradynamia, in supplying nutritive and pleasant food for man and
animals. It contains eighteen genera and seventy-four species, and, as a whole, is a
tolerably well-associated class of plants. It is characterised by having the filaments
of the anthers arranged in two sets (the second set usually consisting of but one fila-
ment, Fig. 221) ; and, as a rule, they are inclosed in the carina or keel of the Papillio-
naceous corolla (Fig. 213). It is divided into three orders, according to the number
of the stamens viz., Hexandria, in which there is but one genus, the Fumaria, or
Fumitory growing in corn-fields ; Octandria, also consisting of one genus, the Polygala
or Milkwort ; and, lastly, Decandria, which comprises the remaining genera. The orders
Hexandria and Octandria offer nothing of importance ; so that it is to the Decandria
that we direct our attention. In this order the ten stamens are invariably arranged in

Fig. 350. Fig. 351. Fig. 352.

Diadelphia Hexandria. Diadelphia Decandria. Diadelphia Octandria.

a set of nine and an odd one, which is not readily separable from the nine by any one
ignorant of its separate existence. It usually lies attached to the thin edge or face of
the mass of filaments. The following are the chief members of this class : the Pisum
or Pea, Vicia or Vetch, Anthyllis or Kidney Vetch, Orobus or Bitter Vetch, Lathyrus or
Vetchling, Hippocrepis or Horseshoe Vetch, Astragalus or Milk Vetch, Ervum or Tare,
Trifolium or Clover, Lotus or Bird's Foot, Ulex or Furze, and Genista or Broom ; the
latter, with the Ulex, Anthyllis, and Ononis being the only instances in which all the
stamens are united at their base. The Pea is the only member supplying human food
under ordinary circumstances ; but in seasons of dearth others have been used, and
again may be used with great advantage. Nearly all the remaining genera are com-
monly used as food for animals, and a very few have medicinal properties, as the
Genista and the Fumaria Officinalis. None are poisonous.

They are, for the most part, climbing plants with pinnate leaves, and the midrib

THE CLASSES POLYDELPHIA AND SYNCENESIA.

167

elongated into a tendril or cirrhus (Fig. 185). The prevailing colours of the corolla
are yellow or red.

CLASS XVIII. POLYDELPHIA.
This class consist* of one genus, Hypericum or St. John's Wort, and eleven genera,

Fig. 353. Polydelphia Polyandria.

and has the stamens divided into three, four, or more sets (Fig. 220).
wise of interest. It belongs to the order Polyandria.

It is not other-

CLASS XIX. SYNGENESIA.

This is the largest class of plants in every Flora, and is one of exceedingly well-
defined characters. It is also one of some difficulty to the young botanist in determining
the species, and even some of the genera ; but the mere class-characters are, even to
him, of most ready discernment. Its distinguishing feature is the union of the anthers
(not necessarily of the filaments also) into a tube through which the pistil passes
(Fig. 222). The flowers are also arranged on a capitulum or head, and, in many
instances, those of the margin or ray differ in size, or other particulars, from those of

Fig. 354.
Polygamia Equalis.

Fig. 355.
Pelygamia Superflua.

Fig. 356.
Polygamia frustanea.

the centre or disk ; and hence the flowers of the head are frequently divided into florets
of the ray and florets of the disk. The whole florets are surrounded by an involucre
of bracts, and each separate floret has a small calyx, which is commonly chaffy. The
part upon which the flowers are placed is called the receptacle (Fig. 193). There are
forty-one genera, and one hundred and thirty-three species.

This class is divided into three orders. The first is Polygamia Equalis, in which all
the flowers are perfect, having five stamens and one pistil, and producing one seed.
It contains 22 genera and 71 species, and is subdivided into three parts, accord-
ing to the form of the corolla. Twelve genera have all the corollas strap-shaped.
Such are the Ciohorium or Chicory, the root of which is ground to powder, and used as
a substitute for Coffee ; Lactuca or Lettuce, which in its wild state is poisonous, but

168 THE CLASSES SYNGENESIA AND GYNANDRIA.

when cultivated may be eaten with impunity ; Prenanthes, or Wall-lettuce ; Leontodon
taraxacum or Dandelion, with milky medicinal juices ; Sonchus or Sow Thistle ; Hiera-

Fig. 357. Fig. 358.

Detached floret of the ray in the Polygamia Superflua. Polygamia Equalis.

cium or Hawk Weed ; Apargia or Hawkhit ; and Tragopogon or Goat's Beard. The ten
remaining genera have all the corollas tubular ; six with the florets spreading so as to
form a hemispherical head and face, with the florets lying parallel and crowded together,
and forming nearly a level surface at the top. Amongst the former are the Carduus and
Cnicus, two forms of prickly thistle, and Arctium or Burdock ; and of the latter are the
Bidens or Bur Marigold, Diotis, Eupatorium, and Chrysocoma.

The second order is Polygamia Superflua, in which all the florets are fertile ; but
yet in many cases those of the ray have pistils only. The marginal florets appear
wanting in the Artemesia or "Wormwood, Tanacetum or Tansy, Gnaphalium or Cud-
weed, and Conyza or Spikenard ; whilst they are developed, and have a strap-shaped
figure, in all the remaining orders. Amongst the latter are found the modest " wee
crimson tipped flower," the Bellis Perrennis, Tussilago farfara or Colt's-foot, Anthemis
or Camomile, Achillea or Millefoil, Senecio or Groundsel, Aster or Starwort, Chrysan-
themum or Ox-eye, and Corn Marigold, Pyrethrum or Fever-few, Solidago or Golden
Rod, Inula or Fleabane, and Cineraria or Fleawort.

The third order is called Polygamia Frustranea, and has perfect and fertile florets of
the disk ; but the florets of the ray have neither stamens nor pistils, and hence the
term " Frustranea." The Centaurea, or Centaury, is the only genus, with its seven
species.

On taking a review of this extensive class we find that the Lettuce, in its cultivated
state, and the dried root of the Chichorium, are the only members which afford nutri-
ment to man. Certain others, as the Sonchus, Leontodon, Carduus, Cnicus, and
Senecio are eaten by various animals. Many members have been more or less
employed medicinally, and it is probable that medicinal properties are possessed by the
whole class. Those which have been most commonly used are the Anthemis, Tus-
silago, Artemesia, Leontodon, Hieracium, and Inula. Some of these, with the
Lactuca and many other members of the class, abound in Laticiferous tissue and milky
juices ; and to these may chiefly be attributed the medicinal effects of the plants. They
grow exclusively, or nearly so, on dry land, and many of them in waste places. But
few have been thought worthy of horticultural cultivation.

CLASS XX. GYXANDKIA.

This is a very curious class of plants, and at the present day are very fashionable.
In this country they grow chiefly in meadow lands and moist soils ; but in tropical

THE CLASS MONCESIA.

169

regions they are beautiful parasites upon decaying trees. No more splendid con',eption

of a flower can be obtained than that whieh is offered by some members of this class

now collected in the Royal Gardens at

Kew. The class is distinguished by

having the stamens situate upon, or

connected with, the style or other part

of the pistil. There are three orders

Monandria, Diandria, and Hexandria;

but all the British genera belong to the

first, except Cypripedium, which has

two stamens, and Aristolochia, whieh

has six stamens.

The order Monandria has ten genera,
while the whole class consists of twelve
genera and thirty-seven species. The

anther is fixed, terminal, and permanent in the Epipactis ; and moveable and deciduous
in the Malaxis and Corallorhiza. It is parallel to the stigma, and of two cells close
together in the Neottia, Goodyera, and Listera ; and either of two vertical cells ;
permanent, fixed to the summit of the style in Orchis, Aceras or Green Man Orchis,
Ophrys or Fly Orchis, and Herminium or Green Musk Orchis.

Our native specimens of this class are not especially interesting, except the common
Orchis, with its variegated corolla and green leaves spotte<?with black, as it is growing
on a rich moist meadow. They are not used as food, except the so-called tubers of a
few members which have yielded an amorphous form of starch. The general charac-
teristic of the class is acridity ; but they are not employed in medicine. The whole class
is peculiar, inasmuch as from the conformation of their sexual organs they need the
intervention of an insect, as the Bee, to carry the pollen from the anther to the stigma>
and ensure fructification.

CLASS XXI. MONCECIA.

In each of the preceding twenty classes every flower has been bisexual, and conse-
quently every tree bearing flowers
must have them in this hermaphro-
dite condition. The three following
classes are exceptions to the general
rule, and have flowers of one sex or
of two sexes, and on the same or on
different trees. In the class Moncecia*
the flowers are unisexual, some
having stamens only and others only
pistils on the same plant. It is a
highly important class, since it contains a considerable number of our forest trees.
It is divided into seven orders viz., Monandria, Diandria, Triandria, Tetrandria,
Pentandria, Polyandria (more than five stamens), and Monodelphia (filaments united
into one brotherhood), and together contains twenty-five genera and one hundred and
eight species.

The order Monandria (one stamen) possesses but two genera the Euphorbia or

Fig. 362. Moncecia Monodelphia.

170

THE CLASS MONCECIA.

Spurge, which is a common weed on waste land, and the Zannichella. Triandria is
diiefly occupied by the Sedges, under the names of Carex, which alone claims sixty of

Fig. 363.
Monoecia Diandria.

Fig. 364.
MonoDcia Monandria.

Fig. 365.
Moncecia Pentandria.

Fig. 366.
Monoecia Tetrandria.

Fig. 367. Monoecia Triandria

the whole hundred and eight species found in the classes Typha or Reed Mace, and
Sparganium or Bur-reed ; all of which, with the Elyna, grow in marshy and muddy
places.

The order Tetrandria (four stamens) has five genera viz., Aluno Glutinosa or
Common Alder-tree, Buxus Sempervirens
or Box-tree, Urtica or Stinging Nettle,
Littorella, and Eriocaulon. The stinging
secreting hairs of the Nettle, with their
circulation, have been described at page 67.
There are only three genera in the order
Pentandria (five stamens) ; Bryonia or
Bryony ; Xantheum, and Amaranthus ;
whilst the order Polyandria (more than five
stamens) has ten genera, several of which
are our most important wooded trees. Thus we find the Quercus or Oak, Betula or
Birch, Fagus or Beech (Fig. 125), and Chestnut and Corylus or Hazel, amongst
trees; with Carpinus, Sagittaria (Fig. 173), Ceratophyllum and Myriophyllum ; and,
last, the Arum Maculatum or Wake Robin (Fig. 76), with its starch-containing cormus.
The valuable Pinus, or Pine-tree, is the sole occupant of the last order, or Monodelphia.

It is scarcely possible, in so heterogeneous an assemblage of plants, to fix upon any
leading common characteristic ; but although no member, except the corm of the Arum,
and the nuts of the Fagus, Quercus, and Corylus, offers anything for the food of man or
beast, neither is any, except the Oak-bark, employed in medicine, it is highly probable
that valuable astringent and perhaps acid properties are common to them "all. The

Fig. 368. Monoecia Pclyandria.

THE CLASS DICECIA.

171

Betula yields a fermenting juice, from which a good wine is produced (page 23) ; and
the Pinus affords turpentine and resins ; but it is the wood which this class yields that
contributes to its value,

CLASS XXII. DICECIA.

This agrees with the former in all the flowers being unisexual, and having either
stamens or pistils alone ; but it differs in this respect, that the two sexes occupy different
trees. Thus one plant has wholly male flowers, and another has exclusively female

Fig. 369. Dicecia Triandria. Fig. 370. Dioecia Icosandria. Fig. 371. Dioecia Enneandria.

ones. It contains fourteen genera and eighty-two species, divided into twelve orders,
viz,, Monandria, Diandria^ Triandria, Teirandria, Pentandria, Hexandria, Octandria,
Enneandria, Decandria, Icosandria, Polyandria, and Monodelphia. This extreme
division of its contents clearly proves that it possesses very heterogeneous materials.

Fig. 372. Dioecia Octandria. Fig. 373. Dioecia Pentandria. Fig. 374. Dioscia Hexandria.

The order Diandria is occupied by the genus Salix a genus which affords sixty- four of
the eighty-two species of the class. It is known by the catkin inflorescence described
at page 106. Triandria and Tetrandria have three genera each ; and of these only one

j Fig. 375. Dioecia Diandria. Fig. 376. Dicecia Monandria. Fig. 377. Dioecia Dodecandria.

I of the latter, Viscum Album, or Mistletoe, deserves mention. The valuable and scarce

| Humulus, or Hop, occupies the outer Pentandria ; and Tamus, or Black Bryony, the order

Hexandria. Populus, or the Poplar-tree, is found in Octandria ; and Mercurialis and

172 THE CLASSES POLYGAMlA AST) CEYPTOGAMIA.

Hydrocharis in Enneandria. Coniferous trees monopolize the last order, Monodel-
phia viz., Juniperus or Juniper, and Taxus, or Yew.

Fig. 378. Dicecia Decandria. Fig. 379. Dioecia Polyandria. Fig. 380. Dicecia Monodelphia.

The Salix and the Populus are capable of yielding a medicinal substance, which is
said to be a good substitute for Quinine ; the Juniperus an oil which is employed both
medicinally and in the preparation of Hollands ; and the Humulus a bitter principle,
which should be used in the manufacture of ale, and a narcotic principle which is
employed in medicine. The Taxus is one of our most enduring trees, and has been
known to live upwards of two thousand years. The latter plant offers glandular woody
tissue, with a spiral fibre (Fig. 60). The Mistletoe Berry, Viscum Album, is an essential
element in our Christmas arrangements, and has been so for many ages. The plant is
one of those which took part in the ancient Druidical rites. The whole class possesses
acrid or narcotic acid poisonous properties.

CLASS XXIII. POLYGAMIA.

This represents a condition of the sexual organs which is intermediate between the
two last classes ; and has hermaphrodite or unisexual flowers indifferently on the same
or on different plants of the same species. It has but one member the Atriplex, a
common and valueless weed on dunghills and waste places. It has seven species.

CLASS XXIV. CRYPTOGAMIA.

The characteristic peculiarity of the members of this class is, that they do not possess
sexual organs, or that they so conceal them that they have not as yet been discovered.
But very few, comparatively, were known to Linnaeus ; and of those known in our day,
the most beautiful, as well as the greatest numbers, are foreign to our shores. Some
of them inhabit the most desolate regions, as the Lichens of Lapland ; whilst others
abound in tropical regions, as the Tree-ferns, to which reference has already been made.
They are commonly known as Sea-weeds, Mushrooms, Lichens, Mosses, and Ferns, all
of which are flowerless Sea- weeds.

The term Algae is a comprehensive term, capable of wider signification than the
corresponding one of Sea- weeds, by which it is commonly represented in our language.
It comprehends a very large proportion of the lowest division of the vegetable kingdom,
or that which seems to be almost common ground between the lowest forms of both
vegetable and animal organization. It is now commonly divided into several groups,
as the Brittle-worts, Confervas, true Sea- weeds, Eosetangles, and Charas.

Brittle-worts (Diatomaceae and Desmidiae) constitute the slime which is found upon
the surface of stems, and are commonly so minute as to be microscopic objects. They
are fragmentary, brittle bodies, generally bounded by right lines, and of a green colour ;
and with the slime in which they nestle afford protection and food to microscopic ani-
malcules. Many of them inhabit salt, and others the fresh waters, and most of them
develop starch within their cells. Amongst the chief genera we may mention Diatonia,

MUSHROOMS. 173

Desmidittm, Achnanthes, Gomphonema, Exilaria, Fragillaria, Micromega, Beckleys,
Cymbella, Navicula, and Euastrum.

Confervas also inhabit both salt and fresh waters, but are commonly of an olive,
violet, and red, rather than a green colour. They consist of a series of cells of various
forms, as cylindrical tubular globes, or elliptical, and grow by the subdivision of their
cells, and the propagation of spores within the cells. Their forms are extremely varied,
and their distribution almost universal. The Protococcus, Hsematococcus, Porphyra
(stewed and eaten, as Lava), Ulva, Common Nostoc, or Star-jelly, Palmella, Con-
ferva, and Penicillum, are genera commonly known.

FueuS) or Sea- weeds, are closely connected with Confervas both in structure and situ-
ation. They differ in fheir mode of reproduction, for the reproductive organs are situate
without the plant, appearing as little green worts invested by a thin membrane ; and
the male organs, or antheridia, have the spiral filament, before described under the
head of Mosses. Some of them are eatable, and are eaten by various people in the
Pacific, as well as in the instances of the Alaria -ZEsculenta, and Fucus Vesiculosus, by
the inhabitants of Ireland, Scotland, and the northern islands. They are, however,
of still greater use to man by affording soda in the impure form of kelp, which is used
largely by soap makers and glass manufacturers, and also iodine, which is yielded by
many genera, but more particularly by the Ecklonia Buccinalis of the Cape of Good
Hope, and by many on our own shores.

Rosetangles (Ceramiceae) or the Corallines, are also Sea-weeds, but usually have a
rose or purplish colour. They consist of cells of various forms, arranged in one or
more rows, so as to produce an articulated frond, and are propagated by spores formed
in threes or fours within a mother cell. They are entirely marine ; and yield a greater
number of genera, which are edible by man or animals, than any other form of Sea-
weeds. Of the edible ones we may instance Plocaria compressa and Chondrus crispus, or
Carrigeen Moss; Rhodomenia palmata, or Dulse; Iridcsa edulis ; and the Laurencia
pwnatifida, or Pepper Dulse. The Plocaria tenax yields glue and varnish, used by the
Chinese in the manufacture of their lanthorns ; the Chondrus crispus yields size ; and
the Rytiphlaa tinctoria produces a valuable dye. This is a very valuable class of
plants.

The Charas are submersed plants of a green colour, with regularly-branched brittle
stems and whorls of small branches or leaves. In some of these, as the Nitella, the
circulation may be Been in its progress up and down the stem by the aid of the
microscope.

MUSHROOMS.

The general term Fungi represents the varied members of this extensive class of
plants, but very inadequately, since the class comprehends, besides the true Mushrooms
or Fungi, Moulds, Morels, Mildews, Blights, and Puff-balls. The members, therefore,
vaiy from a size so minute as to be almost or quite invisible to the naked eye, to a mass
much larger than the human head. They grow, for the most part, upon decaying sub-
stances, and usually increase in size from within. A few, as the Agaricus fastens, are
said to possess lactiferous vessels and spiral filaments. The major part of them are,
moreover, very ephemeral in their character. Some of them are edible, as the common
Mushroom (Agaricus campestris), Helvella or Morel, and Tuber or Truffle, all of
which, with some others, are commonly eaten both in this country and on the Conti-

174 LICHENS A.ND MOSSES.

nent of Europe. Others, however, are very poisonous ; and it is believed that species
which are sometimes wholesome become poisonous when grown under other con-
ditions, or eaten by persons of peculiar sensibilities. Upon the whole, it is a class
of plants which should be sedulously avoided, although a very considerable number are
known to be edible in various parts of the world. The dry rot is due to the Polyporus
destructor, and other species ; the blight of corn to the Puccinia graminis ; the rust to
the Uredos and Puccinise ; and the mildew to the Mucedos (Fig. 301). They also attack
cheese, bread, preserves, fruit, and almost every article of food, and are then known as
mould ; and it is a curious fact that the presence of any perfume prevents their forma-
tion. A few of them are phosphorescent. The number of genera is so vast that it is
useless to attempt any very limited selection,

These are directly opposed to Fungi, inasmuch as they are perennial, and consist of
a lobe and leaf-like thallus. They constitute the gray, yellow, and brown stains which
give an air of antiquity to the walls of our churches ; or they are found on broad patches
of a leprous appearance on the trunks and branches of trees. They are useful to
man in two modes first, by affording dyes as described on page 54, and, secondly, as
food. The latter quality is found in the Cetraria Islandica or Iceland Moss, Cenomyce
rangiferina or Keindeer Moss, Sticta pulmonacea, Alectoria usneoides, and various
species of Gyrophora, which furnishes food to the Canadian hunters. Many others
possess medicinal properties of value. It is an extensive family of plants, but hitherto
it has not been studied with the care which has been bestowed upon other, but not less
valuable and interesting, vegetable productions.

MOSSES.

This great class is subdivided into several portions, and exhibits a degree of organ-
ization considerably beyond those to which we have hitherto referred. Amongst the
subdivision we may instance the Scale Mosses (Jungermanniae), Split Mosses (An-
draeacea), Urn Mosses (Bryaceae), Club Mosses (Lycopodiacea), Crystal Worts (Ric-
ciaceae), Liver Worts (Marchantiaceae), and Horse-tails (Equisetacea). In some
instances, as in the Sphagnum and Polytrichum, the male organs may be seen in con-
stant motion in the early spring months, and appear like two thread-like bodies, with
one extremity thin and attached, and the other enlarged and free, inclosed within a
distinct cell-wall. The same kind of motion is also found in other members of the class,
and is due in some degree to hygrometric influence, as has before been described in
reference to the Urn Mosses.

The Crystalworts are amongst the most diminutive members of the class, and swim
or float upon small collections of shallow water, or attach themselves to the mud.
They are but few in number. The Liverworts are found very abundantly in damp
unfrequented places, on the uncovered ground, inclosed by the walls of ruined castles.
They consist of a broad frond, which lies upon the soil, and emits roots from its under
surface, possessing antheridia and pellate receptacles. They differ from Crystalworts
in having elaters and involucrate spore-cases.

The Scale Mosses (Jungermanwia, Figs. 294 and 29o), possess a far higher degree of
organization, having well and symmetrically expanded leaves, and, in many, a long
Btalk supporting the simple fruit. They abound in tropical regions.

The Horse-tails (Equisetum) possess a fistular articulated stem, surrounded by

FERNS. 175

a layer of hard woody tubes. There are no leaves ; but the external articulated
organs much resemble them. The fruit is borne on the top of the stem, and consists
of a number of masses sessile upon the common rachis. They are widely distributed^
and have the peculiarity of containing a large quantity of silex or flint in their cuticle ;
so much so, that the Equisetum hyemale and other genera are used in the polishing of
metals and furniture.

The Urn Mosses are small, terrestrial, or aquatic plants, with an axis of growth
and minute imbrocated leaves, and differ from all other Mosses in the structure of
their two kinds of reproductive organs. They are an interesting and extensive division
of the family of Mosses, and are more commonly found in temperate than in tropical
climes. Wherever there is moisture, even if soil be almost absent, they will grow,
and they are the first to cover a barren coast, as they are the last to linger when the
atmosphere ceases to be capable of affording nourishment to vegetation. The Sphagnum,
Polytrichium, and almost all plants vulgarly known as Mosses, belong to this division.

FERNS.

The highest division of the Cryptogams is that known as Ferns (Filices), a division
which, in the degree of its organization, far exceeds that of any yet mentioned.
They consist of " leafy plants producing a rhizome, which creeps below or upon the
surface of the earth, or rises into the air like the trunk of a tree." "When a stem
exists it is usually simple, and of even diameter throughout, and bears a tuft of leaves
on its apex, after the fashion of Palms and other endogenous plants, and is composed of
cellular, woody, and scalariform tissues. The reproductive organs are spore cases,
arising from the veins on the under surface, or other part of the leaves ; or they are
situate beneath the cuticle, which they thus throw up in the form of an indusium.

This class is divided into three portions the Ophioglossus or Adder's-tongues, the
Polypodiaceae or true Ferns, and the Danaeaceas or Danaeaunts ; and of these the middle
one, or that of true Ferns, contains nearly the whole of the members of the class. "We
regret that our space does not permit us to enter into detail into this beautiful, varied,
and very interesting tribe of plants ; and the more so, that at the present moment the
Ferns and the Orchis have attained to an enviable popularity.

The Adders-tongues are minute plants, closely allied to the Club Mosses (Lycopo-
diacece), with a hollow pithless stem, containing woody fibre, and possessing leaves with
netted veins

Its reproductive organs consist of spores contained within spore-cases, which are
arranged on a spike on the sides of a contracted leaf. The Dangeacese, on the other
hand, are true dorsiferous Ferns, with reproductive organs sunk within or seated upon
the back of the leaflets. There is also, as in the Adder's-tongue, an absence of the
elastic ring, which is indicative of true Ferns. Both of these divisions of Ferns are
very small, containing together only nine genera.

The true Ferns or Polypodiacese (vaguely designated Filices) are distinguished by
the presence, on the spore-case, of a ring or band of coarse meshes distinctly different
from the tissue of their sides, and too strong to be broken through, when the case opens
to discharge its spores. A few genera are considered edible, as, for example, the Pteris
esculenta, Cyathsea medullaris, Diplazium esculentum, and Gleichenia Hermanni. The
Java Fern is also nutritive, whilst the Aspidium fragrans has been employed as a
substitute for tea, and the Pteris Aquilina and Aspidium Filix-mas have been used in
the manufacture of beer. The genera are very variously distributed over the face of the

176 PRACTICAL APPLICATION OF THE LINN^EAN SYSTEM.

eartn, and in different localities bear very various relations to the total genera of plants ;
but it is certain that the most elegant, as well as the most lofty specimens, are not in-
digenous to our islands. Amongst the English genera we find the Polypodium, "Wood-
sia, Aspidium or Shield Fern, Cystea or Bladder Fern, Asplenium or Spleen Wort,
Scolopendrium or Hart's Tongue, Blechnum or Hard Fern, Pteris or Brake, Adiantum
or Maidenhead, Trichomanes, Hymenophyllum, and Osmunda or Flowering Fern.

Before quitting the Linnsean arrangement, it may be advantageous to our readers if
we give a few simple directions as to the proper mode of examining a plant under this
system.

The first aim of the botanist will be to determine the class and order in which
the plant under examination is arranged. He will, therefore, at once direct his atten-
tion to the flower (if the pknt do not belong to the last order, or that of Cryptogamia),
and see if both stamens and pistils are present together. If he find such to be the case,
the plant is bisexual ; but since, in the twenty-third class, or that of Polygamia, both
unisexual and bisexual flowers exist on the same plant, he will glance at other flowers
on the same stem, and ascertain if such be the case on the plant in question. If all the
flowers are bisexual, he will then attend to the number, length, and position of the
stamens, which, in a majority of instances, will at once direct him to the class sought
for. Thus, if there be two long and two short stamens in all the flowers, the plant is
Didynamous ; and if there be four long and two short stamens universally, he will
refer it to Tetradynamia. He must not, however, expect that in any plant all the stamens
shall be of precisely equal length ; but although such be the case, this will constitute
no important source of fallacy, since half-a-dozen examinations of the stamens of a
Didynamous and a Tetradynamous plant would enable him to perceive that the diversity
in length is not an accidental circumstance, but one which, from its constancy and
relative proportions, is very characteristic. Let him select the common Mint or Fox-
glove, as an example of Didynamia, and the Mustard or "Water-cress as an illustration
of Tetradynamia.

This point having been passed, and having found that all the stamens are of nearly
equal length, he will next ascertain if they are separate from each other down to their
point of insertion. We will first suppose that their foot-stalks or filaments are connected
together through a distance more or less great, but yet so restricted that the anthers
are free ; the plant will belong to one of the three classes Monodelphia, Diadelphia,
or Polydelphia. He will next seek to determine if they form one set, or two or more
sets. To this end, he should take away the corolla, and any other parts which may
interfere with a due inspection of the base of the stamens ; and then with the fingers
try if any part of the mass of stamens will come away naturally, as it were, from other
parts. Thus the Hypericum, or St. John's-wort, possesses a large number of stamens,
which, on being gently pulled asunder at their bases, are readily detached in three or
four masses ; the stamens in each mass being still adherent, and each mass attached to
its neighbour simply by the cohesion of apposition. Such a plant, then, belongs to the
order Polydelphia. Again, the Pea, Bean, or Vetch presents the stamens arranged
precisely as exhibited in Figs. 221 and 351, except that the single stamen is not
so much detached from the mass as represented in these drawings ; and by examining
the concavity of the mass of stamens with the finger-nail, or any pointed instrument,
the odd stamen will be discovered lying close to the mass, but not connected with it.
This indicates the class Diadelphia. This class of plants has almost universally the

PRACTICAL APPLICATION OF THE LINN^EAX SYSTEM. 377

papilionaceous form of corolla, which, on being appreciated, will, in the great majority
of instances, alone suffice to indicate the class. Lastly, when the stamens are united
together by their filaments, as above indicated, but cannot be divided into distinct
bodies, as in the Geranium and Mallow, the plant is Monodelphous.

There may, perhaps, be some little difficulty to the young botanist in determining
whether plants belonging to the Monodelphian and Polydelphian classes have really
their filaments so united ; but a very little attention and practice will show that the
filaments are not separate on both sides down to their base, and, moreover, the
characteristic appearance of the stamens as a whole will soon be appreciated by the
student.

If the filaments be free, but the stamens united together, the plant will belong to
the order Syngenesia ; but as all this great class of plants have aggregated florets placed
as a capitulum (Figs. 354, 355), their appearance is so characteristic, that, after a very
short space of time, the student will not need to examine the stamens to determine the
classification of the plant.

The only other exceptional class is that of Gynandria ; and it is not one which can
be very intelligibly described upon paper. It is composed of the Orchis tribe of plants,
and those closely associated with it ; and if the student will regard attentively the
combined stamens and pistils, and the toute ensemble of the flower of any Orchis, as of
those growing in our moist meadows, or those now universally found in hot-houses, he
will speedily learn how to distinguish this class in an instant, without, however, being
so readily able to explain it to another.

We have considered the foregoing exceptional cases first, not because they are the
most numerous in the great assemblage of plants, but because they have readily
recognised characteristic peculiarities, and because, having excluded them from con-
sideration, the student may give undivided attention to the greater number which yet
remain. If the stamens are free from each other throughout, and are nearly of equal
size (differing somewhat according to the progressive development of the season), and
are not more than ten in number, the plant may be at once referred to its proper class,
as Monandria, &c. ; but if the number should be indefinite say fifteen, or any larger
number the plant may be either Icosandrous or Polyandrous. To determine to which
of the two classes it is to be referred, simply tear away the corolla and calyx piece by
piece ; and if the stamens come away with the pieces as would be the case in the
Rose, Hawthorn, and Apple the plant is Icosandrous. This indicates that the stamens
are Epigynous ; whilst the Hypogynous mode of insertion is characteristic of the class
Polyandria. The Eose may illustrate Icosandria, and the Crow-foot (Ranunculus)
Polyandria.

The small class of Dodecandria is not so easily recognised by its stamens, since the
number is considerable, but somewhat indefinite.

The foregoing directions will suffice as a guide to the student, except in the com-
paratively few instances in which the number of stamens has been unduly increased or
diminished. The increase is less common than the decrease ; and is chiefly restricted
to the classes Triandria and Pentandria, or all the classes below Pentandria, and is
usually to the extent of a duplicate of the original number. Thus a Triandrous plant
occasionally has six stamens, and a Pentandrous one has ten stamens. This little diffi-
culty is overcome by examining other flowers on the same plant, or on a similar plant
growing near to it, when the normal number af stamens will be found on a majority of
thorn.

VOL. II, N

178 PRACTICAL APPLICATION OP THE LINN^EAN SYSTEM.

When there is a decrease in the number of stamens, it is usually accompanied by a
corresponding and equal increase in the number of the petals, and is for the most pan
restricted to the two classes Icosandria and Polyandria. If in either of these cases the
petals are more than five in number, it may be inferred that the innermost rows have
been produced at the expense of the outermost rows of stamens. This, however,
constitutes no sort of difficulty, since a sufficiently large number of stamens remain to
enable the student to determine the class, except in the case of cultivated plants, when
the whole of the stamens may have been converted into petals, as in the perfect Rose
(Fig. 207). We therefore advise the beginner to avoid all garden flowers, and examine
only those which are met with in their wild and uncultivated state.

The classes Moncecia and Diceica are not so readily discovered by a reference to the
stamens of the flower, since for the most part the flowers are small, and without gay
colours, and the stamens are indistinct. He will first strive to ascertain if the flower
under examination has stamens or pistils (since it is unisexual), and will find that the
pistils occupy a central position, and have an expanded base or ovary, whilst the stamens
are usually arranged in a circle, leaving a central vacuity, and are surmounted by a
swollen part or anther. This is not at all times an easy diagnosis in practice ; but it
will aid the student to remember that, for the most part, the members of these classes
are large wooded trees. There are many exceptions to this rule, as in the cases of the
Stinging Nettle and the Sedges ; but the exceptions are perhaps less difficult of
diagnosis than the members which may constitute the rule.

Having thus discovered the Class to which the plant belongs, he will next seek the
Order ; and to this end will chiefly regard the pistils. This will apply perfectly to all
plants having the stamens separate from each other, and of equal size ; and in euch
cases it suffices to count the number of pistils only. The orders of the first fourteen
classes are determinable in this way ; but beyond these, the pistil is not regarded in
determining the class. If, therefore, the plant belong to the class Polyandria, or any
other preceding class, simply count the number of pistils in order to find the order ;
but if it be Didynamous, or Tetradynamous, the student must notice the character of
the seed-vessel or pod. Thus, when a Didynamous plant has an evident more or less
conical ovarium, as in the Digitalis and Scrophularia, the order is Angiospermia ; bnt
if, after tearing away the corolla, he look deeply to the bottom of the calyx, and find a
flattened ovarium with one or two transverse lines on its surface, indicating a division
of the ovarium into two or four parts, as in the Mint, the plant belongs to the order
Gymnospermia. The diagnosis of the two orders in Tetradynamia is somewhat more
arbitrary ; for it depends simply upon the size of the pod. A long pod, as of the Pea,
indicates the order Siliquosa ; and a short, and for the most part a comparatively broad
one, marks the order Siliculosa .

The orders found in the classes Monodelphia, Diadelphia, and Polydelphia, and also
Gynandria, Monoecia, and Dicecia, are determined by counting the number of the
etamens ; whilst those of Polygamia are simply Moncecia or Dicecia. The numerous
class Syngenesia is divided into orders without exclusive reference to its stamens
or pistils, but simply by the arrangement of the florets upon the capitulum. Thus, in
the order Polygamia JEqualis, all the florets are equal, and all possess both stamens and
pistils ; whilst the term Superflua indicates that the florets are divided into those of the
ray and of the disk, and that the former have pistils only. In the third order, or that
of Frustranea, the florets of the ray are destitute of both stamens and pistils.

Thus we have not been able to give such directions as shall enable the student to

PRACTICAL APPLICATION OF THE LINN^AN SYSTEM. 179

determine the order of a plant without having first discovered the class in which it
ought to be placed ; for such was not the intention of Linnaeus when he founded his
arrangement. He will, therefore, first find the class and then the order ; but, in the
great majority of instances, both will be perceived by the same glance.

But both the class and the order are alike dependent upon the presence of a flower ;
and therefore it will be in vain for the inexperienced student to attempt to discover
them, except at the proper season of the year, when the plant is in flower, and whilst
the flower remains perfect.

These two preliminary circumstances are usually got over without any difficulty ;
but the next stages in the investigation require a far wider range of observation. It
is n ow necessary to examine, more or less minutely, every part of the plant. Thus
its height, and the size and form of its stem and root, must be noticed, distinguishing
between herbaceous or annual plants and woody, or those which are more or less perennial.
If the plant be herbaceous, it is necessary to ascertain if the stem be hollow, and if it
have any flutings or other markings upon its external surface ; and in all cases it is
requisite to glance hastily at the general arrangement of the leaves upon the stem or
plant. In reference to the root of herbaceous plants, it may further be observed that
its form must be noticed that is, as to whether it is tuberous or fibrous, or prcemorse,
or any other of the forms previously indicated.

The leaves and the parts constituting the flower are, however, those parts from
which the distinguishing features of plants are usually drawn.

The form of the leaf is a prime consideration ; and the student must notice if it is
round, oval, pointed, or otheiwise, and if equally so on each side of the midrib, and
also whether its edge is entire or divided in various ways. The size, thickness, and
colour should be regarded, and also the character of its surface, as to whether it is
smooth or rough, and if the hairs are distributed evenly over the two surfaces, or only
over one or over a part of one ; and also the precise characters of the hairs, as to whether
they are like bristles or down, or otherwise. Lastly, its venation demands attention
in order to show if the plant be an exogen, as indicated by the reticulated venation, or
an endogen, as shown by its parallel veins. The petiole, in like manner, must be ex-
amined, and afterwards the inquiry made if the leaf is caducous or permanent, and
if it altogether falls oft the stem or withers upon it, as is the case in the induviate con-
dition referred to in its proper place. The points in which leaves differ from from each
other are wonderfully numerous, probably extending to some hundreds ; and all of these
are made use of in describing the characters of plants. Most of them are happily
recognisable by the very apt terms with which this science, above all others, has been
supplied ; so that any inexperienced student, with a descriptive manual in his hand)
would scarcely fail to understand the terms which are employed to enable him to refer
any plant to its proper place.

The flower is, as we have already shown, a compound organ, and offers a great many
objects to the student's attention. First, regard the general arrangement of the flowers
upon the plant, and inquire if they are placed in the axils of leaves (axillary) or other-
wise, and if they terminate a branch rendering it determinate. Then somewhat restrict
the range of observation, and notice that arrangement of the flowers upon the stem
which constitutes the inflorescence, and afterwards proceed to consider an individual
flower, regarding the envelopes from without inwards. The calyx and corolla may both
be monosepalous or polysepa 1 ous. If they are monosepalous, the form must be noticed as
to whether it is rotate or bell-shaped, or otherwise, and its free border inspected, to ascer-

180 PRACTICAL APPLICATION OF THE LINN^EAN SYSTEM.

tain if it is entire or variously divided ; and if divided, the figure, number, and depth
of its divisions will require attention. When a tube exists, as is common in mono-
petalous corollas, its length, width, and general proportions must be observed, and
also any hairs or other organs which may defend the entrance into it. When these
envelopes are polypetalous, the same degree of attention must be given to each sepal
and petal as above directed with regard to the leaves, except that these organs are
usually of more delicate organization than leaves. But whether they consist of one or
of many pieces, it will be equally necessary to notice their texture, colour, and relative
length (that is, whether the corolla is longer or shorter than the calyx), and whether
either or both are caducous or permanent ; and, if caducous, to ascertain whether it falls
early, and in one or in many pieces. Should there be any appendages to these parts
as the corona of the Narcissus, or the nectarium of the Ranunculus they must be
carefully noticed and examined. It will further be proper to notice the relations which
these parts are said to bear to the ovary, that is, as to whether they are superior or
inferior ; and also their relation with the stamens, as to whether those latter organs are
attached to them or not.

In these directions we have already referred, to some extent, to the stamens and
pistils ; but further detail is now necessary. Thus, in reference to both, the presence or
absence of the foot-stalk (filament and style) must be determined ; and if it be present,
its length, figure, and colour should be observed. In but few instances is it coloured ;
but in many the figure is not uniformly cylindrical, but tapering upwards, or awl-
shaped ; and in some instances it assumes a foliaceous character.

The anther demands minute attention, in order to show the mode of its attachment
to the filament, its figure, and the number of the cells into which it is divided. The
pollen seldom calls for examination under the Linnaean system of classification ; but if
the examination be made at a period when the pollen is ripe, and lying loose upon the
anther and other parts of the flower, there can be no difficulty in ascertaining its colour,
size, and general configuration. Its minute anatomy is a subject of great difficulty,
and one into the consideration of which it is not needful that the inexperienced student
should enter.

The style offers perhaps fewer points for observation than the anther, since its
structure is more simple. It will be proper first to notice its divisions, and the mode
in which those divisions, if any, are arranged ; and then to observe carefully its general
configuration, and the precise nature of the exposed free surface upon which the pollen
is destined to fall. Its internal anatomy, or that of its conducting tissue, is not of
importance to this part of our subject. The ovary must be minutely examined; and in
order to do that it will be needful to cut it through transversely, and then ascertain the
number of the cells of which it is composed, and that of the seeds lying within each
cell. It is not uncommon to find fewer seeds than cells, owing to abortion, and that
also must be ascertained. The external configuration of that organ will, of course, call
for attention, and also any bodies which are sometimes met with, as the disk at or near
to its base.

The seed is to be observed chiefly on account of its external configuration, and its
number in relation to the cells in which it lies. The Linncean arrangement calls but
little for any account of its internal anatomy ; and, with the exception of the number
and general nature of its Cotyledons, and some slight reference to the albumen, it will
not be necessary for the student to regard it. The fruit must be noticed in a general
manner that is, as to \vhether it is succulent or otherwise ; and the names which have

CHARACTERISTICS OF PLANTS. 181

been referred to when considering that organ, as well as those of more popular employ-
ment, committed to memory.

All the foregoing particulars are not necessary to enable the student to determina
the genus of any plant, since the characteristic of a genus is, that it possesses only
certain (perhaps but few) features which are common to a number of other most
closely allied plants, which are thence termed species. But if any number of plants,
say ten, agree in certain features, so that they may be associat. d under one head, each
of these will differ from the others in features of greater minuteness ; and, consequently.
a more minute acquaintance with all the parts of a plant is more necessary to determine
the species than the genus.

In order practically to apply these directions, we will give one or two familiar
examples, by way of illustration. Let us first examine the Myosotis, or Forget-me-not.
This plant will be found to have five stamens and one pistil, and consequently is at
once referable to the class Pentandria, and order Monogynia. Having referred to any
synopsis of the Linnaean arrangement, the student will find no fewer than forty genera
described under Pentandria Monogynia, and therefore will need further character-
istics, in order to prevent the necessity of comparing this plant with the descriptions of
all these genera. This is effected by noticing that a certain number of these genera
have an inferior monopetalous corolla, and two or four naked seeds ; and on referring
to the Myosotis he will find that such is the case with that plant also. This, then,
limits his investigation to ten genera, and it will be his duty to read the description of
each, beginning with the first, until he finus that one with which the plant in question
corresponds. The following are the characters of the genus Myosotis :

" Calyx inferior, of one leaf, deeply five cleft ; segments acute, equal. Corolla of
one petal, salver-shaped ; mouth half closed, with five small valves. Filaments very
short ; anthers small, oblong. Ovary, four. Style, thread-shaped, central, as long aa
the tube ; stigma obtuse. Seeds egg-shaped, pointed, smooth."

This description having been found to correspond with the plant under examination,
the next step will be to determine the precise species. The student will now find that
there are seven species described under that genus, and it will be his duty to compare his
plant with the first, and all others, until he finds the one with which it corresponds.
This will probably be far less tedious than it at first sight appears, since, immediately
he discovers in the description of any of the species any feature which differs clearly
from the specimen in his hand, he will not continue the comparison, but at once pro-
ceed to the description of the next species. In this way it is possible to examine a
dozen species in three or four minutes. Having, however, noticed that the description
of the genus and species Myosotis palustris corresponds with his plant, he has then
discovered that which he had been seeking for <m.,the class, order, genus, and species.
The characters of the species are thus described :

" Calyx funnel-shaped, with short broad segments ; leaves oblong, roughish, with
close-pressed bristles, root creeping. Roots very long, creeping ; stem from six to
twelve inches high ; clusters many -flowered ; two or three together ; limb of the
corolla sky blue, the valves of the mouth yellow. Perennial ; flowers in June and
July; grows in marshy places and ditches : common."

The student will thus be able readily to appreciate the different degrees of minuteness
needful to the determination of a genus and a species ; he will observe that the diffi-
culty of determining the genus and species is usually in proportion to the number of
genera found in the same class and order, and of species under the same genus.

182 CHARACTERISTICS OF PLANTS.

"We will now take a more difficult illustration viz., that of the Stinging Nettie
(Urtica). We first notice that the flower is deficient in stamens or pistils, and thence
that it is not bisexual. "We then examine other flowers, and ascertain that this is not
a mere coincidence, but is universal ; and, further, that all the flowers are unisexual,
and that on the same tree there are flowers only male, and others only female. Thus
we refer the plant to the class Monoecia. "We now select a male flower that is, one
having stamens only ; and finding that there are four stamens, we refer the plant to the
order Tetrandria. In this order there are but five genera, and of these one is a tree
the Alder and another is the common Box (Buxus), with both of which the student
will be familiar, and know at once that they cannot refer to the plant in question.
Moreover, two others, Littorella and Eriocaulon, are found, by the description of their
solitary genus, to grow in lakes and marshy places ; and as his plant grew on a bank, or
on some waste diy land, he may exclude them, and thus find that he is referred to the
only remaining genus, that of Urtica. This careless mode of exclusion will not, how-
ever, suffice beyond the point of directing immediate attention to the remaining genus,
and therefore he will at once proceed to compare the description of the Urtica with the
characters of the plant in his hand. The following description will suffice to indicate
the genus Urtica :

" Barren (or male) flower. Calyx of four roundish, concave, equal leaves. Petals
none. Nectary central, cup-shaped. Filaments four, awl-shaped, spreading, as long
as the calyx ; anthers roundish, two-lobed. Fertile (or female} flow&r. Calyx inferior,
of two roundish equal leaves. Corolla none. Ovary egg-shaped. Style none. Stigma
downy. Seed one, naked, egg-shaped, somewhat compressed, polished, embraced by
the permanent calyx."

The term nectary is here used in the indefinite sense in which Linnaeus employed
it, when he assembled very various structures, situate at or about the base of the ovary,
under that appellation, and in the sense in which it is still used by systematic works
on classification. It is not the true nectary found upon the short claw of the petal of
the Kanunculus, since the Urtica has no petals.

The determination of the species is not difficult, since there are but three species of
Urtica, all of which have venomous stinging or secreting hairs, and opposite leaves,
and the distinguishing features are referred to only two or three points. Thus we
will suppose that the plant under examination is the small Nettle, or Urtica urens, and
that the following description will indicate its characters :

" Leaves opposite, broadly elliptical, with about five longitudinal ribs ; clusters
simple. From one to two feet high ; bright green, with venomous stings. Annual;
flowers from June to October ; grows on cultivated ground and waste places."

Having given these two illustrations, we think that the attentive student will find
no difficulty in proceeding with the examination and classification of plants ; but we
think it needful to append one caution. Do not be discouraged if you have difficulty
in referring an unknown plant to its proper place amongst the genera and species ; but
having given due attention and failed, lay the plant aside, or invite the assistance of
some one who may have made further progress in the science. There is no royal road
to learning, and the first steps will ever be toilsome and difficult ; but, as the student
proceeds, he will find that the difficulties gradually and insensibly recede, until, in a
short time, he wonders that he ever regarded them for a moment. Do not at first
fatigue the mind, and discourage the spirits ; but be assured that you, like others, will
overcome them.

NATURAL SYSTEM OF PLANTS. 183

NATURAL SYSTEM OF PLANTS.

The Natural System of Plants differs from the artificial system now detailed ; for
it takes into account the whole organization of the plant, with its habits and properties,
and is not restricted to one or two particular features. The contrast of the two plans of
classification is thus coaeisely stated by the author of the " Vegetable Kingdom :" " The
natural system of Botany being founded on these principles, that all points of resem-
blance, between the various parts, properties, and qualities of plants, shall be taken into
consideration ; that thence an arrangement shall be deduced in which plants must be
placed next each other, which have tne greatest degree of similarity in those respects ;
and that, consequently, the quality of an imperfectly-known plant may be judged of
by that of another which is well known. It must be obvious that such a method
possesses great superiority over artificial systems, like that of Linnaeus', in which there
is no combination of ideas, but which are mere collections of isolated facts, having no
distinct relation to each other. The advantages of the natural system, in applying
botany to useful purposes, are immense, especially to medical men, who depend so much
upon the vegetable kingdom for their remedial agents. A knowledge of the properties
of one plant enables the practitioner to judge scientifically of the qualities of other
plants naturally allied to it ; and therefore the physician, acquainted with the natural
system of botany, may direct his inquiries when on foreign stations, not empirically,
but upon fixed principles, into the qualities of the medicinal plants which have been
provided in every region for the alleviation of the maladies peculiar to it. He is thus
enabled to read the hidden characters with which nature has labelled all the hosts of
species that spring from her teeming bosom." "We do not need therefore to hesitate
when we confidently recommend this plan of classification in preference to the simple
one already given.

As the component parts of a plant are very various, and their relative importance is
somewhat a matter of opinion, and, moreover, as plants resemble and differ from each
other in so many and minute particulars, it is no matter for wonder that various natural
systems have been devised. Indeed it is not possible for any ten of the most learned men
existing to prepare each an original scheme, independent of each other, without pro-
ducing ten systems instead of one system of classification. There have been already about
thirty distinct systems (many of which, however, were simply modifications of one or
more preceding) ; and it is probable that the best one, at the present moment, is so imper-
fect that it must be amended yearly. The great Linnaeus himself gave the outline of a
natural system, in which he arranged all the then known plants under sixty-eight
heads ; but he attached little importance to it. Since his day several others have
appeared, which were original, and which have had great influence in the world. The
first is that of Adrien de Jussieu, who, in 1789, published an admirable system on the
outlines given by our great countryman Kay, in 1703 ; and to this day De Jussieu's
system is held ia high estimation. The next great writer on classification \*as A. P.
de Candolle, and he compiled one hundred and sixty-one natural orders out of the
three great divisions of plants, Dicotyledons, Monocotyledons, and Acotyledons, before
described. These two systems have been the foundation of all those of more modern

184 NATURAL SYSTEM OP PLANTS.

date, including those of Endlicher, who was De Jussieu's great successor, Brogniart,
and Lindley.

The difficulty, at the present day, is to make a good selection, and more particularly
in a work of this nature, which is to be the handbook of botany to so many thousands
of readers both scientific and non-scientific. Our aim must be to obtain that which,
with simplicity, will give the most recent and the most valuable information. On
careful consideration we are of opinion that we shall be doing an injustice to our
readers, if we fail to make them acquainted with the last one above-mentioned the
system of a distinguished countryman, which, as it is based upon most extensive and
usually accurate information, is deservedly supplanting others in the botanical teaching
of the British schools.

THE NATURAL SYSTEM, ACCORDING TO DR. LINDLEY.

Before commencing an examination of this system we must beg our readers to bear
in mind that a close attention is necessary to the minute parts of the plant, and more
particularly of the seed; since, of all organs, that is one possessed of the greatest degree
of constancy. We must also give some degree of encouragement to the student by
stating, that although this system is not so simple as that previously described, it is
yet less difficult than it appears to be. Its difficulty lies at the threshold ; and to
overcome it the student will have the gratification of gaining much interesting
information.

We cannot enter at length into the subject, but shall give an outline of the whole
scheme, and such illustration as may be interesting and useful to the reader, and
necessary to a comprehension of so extensive a subject. The following is a conden-
sation of Professor Lindley's scheme (" Vegetable Kingdom," p. lv., et seq.)

CLASSES.
Asexual, or Fkwerless Plants.

Stems and leaves undistinguishable I. THALLOGENS.

"A Thallus Is a fusion of root, stem, and leaves, into one general mass, and Thallogens are
also destitute of flowers ; they are equally without the breathing pores, so abundantly
formed in the skin of more complex species ; and they multiply by the spontaneous forma-
tion in their interior, or upon their surface, of reproductive spheroids, called spores."

Stems and leaves distinguishable 11. ACROGENS.

*< Beyond Thallogens are found multitudes of species, -which, like Thallogens, are not fur-
nished by nature with flowers, but which otherwise approach closely to the higher forms
of structure, occasionally acquiring the stature of lofty trees. They have breathing pores
in their skin ; their leaves and stems are distinctly separated ; in some of them those
spiral threads, which form so striking a portion of the internal anatomy of a more perfect
species, exist in considerable abundance ; and finally, they multiply by reproductive sphe-
roids or spores, either formed without the agency of sexes, or, if the contrary, shall be
proved at all events not possessing bodies constructed like stamens on the one hand, and
embryos on the other. Their stem, however, does not increase in diameter ; it only grows
at the end, and hence it has given to such plants the name of Acrogens."

NATTJRAI, ORDEE OF PLANTS. 185

Sexual, or Flowering Plant*.
Fructification springing from a thallus .......*. Ml. RHIZCQ

4< Foremost among the more perfect races comes a most anomalous collection of species called
Rhizogens. These plants, leafless and parasitical, have the loose cellular organization of
Fungi ; a spiral structure is usually to be found among their tissues only in traces. Some
of them spring visibly from a shapeless cellular mass, which stands in place of stem ana
root, and seems to be altogether analogous to the Thallus of the Fungi ; and it is probable
that they all partake in this singular mode of growth. Their flowers are like those of
more perfect plants ; their sexual apparatus is complete, but their embryo, which is not
furnished with any visible radicle or cotyledons, appears to be a spherical or oblong homo*
geneous mass."

Fructification springing from a stem.

Wood of stem youngest in the centre ; cotyledon single.

Leaves parallel- veined, permanent ; wood of the stem always
confused iv. ENDOGENS.

** Endogens consist of species whose germination is endorhizal, whose embryo has but one
cotyledon, whose leaves have parallel veins, and whose trunk is formed of bundles of spiral
and dotted vessels, guarded by woody tubes, which bundles are arranged in a confused
manner, and are reproduced in the centre of the trunk."

Leaves net-veined, deciduous ; wood of the stem, when peren-
nial, arranged in a circle with a central pith V. DICTYOGEKS.

" Dictyogens are Endogens, but with the peculiarity that the root is exactly like Exogens
without concentric circles, and the leaves fall off the stem by a clean fracture, just as in
that class."

"Wood of stem youngest at the circumference, always concentric ;
cotyledons 2 or more.

Seeds quite naked vi. GYMNOGENS,

* 4 Gymnogens are a division of Exogens which, in the sexual apparatus, have no style ana
stigma, but are so constructed that the pollen falls immediately upon the ovules, a pecu-
liarity analogous to wtiat occurs among reptiles in the animal kingdom."

Seeds inclosed in seed-vessels vn. EXOGENS.

" The class at Exogens is composed of innumerable races, having an exorhizal germination,
an embryo with two or more cotyledons, leaves having a net- work of veins, and a trunk
consisting of woody bundles, composed of dotted and woody tubes, or of woody tubes alone,
arranged around a central pith, and either in concentric rings or in a homogeneous mass,
but always having medullary plates forming rays from the centre to the circumference,
and reproduced on the circumference of the trunk, whence their name of Exogens."

CLASS I. THAXLOGETCS. 939 Genera ; 8394 Species.

ALLIANCES OF THALLOGENS.

L AKUT,M. Cellular flowerless plants, nourished through their whole surface by the medium in
which they vegetate ; living in water or very damp places ; propagated by zoospores,
coloured spores, or tetraspores. 283 Gen. ; 1994 Sp.

Natural Orders. 1. Diatomacese, or Brittleworts. 2. Confervacese, or Confervas. 3. Fuca-
cese, or Seaweeds. 4. Ceramiacese, or Rosetangles. 5. Characea, or Charads.

186 NATURAL ORDER OP PLANTS.

2. FUNQALKS. Cellular fiowerless plants, nourished through their thallus (spawn or mycelium) ;
living in air; propagated by spores, colourless or brown, and sometimes inclosed in asci;
destitute of green gonidia. 598 Gen. ; 4000 Sp.

Natural Orders. 6. Hymenomycetes, Agaricaceaa, or Toadstools. 7. Gasteromycetes,
Lycoperdaceae, or Puffballs. 8. Coniomycetes, Uredinaceae, or Blights. 9. Hypho-
mycetes, Botrytaceae, or Mildews. 10. Ascomycetes, Helvellacese, or Morels. 11. Physo-
inycetes, Mucoracese, or Moulds.

S. LICHKNALES. Cellular flowerless plants, nourished through their whole surface by the medium
in which they vegetate; living in air; propagated by spores usually inclosed in asci; and
aiways having green gonidia in their thallus. 58 Gen. ; 2400 Sp.

Natural Orders. -12. Graphidacese, or Letter-Lichens. 13. Collemacese, or Jelly-Lichena.
14. Parmeliaceae, or Leaf-Lichens

CLASS II. ACROGENS 310 Genera; 4086 Species.

ALLIANCES OF ACROGENS.

4. MCSCALKS. Cellular (or vascular). Spore-cases immersed or calyptrate (i.e., either plunged in

the substance of the frond, or inclosed within a hood having the same relation to the spores
as an involucre to a seed-vessel). 113 Gen. ; 1822 Sp.

Natural Orders. 15. Ricciac'eae, or Crystalworts. 16. Marchantiaceae, or Liverworts.
17. Jungermanniaceae, or Scalemosses. 18. Equisetaceae, or Horsetails, 19. Andrseacese,
or Splitrnosses. 20. Bryaceae, or Drnmosses.

5. LYCOPODALES. Vascular. Spore-cases axillary or radical, one or many-celled. Spores of two

sorts. 6 Gen. ; 224 tip.
Natural Orders. 21. Lycopodiacece, or Clubmosses. 22. Marsileaceae, or Pepperworts.

6. FIUCALRS. Vascular. Spore-cases marginal or dorsal, one-celled, usually surrounded by an

elastic riug. Spores of but one sort. 192 Gen. ; 2040 Sp.

Natural Orders. 23. Ophioglossaceas, or Adders' Tongues. 24. Polypodiaceae, or Ferns.
25.

CLASS III. RHIZOOENS. 21 Genera; 53 Species.

ALLIANCE THE SAME AS THE CLASS.

Natural Orders. 26. Balanophoraceae, or Cynomoriums. 27. Cytinaceae, or Cistusrapes.
28. Rafflesiacese, or Itafflesiads.

CLASS IV ENDOGENS. H20 Genera; 13684 Species.

ALLIANCES OP ENDOGENS.

Flowers glumaceous (that ts to say, composed of bracts not collected in true whorls, but consisting qf
imbricated colourless or herbaceous scales).

7. GLUMALES. 439 Gen. ; 6186 Sp.

Natural Orders. 29. Graminaceae, or Grasses. 30. Cyperaceae, or Sedges. 31. Des-
vauxiaceae, or Bristleworts. 32. Restiaceee, or Restiads. 33. Eriocaulaceae, or Pipeworte.

Flowers petaloid, or furnished with a true calyx or corollo^ or with both, or absolutely naked ;
$ (that is, having sexes altogether in different flowers, without half-formed rudiments of the
absent sexes being present}.*

The following signs are employed in this scheme :

2 Signifies a bisexual, or hermaphrodite plant.

^ An unisexual, or male plant.

9 An unisexual, or female plant.

Flowers having two coverings, as calyx and corolla, are said to be Diclamydeous; and one cover.
Ing, Monoclamydeout. It they vary so that some have one and others two coverings, they are called
Monodiclamydeoui.

NATURAL ORDER OF PLANTS. 137

8. ARALES. Flowers naked, or consisting of scales, 8 or 3 together or numerous, and then sessile

on a simple naked spadix ; embryo -xile ; albumen mealy or fleshy. (Some have no albumen.)
41 Gen. ; 278 Sp.

Natural Orders. 34. Pistiaceae, or Lemnads. or Duckweeds. 35 Typhaceae, or Typhads,
or Bulrushes. 36. Araceae, or Arads. 37. Pandanaceje, or Screwpines.

9. PALMALES. Floweio perfect (with both calyx tmd corolla*, Sfasile on a branched scaly spadix ;

embryo vague, solid ; albumen horny or fleshy. Sonr.c films are $ . 73 Gen. ; 400 Sp.

Natural Orders. 38. Palmaceae, or Palme.

10. HTDRALES. Flowers perfect or imperfect, usually sop-tttred; embryo axile, without albumen

aquatics. (Some are $ .) 26 Gen. ; 48 Sp.

Natural Orders. 39. Hydrocharidaceae, or Hydrocharads. 40. Naiadaceae, or Naiada. 4C
bis. Triuriuaceae, or Triurids. 41. Zoateract., or f eawracks.

** Flowers furnished with a true, calyx und corolla, adherent to the ovary ; 5 .

11. NAHCISSALKS. Flowers symmetrical; stamens 3 or 6. or more, all perfect; seeds with albumen.

(Some Bromeliaccae have a free calyx ana corolla.) 163 Gen. ; 1238 Sp.

Natural Orders. 42. Bromeliaceae, or Bromeliads. 43. Taccaceae, or Taccads. 44. Flaemo-
doracese, or Bloodroots. 45. Hypoxidaceae, or B ypoxids, 46. AmaryllidaceaD, or Amaryl-
lids. 47, Iridaceae, or Irids.

12. AMOMALES. Flowers unsymmetrical ; stamens 1 to 5, some at least of which are petaloid ;
seeds with albumen. 39 Gen.; 427 Sp.

Natural Orders. 18. Musacae, or Musads, 49. Zingiberaceae, or Gingerworts. 50. Maran-
taceae, or Marants.

13. ORCHIDALES. Flowers unsymmetricsl ; stamens 1 to 3; seeds without albumen. 404 Gen.;
3035 Sp.

Natural Orders. 51. Burmanniaceee, or Burmanniads. 52. Orchidacoae, or Orchids. 53.
Apostasiaceae, or Apostasiads.

Flowers furnished with a Inie calyx and corolla, free from the ovary ; .

14. XYRID ALES. Flower s half herbaceous, 2-3-petaloideous ; albumen copious. 24 Gen. ; 336 Sp.

Natural Orders. 54. Philydracesa, or Waterworts. 55. Xyridaceae, or Xyrids. 56. Com-
melynaceae, or Spiderworts. 57. Mayaceae, or Mayacs.

15. JUNCALES. Flowers herbaceous, dry, and permanent, scarious if coloured; albumen copious.

(Some Callas have no albumen.) 27 Gun. ; 260 Sp.

Natural Order*. 85. Juncaceae, or Rushes. 59. Orontiacese, or Orontiads.

16. LILIALKS. Flowers hexapetaloideous, succulent, and withering; albumen copious. 171 Gen. ;

Natural Ordert. 60. Gilliesiacess, or Gilliesiads. 61. Melanthacese, orMelanths. 62. Liliacea,
or Lilyworts. 63. Pontederaceae, or Pontederads.

17. ALISMALES. Flowers 3-6-petaloideous, apocarpal ; albumen none. (Some Alismads are abo.

lutely 93.) 14 Gen. ; 101 Sp.

Natural Ot ders.64. Butomacese, or Butomads. 65. Alismaceae, or Alismads. 66. Junca-
cinaceaa, or Arrow-grasses.

CLASS V. DiCTYOQBNS. 17 Genera; 268 Species.

yatural Orders. 68. Dioscoreaceae, or Yams. 69. Smilacese, or Sarsaparillas. 70. Phile.
siacese, or Philesiads. 71. Trilliacese, or Parids. 72. Roxburghiaceae, or Roxburgh-

188 NATURAL ORDfiR OF PLANTS.

CLASS VI. GYMNOGENS. 37 Genera ; 210 Species.

Natural Orders. -73. Cycadeaceae, or Cycads. 74. Pinacese, or Conifers. 75. Taxaceae,
or Taxads. 76. Gnetaceae, or Joint Firs.

CLASS VII. ExooEm-^6191 Genera; 66225 Species.

ALLIANCES OF EXOGENS.

SUB-CLASS I. DICLINOUS EXOGENS.

Flowers $ Q, without any customary tendency to $ .

.. Flowers in catkins, achlamydeous or monochlamydeous ; carpels superior ; embryo
small, with little or no albumen. 13 Gen. ; 358 Sp.

Natural Orders.-*!!. Casuarinaceae, or Beefwoods. 78. Betulaceae, or Birchworts. 79.
Altingiacese, or Liquidambars. 80. Salicaceae, or VVillowworts. 81. Myricaceaa, or
Galeworts. 82. Elteagnaceae, or Oleasters.

19. UaTiCALKS.-'Flowers scattered, monochlamydeous ; carpel single, superior ; embryo large, lying

in a small quantity of albumen. 61 Gen. ; 572 Sp.

Natural Orders. S3. Stilaginaceae, or Antidesmads. 84. Urticacese, or Nettleworts. 85.
Ceratophyllaceae, or Hornworts. 86. Caunabinacese, or Hempworts. 87. Moracese, or
Moraus. 88. Artocarpaceae, or Artocarpads. 89. Platanaceae, or Planes.

20. EUPKORBIALES. Flowers scattered, monodichlamydeous ; carpels consolidated, superior ; pla-

centae axile ; embryo surrounded by abundant albumen. (Albumen occasionally absent). 203
Gen. ; 2527 Sp.

Natural Orders. SO. Euphorbiaceaa, or Spurgeworts. * Gyrostemoneae. 91. Scepaceae,
or Seep ids. 92. CallitrichaceoB, or Starworts. 93. Empetraceee, or Crowberries. * Batidese.
94. 1 NepenthaceaB, or Nepentha.

21. QUERNALKS. Flowers in catkins, monochlamydeous; carpels inferior; embryo amygdaloid,

without albumen. 12 Gen ; 292 Sp.

Orders. 05. Corylaceae, or Mastworts. 96. Juglandacese, or Juglands.

32. GARRYALES. Flowers monochlamydeous, sometimes amentaceous ; carpels inferior ; embryo
minute, in a large quantity of albumen. 3 Gen. ; 7 Sp.

Natural Orders. -97. Garryaceae, or Garryads. 98. Helwingiaceae, or Helwingians.

23. MENISPERMALES. Flowers monodichlamydeous ; carpels superior, disunited : embryo sur-

rounded by abundant albumen. 39 Gen. ; 281 Sp.

Natural Orders. 99. Monimiacege, or Monimiads. 100. Atherospermaceze, or Plume-Nut-
megs. 101. Myristicaceae, or Nutmegs. 102. Lardizabalacese, or Lardizabalads. 103. Schi-
zandracese, or Kadsurads. 104. Menispermaceae, or Menispermads.

24. CXJCTRBITALES. Flowers monodichlamydeous ; carpels inferior ; placenta parietal ; embryo

without albumen. 61 Gen. ; 433 Sp.

Natural Orders. 105. Cucurbitacese, or Cucurbits. 106. Datiscacete, or Datiscads. 107.
Begomaceae, or Begoniads.

Natural Orders. 108. Papayace ae, or Papayads. 109. Pangiacets, or Pangiads.

NATURAL ORDER OP PLANTS. 189

SUB-CLASS II. HTPOGTNOUS EXOOENS.
Flowers g , or $ 9 ; stamens entirely free from the calyx and corolla.

26. YIOLALES. Flowers monodichlamydeou* ; placentae parietal or sutural : embryo straight, with

little or no albumen. 98 Gen. ; 1282 Sp.

Natural Orders. 110. Flacourtiacese, or Bixads. 111. Lacistemaceae, or Lacistemads.
112. Samydaceae, or Samyds. 113. Passifloraceae, or Passionworts. 114. MalesherbiaceaB,
or Crown worts . 115. Moringaceae, or Moringads. 116. Violaceae, or Violetworts. 117.
Frankeniaceae, or Frankeniads. 118. Tamaricacese, or Tamarisks. 1 19. Sauvagesiacese, or
Sauvageads. 120. Crassulaceae, or Houseleeks. 121. Turneraceee, or Turnerads.

27. CISTALES. Flowers monodichlamydeous ; placentae parietal or sutural ; embryo curved or spiral ;

with little or no albumen. 214 Gen.; 2166 Sp.

Natural Orders 122. Cistaceae, or Rock Roses. 123. Brassicaceae, or Crucifers. 124. Rese-
daceae, or Weldworts. 125. Capparidaceae, or Capparids.

28. MALVALES. Flowers monodichlamydeous ; placentse axile ; calyx valvate in aestivation ; corolla

imbricated or twisled ; stamens definite or 00 : embryo with little or no albumen. 160 Gen. ;
1933 Sp.
Natural Orders. 126. Sterculiaceae, or Sterculiads. 127. ByttneriaceaB, or Byttneriads. 128.

Vivianiaceae, or Vivianads. 129. Tropaeolacese, or Indian Crosses. 130. Malvace, or

Mallowworts. 131. Tiliucc-ae, or Lindenblooms.

29. SAPINDALES. Flowers monodichlamydeous, unsymmetrical ; placentae axile ; calyx and corolla

imbricated ; stamens definite ; embryo with little or no albumen. (Stamens rarely 00.) 132

Gen. ; 1656 Sp.

Natural Orders. 132. Tremendracese, or Poreworts. 133. Polygalaceae, or Milkworts. 134.
Yochyaceae, or Vochyads. 135. Staphyleaceae, or Bladder Nuts. 136. Sapindaceae, or Soap-
worts. 137. Petiveriaceae, or Petiveriads. 138. Aceraceae, or Maples. 139. Alalpig-
hiaceae, or Malpighiaas. 140. Erythroxylacese, or Erythroxyls.

80. GUTTIFERALES. Flowers monodichlamydeous ; piacentae axile ; calyx imbricated ; corolla imbri-

cated or twisted ; stamens 00 ; embryo with little or no albumen. (Stamens sometimes
definite in number.) 93 Gen. ; 642 Sp.

Natural Orders. 141. Dipteracese, or Dipterads. 142. TernstrBmiaceae, or Theads. 143.
Rhizobolaceee, or Khizobols. 144. Clusiaceae, or Guttifers. 145. Marcgraviaceae, or Marc-
graviads. 146. Hypericaceae, or Tutsans. 147. Reaumuriacffi, or Keaumuriads.

81. NTMPHALES. Flowers dichlamydeous ; placentae axile or sutural ; stamens 00 ; embryo on the

outside of a very large quantity of mealy albumen. (A part have no albumen.) 8 Gen.; 56 Sp

Natural Orders. 148. Nymphaeaceae, or Water-lilies. 149. Cabombaceae, or Water-shields.
150. Nelumbiaceae, or Waterbeans.

32. RANALES. Flowers monodichlamydeous ; placentae sutural or axile ; stamens 00 ; embryo

minute, inclosed in a large quantity of fleshy or horny albumen. 119 Gen. ; 1703 Sp.
Natural Orders. 151. Magnoliaceae, or Magnoliads. 152. Anonaceae, or Anonads. 153. Dil-
leniacese, or Dilleniads. 154. Rammculaceae, or Crowfoots. 155. Sarracenniaceae, or Sar-
raceniads. 156. Papaveraceae, or Poppyworts.

33. BERBERALES. Flowers monodichlamydeous, unsymmetrical in the ovary; placentae snturv.,

parietal, or axile ; stamens definite : embryo inclosed in a large quantity of fleshy albumen.
79 Gen. ; 604 Sp.

Natural Orders. 157. Droseraceae, or Sundews. 158. Fumariaceae, or Fumewort". 159.
Berberidaceae, or Berberids. 160. Vitaceae, or Vineworts. 1 61 . Pittosporaceae, or Pittos-
porad. 162. Olacaceae, or Olaci.ds. 163. Cyrillaceae, or Cyrillads.

JM. EEICALES. Flowers dichlamydeous, symmetrical in the ovary; placentae axile; stamens definite-
embryo incloKed in a large quantity of fleshy albumen. (Stamens occasionally adherent to
the corolla.) 89 Gen. ; 1215 Sp.

Natural Orders. 164. Humiriaceae, or Hnmiriads. 165. Epacridaceae, or Epacrids. 166.
Pyrolaceee, or Winter-greens. 167. Fran coaceae, or Francoads. 168. Monotropaceoo, or
Fir-rapes. 169. Ericaceae, or Heathworts.

190 NATURAL ORDER OF PLANTS.

85. RUTALES. Flowers monodichlamydeous, symmetrical ; placentae axile ; calyx and corolla imbri
cated, if prespnt ; stamens definite ; embryo with little or no albumen. (Occasionally $ $).
236 Gen.; \2MSp.

Natural Orders. 170. Aurantiaceae, or Citronworts. 171. Amyridaceae, or Amyrids. 172.
Cedrelacea, orCedrelads. 173. Meliacese, or Meliads. 174. Anacardiaceae, or Anacards, or
Terebinths. 175. Connaraceae, or Connarads. 176. Rutaceae, or llueworts. 177. Xan-
thoxylaceae, or Xanthoxyls. 178. Ochnacea3, or Ochnads. 179. Simarubaceae, or Quaa-
siads. 180. Zygophyllaceae, or Bean-capers. 181. Elatmaceae, or Water-peppers. 182.
Podostemaceae, or Podostemads.

36. GBRANIALES. Flowers monodichlamydeous, symmetrical ; placentae axile ; calyx imbricated ;
corolla twisted ; stamens definite ; embryo with little or no albumen. 19 Gen. ; 1033 Sp.

Natural Orders. 183. Linaceae, or Flaxworts. 184. Chlaenaceae, or Chlenads. 185. Oxali-
daceae, or Oxalids. 186. Balsaininaceae, or Balsams. 187. Geraniaceae, or Cranesbills.

S7. SILENALES. Flowers monodichlamydeous ; placenta free, central ; embryo external, curved
round a little mealy albumen ; carpel? more than one, completely combined into a compound
fruit. (Some slightly peryginous, others 9.) 118 Gen. ; 1829 Sp.

Natural Orders. 188. Caryophyllacere, or Silenads. 189. Illecebraceas, or Knotworts. 190. i
Portulaceae, or Purslanes. 191. Polygoiiaceae, or Buckwheats.

38. CHENOPODALES. Flowers monochlamydeous ; placentae free, central ; embryo external, either

curved round or applied to the surface of a little mealy or horny albumen ; carpels solitary, or i
if more than one, distinct. (Some slightly perigynous, others $). 125 Gen. : 803 Sp.

Natural Orders. 192. Nyctaginaceae, or Nyctagos. 193. Phytolaccaceae, or Phytolaccads. ;
194. Amarantaceae, or Amaranths. 195. Chenopodiaceae, or Chenopods.

89. PIPERALES. Flowers achlamydeous ; embryo minute, on the outside of a large quantity of
mealy albumen. (Occasionally 9). 27 Gen.; 622 Sp.

Natural Orders. 196. Piperaceae, or Pepperworts. 197. Chloranthaccse. or Chloranths.
198. Saururaceae, or Saururads.

SUB-CLASS III. PERIGYNOUS EXOOENS.

Flowers $ , or <J 9 ; stamens growing to the side of either the calyx or the corolla ; ovary superior,

or nearly so.

40. FICOIDAI.ES. Flowers monodichlamydeous ; placentae central or axile; corolla, if present, poly.

petalous; embryo external^ and curved round a small quantity of mealy albumen 24' Gen
466 Sp.

Natural Orders. 199. Basellaceae, or Basellads. 200. Mesembryaceae, or Ficoids. 201. Tetra-
goniaceae, or Aizoons. 202. Scleranthaceae, or Scleranths.

41. DAPHX ALES. Flowers monochlamydeous; carpel solitary; embryo amygdaloid, without albumen.

Natural Orders. 203. Thymelaceae, C/ Daphnads. 204. Proteacese, or Proteads 205 Lau
racese, or Laurels. 206. Cassythaceae, or Dodder-laurels.

42. ROSALES. Flowers monodichlamydeous ; carpels more or less distinct : placentse sutural seeds

definite ; corolla if present, polypetalous ; embryo amygdaloid, with little or no albumen.
551 Gen.; /491 Sp.

Natural Orders.-207. Calycanthaceae, or Calycanths. 208. Chrysobalanaceaa, or Chrysoba-
lans. 209. Fabaceae, or Leguminous plants. 210. Drupaceje, or Almondworts. 211.
Pomaceae, or Appleworts. 212. Sanguisorbaceae, or Sanguisorbs. 213. Rosaceas, or

43. SAXIFRAOALES. Flowers monodichlamydeous ; carpels consolidated ; placentae sutural or axile

seeds 00; corolla, if present, polypetalous; embryo taper, with a long radicle, and a little or
no albumen, 89 Gen.; 761 Sp.

Natural Orders. 214. Saxifrages?, or Saxifrages. 215. Hydrangeaoese, or Hydrangads
ia Cunoniad8 - 217 ' B ^^ceo3, or Brexiads. 218. Lythracei, or

NATURAL OBDER OF PLANTS. 191

44. BHAMNAI-KS. Flowers monodichiamydeous ; carpels consolidated; placentae axilc; fruit e<ip-

sular, berried, or drupaceous ; seeds definite ; embryo amygdaloid, with little or no albumen.
323 Gen. ; 1034 Sp.
Natural Orders 219. Penaeaceae, or Sarcocollads. 220. Aquilariacese, or Aqui.ariads.

221. Ulmaceaj, or Elm worts. 222. Rhamnaceae, or Khamnads. 223. Chailletiaceae, or

Chailletiads. 224. Hippocrateaceae,or Hippocruteads. 225. Celastraceae, or Spindle-trees.

226. Stackhousiaceae, or Stackhousiads. 227. Sapotaceoe, or Sapotads. 228. Styracaceae,

or Storaxworts.

45. GENTIANALES. Flowers dichlamydeous, monopetalous ; placentae exile or parietal; embryo

minute, or with the cotyledons much smaller than the radicle, lying in a large quantity 01
albumen. 221 Gen.; 1580 Sp.

Natural Orders. 229. Ebenaceae, or Ebanads. 230. Aquifoliaceae, or Hollyworts.
231. Apocynacere, or Dogbanes. 232. Loganiacese, or Legoniads. 233. Diapensiaceae, or
Diapensia'ds. 234. Stilbaceae, or Stilbids. 235. Orobanchaceae, or Broomrapes. 236. Gen-
tianaceae, or Gentianworts.

46. SOLAVAI.ES. Flowers dichlamydeous, monopetalous, symmetrical ; placentae axile ; fruit 2-3-

celled ; embryo large, lying "in a small quantity of albumen. (Occasionally aehlamydeous or
polypetalous)'. 298 Gen. ; 2934 Sp.

Natural Orders. 237. Oleaceae, or Oliveworts. 238. Solanaceae, or Nightshades.
239. Asclepiadaceae, or Asclepteds. 240. Cordiacese, or Sebestens. 241. Convolvulaceae,
or Bindweeds. 242. Cuscutaceae, or Dodders. 243. Polemoniaceae, or Phloxworts.

47. CORTUSALES. Flowers dichlamydeous, monopetalous, symmetrical; placenta free, central;

embryo lying among a large quantity of albumen. (Occasionally monochlamydeous, or poly-
petalous). 86 Gen. ; 880 Sp.
Natural Orders. 244. Hydrophyllacese, or Hydrophyls. 245. Plumbaginaceae, or

Leadworts. 246. Plantaginaceae, or Ribworts. 247. Primulacea3, or Primworts. 248.

Myrsinaceae, or Ardisiads.

48. ECHIAI.ES. Flowers dichlamydeous, monopetalous, symmetrical, or un symmetrical ; fruit nuca-

mentaceous, consisting of several one-seeded nuts, or of clusters of them, separate or separable ;
embryo large, with little or no albumen. (Very rarely hypogynous !) 280 Gen. ; 4158 Sp.

Natural Orders. US. Jasminaceae, or Jasminworts. 250. Salvadoraceae, or Salva-
dorads. 251. Ehretiaceae, or Ehretiads. 252. Nolanaceae, or Nolanads. 253. Bora-
ginaceae, or Borageworts. 254. Brunoniacete, or Brunoniad?. 255. LamiaceaB, or Labiates.
256. Verbeuaceae, or Verbenes. 257. Myoporacese, or Myoporads. 258. Selaginaeeae, or
Selagids.

49. BIGNONIALES. Flowers dichlamydeous, monopetalous, unsymmetrical ; fruit capsular or berried,

with its carpels quite consolidated ; placentae axile, or parietal, or free central; embryo with
little or no albumen. 408 Gen. ; 3508 Sp.

Natural Orders. 259. Pedalinceae, or Pedaliads. 260. Gesneraceae, or Gesnerworts.
261. Crescentiaceae, or Crescentiads. 262. Bignoniacese, or Bignoniads. 263. Acan-
thaceae, or Acanthads. 264. Scrophulariaceae, or Linariads. 265. Lentibulariaceae,
or Butterworta.

SUB-CLASS IV. EPIGTNOUS EXOGENS.

Flowers 2 > or 29' stamens growing to the side of either the calyx or corolla ; ovary inferior, or

nearly so.

50. CAMPANALES. Flowers dichlamydeous, monopetalous ; embryo with little or no albumen. 1102

Gen.; 10491 ,Sp.

Natural Orders. 266. Campanulaceae, or Bellworts. 267. Lobeliaceae, or Lobeliads. 208.
Goodeniacese, or Goodeniads. 269. Stylidiaceae, or Style-worts. 270. Valerianaceae, or
Valerianworts. 271. Dipsacaceae, or Teazleworts. 272. Calyceraceae, or Calycers. 273.
Asteraceae, or Composites.

51. MTRTALES. Flowers dichlamydeous, polyprtalou" ; placentae axile ; embryo with littl or no

albumen. (Occasionally monochlamydecus) . 253 Gen. ; 3340 Sp.

Natural Orders. 274. Combretaceae. or Myrobalans. 275. Alangiacese, or Alan-
giads. 276. Chamselauciaceae, or Fringe Myrtles. 277. Haloragaceae, or Hippurids.
278. Onagraceae, or Onagrads. 279. Khizophoraceae, or Mangroves. 280. Belvisiaceae, 01
Napoleonworts. 281. Melastomaceoe, or Melastomads. 282. Myrtaceae, or Myrtleblooine
283. Lecythidaceae, or Lecytha.

192 CONCLUDING SUMMARY.

52. CACTALBS. Flowers dichlamydeous, polypetalous ; placentae parietal; embryo with little or no

albumen. 39 Gen. ; 900 Sp.

Natural Orders. -284. Homaliacese, or Homaliads. 285. Loasacese, or Loasads. 286. Cno-
taceae, or Indian Figs.

53. GBOSSALES. Flowers dichlamydeous, polypetalous ; seeds numerous, minute ; embryo small,

lying in a large quantity of albumen. 22 Gen. ; 208 Sp.

Natural Orders. 287. Grossulariacese, or Currantworts. 288. Escalloniaceae, or Escal-
loniads. 289. Philadelphaceae, or Syringas. 290. Barringtoniaceos, or Barringtoniads.

64. CIKCHONALES. Flowers dichlamydeous, monopetalous ; embryo minute, lying in a large quantity

of albumen. 305 Gen. ; 3243 Sp.

Natural Orders. 291. Vacciniaceae, or Cranberries. 292. Columelliaceae, or Columel-
liads. 293. Cinchonaceae, or Cinchonads. 294. Caprifoliaceae, or Caprifoils. 295.
Galiacese, or Stellates.

65. UMBELLALES. Flowers dichlamydeous, polypetalous ; seeds solitary, large; embryo small, lying

in a large quantity of albumen. 322 Gen. ; 1780 Sp.

Natural Orders. 296. Apiaceae, or Umbellifers. 297. Araliaceae, or Ivyworts. 298. Corna-
ceae, or Cornels. 299. Hamamelidaceae, or Witch-Hazels. 300. Bruniaceae, or Bruniads.

56. ASARALES. Flowers monocblamydeous ; embryo small, lying in a large quantity of albumen.
49 Gen. ; 652 Sp.

Natural Orders. 301. Santalacese, or Sandalworts. 302. Loranthaceas, or Loranths.
303. Aristolochiaceae, or Birthworts.

Had our space permitted, we should now proceed to consider the various alliances
and natural orders in detail, so as to lay before our readers a complete account of the
whole kingdom of plants ; but we must content ourselves with the extended scheme
which we have now inserted.

"We have but little to add to the directions which we gave for the prosecution of the
study of classification under the Linnsean system ; but it is important to bear in mind,
that under the natural arrangement the stamens and pistils play a subordinate part,
and are only accounted as a portion of the whole constitution of the plant. But
very minute and constant attention is directed to the ovule and the seed ; so that a
pocket magnifier of moderate power is at all times necessary.

KDWAED SMITH, M.D

BOTANICAL INDEX.

Abies (Lat. " a fir tree"), secretions from the, 49.'

Acacia catechu (Gr. akakia, an Egyptian thorn,

1 and German katchu, an astringent herb),
tannic acid obtained from, 50, 54; pollen of
the, 122.

Acer campestris (Lat. the " field maple," from
acer sharp), 75.

A. saccharinum (Lat. the " sugar - yielding
maple"), 23.

Acids, vegetable secretions, 50.

Acotyledonous seeds (Gr. a privative, and cotyle
a cavity " wanting cotyledons"), 135.

Acrogens (Gr. acros the summit, and ginomai
to grow), Class II. of Lindley, 186.

Acrostalagmus cinnabarius (Gr. akros the sum-
mit, and stalagma a distilled drop; Lat.
"cinnabar"), 145.

Adder's-tongues, 175.

Adnate stamens (Lat. adnata growing to), 121.

Aerial roots, 92.

Aerial stems, 72.

JEsohynomene (Gr. aischynomai to be sensitive),
section of the, 16.

Agaricus campestris (Lat, " the field mush-
room"), 147.

Agaricus foetens, and A. campestris, 173.

Agave Americana (Gr. agavos admirable), the
American flax-plant, 22 ; stomata of the, 62.

Aggregati (Lat. "aggregata "), Class II. of
fruits, 132.

Air-chambers of an aquatic plant, 12.

Albumen of seeds, 135.

Alder bark, a vegetable dye, 54.

Alder tree, section of its root, 17.

Algae (Lat. alga a sea-weed), some of them
claimed both by the botanist and the zoolo-
gist, 5 ; family of the, 147 ; comprehend a
large proportion of the lower vegetable king-
dom, 172.

Algales, 185.

Alismales (Gr. alisma the water-plantain), 187.

Alkanet root, a vegetable dye, 54.

Allium (Lat. " an onion "), 41 .

A. porrum (Lat. "the leek"), cells from the
flowering stem of the, 9.

Aliman's botanical investigations, 38, 39.

Alnus (Lat. "the alder tree"), 17.

A. glutinosa, 54.

Amentales (Lat. amentum a catkin), 188.

Amnios of the seed (Gr. amnion a thin

brane), 36.
Amomales (Gr. a and momos a counter-poison),

187.
Amphitropal of the ovule (Gr. amphi about, and

trope a turning), 128, 129, 135.
Amygdalus amara (Gr. amagdala an almond,

and Lat. " bitter "), oil of the, 47.
Anatropal of the ovule (Gr. ana backwards, and

trope a turning), 128, 129.
Anchusa Italica(Gr. angchousa paint, and trope

a turning), 128, 129.
A. tinctoria (Lat. "tinted"), 54.
Andropogon schoenanthus (Gr. aner a man, and

pogon a beard ; schoinos a rush, and anthos

a flower), oil of the, 47.
Anethum graveolens (Gr. ano upwards, and

Meotorun; Lat. "strong-smelling"), oil of

the, 47.
Angiospermia (Gr. angos a vessel, and sperma

seed), order of, 153 et passim.
Angular-lobed leaf, 98.
Animalcules, the source of silica, 55.
Annatto, a vegetable dye, 54.
Anther of the stamen (Gr. anthos a flower), 118,

119; of flowers, 180.
Antheridia of the fern (Gr. anthera belonging

to flowers), 141; of mosses, 143.
Anthocarpi (Gr. anthos a flower, and karpo*

fruit), 132.
Anthracite coal (Gr. anthrax coal), porous cruet

from, 17.
Antirrhinum, pollen tubes in the pistil of the,

122.
Apocarpus ovary (Gr. apo from, and karpos

fruit), 126.

Apocarpi, Class I. of fruits, 131.
Aporum anceps (Gr. a and poros, wanting

pores; Lat. anceps double), tubercles and

cavities of the, 20.
Apple, its seed inclosed by sclerogen, 13; acid

juices of the, 50.
Apple-leaf, stomata of the, 61.
Aquatic plants, circulation in, 15.
Arales (Lat. aro to plough), 187.

194

INDEX.

Arabians, the early cultivators of botany, 3.

Arachis hypogaea, 45.

Arenga saccharifera (Ind. " the palm," and Lat.
" sugar-producing "), 53.

Aril of the nutmeg, 137.

Aristotle regarded as the founder of the science
of botany, 2.

Armeria fasciculata (the Sweet William), pollen
of the, 122.

Arrow-headed leaf of the Sagittaria, 98.

Arum maculatum (Egypt, arum a herb, and
Lat. maculatum spotted), starch secreted from
the, 33, 38 ; corm of the, 71 ; inflorescence of
the, 106.

Asarales, 192.

Assafoetida (Lat. asa a gum, and fcetida stink-
ing), whence produced, 49.

Astralagus gumnifera (Lat. "the ankle-bone"
and "gum-bearing"), whence obtained 48.

Atar of Keova, a vegetable oil, 47.

A. of Roses, a vegetable oil, 47.

Australia, gum-trees of, 49.

Axis of plants, 90.

Bacca, the berry, 133, 134.

Balsam, ducts of the, 27.

Banana tree, cells of its leaves, 11.

Banksia, stomata of the, 63.

Banyan tree, its immense size, 30.

Baphil nitida, 54.

Bark of exogenous stems, 75, 77; its various
divisions, 77, 78; its uses, 79; branching
vessels of the, 79.

Bassia latifolia, &c. (in honour of Antonio Bassia,
and Lat. " broad-leaved "), 46.

Beech tree, concentric layers of sclerogen in the
cells of its bark, 14 ; representation of the, 73.

Beet-root, sugar obtained from the, 52.

Benzoin, whence produced, 49.

Berberis vulgaris (Lat. " the common ber-
berry "), leaflets of the, 101 ; stamen of the,
118.

Berber ales, 189.

Berg Mehl, the source of silica, 55.

Betula (Lat. "the birch"), 27; oil of the bark
of, 47.

B. alba (Lat. " the white birch tree "), 23.

Bignonia, section of a stem of the, 84.

Bi>:noniales, 121.

Birch tree, fermented juice of the, 23 ; ducts of
the, 27.

Bitter almonds, oil of, 47.

Bixa orellana (S. American), a vegetable dye ob-
tained from, 54.

Black, and Blue, the principal colours presented
by plants, 53.

Boletus (Lat. "a gigantic mushroom"), elon.
gated cells of the, 11, 15.

Borassus flabelliformis (Gr. borassos the palm,
and Lat. "fan-formed"), the Palmyra palm,
23, 24.

Botanical gardens, 3.

Bothrenchyma (Gr. bothrion a pit, and enchyma
an injection), a pitted tissue, 17 ; its great im-
portance, 18.

BOTANY, the important objects of, 1; historical
notices of, 2 ; its distinguished promoters, 3.
The early Classification of PLANTS, 3 ; their
structure, 5; the elementary and cellular
tissues, 7 et seq. ; their woody fibre ; the vas-
cular tissue, 25 ; the lacticiferous vessels, 29 ;
their secretions, 32 et seq. ; their, colouring
principles, 53 ; their organs, 57 ; their stomata,
61, and hairs, 65 ; the glands, 69 ; the corm
and the bulb, 71 ; wooded stems, 73 ; the pith,
76 ; the bark, 77 ; the wood, 79 ; longevity of
trees, 83 ; their cellular structure, 85 ; the
roots of plants, 90; the leaves, 93 et seq.
Organs of reproduction, the inflorescence, 105
et seq. ; the stamens, 116 et seq.; the pistil,
123 et seq. Classification of fruits, 131 et seq.
Flowerless plants, Ferns, 138; mosses, 143;
lichens, 145; algae, 147. Classification of
plants, 149; the Linnaean system, 151 182.
Natural Order of plants, 183. Dr. Lindley's
system, 184192.

Bract, the, of inflorescence, 108, 109.

Brake fern, scalariform vessels in the, 28.

Branches of trees, 73, 74.

Brassica rapa (Lat. brassica a cabbage, and rapa
rape root), the turnip, 32 45.

B. napus, 45.

Brazil wood, a vegetable dye, 54.

Brittle-worts, the slime of stems, 172.

Brown, one of the principal colours of vegeta-
tion, 53.

Bryophyllum calycinum (Gr. bryo to sprout, and
phyllon &\ea.f ; Lat. caZyzacup), leaf of the, 104.

Buck's botanical investigations, 36, 37.

Bulb of plants, 71.

Butter, a vegetable secretion, 46.

Cacao butter, whence produced, 46.

Cactus, crystals from the cuticle of a, 41, 42.

Cactales, 192.

Caesalpina Braziliensis (in honour of C. Ccesal-

pinus, and Lat. "Brazilian"), 54.
Cajeputi oil, a vegetable secretion, 47.
Calamus aromaticus (Lat. "an aromatic reed"),

oil of the, 47.
Calyx (Lat. " a cup "), a part of inflorescence,

109111.

INDEX,

195

Cambium, the formative fluid of trees, 5, 6.
Caniina of the petal (Lat. caminus a chimuey),

114.
Campanula (Lat. " a little bell "), hairs of the,

68.

Campanales, 191.
Camphor, a vegetable oil, 48.
Campylodiscus clypeus (Gr. kampylos bent, and

diskos a disk; Lat. "a shield"), eilicious

skeleton of the, 55.
Campylotropal of the ovuie (Gr. kampylos, and

trope a turning), 128, 129, 135.
Camwood, a vegetable dye, 54.
Cane, sugar produced from the, 52.
Cane sugar of the Southern States, 23.
Canna bicolor (Lat. canna a cane, and bicolor

two-coloured), spiral vessels of the, 25.
Caoutchouc (Ind. "elastic gum"), produced

from vegetable juice, 31.
Capillaries of the Frog's foot, 29.
Capitulum (Lat. caput a head), in the order Com-

positse, 106.

Capsule of the poppy, 133, 134.
Carapa or Crab oil (Gr. karabos a crab), whence

obtained, 46.
Caryophyllum aromaticum (Gr. caryona a nut,

and Lat. "aromatic "), oil of the, 47.
Carpels of the pistil (Gr. knrpos fruit), 125, 127.
Carrot, vegetable secretion of the, 32.
Carthamus tinctoria (Arab, qnortom to paint, and

Lat. "tinted"), 54.
Cartilage from the ear of a rat, 15.
Carum carui (from Caria in Asia Minor), car-

raway oil of the, 47 ; the carraway seed, 109.
Cassava meal, starch secreted from, 33.
Castor oil, a vegetable secretion, 45.
Castor oil plant, tube from the, 8.
Catechu (Germ, "an astringent herb"), tannic

acid obtained from, 50 ; a vegetable dye, 54.
Catkins of the willow, 105, 106.
Caudex of the root (Lat. caudex a stem), 91, 92.
Caulisexcurrens(Lat. "abranching stalk"), 73.
Cells of plants described, 9, 10 ; of the orange,

10 ; forming a tube, 1 1 ; various terms for

defining their shapes, 1113; multiplication

of, 16 ; of the pith of trees, 75 ; of the sta-
men, 121.

Cellular structure of leaves, 94.
Cellular tissues, 8 ; uses of the, 15, 16.
Cephalotus (Gr. kephalos headed), pitcher of the,

103.

Cbalaza (Gr. " hail") of the ovule, 129.
Chara vulgaris (Gr. chairo to delight, and Lat.

"common "), spiral fibres of the, 144, 145.
Charas (sea-weeds) described, 173.
Chelidonium (Gr. chelidon a swallow), lactici-

ferous juices of the. 28.
Chelsea, medical botanical gardens at, 3.

Chenopodales (Gr. chen a goose, ana poaes feet),
190.

Chestnut, spiral vessels of the, 26 ; starch grains
oftho, 37; leaf of the, 97.

China grass, substituted for flax, 22.

Chlorophyl (Gr. chloros green, and phyllon a
leaf), one of the chemical colouring principles
in vegetables, 53.

Chromule (Gr. chroma colour), one of the che-
mical colouring principles in vegetables, 53.

Cinchonales (Peruvian bark trees), 192.

Cinnamomum zeylanicum (Arab, kinamon), oil of
the, 47.

Circulation of plants, 17 ; woody fibre the chief
organ of the, 20.

Circuma longa, 54.

Cistales (Gr. kistos a capsule), 189.

Citric acid, whence derived, 50.

Citrus (Lat. '-the orange"), hexagonal cells of
the, 10.

C. limonum, oil of the, 47.

CLASSES and OKUKUS, origin and characteristics
of the, 151 ; tabular view of the, 152, 153. The
Classes of Linnaeus from I. to XXIV., Monan-
dria, and Diandria, 153; Triandria, 154; Te-
trandria, ar:d Pentandria, 155; Hexandria
157; Heptandria, 158; Octandria, 159; Enne-
andria, and Decandria, 160 ; Dodecandria, and
Icosandria, 161 ; Polyandria, 162 ; Didynamia,
163 ; Tetradynamia, 164 ; Monodelphia, 165 ;
Diadelpbia, 166; Polydelphia, and Syngenesia,
167 ; Gynandria, 168 ; Monfficia, 169 ; Dicecia,
171 ; Polygamia, and Cryptogamia, 172. In-
structions for ascertaining the, 176 etseq.

Classes of plants, according to the Natural sys-
tem of Dr. Lindley, 184 et seq. Class L to
VII., Thallogens, 185 ; Acrogens, Rhizogens,
andEndogens, 186; Dictyogens, 187; Exogens,
with their sub-classes, 188192.

Classification of fruits, 131 ; of plants, 149; the
Linnaean system of, 151 ; illustrations of, 17G
et seq.

Clematis, section of a stem of the, 84.

Cloves, oil of, 47.

Club mosses, 142.

Cocoa-nut oil, a vegetable secretion, 44 ; its che-
mical constituents, ib.

Cocoa-nut palm, obtained from vegetable tissue,
23.

Cocoa-nut shell, wall-cells of the, 13.

Cocos nucifera (Portuguese macaco a monkey,
and Lat. nucifera nut-bearing), the cocoa-nut
palm, 23, 44.

Colchicum autumnale (from the city Colchis, and.
Lat. " autumnal "), starch cells of the, 36.

Collomia grandiflora (Gr. kolla glue, und Lat
grand-flcra bright-flowered), 14,

Colium (Lat. " the neck "/of the plant, 58.

196

INDEX.

Colour, the numerous shades of in vegetables, 53.
Colouring principles of plants, 53 ; the various

dyes, 54.

Composite, bracts of the order, 109.
Compound leaves, 99.
Cone, naked seeds of the, 129.
Confervas (Lat. confero to join or heal a wound),

ciliated spores of the, 4, 148 ; described, 173.
Conifer (Lat. " cone bearing "), the fir tribe,

19, 20.

Copal, whence produced, 49.
Coriandrum sativum (Gr. kova a bug, from the

smell of its leaves ; and Lat. " springing up") ,

oil of the, 47.
Cork, the bark of exogenous stems, 77, 78 ; tannic

acid secreted from, 50.
Corm of plants, 71.
Cornus maculae (Lat. cornu a horn, and maculce

spots), intercellular spaces in disease of the, 12.
Corolla (Lat. "a little crown"), its inflorescence,

112, 113; various forms and specimens of the,

114, 115 ; its anatomical structure, 115.
Corona of the tree, 73.
Cortusales, 191.
Corylus avellana (Lat. corylusfhe hazel-tree, and

avellana a filbert-nut), 25, 26.
Corymb, the, of inflorescence, 107.
Cotton, the fibre of illustrated, 23.
Cotton-plant, a textile fabric, 16; seeds of the,

45, 134.
Cotyledons (Gr. kotyle a cavity) of a plant, 58 ; of

the seed, 134; seed-leaves, 135, 136.
Cow tree, milky juice of the, 30.
Creeping stems of plants, 70.
Croton oil, a vegetable secretion, 46.
Cruciferae (Lat. crux a cross, and fero to bear),

starch secreted from the, 32.
Cryptogamia (Gr. krypto 1o conceal, and gamin a

marriage), Class XXIV. of Linnaeus, 172; its

orders Filicels, Lycopods, Lichenals, Fungals,

and Algal?, 153 et passim.
Crystalworts, description of, 174.
Cubical cells, 11.

Cucurbitales (Lat. cucurbila a gourd), 188.
Cudbear, a vegetable dye, 54.
Cupule, the, of inflorescence, 109.
Curcuma leucorrhiza (Arab, kurkum cleansing;

Gr. leukos white, and riza a root), East Indian

arrow-root, 35.

Cuticle of the plant, 60 ; endogenous stems, 87.
Cycas revoluta (Gr. kykas the Ethiopian palm,

and Lat. revoluta wound around), the Sago

palm, 34; hairs of the, 66.

Dandelion, lacticiferons vessels of the, 28.
Daphnales (Gr. daphne laurel), 190.

Daucus carota (Gr. daucos hot, and Fr. carotce a

carrot), 32.

De Candolle, the promoter of botanical classifica-
tion, 3.
Decagynia (Gr. deka ten, and gyne a female),

the order, 153 et passim.

Decandria (Gr. deka ten, and andres males),
Class X. of Linnaeus, 152, 160 ; the order, 153
et passim.
Decurrent leaf, 101.
Dehiscence of fruits, 131.
Desmidieae (Gr. desmos a hinge), varieties 01

the, 5.

Deutzia scabra (in honour of John Deutz of Am-
sterdam;* and Lat. scabra rough with hairs),
flinty hairs on the leaf of the, 56, 65.
D. corymbosa (Lat. corymbus a bunch), hairs of

the, 65.

Diadelphia (Gr. dis double, and adelpheia bro-
therhood), Class XVII. of Linneeus, 166.
Diadelphous stamens, 117.

Diandria (Gr. dis, and andres males), 118;
Class II. of Linnaeus, 152, 153 ; order of, 153
et passim.
Diatomacea (Gr. dia through, and temno to cut),

silicious skeletons of the, 55.
Diclinous Exogens, a sub-class of Lindley, 188.
Dicotyledonous seed (Gr. dis double, and cotyle

a cavity), 136.
Dictyogens (Gr. dictyon a net, and genia

growth), Class V. of Lindley, 187.
Di-lynamia (Gv.dh double, and dynamis power),

Class XIV. of Linnaeus, 152, 162.
Didynamous stamens, 118.
Digynia (Gr. dis, and gyne a female), order of,

153 et passim.

Dioacia (Gr. dis, and oikia habitation^, Class
XXII. of Linnaeus, 152, 171 ; its various orders,
153, 171.

Dionaea muscipula (Gr. Dioncea one of the
names of Venus, and Lat. muscipula a mouse-
trap), sensitiveness of the, 4.
Dipsacus fullonum (Gr. dipsakos thirsty, and

L&t.fulio a fuller), the fuller's teasel, 65.
Disk of the stamen, 123.
Dissepiments of the pistil, 127, 128.
Divi-divi, tannic acid obtained from, 50.
Dodecagynia (Gr. dodeka twelve, and gyne a

female), the order, 153 et passim.
Dodecandria (Gr. dodeka, and andres males),
118; Class XI. of Linnaeus, 152, 161; the
order, 153 et passim; directions for ascertain-
ing its class and order, 177.
Dotted cells, 12.

Dracaena Draco (Gr. dra/cainn, female of draco
a dragon), plant of the, 49.

Misprinted Denteta and Dent* in the text.

INDEX.

Dragon's-blood, whence produced, 49.

Drosera, the sun-dew, 156.

Drupa, etone-fruit, 133.

Oryobalanops camphora (Gr. dryo a forest, and
ballo to germinate), camphor-oil of the, 48.

Duckweed, stamen of the, 118.

Ducts (Lat. duco to lead), vegetable tubes, 27.

Dyes, vegetable, the various plants which secrete
them, 53.

Dyticus (Lat. dytikos diving), the water-beetle,
27.

Echiales (Gr. echis a viper), 191.

Eleeagnus (Gr. elaia the olive), hairs of the, 65.

Elementary tissues of plants, 5 et seq.

Elliptico-lanceolate leaf, 96.

Elm leaf, 95.

Elm tree, pores and spiral fibres of the, 17.

Embryo of the seed, 134 ; its direction, 135.

Endocarp of fruit (Gr. endon within, and karpus
fruit), 130.

Endogens (Gr. endon, and ginomai to grow),
Class IV. of Lindley, 186.

Endogenous stems, peculiar to tropical regions,
86; their component parts, 87 ; sections show-
ing their structure, ib. ; the cuticle, ib. ; their
vascular structure, 88 ; the pith, 89 ; peculiar
characteristics of, 90.

Endosperm (Gr.emfon, and sperma the seed), 135.

Enneandria (Gr. ennea nine, and andres males),
Class IX. of Linnaeus, 152, 160 ; order of, 153
et passim.

Epic oil, whence obtained, 46.

Epicarp of fruit (Gr. epi upon, and karpos fruit),
130.

Epidermis of the plant (Gr. epi, and dermis the
skin), cells of the, 6, 60 ; a layer of inspissated
organic mucus, 60 ; the external layer of bark,
77.

Epigynous exogens (Gr. epi, and gyne a female ;
exo and ginomai to grow outwards), a sub-
class of Lindley, 171.

Epigynous stamens, 117.

Epipblaeum (Gr. epi, and phlao to break), the
cork of the bark, 77, 78.

Equisetum (Lat. "horse-tail"), 144.

E. hiemale, 56.

Ericales (Lat. erica heath), 189.

Euonymus Japonicus (Gr. eu good, and onoma
a name ; Lat. "of Japan "), vertical section of
its leaf, 95.

Euphorbia balsamifera (from Euphorbus a phy-
sician, and Lat. " balsam -bearing "), milky
juices of the, 30, 31 ; starch-cells of the, 39.

Euphorbiales, 188.

Exogens (Gr. exo and ginomai to grow out-
wards), Class VII. of Lindley, 188; sub-
classes of, 188192.

Exogenous stems, their various parts, 75; the

pith, ib. ; the medullary sheath, 76 ; the

medullary rays, 77 ; the bark, ib. ; various

sections of, 77, 81 ; the wood, 79 ; immense

growth of, 82 ; longevity of, 83 ; their cellular

structure, 84, 85 ; their general configuration,

85.

Fagus (Lat. "the beech tree"), 14.
Fagus castanea, the chestnut, 26.
Fascicle, the, of inflorescence, 106, 107.
Fat, a vegetable secretion, 42.
Fat-cells in animals, 15.
Ferns, 138; varieties and specimens of, 139;

arrangements of the stem, 140; fronds of the,

141; the different genera of, 175, 176.
Festuca pratensis (Lat. "a field stalk"), the

common meadow grass, 56.
Fibre cells from the leaves of different plants,

14, 15.
Fibres of plants, elementary, 7, 8; woody, 19;

various illustrations of, 20 et seq. ; different

textile materials, 23.

Flbrilla of the root (Lat. "a little fibre"), 91, 92.
Fibro-cellular tissue, 14, 15.
Ficus elastica (Lat. ficus a fig-tree, and elastica

elastic), the India-rubber fig-tree, 29.
F. Indica (Lat. " Indian "), secretions of the, 49.
F. religiosa (Lat. "sacred"), the banyan-tree,

30, 31 ; secretions of the, 49.
Ficoidales, 190.

Fig-tree, milky juice of the, 31
Filament of the stamen, 118, 119.
Filices (Lat. "Ferns"), 175.
Filicales, 186.
Fir wood, section and glands of the, 19 ; pores of

the, 20.
Fixed oils, 43.
Flax, consists of woody fibre, 21 ; its antiquity,

22 ; its utility and value, 22, 23 ; fibre of

illustrated, 23.
Flax-plant, woody fibre of the, 19; American,

22.

Flint, sources of, 55.
Flowerless plants, 138 ; ferns, ib. ; mosses, 142 ;

lichens, 145; fungi, 146; algae, 147; sexual

organs of, 148.
Flowers, organs of reproduction in, and their

various terms, 105 et seq.; instructions for

ascertaining their class and order, 176 et seq.
Fluid, formative, of plants, 6.
Forest trees, their vast power of resistance, 21.
Fo villa of the stamen (Lat. joveo to nourish),

121.

Fragaria (Lat. fragum a strawberry), 9, 10, 26.
Frog's foot, capillaries of the, 29.
Fronds of the fern, 138141.
Fruit, 129 et seq. ; its various parts, 130 ; the

1=98

INDEX.

seed and the pericarp, ib. ; classification of, 131 ;

different modes of dehiscence, 131 ; various

kinds of, 133.
Fucus (Gr. phykoi sea-weeds), their structure

and situation, 173.
F. vesiculosus (Gr. phykos, and vesiculus a

bladdefr), 146.
Funaria hygrometrica (~,at. funis a rope, and

Gr. "damp-measuring "), urns of the, 143.
Fungi, family of, 146, 147 ; description of, 173.
Fungales, 186.

Funis of the seed (Lat. " a rope "), 137.
Fuschia, pollen of the, 122.
Fustic, a vegetable dye, 54.

Gallic acid, whence obtained, 50.

Gallionella sulcata, silicious skeleton of the, 55.

Gamboge, whence produced, 49.

Garcinia purpurea (in honour of Dr, Garcin,
and Lat. " purple-coloured"), 46.

Garden bean, seed of the, 136.

Garryales (in honour of Nicholas Garry, of the
Hudson's Bay Company), 188.

Genera of plants, characteristics of the, 181.

Gentianales, 191.

Geraniales (Gr. gei-anion, a geranium), 190.

Ginger, stamen of the, 118.

Glands of woody fibre, 19 ; of plants, 69 ; their
characteristics, 70.

Glans, the acorn, 133.

Gleiditsia, leaf of the, 99.

Glume, the, of grasses, 108, 109.

Glumales, 186.

Gomuto palm (Malabar "a palm"), wine ob-
tained from the, 23.

Gooseberry, acid juices of the, 50.

Gossypium (Gr. gossipion the cotton-plant), 45.

Gourd, seed of the, 6.

Grains of starch in different plants, 35, 36.

Grape sugar, whence obtained, 52.

Grass, stem and leaf of, 102 ; monocotyledonous
seed of, 135.

Grass oils, vegetable secretions, 47.

Grasses, starch secreted from, 32 ; inflorescence
of, 108, 109.

Gray and Green, principal colours in vege-
tables, 53.

Grew, Nehemiah, a promoter of botanical
science, 3.

Gridiron tissue, 18.

Grossales (Lat. grossiis, a green fig), 192.

Ground-nut oil, a vegetable secretion, 45.

Guizotia oleifera (in honour of Guizot, and Lat.
" oil-bearing "), seed of the, 46.

Gum, a vegetable secretion, 48.

Gum- Arabic, whence obtained, 48.

Gum Senegal, whence obtained, 48.

Gutta-percha (Malay, gutta gum, and Peicha

the island whence obtained), produced from

vegetable juice, 31.
G. Podiah, a vegetable wax, 46.
Guttiferales, 189.
Gymneuralactiferum (Gr. gymnos naked, neura

nerves ; and Lat. lactiferum milk-bearing), 30.
Gymnogens (Gr. gymnos, and ginomai to grow),

Class VI. of Lindley, 188.
Gymnospermia (Gr. gymnos, and sperma seed),

the order, 153 et passim.
Gynandria (Gr. gyne a female, and oner a male),

Class XX. of Linnams, 152, 168.
Gynandrous flower, 121.
Gyrophora murina (Gr. gyros a circle, arid

phero to bear), 54.

Haematococcus binalis (Gr. haima blood, and

kokkos a berry; Lat. binalis double), its

various stages of development, 16.
Haematoxylon campechianum (Gr. haima, and

ay Ion wood ; Lat. campus an open field).
Hairs of plants, 65 et seq. ; varieties of, 66, 67 ;

circulation of the, 67; different names and

properties of, 67.

Hampton Court, botanical gardens of, 3.
Hastate leaf (Lat. " spear-shaped "), 97.
Hazel nut, spiral vessels of the, 26.
Hallebore fojtidus (Lat. "stinking hellebore"),

poisonous secretions of the, 67.
Hemlock bark, tannic acid obtained from, 50.
Hemp consists of woody fibre, 21 ; its power of

resistance, 22.
Heptagynia (Gr. hepta seven, and gyne a

female), the order, 153 et passim.
Heptandria (Gr. hepta, and andres males), Class

VII. of Linnaeus, 152, 158; the order, 153 et

Herbaceous plants, different parts of, 60.
Herbs, their component parts, 74.
Heterotropal of the seed (Gr. heteros irregular,

and trope a turning), 135.
Hexagynia (Gr. hex six, and gyne a female),

the order, 153 et passim.
Hexandria (Gr. hex, and andres males), Class

VI. of Linnaeus, 152, 157; order of, 153 et

passim.

Hilum (Lat. the "black speck of a bean"), 136.
Horse-tails, notices of, 174, 175.
Hya-hya, milky juices of the, 30.
Hydrales, 187.
Hydrocotyle vulgaris (Gr. hydor water, and

cotyle a cavity; Lat. "common"), leaf of the,

95.
Hypnum castrensis (Gr. hypnos sleep, and Lat.

"pertaining to the field"), 143.
Hypocrateriform corolla (Gr. upo under, kratet

INDEX.

199

a cup, and Lat. forma form; Lat. corolla a
little crown), 115.

Hypogynous Exogens (Gr. upo, and gyne a
female, exogens growing outwards), a sub-
class of Lindley, 189.

Icosandria (Gr. eikosi twenty, and andres males),

118; Class XII. of Linnams, 152, 163; the

order, 153 et passim.
Illicium anisatum (Lat. illicio to allure, and ani-

tum the herb anise), 13.
Ilpa oil, whence expressed, 46.
Imbricated scales of the leaf-bud, 104.
Indian corn, oil secreted from, 45.
India-rubber, produced from vegetable juice, 31.
India-rubber fig-tree, milk vessels of the, 29.
Indigo, a vegetable dye, 54.
Indigofera tinctoria (Lat. Indica Indian, and

fero to bear ; tinctus i dye), 54.
Inflorescence of plants, .05 ; the various terms,

processes, and specimens of, 105 et seq. ; the

different members of, 179 et seq.
Inter-cellular spaces of plants, 12 ; importance

of, ib.
Involucre (Lat. involucrum a covering), the com.

mon, 109.
Iris (Gr. "the rainbow"), starch grains of the,

38; stomata of the, 61.
Ivory nut, sections of its bark, and thick wall

cells, 13.

J
Jasminum grandiflorum (Gr. ia a violet, and

ostne smell ; Lat. " superbly flowered "), oil

of the, 47.
Juglans regia (Lat. Jovis glans the nut of Jove,

and regia royal), the wall-nut, 26.
Juncales (Lat. juncus, a rush), 187.
Jungermannia (from Louis Jungermari), fibres of

the, 7; fructification of the, 144174.
Jussieu, the distinguished promoter of botanical

classification, 3.

Kew, botanical gardens of, 3.
Kino, tannic acid obtained from, 50.
Kiriaghuma, milky juices of the, 30.
Kokum butter, whence obtained, 46.
Kutch, tannic acid obtained from, 50.

Lac, a resinous secretion, 48, 49 ; various species

of, 49.

Lace tree, bark of the, 21, 78.
Lacticiferous vessels (Lat. lac milk, and fero to

bear), 28, 29 ; their great utility, 30.
Lagetta lintearia (the name in Jamaica; Lat.

lintearia lint-like), the lace tree, 21, 78.
Lamina, the blade of the leaf, 96.

Lanceolate leaf, 96.

Larch bark, tannic acid obtained from, 50.

Lavandula (Lat. lavo to wash), lavender oil, 47.

Leaf-bud of plants, 103, 104.

Leaves, stomata of, 61 et seq. ; of endogenous
plants, 90; definition of the term, 92 ; venation
of, 98 ; cellular structure of, 94 ; their forms,
95 et seq. ; consist of two parts the petiole
and the lamina, 96 ; divided into simple and
compound, 96 ; the distinguishing features of
plants, 179.

Leek, cells from the flowering stems of the, 9.

Leeuwenhoeck's botanical investigations, 36.

Legumen, pulse, 133, 134.

Lemons, oil of, 47.

Leontodon (Gr. leontos and odous the lion's
tooth), the dandelion, 28.

Liber, the vascular part of the bark of trees, 78.

Lichens, characteristics of, 145 ; description of,
174.

Lichenales, 186.

Lily, transverse structure of its leaf, 60; stomata
of the, 62 ; naked bulb of the, 71 ; stamen of
the, 118.

Liliales, 187.

Lime tree, ducts of the, 27 ; raphides from its
bark, 42.

Limnocharis Plumeri (Gr. limne a marsh, and
charis dear), air-chambers of the, 12.

L. Humboldtii, milk vessels of the, 29, 30.

Liudley, Dr., his classification of fruits, 131 ; his
natural system of plants, 184 et seq.

Linnaeus, the great promoter of botanical sci-
ence, 3 ; his system of classification by Classes
and Orders, 151172; his sexual system, 152.
On the practical application of his system, 176
et seq.

Linseed oil, a vegetable secretion, 44, 45.

Linum (Lat. "the flax plant"), woody fibre of
the, 19.

Liverworts, foliaceous organs of the, 144, 145 ;
description of, 174.

Loculicidal dehiscence of fruit, 131.

Logwood, a vegetable dye, 54.

Lycopodium aphodium (Gr. lykos a wolf, and
pous a foot; apo from, and odous a tooth),
142.

Lycopodales, 186.

Lyrate-shaped leaf, 97.

Madder, a vegetable dye, 54.
Mallow, monodelphous stamens of the, 117.
Malvales (Lat. malva the herb Mallows), 189.
Mandiocca farinha, starch secreted from the, 33
Manure, silicious contents of, 57.
Maple tree, the sugar-yielding, 23 ; section ol
the, 75.

200

INDEX.

Marchantia (in honour of Nicholas Marchant of

France), stomata of the, 62.
M. polymorpha (Gr. polus much, and morphe

change), 144, 145.

Marco Polo, his botanical researches, 3.
Marsilea pubescens (in honour of Count Mar-

sigli of Bologna ; Lat. pubescens modest), 142.
Martin, M., his botanical investigations, 36, 37.
Meadow grass, silicious coating of, 56.
Medullary rays (Lat. medulla marrow) of

exogenous stems, 75, 77.
Medullary sheath of exogenous stems, 76.
Melaleuca (Gr. melas black, and leucos white),

oil of the, 47.

Membrane, elementary, formation of the, 6.
Menispermales (Gr. mene the moon, and sperma

seed, 188.
Mentha peperata (from the mythological nymph

of that name, and Lat. " peppered"), pepper-
mint oil, 47.

M. viridis (Lat. " green"), spear-mint oil, 47.
Mesophlaeum (Gr. tnesos middle, and phlao to

break), a division of the bark of trees, 77, 78.
Meum fcEniculatum (Gr. melon lesser, and Lat.

foenum hay), oil of the, 47.

Milk-bearing vessels, 28, 29; their great utility, 30.
Mimosa(Gr. mimos amimic), the sensitive plant, 4.
Mimosa bark, tannic acid obtained from, 50.
Miniak kawon, the tallow tree of Java, 46.
Monandria (Gr. monos one, and aner male), 118 ;

Class I. of Linnaeus, 152, 153 ; the order, 153 et

passim.
Monocotyledonous seeds (Gr. monos, anditofyfe a

cavity), 135, 136.
Monodelphia (Gr. monos, and adelphos a brother),

Class XVI. of Linnaeus, 152, 165; the order, 153

et passim.

Monodelphous stamens, 117.
Moncecia (Gr. monos, and oikia a habitation),

Class XXI. of Linnaeus, 152, 169 ; the order,

153 et passim.
Monogynia (Gr. monos, and gyne a female), the

order, 153 et passim.
Morison, Robert, a great promoter of botanical

science, 3.

Mosses, organs of, and varieties, 142 et seq. ; de-
scription of, 174; scale mosses, 174; urn

mosses, 175.
Mucor mucida (Gr. mykis a small fungus, Lat-

" slimy"), 147.

Mummy cloth, a texile fabric, 16.
Muriform cells, 11.
Musa paradisaica (Lat. ' ' the Muse of Paradise " ) , |

the Banana tree, 11.
Muscales (Gr. moschos musk), 186.
Mushrooms, ovoid cells of, 10 ; elongated cells,

] I ; different kinds of, 11 ; family of, 146,

14.7 ; description of, 173.

Mustard seed, a vegetable secretion, 46.
Myosotis (Gr. myos a mouse, and otos of the ear),

characters of the genus and species, 181.
Myrodendron punctuatum (Gr. myros ointment,

and dendron a tree; Lat. punctus pointed),

stomata of the, 62.
Myrrh, whence produced, 49.
Myrtle wax, a vegetable secretion, 47.
Myrtales, 191.

Narcissus, corona of the, 114.
Narcissales, 187.

Natural system of plants, 183 et seq.
Navicula grandis (Lat. " a small boat''), silicions

skeleton of the, 55.
Nectary, use of the term, 182.
Nepenthes (Gr. " removing sorrow"), pitcher of

the, 103.
Nerium oleander (Gr. neros humid, and "the

olive tree"), 60 ; stomata of the, 62, 63.
Nettle, stinging, characteristics of the genus and

species, 182.

Nodes of a plant (Lat. nodus a knot), 58, 59.
Nucleus, the growing point of the ovule, 129, 134.
Nuphar lutea, the yellow water-lily, 11.
Nut-galls, a vegetable dye, 54.
Nutmeg, aril of the, 137.
Nymphsea alba (Lat. " the white Water-

nymph"), 114.
Nymphales, 189.

Oak bark, tannic acid secreted from, 50.

Oak-galls, whence obtained, 50.

Oat, silicious formation of the, 56.

Ob-cordate leaf, 97.

Obovate leaf, 97.

Ochrea (Gr. ochros yellow), the sheath of the

stem, 103.
Octandria (Gr. octo eight, and andres males),

Class VIII. of Linnaeus, 152, 159 ; the order,

153 et passim.
OEnothera* biennis (Gr. oinos wine, and theros

summer ; Lat. " twice a year "), pollen tubes

in the, 122.
Offset of plants, 73.
Oils, vegetable secretions, 42, 43, 47 ; their long

preservation, 42 ; their social uses, 43 ; their

great variety, 4346.
Olea Europeea (Lat. olea oil), olive oil, 43.
Oleo-resins, 48.

Olive oil, a vegetable secretion, 43.
Onion, raphides found in the, 41.
Ophioglossum vulgatum (Gr. ophis a serpent,

and glossaz. tongue), fructification of the, 139
Opium, a vegetable secretion, 50 ; its cultivation

and uses, 51.

Misprinted JEnothtra in the text.

INDEX.

201

Opuntia vulgaris (from Opus a city of Locris, and
Lat. vulgaris common), fibre cell from the, 14.

Orange, cells of the, 9, 10.

Orange flowers, oil of, 47.

Orange tree, compound leaf of the, 101.

Orbicular-lobed crenate leaf, 98.

Orchall, a vegetable dye, 54.

Orchis (Gr. orchis a plant), fibre cells from the
leaves of the, 14, 15 ; gynandrous flower of
the, 121.

Orchidales, 187.

Orders of plants of Linnaeus, 153 172 ; direc-
tions for ascertaining the, 178. See Classes.

Organs of plants, 57 et seq. ; of reproduction,
105 et seq.

Oryza sativa (Gr. oryza rice; and Lat. sativa
that may be sown), common rice, 56.

Orthotropal of the ovule (Gr. orthos right, and
trope a turning), 128, 129, 135.

Ovary of the pistil, 123, 124 ; illustrations of the,
126.

Ovule (Lat. ovum an egg), the unripe seed of the
plant, 128 ; its various parts and names, 128, 129.

Oxalate of lime raphides, crystals of, 42.

Oxalic acid, whence derived, 50.

Palece of inflorescence, 109.

Palm, arrangement of woody fibre in the, 88.

Palm forest, of endogenous growth, 86.

Palm oil, a vegetable secretion, 44.

Palm sugars, whence obtained, 52.

Palm wine obtained from vegetable tissue, 23.

Palmales, 187.

Palmate-leaf, 98.

Palms, various species of, 23.

Palmyra palm, wine obtained from the, 23, 24.

Palo de Vacca (Span, "the cow tree"), milky

juices of the, 30.
Pandanus, the screw pine (Malay " something to

be regarded"), emits aerial roots, 91.
P. ordoratissimus (Malay Pandanus, and Lat.

"most odoriferous"), oil of the, 47.
Panicle, a raceme, 106, 107.
Papaver (Lat. " the poppy"), 28.
P. somniferum (Lat. papaver, and tomnifer

causing sleep), 45.

/apayales (Malabar papata the Papaw tree), 188.
Paper, manufacture of, 6 ; materials from which

it is manufactured, 16.
Papilionaceous form of corolla, 115.
Pappus, a superior calyx, 111.
Papyrus (Lat. " paper "), early use of, 16.
Parenchyma (Gr. para from, and chymos juice),

the cellular tissue, 8 ; connexions and func-
tions of the, 95.
Farmeiia (Lat. parma a shield, and heileo to

inclose), section of a shield in the, 146.
VOL. II.

P. perlata, and P. tartarea, vegetable dyes, M.

Pea, starch cells of the, 35, 39.

Peach wood, a vegetable dye, 54.

Pear, thick- walled cells from the, 13 ; acid juices
of the, 50.

Peduncle, the foot stalk, 105; of the pistil, 123, 124-

Pentagynia (Gr. pente five, and gyn* a female),
the order, 153 et passim.

Pentandria (Gr. pente five, and and res males),
Class V. of Linnaeus, 155 ; the order, 153 et
passim.

Perfoliate leaf, 101.

Perianth (Gr. peri around, and anthos a flower),
a part of inflorescence, 109, 110.

Pericarp of fruit (Gr.peri, and karpos fruit), 130.

Perigynous Exogens (Gr. peri, and gyne a fe-
male ; exogens growing outward), a sub-class
of Lindley, 189, 190.

Perigynous stamens, 117.

Perisperm (Gr. peri, and sperma the seed), 135.

Persian berries, a vegetable dye, 54.

Perspiration of plants, 17.

Petals of the corolla, 113 ; stamens converted
into, 114.

Petiole, the leaf-stalk, 96; described, 101, 102.

Pharus cristatus (Gr. pharos a covering; and
Lat. "bearded"), 96.

Phragmites (Gr. phragmos a hedge), section of
its stem, 90.

Phytelephus macrocarpa (Gr. phyton a plant,
and elephas ivory; makros long, and karpos
fruit), the ivory nut, 13.

Phytozoa(Gr.pAytonaplant, and zoa living), 145.

Pimpinella anisum (Lat. bipinnatus twice pin-
nate, and " anise "), aniseed oil of the, 47.

Pinnate leaves, various forms of, 99, 100.

Pinnatifid leaves (Lat. pinnatus feathered), 97.

Pinus palustris (Lat. " the marshy pine "), vege-
table secretions of the, 48.

P. sylvestris (Lat. " the wood pine "), 8*.

P. Webbiana, thick- walled cells of the, 7.

Piperales (Lat. piper pepper), 190.

Pistil, the female part of inflorescence, 122128 ;
Greek terms applied to, and its different parts,
123 ; the distinguishing characteristics of the
orders of plants, 178 et seq.

Pisum (Lat. "a pea"), starch cells of the, 35, 39.

Pitch, a vegetable secretion, 49.

Pitchers of various plants, 103.

Pith of exogenous stems, 75, 76 ; uses of, 76 ; of
endogenous plants, 89.

Pitted tissue, 17 ; its importance, 18.

Placentae (Lat. placenta a cake) of the ovule,
127, 128, 129 ; of the seed, 136.

Plantain, starch secreted from the, 33.

PLANTS, early classification of, 3 ; the correct de-
finition of, 3, 5 ; sensitiveness of, 4 ; anatomy
or structure of, a ; the tissues of, 6 et seq. ;
2 a

202

INDEX.

the woody fibre of, 19 ; the lacticiferouo ves-
sels, 28; secretions of, 3156; colouring
principles of, 53 ; organs of, 57 ; the stem, 58 ;
the nodes, ib.; the cuticle, 60; the stomata,
61 ; hairs of, 65 ; prickles, 68 ; scurf of, ib. ;
the glands of, 69 ; the stems, TOetseq. ; divided
into trees, shrubs, and herbs, 74 ; the pith, 76 ;
the bark, 77 ; the wood, 79 ; immense growth
and longevity of, 82, 83 ; cellular structure, 84 ;
vascular structure, 88 ; the pith, 89 ; the roots,
90; the leaves, 92104; the inflorescence,
105 et seq. ; the stamens, 116 et seq. ; the
pistil, 123; fruits of, 131; the seed, 134;
flower less plants, 138 ; ferns, ib. ; mosses, 143 ;
lichens, 145 ; algae, 147 ; their classification,
149 ; the Linnaean system of classifying, 151
182 ; characteristics of, 179 et seq. ; the natural
order of classification, 183; Dr. Lindley's sys-
tem of classifying, 184192.

Pleurenchym (Gr, pleuron a side, and, chymos
juice), a woody tissue, 18.

Pleurothalis (Gr. pleuron, and thalia bloom),
fibre cell from its leaf, 14.

P. ruscifolia (Gr. P. and Lat. " russet leaves "),
cells in the leaf of the, 15.

Pliny tallow, whence produced, 46.

Plumule of the plant (Lat. pluma soft down),
58 ; of the seed, 136.

Pollen of the stamen, 118121 ; grains of the, 122.

Pollen tubes, 121, 122.

Polyandria (Gr. polys many, and andres males),
Class XIII. of Linnaeus, 152, 162 ; the order,
153 et passim.

Polyaudrous flower of the poppy, 118.

Polydelphia (Gr. polys, and adelphoi brethren),
Class XVIII. of Linnaeus, 152, 167.

Polydelphous stamens, 117.

Polygamia (Gr. polys, and gamot marriage),
Class XXIII. of Linnaeus, 152, 112 ; the order,
15? et passim.

Polygynia (Gr. polys, and gyne a female), the
order, 153 et passim.

Polypodium vulgare (Gr. polys, antipodes feet),
the common fern, 139.

Polytrichum commune (Gr. polys, and inches
hairs), antheridium of the, 143.

Pomum, the apple, 133.

Poppy, lacticiferous vessels of the, 28 ; polyan-
drous flowers of the, 118 ; placentae in the, 128.

Poppy oil, a vegetable secretion, 45.

Pores of plants, 17 ; of woody fibres, 20.

Potato, section of a, 5 ; its vegetable secretion,
32 ; starch cells of the, 35, 39 ; disease in the,
40 ; in its healthy and diseased conditions, ib. ;
underground stem of the, 70.

Potato plant, spiral vessels of th, 26 ; stamen of
the, 118.

Prickles of plants, 68.

Primine of the ovule, 128, 129, 134.

Promelia perforata, 146.

Protococcus viridis (Gr. protos the first, and o#
cut berry; Lat. viridis green), clusters of, 5.

Pseudo-bulbs of orchidaceous plants, 73.

Pteris aquilina (Gr. pteris a fern, and Lat. agitt*
Una eagle-like), 28.

Pterocarpus Santalinus (Gr. pttros winged, and
carpos fruit), 54.

Pyroligneous acid (Gr. pyros tire, and Lat. lig-
num wood), whence obtained, 50 ; its uses, ib.

Quekett, Professor, lectures of, 8.

Quercitron bark (Lat. quercus an oak, and eiU

rus citron), a vegetable dye, 54.
Quercus (Lat. "an oak"), the various species

whence tannic acid is obtained, 50.
Q. infectoria (Lat. Q. and inficio to dye), 54.
Quernales, 188.

Raceme, the, of inflorescence, 106, 107.
Radicle of a plant, 58 ; of the seed, 136.
Ramalina furfuracea (Gr. ramale a withered

bough; and Lat. furfur bran), a vegetable

dye, 54.
Ramenta of plants (Lat. ramentum the scraping

of anything), 69.
Ranales (Lat. ranee frogfc), 189.
Rape oil, a vegetable secretion, 45.
Raphe of the ovule, 129.
Raphides (Gr. raphis a needle), vegetable secre*

tions of, 41 ; found in the common onion, ib.
Rat, cartilage from the ear of a, 15.
Ray, John, a promoter of botanical science, 3.
Receptacle of flowers, 105.
Red, one of the principal colours in vegetables, 53,
Red sanders, a vegetable dye, 54.
Reed, section of its stem, 90.
Reniform leaf (Lat. "kidney-shaped"), 98.
Reproduction. See Organs of.
| Resin, a vegetable secretion, 48.
Reticulated duct, 27.
Rhamnus infectoria (Gr. rhamnos a white thorn,

and Lat. inficio to dye), 54.
Rhamnales, 191.
Rheum, the rhubarb, 41.
Rhizogens (Gr. rhiza a root, and ginomai to

grow), Class III. of Lindley, 186.
Rhubarb, crystals found in the root of the, 41.
Rhuscoriaria (Lat. "rue," and corium leather),

tannic acid obtained from, 50.
R. cotinus (Lat. JR. and cotinus a wild olive), 54.
Rice, starch cells of, 35, 39.
Rice paper of the Chinese, section of the, 16.
Ricinus communis (Lat. ricinus the name of an

insect resembling the flower, and

INDEX.

203

common), tube from the, 8; castor oil ex-
tractad from the seeds, 45.

Ringent corolla, 115.

Roccella fuciformis, and R. tinctoria (Portug.
roccha a rock), vegetable dyes, 54.

Roots of plants, 90, 91.

Rootstock, of plants, 73.

Rose, specimen of a perfect one, 113.

Resales, 190.

Rosetangles, sea-weeds, described, 173.

Rosmarinus (Lat. ros dew, and marinus pertain-
ing to the sea), oil of, 47.

Rubia tinctoria (Lat. rw&tw red, and tinctiu a
dye), 54.

Runner, roots and leaves of the, 72 ; a creeping
stem, ib.

Rush, star-shaped cells from the stem of a, 11.

Russia leather, causes of its durability, 47.

Rutales (Sax. ruta rue), 190.

Saccharinum offlcinale (Lat. saccharum sugar,
and officinale of the shops), representation of
the, 52, 90.

Saccolobium guttatum (Gr. sakkos a sack, and
lobos a lobe ; Lat. guttatum drop-spotted),
fibre cell from its leaf, 14.

Safflower, a vegetable dye, 54.

Sage, stamen of the, 1 18 ; pollen of the, 122.

Sago palm (Malay tagu a palm), starch cells of
the, 34, 35, 39; hairs of the, 66 ; fibres of the,
134.

Saguerus saccharifera (Javanese sagu a palm-
tree, and Lat. " sugar-bearing"), wine obtained
from the, 23.

Salisburia adiantifolia (from R. H. Salisbury;
Gr. adiantos dry, and Lat. folia leaves), bor-
dered pores of the, 20.

Salix (Lat. "the willow"), 27.

Salvia (Lat. " sage"), pollen of the, 122.

Sambucus nigra (Gr. sambuke an ancient harp
made of elder wood, and Lat. nigra black),
pith of the, 75.

Santalum alba (Persian sandul-safed the sandal-
wood of India, and Lat. " white " ), oil of the, 47.

Sapotacea (Lat. sapo soap), class of the, 31.

Sapindales, 189.

Sarcina (Lat. " a pack"), cells of the, 8.

Sarcocarp of fruit (Gr. sarkos of flesh, and karpos
fruit), 130.

Sarracena (in honour of Dr. Sarraein of Quebec),
pitcher plant leaf of the, 103.

Saxifragales (Lat. saxum a stone, and frango to
break- Saxifrage), 190.

Scalariform duct (Lat. scalaa, ladder, and/orma
form), 27, 28.

Scale mosses, their characteristics, 144 ; notices
of. 174.

Scape of the flower, 105.

Scarlet Pimpernel, dehiscence of the, 131.

Schizagonium murale (Gr. schiza a cleft, and

0seed ; Lat. muralis pertaining to a wall),

filament of the, 5.
Scilla Mauritanica (Gr. sttlla a bulb, and Lat.

" Mauri tanian"), the squill, 41.
Scirpus Romanus (Lat. "a bull-rush"), pollen

of the, 122.

Sclerogen (Gr. skleros hard, and gennao to en-
gender), the tissue so called, 7 : concentric

layers of, 14.

Scotch fir, its numerous sectional rings, 84.
Screw pine emitting aerial roots, 91, 92.
Scurf of plants, 68.
Sea-weeds, cellular structures of, 146 ; family

of, 147 ; the fucus, 173. See Algse.
Secretions of plants, woody fibre the storehouse

of the, 20 ; starch, raphides, oils, fats, gums,

acids, opium, sugar, silica, &c., 3155 ; reser-
voirs of, 48.

Secundine of the ovule, 129, 134.
Seed of flowers, 18, 134; its various parts, ib. 5

its relation to the fruit, 135; the different

terms applied to, 135.
Semianatropal of the ovule (Lat. semi half, Gr. ana

backwards, and trope a turning), 128, 129, 135.
Sempervivum tectorum (Lat. semper vivo to live

for ever, and tectum a roof), the common

house leek, 73.
Sensitiveness of plants, 4.
Septa (Lat. septum a wall) of the ovule, 127.
Septicidal dehiscence of fruit (Lat. septum, and

ccedoio cut), 131.
Septifragal dehiscence of fruit (Lat. septum, and

frango to break), 131.
Serrate leaves (Lat. serrata saw-like), 97.
Sesamum orientale (Lat. sesama sesame, and

"oriental"), 46.

Sesamum oil, a vegetable secretion, 46.
Sessile inflorescence, examples of, 105.
Sessile leaves (Lat. sessilis creeping), 96.
Sexual organs of flowerless plants, 148.
Sexual system of Linnaeus, 152.
Shea butter, whence obtained, 46.
Shell-lac, a vegetable secretion, 49.
Shrubs, their component parts, 74.
Silenales, 190.
Silica, vegetable secretions of, 55; sources of,

55, 56. ; proportion of in various vegetable

substances, 57.
Siliculosa (Lat. "a small pod"), the order, 153

et passim.

Siliqua, a pod, 133, 134.
Siliquosa (Lat. "a large pod"), the order, 153

et passim.
Silk, produced from the animal kingdom, 22 ; ita

power of resistance, 22 ; fibre of illustrated, 82.

204

LSDEX.

Sinapis, the mustard plant, 46.

Sipbonia elastica (Gr. siphon a siphon, and Lat*
"elastic "), milky juice of the, 31.

Solanum tuberosum (Lat. solatium the night-
shade, and tuberosum cellular), the potato
plant, 26, 32 ; stem of the, 70.

Solanales, 191.

Soredia of lichens, 146.

Sori of the fern, 139.

Spadix, a part of inflorescence, 106.

Spagnum (Gr. spao to suck up), leaf of the moss
so called, 6.

Sparganium ramosum (Gr. sparganon a fillet,
and ramosum branching), cells from the leaf
of the, 11.

Spathe, the, of inflorescence, 109.

Species of plants, characteristics of the, 181.

Spider orchis, pseudo bulbs of the, 73.

Spike, inflorescence of the, 105, 106.

Spiral fibres of plants, 17 ; of the scale moss,
144, 145.

Spiral vessels of plants illustrated, 25 ; uses of
the, 26.

Spires of plants, 68.

Sponge, representation of the, 4.

Spongiolaoftheroot(Lat. "a little sponge"), 91.

Sporangium of mosses (Gr. sporos seed), 144.

Spores of Confervae (Gr. sporos}, motion of the,
4; of the fern, 139, 140, 141 ; of mosses, 144;
of sea-weeds, 147.

Spruce beer of Norway, obtained from vegetable
tissue, 23.

Squill, crystals in the bulb of the, 41.

Stamen (Lat. "a filament"), an essential part
of inflorescence, 116 122 ; various Greek
terms applied to the, 116, 117.

Stamens converted into petals, 114 ; different
forms of the, 118 ; classes of Linnaeus arranged
according to the, 118 ; the distinguishing cha-
racteristics of the classes of plants, 176 et seq.

Star-anise, cells from the seed of the, 13.

Starch, existence of in vegetable and animal
productions, 5 ; vegetable secretions of, 31 et
seq. ; grains of, in different plants, 35 et seq.

Starch granules, theory of, 36, 39.

Star-shaped or stellate cells, 11.

Stem of a tree, section of the, 6.

Stem of a plant, its various parts, 58 ; its general
divisions, 73.

Stems, herbaceous, 59, 60 ; of wooded plants, and
their varieties, 70, 73 et seq. ; exogenous, 75 ;
and endogenous, 86 (which see) ; the roots,
leaves, &c., 90, 92 et seq. See Trees.

Stigma of the pistil, 123.

Stinging hairs of plants, 67.

Stipels of leaves, 103.

Stipes of the fern, 140.

Stipules of plants (Lat. stipula a straw), 103.

Stomata of piants (Gr. stoma a stomach), 61 et
seq. ; number found on leaves, 63 ; th eir nature
and formation, 64.

Strawberry, primordial utricle of the, 9 ; cella
of the, 10.

Strawberry leaf, spiral vessels of the, 25, 26 ;
leaf divided into three leaflets, 99.

Strobilus, the pine apple, 133.

Style of the pistil, 123, 124; of flowers, 180.

Sub-classes of Lindley, Diclinous, Hypogynous,
Perigynous, and lipigynous Exogens, 188192.

Sucker of plants, 72.

Sugar, produced from vegetable tissue, 23, 51 ;
its cultivation and general use, 52 ; obtained
from the beet -root, sugar -inaple, and the
sugar-cane, 53.

Sugar-cane, cells of the, 8 ; representation of the,
52 ; horizontal section of the, 90.

Sumach (Pers. sumak rue), tannic acid ob-
tained from, 50.

Sutures of the stamen, 119 ; of the pistil, 127.

Sweet-burr reed, cells from the leaf of the, 11.

Syncarpi (Gr. syn together, and karpos fruit),
Class III. of fruits, 132.

Syngenesia (Gr. syn, and ginomai to grow), sta-
mens of the, 117; Class XIX. of Linnaeus,
152, 167.

Synocarpus ovary (Gr. syn, and karpos fruit),
126.

Tallow, a vegetable secretion, 46.

Tannic acid, obtained from various sources, 50.

Tannin, a vegetable secretion, 50.

Tapioca plant, vegetable secretion of the, 32.

Tar, a vegetable secretion, 49.

Taxus baccata (Lat. taxus the yew, and baccata

producing berries), 20.
Teazel, hairs of the, 65.
Tendrils of leaves, 102.
Tercine of the ovule, 134.
Terra Japonica (Lat. "earth of Japan), tannic

acid obtained from, 50.
Tetradynamia (Gr. tessares four-fold, and dyna-

mis power), Class XIV. of Linnaeus, 152, 164.
Tetradynamous stamens, 118.
Tetragynia (Gr. tessares, and gyne a female),

the order, 153 et passim.
Tetrandria (Gr. tessares, and andres males),

Class IV. of Linnaeus, 152, 155; the order, 153

et passim.
Textile materials, their respective characters

illustrated, 23.

Thalamus of the flower (Lat. " a bed "), 105.
Thallogens (Gr. thallos an organ of vegetation),

and ginomai to produce), Class I. of Lindley,

185.
Theobroma cacao (Gr. theos divine, and Iroma

food; Portug. maooco monkey-face), 46.

INDEX.

205

Thick-walled cells, 12, 13.

Thymus (Gr. " thyme"), oil of the, 47.

Tilia (Lat. " the lime tree "), 27, 42.

Tissues of plants, 5 et seq. ; cellular, 8 ; variety
of, 18 et seq. ; vascular, 25 27 ; unity of de-
sign in the, 28.

Torula cerevisiae (Lat. torvt a bed, and cerevisia
ale), cells of the, 8, 10.

Tous les mois (Fr. " every month"), starch cell
of the, 35, 36.

Tracheae of insects (Gr. trachea the windpipe),
similar to the spiral vessels of plants, 27.

Trachenchym (Gr. trachea, and enchyma injec-
tion), the vascular tissues, 25.

Tradescantia virginica (in honour of John Trade-
Kant, gardener to Charles I. ; and Lat. " vir-
gin-like "), hairs of the, 67.

Trees, woody fibre the cause of their stability,
21 ; their component parts, 74 ; various repre-
sentations of, 74; sections presenting the
different parts, 75 ; sections showing their
annual growth, 81, 85 ; immense size of, 82 ;
their great longevity, 83 ; cellular structure of,
84, 85 ; various sections of, ib. See Stems.

Triandria (Gr, treis three, and andres males),
Class III. of Linnaeus, 152, 154; order of, 153
et passim.

Trigynia (Gr. treis, and gyne a female), order of,
153 et passim.

Triticum (Lat. " wheat "), 56.

Tuber of plants, 71.

Turmeric, a vegetable dye, 54.

Turnip, vegetable secretion of the, 32.

Turnip-seed oil, a vegetable secretion, 45.

Turpentine, a resinous secretion, whence ob-
tained, 48.

Ulmus (Lat. " tke elm tree"), pores and fibres
of the, 17.

Umbel (Lat. umbellaa. fan) of inflorescence, 107,
108.

Umbellales, 192.

Umbilicaria pustulata (Lat. umbilicus the nave,
andpustulata blistered), a vegetable dye, 54.

Unguis of the petal (Lat. " a claw "), 114.

Urceolus of inflorescence (Lat. " a little water-
pitcher "), 109.

Urn mosses, 143, 175.

Urtica, the stinging nettle, 182.

Urticules, 188.

Vallisneria spiralis (frrm Antonio Valesneri, and
Lat. spiralis spiral), circulation in the, 15.

Valonia (an acorn), tannic acid secreted from, 50.

Vascular structure of endogenous steins, 88 ; ita
uses, 89.

Vascular tissues, 2527.

Valeria Indica (in honour of Abraham Peter*

and Lat. " Indian"), Pliny tallow, 46.
Vegetable butters, tallow, and wax, 46.
Vegetable dyes, 54.
Vegetable secretions, 3155.
Venation of leaves, 93, 94.
Venus' fly-trap, sensitiveness of the, 4.
Vine, section of its stem, 7 ; twining stem of the, 72.
Violet, placentae of the, 128.
Violales, 189.

Viscum album (Lat. " the misletoe berry "), 9.
Volatile oils, vegetable secretions, 47.

Walnut, spiral vessels of the, 26; chambered pith

in the, 76.

Water-beetle, trachea of the, 27.
Water-lily, stamens and petals of the, 114.
Water-plant, milk vessels of the, 29.
Wattle-tree, tannic acid obtained from the, 50.
Wax, vegetable secretions of, 46.
Wheat, starch cells of, 35, 39 ; silicious cuticle

from its husk, 56.
White, one of the principal colours in vegetables,

53.

Whorl of leaves surrounding the stem, 100.
Whorls, their inflorescence, 112.
Wigandia urens (in memory of John Wigand, a

Bishop of Lithuania; and Lat. "burning"),

poisonous hair of the, 67.

Willow, ducts of the, 27 ; catkins of the, 105, 106.
Wood, the various parts formed in exogenous

stems, 79; its modes of growth, 80, 81, 85.
Wooded stems, their varieties, 71, 73 et seq.;

divided into two great classes exogenous, 75 ;

and endogenous, 86 which see.
Woody fibre, or tissue, 18 ; two kinds of, 19 ;

plain and glandular, 19 ; various illustrations

of, 19 ct seq. ; the chief organ of circulation,

20 ; gives stability to the tree, 21 ; uses of the,

20, 21 ; its size, 24 ; of endogens, 88.
Wool, fibre of, illustrated, 23.

Xyridales (Gr. xyros acute, like rushes), 187.

Yeast plant, cells of the, 8, 10.

Yellow, one of the principal colours in vege-
tables, 53.

Yellow gum, whence produced, 49.

Yew, spiral fibres of the, 20.

Yucca dulce (the name in St. Domingo, and Lat.
dulce sweet), the tapioca plant, 32.

Y. gloriosa, stomata of the, 62.

Zea Mays (Gr. zao to nourish, and Ind. maixf)'
Indian corn, 45 ; stomata of the, 62.

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