Tine
 
   

With the Author’s, compliments:

“On the Structure, the ‘Occurrence
in Lancashire, and the Source of
Origin of Naias graminea, Del.,

jee ” Bt
var, Delile:, Magnus.
&
BY Lt et “eee
: AUB 2 195873
‘CHARLES BAILEY, F.L.S. \ . Ue
NX hs 2 WR Sf
ae echoed
A Risum# OF COMMUNICATIONS MADE 10.
THE LEEUWENHOEK MICROSCOPICAL CLUB,
AND TO : ii d : ‘i

‘THE MANCHESTER LITERARY AND PHILOSOPHICAL SOCIETY.

: Rerxwrep FROM THE ‘JOURNAL OF’ BOTANY,’ Nos. 262 AND 268, Vou. XXII, ror

OctoBER AND NovEMBER 1884.

 
Tab. 249.

Journal. of Botany.

Naias graminea, Del., var. Delilei, Magnus,

 

from Reddish, near Manchester.
Jo ILLUSTRATE PAPER BY MR. CHARLES BAILEY.
Tab. 250.

Journal of Botany.

 

 

 

 

 

Naias graminea, Delile,
Srom Lower Egypt.
Jo ILLusTRATE PAPER BY MR. CHARLES BAILEY.
“On the Structure, the Occurrence
in Lancashire, and the Source of
Origin of Naias graminea, Del.,
var. Delilet, Magnus.”

BY

CHARLES BAILEY, F.L.S.

A RESUME OF COMMUNICATIONS MADE TO

THE LEEUWENHOEK MICROSCOPICAL CLUB,
gh Wh a8

SP Gh
AND TO O .

THE MANCHESTER LITERARY AND PHILOSOPHICAL ‘SOCIETY.

Ries!

4 4

REPRINTED FROM THE ‘JOURNAL OF BOTANY,’ Nos. 262 anp 263, Vou. XXII., For

OoToBER AND NOVEMBER 1884.
ce,

QK 30
Bis

@ifo2g

I DEDICATE THESE PAGES TO THE MEMORY OF
AN OLD AND VALUED FRIEND—

THE LATE JOHN HARDY,

or 118 Emspren Street, Huumu, MAaAncHESTER;
WHO DIED, SUDDENLY, 150H SEPTEMBER, 1884.
He was THE FIRST PRESIDENT OF
THE LEEUWENHOEK MICROSCOPICAL CLUB,
AND A FORMER VICE-PRESIDENT OF

THE MANCHESTER SCIENTIFIC STUDENTS’ ASSOCIATION.

CHARLES BAILEY.

Ashjield, College Road,
Whalley Range, Manchester,
20th September, 1884.

a ie
NOTES ON THE STRUCTURE, THE OCCURRENCE IN
LANCASHIRE, AND THE SOURCE OF ORIGIN, OF
NAIAS GRAMINEA Deume, var. DELILEI Maenus.

(PuatEs 249—252.)

Page Page
I. Introduction . . . » 3 XII. The Pollen .... . 18
II. The Genus, and its divisions 4 XIII. Fertilization. . . . . 19
III. Synonymy of the Elan » 4 XIV. The Fruit. . . .. . 20
IV. The Stem . . iO XV. The Roots. . . 22
V. The Leaves. . . ... 7 XVI. The Lancashire Locality . 23
VI. The Leaf-spines . . . . 8 | XVII. Geographical Distribution 25
VII. The Leaf-sheath . . . . 10 | XVIII. Its probable source of
VIII. Leaf-structure. . . . . 12 origin. . 25
IX. The Inflorescence. . . 14 XIX A Histological peculiarity 27
X. The Pistilliferous Flower . 15 XX. Explanation of the Fi-
XI. The Antheriferous Flower . 17 gure. . 2. . 1. 29

I.—Inrropuction.

Naias graminea Del., Plate 249, fig. 1, and Chara Braunii Gmel.
were first reported as occurring in a natural state in England at
the Meeting of the British Association at Southport in September,
1888. Their addition to the flora of South Lancashire and of
Britain is due to the Biological Society of Ashton, and to Mr.
John Whitehead, of Dukinfield. They were discovered during the
exploration of the Ashton-under-Lyne district in acquiring the
necessary material for the compilation of a fauna and flora of
the neighbourhood, for presentation to the Biological Section of
the British Association. An abstract of this communication, made
by Mr. J. R. Byrom, of Ashton, is printed on pp. 541-548 of the
‘Report of the Fifty-third Meeting of the British Association.’

Few portions of Great Britain are so well known, botanically,
as most of the northern counties of England, and yet a concerted
systematic examination of so well-worked a district as Ashton has
brought to light many novelties, besides two, if not three, plants
not previously known to be British. To those who know what a
large number of practical botanists there are in the North of
England, and with what zest so many of their number pursue
botanical studies in their hard-earned leisure, it has always seemed
a matter for regret that so little of their accumulated knowledge
finds its way into print; and the instance of what has been done
by the Ashton botanists should stimulate other local societies to
make similar efforts.

The actual discoverer of the Naias was Mr. James Lee, of
Denton; he brought it to Mr. Whitehead, who sent it to me early in
September of last year as a possible Natas, and, from plants which
I afterwards gathered in situ with the discoverer and Messrs. White-
head and Byrom, it was finally determined by Mr. H.N. Ridley, of
the British Museum, to be Naias graminea Del. or Caulinia alag-
nensis Pollini. Subsequently Dr. Magnus, of Berlin, has given it
4 ON NAIAS GRAMINEA DEL,, VAR. DELILEI MAGNUS.

the varietal name of Delilei, on account of a structural peculiarity
which will appear further on.

Tl.—Txse Genus anp its Divisions.

The genus gives its name to the natural order Naiadacee, which
is allied to the Potamogetonacea, but systematists are by no means
agreed as to the respective limits of either family. Willdenow
separated the group to which N. graminea belongs from Naias
proper, under the generic name of Caulinia,* on account of the
male flowers not having the quadrifid perianth of Naias proper ;
but Robert Brown reunited the two groups of Naias and Caulinia
into Naias Linn. There ig no doubt, however, that each of these
divisions forms a very natural group sharply separated from the
other by well-marked characters drawn from the leaf, stem, and
fruit. All these points have been carefully worked out by Dr. P.
Magnus in a work which he modestly entitled ‘Beitrage zur
Kenntniss der Gattung Najas, L.’ (Berlin, 1870); and no one can
investigate the morphology and anatomy of a plant of this genus
without admiring the minute and conscientious investigations of
this author. In preparing the following notes I have referred
again and again to this memoir, and I cannot speak too highly of
the help derived from it.  — :

Dr. Magnus gives the following diagnoses of the two subdivisions
of the genus, viz.:—

« § Eunagsas Asch.—Spine-teeth chiefly on the stem and backs
of the leaves. Flowers dicecious (? in all). Anther four-chambered
(? always). Seed-shell consisting of a many-layered stony paren-
chyma. Conducting bundles of the stem divided from the inter-
cellular spaces by two to three layers of parenchyma-cells. Leaf
furnished with a small-celled epiderm, which rises very sharply
from the large parenchyma-cells of the leaf. /

“ § Cavuinia Willd. — Spine-teeth absent from the stem and
backs of leaves. Flowers in most species moncecious (? in all).
Anther one- to four-chambered. Seed-shell formed of three layers
of cellular tissue. Conducting bundles of the stem divided from
the intercellular spaces by a layer of parenchyma-cells; leaf without
the small-celled epiderm.”’—‘ Beitrage,’ pp. 55, 56.

The plant which forms the subject of this notice belongs to the
section Caulinia, and its synonymy*and principal book-references
are the following :—

III.—Synonymy or tHe Prant.

Najas graminea Delile, Flore de l’Egypte. Mémoire sur les plantes
qui croissent spontanément en Egypte; par Alire Raffeneau
Delile, p. 1. Flore Aigyptiace illustratio No. 874, p. 75.
Explication des planches, p. 282, pl. 50, fig. 3.

Chamisso, Aquatice queedam diverse affinitatis. Linnea, vol.
iv., 1829, pp. 502-8. :

 

* ‘Mémoires de VAcadémie Royale des Sciences de Berlin, 1798, classe de
Philosophie Expérimentale,’ page 87. -
ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 5

Kunth, Enumeratio Plantarum, &., Tom. iii., p. 115.
Boissier, Flora Orientalis, vol. v., p. 28.
Compendio della Flora Italiana compilato per cura dei Professori
V. Cesati, G. Passerini, e G. Gibelli. Par. i., p. 205.
Najas alagnensis Pollini, Hort. et province. Veron. pl. nov. vel. min.
cogn., p. 26. Flora Veronensis quam in prodromum Flore
Italie septentrionalis exhibit Cyrus Pollinius; Tom. iii.,
p. 49 (1824).
L. Reichenbach, Flora Germanica Excursoria, No. 920, p. 151.
Chamisso, Aquatice quedam diverse affinitatis in Linnea,
vol. iv., p. 502 (1829).
Antonii Bertolonii, M.D., Flora Italica sistens plantas in Italia
et in insulis circumstantibus sponte nascentes. Tomo x.,
fase. iii., p. 296. ;
Naias serristipula Noce. et Balb., Ic. Fl. Ticin., Tab. 15 ex specim.
sicc. delineata. :
Naias tenuifolia Aschers., Atti della Societa Italiana di Scienze
naturali, pp. 267 & 268. Non R. Br.
Najas graminea Del., var. Delile) Magnus, Berichte der deutschen
botanischen Gesellschaft; Band i., Heft 10, Jahr. 1883,
pp. 522 & 523.
Caulinia alagnensis Pollini, Plant. Veron., 26.
Diar. Brugnatelli Giorn. ann. 1816, T. ix., p. 175.
Bluff et Fingerhuth, Compendium Flore Germania, Sectio i.,
ed. alt. 1i., p. 585.
Flora Italiana, .... di Filippo Parlatore, vol. it., pp. 665, 666.
Caulinia intermedia Balb., Elench. recentium stirpium, quas Pede-
montane flore addendas censet., &c.; in Mem. della R.
Accad. di Tor. Ann. 1818, Tom. 23, p. 105.
Balb. et Nocca, Flor. Ticin., Tom. ii., p. 168, tab. 15.
Nocca, Clav., ii., p. 91.
Caulinia microphylla Nocc. et Balb., Flor. Ticin., Tom. ii., p. 163,
tab. 16.

Tt still remains a question whether this plant should bear
Delile’s name, or Pollini’s name, according as the one or the other
had priority in publication, as has been pointed out by Prof.
Ascherson in ‘ Atti della Societa Italiana,’ vol. x., p. 267, where
he shows that the description.of the plant of Pollini was certainly
published in 1814; whilst the Memoir of Delile, although perhaps
printed in 1818, was not published until some later-year. I cannot
elucidate this point further, as my copy of Delile has no title-page,
and my edition of Pollini’s ‘Flora Veronensis’ is that of 1824.
Pollini’s herbarium-specimen of the Italian plant is preserved
among the possessions of the Society of Naturalists of Rhenish
Westphalia, in Bonn.

The Italian plant is not the same as Robert Brown’s Naias
tenuifolia, Prodr. Fl. Nov. Holland., p. 545, published in 1810, on
account of the entirely different structure of the male flower (see
Plate 251, fig. 15); otherwise the name would have taken prece-
dence of Pollini’s and Delile’s.
6 ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS.

Whether the plant found in Japan, at Yokohama, is identical
with Naias graminea Del. is uncertain, but the description of it by Herr
C. J. Maximowicz may stand for the Lancashire plant :—‘ Mollis
elongata, foliis verticillatis patentibus rectis argute spinoso-serru-
latis, apice 2-8 cuspidatis, dentibus incurvis 1-cellulosis minutis ;
stipulis distinctimus lanceolatis foliaceis folii ad instar serrulatis ;
fructu lineari-oblongo, granulato. Nippon, in fossis circa Yoko-
hamam semel inveni fructiferam.” *

IV.—Tue Srem.

The stems vary in length from a few inches to upwards of two
feet, and they have many branches. Considering the large number
of leaves which they support, the stems are comparatively weak ;
they do not vary much in diameter from the base to the summit ;
vertical sections of the upper internodes are not quite so circular as
those of the lower internodes.

 

If we examine one of these internodes we find that the centre of
the shaft consists of a small channel, surrounded by two or three
layers of elongate cells somewhat closely aggregated; surrounding
these is a layer of much larger cells, hexagonal in outline, and
having thinner walls than those which protect the central channel.
From this central mass radiates a series of from eight to twelve
prolongations of the central hexagonal cells, meeting as many out-
growths from the tissue which forms the circumference of the
internode, and arranged like the spokes of a wheel. See fig. 42.

 

* Diagnoses breves plantarum novarum Japoniw et Mandschuria; in Bulleti
de l’Acad. Imp. des Sciences de St. Petersburgh. Vol. ii., pp. 71, 72. 1867. on
ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 7

The rays enclose an equal number of large intercellular cavities,
each cavity being bounded by the central and peripheral paren-
chyma at either end. The cavities occur in every internode,
whatever its age, but they are limited in the direction of the axis
by the node. The rays consist of a single row of cells, except at
the points where they join the circumference and centre; they are
not always as regular as they are drawn in fig. 42, as they
occasionally branch at each end so as to enclose a smaller inter-
cellular cavity.

The circumferential tissue of each internode consists of three
or four rows of elongate cells having a hexagonal outline, ‘ith
sinuous edges. The cells are all uniform in size, the outermost
layer not being smaller than the rest, as it is in Naias flewilis. The
external edge of the outer row of cells is slightly thickened, but I
cannot detect any epidermal cells.

In the posthumous work of Prof. Parlatore, entitled ‘ Tavole
per una ‘‘ Anatomia delle piante aquatiche,”’ a drawing is given of
the transverse section of the Italian Naias graminca, but it differs
from my drawing (fig. 42) in showing an epidermis of distinct
square-shaped cells. The central bundle is also made to consist of
about half a dozen rows of cells, smaller in size than I find them in
the Reddish plant. I reproduce Parlatore’s figure on Plate 252,
fig. 86.

Chatin, in his valuable but incomplete work, ‘ Anatomie com-
parée des Végétaux,’ did not quite reach the Naiadacee in the
volume devoted to aquatic plants, or his drawings would have been
useful for comparison ; it is much to be desired that this fine work
had been completed, as well for the parasitic plants as for the
aquatic. The Naiade are not yet figured by Reichenbach in his
‘Icones Flore Germanice et Helveticer,’ &c.

V.—Tue Leaves.

The leaves grow in tufts at the side of each inter-
\ node, and they are rather more lateral than they are
represented in Delile’s figure, reproduced two-thirds the
original size in Plate 250, fig. 8. In the living state,
as seen in the water from above, they have a light
olive-green shade, much duller than that of the bright
green leaves of Naias flemilis. In the dried state they
become much darker, particularly in the older leaves,
but the younger tufts retain the light green colour of

the living plant. ,

In shape the leaves are linear, broadly channelled
in their lower portion (figs. 64 & 65), thickened in the
region of the midrib: (figs. 60 to 68), and slightly
keeled on their lower surface; in length they vary
from } in. to 12 in., and they are 1-24th in. broad
or less (see Plate 249, fig. 2). The sides of the fully-

j developed leaf are parallel for the greater portion of
their length, but at their base they widen out into a
Fic. 43. broad sheath bearing two upright auricles applied to
8 ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS.

the stem and half-clasping it (figs. 52 to 55). The

( extremity of the leaf is gradually attenuated, and ends

in from one to three spines (fig. 48) ; the extremities

are frequently truncate, so that the spines give it a
cuspidate character (fig. 44).

The margins of the sides, sheath, and free ex-
tremity are studded with erect, unicellular, yellowish
brown spines (figs. 47 to 49), whose colour presents a
contrast to the transparent marginal cell-walls, and to
the green contents of the cells of the lamina of the leaf.
The spines are acuminate, slightly curved, and gradually
narrowed from the base to the sharp point.

VI.—Txe Lear-sprves.

The form of the spine, or tooth, on the margin ot
| the leaf furnishes good discriminating characters be-
\ N tween the various species of Naias, as was long ago
Fie. 44. pointed out by the late Al. Braun in one of the earlier
numbers of this Journal (vol. ii., 1864, pp. 274-279).
The simplest form of tooth is that of N. flewilis, where, in Dr.
Boswell’s Loch Cluny specimens, the base of the spine is in the
same plane as the leaf-margin. The spine springs from a dilatation
between two of the marginal leaf-cells (fig. 45), each of which nearly
equally supports the spine to the extent of one-third its length, rarely
more. Sometimes the two marginal cells are separated from each
other by the spine (see fig. 46).

 

\
‘!
\\

 

SE

 

 

 

 

Fie. 45. Fie. 46. Fie. 47. Fie. 48. Fie. 49.

In Naias graminea the type of spine is similar, but it differs from
that of N. flewilis in having a bi-celled base whose sides unequally
support the spine. The lowermost of the two basal cells diverges,
at its upper end, from the line of the leaf-margin, so as to wholly
ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 9

support the lower end of the spine (see fig. 47). The uppermost
cell, on the other hand, acts as a support to the inner side of the
spine for fully one-half its length; it also partially underlies the
upper end of the lowermost basal cell, and thus its three-sided profile
fills up the axil of the spine and adds considerably to its rigidity, as
compared with the arrangement in N. flewilis (comp. fig. 45). Oc-
casionally a third cell makes its appearance, as shown in fig. 48, and
not infrequently there is an auxiliary spine between the upper sup-
porting cell and the original spine (see fig. 49). In all these cases,
however, the axillary, or uppermost, basal cell distinguishes the type
of tooth from the characteristic tooth of N. flemilis. Cesati gives
figures of the dentition of these two species in Plate IT. of ‘Linnea,’
vol. xxxvi.; but he makes that of N. alaganensis much nearer to that
of N. flewilis than I find it to be in the Manchester plant.

A third type of spine is furnished by Naias minor
All. (Caulinia fragilis W.). This shows an advance
upon the basal arrangement of the spines of N. flewilis
and N. graminea, in being formed of more than three
. cellg (see fig. 50). The entire tooth stands much above
the line of cells which forms the margin of the leaf.

Upon comparing these figures (which I have care-
fully made from typical specimens) with those given by
Braun on p. 275, vol. ii. of this Journal, it will be seen
that my drawings present considerable variation from
his, particularly in N. flewilis. It is possible that
Braun’s figures were meant to be diagramatic, and
representative of groups rather than of species; for

Fie. 50. convenience of reference I have reproduced them in
Plate 251, figs. 6 to 8.

The other end of the series of types of spines is represented
by the tooth of N. major, where there is not only a multicellular
base, but the spine itself is compounds one terminal dark brown
cell resting upon several elongate dark brown cells, the whole
. forming a very conspicuous tooth

standing well out from the plane of
the leaf-margin. Fig. 51 gives a
tooth of this species from one of the
late Dr. Wirtgen’s specimens from
the mouth of the Moselle, near
Coblentz.

In N. graminea the spines are
situated on the leaf-margins only
(never on the midrib) at intervals
equal to from one-half to the whole
breadth of the leaf. Figs. 47 to 49
have been drawn from spines on the

edge of the middle portion of the leaf.

Their shape is constant on the sides

of the lamina, but they become longer

pa on the sheath, and at the apex of the
ASO leat.

Fie. 51. : B

 

 
10 ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS.

VII.—Tue Lear-sneats.

The leaf-sheath is another important character in distinguishing
the species of Naiade, the extent of the dilatation, and the form of
the auricle, when present, furnishing useful marks of discrimination.

The types given by

_Braun in the ‘Journal
of Botany,’ vol. ii., p.
274, are re-drawn on
Plate 251. figs. 10 to 14,
but, as will be seen from
what follows, the Red-
dish plant differs con-
siderably from Braun’s
figure of N. graminea,
unless he meant it to
serve as a general figure
of the type of sheath
in his super-species N.
tenuifolia.

In the English Naias
graminea the base of the
lamina of the outermost
pair of leaves suddenly
dilates into a pair of
upright auricles, or ears,
which are continued be-
low so as to form a more
or less ample sheath (see
fig. 52); the size of the
sheath presents con-
siderable variations, ac-
cording to the age and
the position of the leaf
to which it belongs (see
figs. 52 to 55). Isee no
trace of any intravaginal
scales (squamule) at the
base of the leaf-sheath,
such as are found in
Naias major and in theal-
ied genus Phucagrostis.
Fig. 29, Plate 251, shows
the scales of Naias major
im situ ; one of the scales
is drawn separately in
fig. 80 on the same
plate.

The auricles in their
turn vary in shape and
size, but I have not met

 
ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 11

with them so regularly oval nor so acute as they are represented in
Braun’s figure (fig. 14, Plate 251); on the contrary, I never find them
acute, and, though somewhat parallel-sided, they gradually taper
from their base to their elongate truncate apex (see figs. 52 and 54).
_. More often than not the auricle is larger on one side than the other, as
in figs. 54and 55. The auricles are confined principally to the first

  

Fra. 54.

pair of leaves of each fascicle, and the sheaths of the pair embrace the
““Teaf; most often these are the only leaves in the fascicle which
possess auricles (see Delile’s figure on Plate 250, fig. 4). The next
pair of leaves has auricles which, when present, form a more acute
sinus with the lamina (fig. 55); but as we approach the centre of
each fascicle the leaves are
destitute of auricles, and
pass into short lanceolate
bracts, in the midst of
which we find the flowers.
In Scotch specimens

of Natas flewilis the leaf-
sheath is of another type;
the base of the limb widens
outintoa sheath more than
twice the breadth of the
limb, and at an angle of
about 45°; but there is no
approach to an auricle on
either side. The shoulders
of the sheath are crowded
with teeth, but they are
infrequent on the sides.
Fia. 57. See figs. 56 and 57, and

  
12 ON NAIAS GRAMINEA DEL., VAR. DELILE] MAGNUS.

compare them with the slightly different figure of Braun on Plate
251, fig. 10.

For drawings of the leaf-sheaths of Natas minor and N. major see
Plate 251, figs. 9 & 29, and compare the former with Braun’s figure,
Plate 251, fig. 11.

 

 

The margins of the auricles of N. graminea, and more particularly
their free extremities and inner sides, are crowded with strong,
spiny, tawny-brown cells, similar to those on the lamina; but they
occur at much shorter intervals, and the cells at the base of the
spines are more loosely aggregated (see fig. 58), so that there is no
well-defined series of marginal cells as in the lamina. The basal
cells which support the spines have their longest diameter in the
direction of the spine.

 

In N. flewilis (fig. 59) the cells are more loosely aggregated also,
but the line of marginal cells, though not so well-defined as in the
lamina, is more clearly apparent than it isin N. graminea. The
cells of the sheath, as well as the marginal cells of the lamina, of
N. flewilis ave larger and longer than they are in N. graminea; but
the two species may be distinguished by the length of the imbedded
portion of the spine, which in N. flewilis is less, and in N. graminea
is more, than one-third of its free length. The leaf-cells of N. fleailis
generally are larger than those of N. graminea (compare figs. 45 and
46 with figs. 47 to 49, and fig. 58 with fig. 59, all of which are
drawn to the same scale). i

VITI.—Lear-srructure.

The anatomy of the leaves of N. gramineais simple. The margins
of the lamina to the extent of one-third the breadth are composed of
two layers of cells (see figs. 68 and 65), which in the Reddish
specimens do not present that contrast in the size of the cells of
ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 13

the superior and inferior layers which Dr. Magnus mentions on
p. 51 of his ‘Beitrage.’ No doubt the cells of the convex side ef the
lamina are slightly the smaller, but the difference is not so marked
as they are represented in Plate 252, figs. 81 to 38, which are
copied from the figures given by Dr. Magnus.

: There are no stomata on the leaves,
and no epidermis; but the surface-cells in
all parts of the plant have intermixed with
them reddish pink pigment-cells, which
become brown with age. They are probably
resinous, as they are the last to decay;
similar cells occur in other species of
Naias.

The central portion of the leaf is
much thicker than the sides, because at
this point the two layers of the lamina
diverge from each other so as to enclose a
central bundle of small-sized cells, sur-

rounded by a layer of six or eight larger-
ese ye ca EO” sized cells. On either side of this central
EES tissue are two intercellular cavities, which
greatly exceed in size the cells which bound
, them (see figs. 60 to 65).
? In his ‘Beitrage,’ pp. 51 and 52, Mag-
nus describes Naias graminea as possessing
bast-cells in certain fixed positions in the
leaf, namely, close to the margin, and im-
mediately above and below the central
bundle on the upper and lower surfaces of the leaf (see figs. 81 to 33
on Plate 252). These bast-cells I cannot discover, after prolonged
search, in any portion of the Reddish plants; but as
Magnus states (p. 52) that Damietia specimens collected
by Ehrenberg, and Cairo specimens collected by
Schweinfurth, also have these bast-cells wanting, it is
clear that the Reddish plant corresponds in this par-
ticular with the plants from Lower Kigypt.

On the other hand, the plant from the Italian sta-
tions possesses bast-cells. I found them clearly marked
in specimens in my herbarium collected by Signor
Malinverni, ‘‘In stagnis fossis et oryzetis circa Quinto
Vercellensis ditionis pago estate 1875”; the accom-
panying figure has been drawn from the leaf of one of
these plants (fig. 66).

The line of libriform cells is the central one of the
three series which I have drawn; it is most clearly
apparent when viewed as a transparent object, from the
circumstance that its cells do not contain chlorophyll,
and hence it is visible as a transparent colourless line
in the midst of green tissue.

An isolated bast-cell is given in fig. 84 on Plate 252,
and their position in the leaf is shown in figs. 31 to 83

 

    
 
  

ect Srin

   

 

 
14 ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS.

on the same Plate at the points marked b. In the upper part of
fig. 32 the single cell seems to have been multiplied into three, but,
as Dr. Magnus explains in his memoir, these long Y-shaped cells are
arranged in a single linear series at the edge of the leaf; the
bifurcating end of one cell encloses the solitary attenuated end of
the one next to it; a section at such a junction severs the three
interlocked ends of two contiguous cells. :

The absence of this libriform tissue in the Lancashire plant has
a bearing in determining its source of origin, as will be noticed
further on.

Between the Italian and the Lancashire plants I notice one
other point of difference, which may be due to the period of growth.
Above and below the central bundle of the leaf, but particularly on
the lower surface, the external cells are densely packed with starch-
grains, very similar to what is met with in the external membrane
of the fruit. Although starch-granules are present in the membrane
of the fruits of the Lancashire plant, I have failed to discover a
single instance of their occurring in quantity in the leaves.

All the cells of the leaf exhibit a very striking circulation of
their contents against the cell-walls; the chlorophyllean granules
and other protoplasmic bodies being very large, and the cell-walls
being very transparent, the plant furnishes a splendid illustration
of circulation, more so than in any plant which I have examined.

IX.—Tae InruorEscence.

The construction of the flowers of the genus Naias and their
morphology have been minutely studied by Dr. Magnus, and the
results given in his ‘Beitrage,’ pp. 26 to 88. In referring to the
development of a side-shoot of N. graminea he says that many of
the internodes are suppressed, and that from three to five pairs of
leaves spring from the axis before we reach the flowers, which occur

to the number of from two to four all in one node. He adds that
it is worthy of notice that the male flowers are found on those parts
of the shoots which have long internodes, while the female flowers
oceur only on those shoots where the internodes are suppressed.
This was not the structure in the Lancashire
plant. Quite as often as not pistilliferous flowers
were found in the axil of the first pair of leaves of
the tuft. Antheriferous and pistilliferous flowers
are found side by side (see figs. 67 and 68) in the
axil of the same leaf. Both kinds of flowers are
also found in all stages of development, quite young
ones lying side-by-side with those more developed.
The great majority of the plants produced fully-
developed flowers, both male and female, the latter
being much the more numerous. The species is
monecious; even in those instances in which I found only female
flowers on the individual plant, I could not be sure that male
flowers had not been produced, or would not have been produced later
on, It was not usual, though by no means infrequent, to find both

 
ON NAIAS GRAMINEA DEL,, VAR. DELILEI MAGNUS. 15

sexes in the same fascicle, at equal stages of development (figs. 67
and 68), and mature and immature flowers enclosed by the same
bract (see figs. 81 and 86).

The flowers begin to occur
immediately within the axil of
the first pair of leaves in each
fascicle, but there is frequently
an outlying pair of leaves below
the fascicle which does not con-
tain flowers. The oldest flowers
are always at the base of the
fascicle. When mature, the fruits
are plainly visible to the naked
eye (see Delile’s figure on Plate
250, fig. 4), but they can be
detected, when present, by the
touch. The female flowers are
rarely solitary, but occur in twos,
threes, or fours; in the earlier
stages of development they are
sometimes more numerous. The
male flowers are more often soli-
tary. In the centre of the fascicle
are the youngest flowers (see figs.
68 and 69).

In appearance the flowers look
as if they were ordinary anthers
and pistils, ¢.¢., that they possess
no perianth; but-Dr. Magnus
has shown that their outermost
covering is really a perianth
which more or less closely invests
the anthers and pistils. In fig.
16 on Plate 251 the perianth
has been drawn back from the
exposed anther of N. major. Figs.
22, 24, 25, and 28 show the
natural reflexion of the perianth-
leaves in the male flower of N.
major.

All the flowers are sessile,
and I have endeavoured to con-
vey, in the accompanying figures,
accurate representations of each.

X.—Tae Pistmurrerous FLower.

 

Fie. 69. The female flower consists of

an elongate flask-shaped body,

with a long neck which bifurcates at its free end (figs. 68 and 70),

like the bifid stigma of a Carex, such as C. ovalis, The outer
covering is the perianth; the body which it encloses is the pistil,
16 ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS.

In its early stage the lower, or flask-shaped,
portion consists of a globose or ovate body,
surmounted by a flat parallel-sided band, of
nearly the same breadth as the lower portion
(fig. 67). The upper portion or neck of the flask
divides about half-way up into two divisions, like
the stigma of an ordinary flowering plant (see
fig. 71). This stigmatoid portion attains its
maximum length very early. The basal portion
contains a single anatropous ovule, and it en-
larges both outwards and upwards until it is twice
the length of the style-like portion (see fig. 70).

The investing membrane (fig. 88)—which can
be removed like the calyptra of a Polytrichum—is
made up of one or two layers of cells, which vary
in shape according to their position. The portion
which covers the ovule consists of elongate cells
with truncate ends, and these cells are densely
packed with rounded grains of starch very uniform
in size. The starch makes its appearance in the
later stages of the growth of the membrane. The
portion which covers the long neck of the flask-
shaped body is also mostly composed of long
cells; but the cells which occur on the margins of the stigmatoid
divisions of the free ends are only one-third the length of the
central cells, and their outer ends are somewhat enlarged so as to
make the edge of the stigmatoid divisions minutely papillate, as if
to afford better attachment for the
grains of pollen (fig. 72). The cells
of the base of the neck are much
broader than any of those in other
parts of the investing membrane, and
they are also more loosely aggregated
at that point.

A central canal runs throughout
the narrow portion which simulates
the style, and at the point where it
reaches the chamber which contains
the ovule it becomes slightly con-
stricted (fig. 71); but immediately
Fic.71. Fic. 72. Fic. 73. below the constriction it widens out

into a cupola-shaped cavity, whose
upper portion or roof is lined with a few unicellular hairs (figs.
72 and 78). Below this cavity is the ovule. The accompanying
drawings (figs. 67 to 78) illustrate the female flower in some of its
stages of development.

No portion of the pistilliferous flower bears any spines similar
to those which occur on the bracts and leaves; such spines are
present in some of the species of Naias.

 

 
ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 17

XI.—Tue Anruerirerous FLower.

The male flowers are not so numerous as the female flowers,
and they grow intermixed with them. Although I have frequently
found plants of Naias graminea in which none but pistilliferous
flowers could be detected at the period of examination, such ten-
dency towards dicecism never showed itself when anther-bearing
flowers were present. When the latter occurred on a plant
pistilliferous flowers were invariably present, and oftener than not
side by side with them (see figs. 67 and 68).

My observations of the anther do not quite coincide with the
descriptions and figure given by Dr. Magnus; I have consequently
given a larger number of illustrative drawings of these organs.
The drawing of Dr. Magnus is reproduced on Plate 252 in fig. 35.

When young they are oval-shaped bodies borné upon
a very short stalk (see figs. 74 and 76). So much do they
resemble the anther of an ordinary flowering-plant that
I was a long time in realising that the outer body which
I was examining was the membrane which formed the
perianth. The perianth closely invests the anther
throughout all its stages of growth, and, from all that
IT have seen, it keeps pace uniformly with the growth of
the membrane of the anther.

The anthers of this genus, according to Dr. Magnus, .
are axis-growths which, when ripening, are pushed
through the perianth, rupturing that membrane some-
what irregularly, and they finally dehisce at their apex.
That the anthers of the Reddish plant dehisce at the
apex there is no doubt, but I have seen no trace of the
rupturing of the outer perianth-membrane through the
emergence of the anther proper; on the contrary, the
summit of the flower presents a regularity of parts for
which Dr. Magnus’s observations did not prepare me.
The rupturing of the perianth in N. major is shown in
figs. 22 and 28 on Plate 251.

In an early stage the antheriferous flower of N.
graminea has its outer membrane prolonged into two
erect rounded ears, which are continued down the sides
as keels or ridges (figs. 67 and 75). The young pollen
at this stage is distinctly seen through the membranes of
the flower and of the anther (fig. 76). The anther then

Fie. 76. becomes more elongate by its upward growth; a slight

groove makes its appearance longitudinally, corresponding

with the principal dissepiment of the anther (fig. 68); the upright
ears and the keels lose their prominence, and the separate pollen-
grains are not so distinguishable (fig. 77). Finally, the mature
quadrilocular anther is an ovoid cylindrical body having two narrow
ridges covering the summit, and descending about half-way down
the covering of the flower (fig. 78). For comparison, see an
antheriferous flower of N.. minor in Plate 251, fig. 17; a transverse
section of N. major in fig. 18; a vertical section of N. major in

 
18 ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS.

fig. 28; a vertical section of N. minor in fig. 27;
and a vertical section of N. major. in fig. 21.

The membrane which invests the anther is
formed of close-ranked, elongate, translucent
celis, six to twelve times as long as broad, and
tinged with a beautiful rose-colour; the super-
position of this rosy membrane over the lemon-
coloured pollen of the anther gives the flower a
tawny-orange appearance, which readily attracts
notice, even without the aid of a lens. The cells
which compose the ridges in the upper half of
the flower are larger and broader than those of
the rest of the membrane.

Robert Brown’s N. tenuifolia has considerable
affinity with the Manchester plant, but, inde-
pendent of other differences, the anther is very
dissimilar on account of its external tunic termi-
nating in a narrow elongate beak, which bears a
number of brown spiny teeth at its free end (see
fig. 15, Plate 251). At the period of dehiscence
the internal tunic which contains the pollen
separates itself from the external membrane, but,
instead of its emerging through the summit of
the beak of the perianth, it is thrust through a
rupture in the side.

In N. graminea the external membrane closely
invests the inner membrane, but it is not pro-
jected beyond it in the form of a beak; and
I have not seen a vestige of a brown spiny cell
on any portion of the male flower.

 

XII.—Tse Powen.

The pollen of the various species of Naias does not seem to
have been much noticed by observers. Magnus does not allude to
it, nor give any figures of pollen-grains for any of the species ; and
contradictory statements are made by some authors. Thus the
drawings of Braun, engraved in fasc. x., plate i., of the ‘ Genera
plantarum flore germanice ’ of Nees ab Esenbeck, show a globose
pollen for Naias minor (Caulinia fragilis) in situ, and for Naias major
in separate grains (see Pl. 251, fig. 19), and in his diagnosis of the
genus (Caulinia) he specifies “‘ pollen globosum, magnum.” This
statement seems to be the foundation for the similar statement in
the works of later authors, one of the most recent being given in
the ‘ Genera plantarum’ of Bentham and Hooker, vol. iii., p. 1018,
viz., pollen globosum.” In the ‘Compendio della Flora Italiana,’
of Cesati, Passerini, and Gibelli, part 1, p. 204, tab. xxvii., fig. 1,
the pollen of N’. major is elliptico-cylindrical like a grain of rice,
say from two to three times longer than broad (see Pl. 251, fig. 26),
In the ‘Flora Danica,’ Plate 2121, the pollen of Najas marina
(Caulinia fragilis) is of an elliptical form, not quite twice as long ag
broad. .
ON NAIAS GRAMINEA DEL., VAR. DELILEI. MAGNUS. 19

This divergence of form in the pollen-grain of Naias major
suggests at first sight inaccuracy of observation, but I have found
both globose and elongate pollen in the anthers of the Lancashire
Naias graminea. The globular form is represented in fig. 79, and
the elliptical form is given in fig. 80, both drawn to the same scale.

 

Undoubtedly the pollen is globular in its early stages, but, after
selecting what appeared to be perfectly mature anthers just at the
period of dehiscence, the pollen which emerged was found to be
globose, as drawn, in one anther, and elliptico-cylindrical in another
anther. Whether the globose pollen ultimately passes into the
elliptical form, and that the latter represents the mature pollen, or
whether there is a dimorphism in the pollen-grain, I cannot
pronounce; I can only certify to the occurrence of both forms in
plants from the same station, and that the globose form is much
the rarer of the two.

In its fresh state the pollen-grain is of a pale yellow colour, and
its contents are granular. It must be produced in great abundance,
as I have frequently found it in a free state in the water of the
glass jars which have held the living plant during these investi-
gations; grains also occur floating about in the chloride of sodium
solution, which I use for mounting the dissections of the plant for
permanent microscopic examination.

XITI.—Ferrinization.

The pollination of Naias graminea is entirely effected in the
water, as there is no provision for an elongation of the peduncle to
raise the pistilliferous flowers up to the surface of the water, as in
Potamogeton Zizii, Valisneria, Anacharis, and other aquatic plants.
The structure of the inflorescence forbids its being considered a
cleistogamous flower ; whether it is an aquatic type of an anemo-
philous or an entomophilous plant I cannot determine.

Some observations I have noted for recording here are of some
interest, as they suggest that pollination is effected in two ways.
In the station in which the Naias occurs near Manchester the very
slight natural flow of the water in the canal towards the locks is
quite sufficient for the transport of the pollen, and, though I have
not purposely taken some of the canal water to see if it contained
20 ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS,

free pollen, my home observations leave me no doubt that pollen is
carried to the pistilliferous flowers by the current ; in such case the
plant would be hydrophilous. While, however, examining portions
of a living plant on which were ripe anthers, I noticed a colony of
Vorticellide attached to one of the fascicles of leaves; the grace
and activity of its movements led me to watch it for a considerable
time, and whilst so watching it I witnessed grains of pollen
whirled in all directions, or drawn into the vortex of the animal
by its marginal cilia. The alternate contraction and elongation of
the elastic and thread-like pedicles of the colony kept the pollen-
grains in constant motion, which left me no doubt that at times the
grains would be directly borne to the stigmatoid appendages of the
pistilliferous flowers.

The canal-water is most prolific in animal life; beetles, molluses,
leeches, rotifers, polyps, larve of insects, &c., must surely prove
potent factors in transporting pollen not only in the tepid water of
the Reddish canal, but in the still water of pools and ditches. If
we carefully look for instances of their intervention we cannot fail
to find distinctive protozophilous plants, dependent for their ferti-
lisation upon animal life in the aqueous world, in much the same
way as we find entomophilous plants in the aérial world.

It is a very happy circumstance that Sir Joseph Hooker should
have indicated the forms of pollination which prevail in many
of our native plants, where known. Sprengel, Darwin, Miiller,
Lubbock, Kerner, and many others have largely increased our
knowledge of this subject for terrestrial plants, but its extent after
all is very limited ; we have but ascended a few steps leading up to
the vestibule, whilst the great temple of truth is beyond. ‘While,
as regards aquatic plants, and particularly those which are wholly
submersed throughout their lives, like Naias graminea, Stratiotes,
&c., our knowledge is even more and more limited. Hence Sir
Joseph Hooker has earned the thanks of British botanists by
bringing into prominence, in his ‘ Student’s Flora,’ this important
feature in the economy of our native plants.

XIV.—Tae Frorr.

Up to the time of the fer-
tilization of the ovule the outer
membrane of the flower—the
perianth, and the investing
membrane of the ovule con-
tained within the perianth,
both remain transparent or
semi-transparent. After pol-
lination has taken place the
membrane of the ovule be-
comes turbid and thickens,
while the ovule itself enlarges
and becomes a mature fruit,
covered with a testa formed of
al cells (figs. 81 to
83).

 
ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 21

The fruit is sculptured with a network of raised ridges
which thus produce depressions in the shell; this sculpture
seems to have its seat in one of the inner membranes of the
shell, since it cannot always be distinguished through the most
external layer. As far as I have been able to make it out,
it is somewhat after the character of the accompanying fig. 84;
but this must be looked upon as a diagramatic interpretation
of what is supposed to be seen, rather than an actual repre-

 

sentation of fact. In the same way I have drawn the testa of
Naias flewilis in fig. 85 from a single mature fruit in one of Dr.
Boswell’s Loch Cluny specimens; I am more sure of the cor-
rectness of this figure than of that of N. graminea, but it
represents what is seen in a single fruit only. It would there-
fore appear that the sculpture of N. flewilis is quadrangular,
while that of N. graminea is hexagonal; but too much must
not be made of observations founded on such a limited basis.

According to the observations of Cesati* the fruits of the
Italian N. alaganensis are granulose-punctate, which fairly well
describes the appearance of the outer covering of the Manchester
plant; but Cesati’s figure in ‘Linnwa,’ l.c., Table ii., fig. 2d,
makes the fruit much more papillate than I find it in the Lancashire
form. On the other hand, this same observer makes the fruit of
N. flexilis shining and obscurely angular, and he so draws it in his
plate.

The explanation of this difference in the form of sculpturing is
probably due to the fact that the external membrane more or less
obscures the underlying layer, and thus the latter is seen by
observers according as the transparency of the outer layer admits
of it. For the further elucidation of this point I have reproduced
the figures of Dr. Magnus in Plate 252, where figs. 40 and 41 show
the arrangment of the coats of the fruit of N. graminea from Cairo,
and figs. 37 to 39 those of N. flexilis.

At Reddish mature fruits of N. graminea are produced in great
abundance ; scarcely a plant occurred without fruits. In the many
hundred plants which I have examined I have not seen a single
instance where the beak of the fruit was other than bifid, unless
it had broken off altogether, as represented in figs. 81 and 83,

 

* «Die Pflanzwelt im Gebiete zwischen dem Tessin, dem Po, der Sesia und
den Alpen,” (‘ Linnea,’ vol. xxxii., 1863, pages 259 and 260).
Sa

22

ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS.

and in the middle fruit of figure 86. This division of the beak into
two branches is a constant character, and very clearly distinguishes
it from the four-rayed beak of Naias flewilis (fig. 87).

 

Fia, 86. ‘ Fia. 87.

One other point of differentiation between Naias graminea and
N. flexilis rests in the shape of the fruit. In the former the ends
are more abruptly narrowed into the base and the beak than they
are in the latter, which has gradually narrowing ends; compare
figs. 86 and 87. Cesati’s figures in ‘Linnea’ xxxii., Plate 2,
confirm this conclusion.

 

Fia, 88.

The perianth easily separates from the fruit; it.
is represented in fig. 88. The portion which covers
the body of the fruit consists of a single layer of cells.

XV.—Tue Roors.

The roots are of great length, creeping in the soft
black mud of the bed of the canal; they are given
off from the nodes in verticils. They are capillary,
uniform in diameter, even when nine inches long,
tawny-orange in colour, and I have not seem them
branch.

In internal structure they bear some resemblance
to the stems. There is a central channel surrounded
by a mass of elongate cells hexagonal in outline
smaller in size, and with thinner walls than those of

the rest of the cells within the cylinder. Outside this area is
a row of cells whose walls are darker coloured than any of the
others (except the cells which form the exterior of the cylinder)
and they so arrange themselves as to form a sheath round the
central cells ; from this row of cells numerous short branches are

given off which enclose intra-cellular cavities, similar to those
ON NAIAS GRAMINFA DEL,, VAR. DELILE MAGNUS. 238

in the stem, but much smaller and more circular (see fig. 89).
These cavities are regularly arranged in one series round
the central mass, as in the stem, but there are occasionally
outlying cavities in the neighbourhood of the external orange-
coloured cells, as shown in fig. 89. Enclosing the whole is
, a layer of larger-sized cells, of
a dark brown colour, and more
angular in outline than any of
the other cells. In the midst of
these cells, but on the outermost
side, are a few cells filled with a
rich tawny brown pigment. The
walls of the circumferential cells
are all very thin, and they have
the rich colour of the pigment
cells.:

In addition to the roots proper
the plant gives off adventitious
roots from the stem-nodes, as re-
presented in Plate 249. These
are generally given off singly from
between the first pair of leaves of
the fascicle; occasionally two proceed from the same node, but in
such case the second root emerges on the opposite side of the node.
In the lower portions of the stem the adventitious roots become
more numerous from each node, and they begin to acquire the
orange colour of the roots proper. They attain a length of from
half an inch to six inches or more, and they have a similar
internal structure to that of the roots proper ; the peripheral cells,
however, do not possess the angular character nor the tawny colour
of the outer layer in the lower roots. The tissue is more loosely
aggregated ; the intra-cellular cavities are fewer in number and
smaller, scarcely exceeding the size of the cells which surround
them. The central cavity is present, ae well as the surrounding
sheath, but the cells of the latter are fewer than they are in the
root proper. The external cells do not differ much from the inner
cells either in shape or in colour, the rich pigment of the corre-
sponding layer in the root being absent.

 

 

XVI.—Tse Lancasurre Locarrry.

The occurrence of a Natas in Lancashire was so unexpected a
circumstance that I was pleased, through Mr. Whitehead’s kind-
ness, to have the opportunity of seeing the plant in its station in
the canal at Reddish, near Manchester. The precise locality was not
intended to be published, but as the station seems to be well known
to so many local botanists there is no further need to suppress it.

When I first visited the canal, on the 14th September, 1883,
the Naias grew in an area of about a quarter of a mile in length;
in some portions of this space it was the prevailing plant, wholly
covering the canal-bed, while in other portions it was intermixed
with Potamogeton rufescens, P. obtustfolius, P. crispus, P. pusillus,
24 ON NAIAS GRAMINEA DEL,., VAR. DELILEI MAGNUS.

Myriophyllum, and Anacharis. Except in so far that the station,
like most canals, was an artificial one artificially supported, there
seemed nothing in the accompanying vegetation to suggest that the
Naias was not aboriginal. All the other plants were of the
prevailing canal character, the non-native Anacharis being as much
at home as any of them.

The temperature of the canal water is, however, artificially
raised by the discharge of hot water from boilers and condensing
tanks attached to the cotton-mills and other works, which are
erected on the banks of the canal. In the declining evening of
my first visit the water was quite warm, say about 90° Fahr.
This abnormal temperature must be looked upon as the important
factor in the struggle for existence maintained by this plant. In
subsequent visits to the canal the temperature of the water was
not met with so high as it was found on the first occasion; still,
with the fitful discharge of hot water into the canal at many
points, its average temperature must be many degrees above the
normal point for the neighbourhood. It might have been expected
that the vegetation which grows in this tepid body of water would
have shown signs of luxuriance, but such does not appear to be the
case. The most striking variation is met with in .Potamogeton
crispus, which becomes dwarfed, particularly in stations where
there is an inflowing stream of warm water.

Two other plants which grow in the same canal ought to be
noticed in this connexion. ‘The first of these is the Chara Braunit
Gmel., which the Messrs. Groves figured and described in the
‘Journal of Botany’ for January, 1884, t. 242, p. 8. This plant

_ affects the edges of the canal, but it also occurs in the deeper
water of the centre, where it is more liable to be cut down by the
passing barges. Another interesting plant grows with the Chara,
whose identity is by no means settled, and it may prove worthy of
a more detailed notice viz., a species of Zannichellia.

Mr. Whitehead had mentioned to me, on the occasion of our
joint visit, that Z. palustris had been recently found in the canal,
and as it was an infrequent plant in the district surrounding
Manchester, I was anxious to procure specimens, although it
involved a moonlight search. It was while hunting for this plant
that, unknown to myself or to my companions, I collected the Chara
in the darkness; the specimens were very fragmentary, but from
them Mr. Arthur Bennett determined the plant to be the Chara
Brauniti, new to the British Flora. In justice to Mr. Whitehead it
ought to be stated that he and Mr. Armitage had collected it in
the same station a fortnight or so prior to my visit.

The Zannichellia grows in the soft mud in the shallower parts
of the canal, with Chara Braunii and Potamogeton pusillus; it also
occurs in places where the water scarcely covers it. It would
appear to flower and fruit in the mud as well as in the water, but
the fruits which are produced: in mud are of a very pale yellow-
green, on account of their imperfect exposure to the light. From
the dwarf, creeping, habit of the plant it seems to have an affinity
with the form of 2. pulustris, named 4. repens Benningh. The
ON NATAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 95

characters of the Reddish plant. agree with the description of
4. repens in essential points, but the stigma is not usually more
enlarged than in Z. palustris, whereas this feature is a decided
character, both in the diagnosis and in Reichenbach’s plate.* In
the spring and early summer it has large reserve-buds, of the size
of peas, from which the shoots take their rise.

One of its peculiarities is, that it has four or five rows of spines
or protuberances on the dorsal and ventral edges of many of its
carpels, and much more prominent than they are in Z. pedunculuta,
Z. gibberosa, and Z. polycarpa,

Delile reports + finding Zannichellia palustris in a lake near to
Fareskour in Lower Egypt, along with Naias muricata. It would
be interesting to determine whether the form is the same as that
which occurs in the canal at Reddish. Local botanists also ought
to keep an eye upon the possible occurrence of the rare Naias
muricata, figured and described by Delile; so far it has only been
recorded for Hgypt and Arabia.

The locality which produces such an extra-anglican species as
Naias graminea voust be worth exploring for the animal life which
is fostered by the same high temperature which has sustained the
Chara and the Naias.

XVII.—Gerocraraicat Distrrsution.

Naias graminea is distributed over a wide area. It occurs in a
natural state in the northern and central parts of Africa, in Syria
(Plain of Sharon: ‘ Memoirs of the Palestine Exploration Fund,’
Fauna and Flora, p. 416), and Persia, in the Indian Archipelago
and other warm regions of Asia, and probably in Japan. It does
not occur in Europe except as a colonist, it having been introduced
(according to the Italian botanists) with Hast Indian rice, into
districts where that cereal is cultivated, as in the plains of
Lombardy and. Venice ; the Italian localities are given in Cesati’s
‘“Compendio della Flora Italiana,’ as Alagna-in Novara, Balzola
between Vercelli and Casale, Merlato near Milan, Upper Ver-
cellese, Strasoldo nel Friuli near Palmanavo. It has also been
reported from the extreme north-eastern portion of Austria; but
it is not native in any of its Huropean stations, and it is an
introduction in Lancashire. It becomes, therefore, an interesting
question to account for its appearance in a country which does not
grow the rice which it consumes.

XVIII.—Its propaste Source or Oricin.

When this plant was exhibited at the British Association at
Southport, in September last year, I expressed the opinion in the
Biological Section, that it had probably been introduced into the
Reddish locality with Egyptian cotton. This class of cotton is not
one of the staple articles of consumption in the Stockport district,

 

* Icones Flore Germanicer, &c., vol. vii., fig. 20, pl. xvi.
+ ‘Flore de l’Egypte,’ vol. ii., p. 281; and also on page 75 under No. 872.
26 ON NAIAS GRAMINEA DEL.,.VAR. DELILEL MAGNUS,

but there is one mill on the banks of the canal (Houldsworth’s)
which consumes Egyptian cotton largely, and from it, if not from
others, the fruits of the Naias may have been transported to the canal.
Last autumn, Mr. J. Cosmo Melvill and myeelf carefully examined
the large condensing tank in the yard of this mill, but we could
not find a trace of the plant; the water was of a high temperature
and little vegetation was found in it, but its depth was beyond our
means of properly exploring it.

Alire Raffenau Delile * gives an account of the culture of rice
in Egypt, and shows that the water used for the young plants is
drawn fron the Nile by fixed machines during the principal part of
the year; but in times of inundation, during the rising of the river,
the water is naturally distributed, its particular course being
regulated by the embankments which protect the fields. He states
that the plant grows in the canals of the rice-fields at Rosetta and
in the Delta, but he considered it only a variety of Naias fragilis,
which grows in the same waters.

The irrigation of modern Egyptian cotton plantations will be
effected by much the same means, the Nile, with its artificial
ramifications, being the chief water supply of the country. Fruits’
of the Naias may reach Egypt from Abyssinia, or from the great
lakes of Equatorial Africa; the Nile water supplied to the growing
cotton-plant will be accompanied by these fruits, some of which
would be left dry upon the surface after the water had percolated
through the upper soil, but they would not germinate there.
Hither by the agency of the wind, or through accidental contact
with the soil, they become mixed with the cotton exported to
England. When the bales of cotton reach the Lancashire mills,
the fruits of the Naias would be removed in the blowing-room, or
by the carding-engines. The refuse is turned out of the mill into
the yard, whence the wind and other agencies transport the fruits
into the tepid water of the canal; here they meet with a suitable
nidus for germination and growth, and the result is the appearance
of an alien in our flora.

If these surmises have any substratum of truth, the Naias may
occur in any mill-pond connected with works where Egyptian
cotton is used, and where the water is raised to a permanently high
temperature by the condensation of steam from the boiler. As
Tigyptian cotton is largely used in Bolton, the mill-ponds and
canals of that neighbourhood may be expected to contain Naias
graminea and other Egyptain aquatic plants, as Naias muricata
Del., Chara Braunii Gmel., &e.

The Egyptian origin of the plant is to some extent confirmed
by the form of Chara Braunti which grows at Reddish being very
near the form of that species which occurs in Northern Africa.
Whether there is anythmg showing an affinity to the Egyptian
plant in the peculiar form of Zannichellia which grows in the same
canal, I have not the means of determining; but both it and the

 

* «Mémoire sur les plantes qui croissent spontané ’ +
pp. 16, 17. Pp ment en Egypte,’ vol. ii,,
ON NAIAS GRAMINEA DEL., VAR. DELIL&I MAGNUS. 27

Chara Braunit are so often associated together as to give a strong .
colour to the surmise of their common origin. There is nothing in
the recorded distribution of Chara Braunit to forbid its being
ultimately shown to be aboriginal, but until it is recorded from
other British stations, with fewer doubtful surroundings than it
has in the Manchester station, it can only be looked upon as a
colonist.

XIX. —A Histonoeican Prcurtariry.

A still stronger proof of its Egyptian extraction is furnished
from the histological side. This part of the case has been dealt
with by Dr. Magnus, in a paper read to the German Botanical
Association at Berlin, December 11th, 1888, and I make no
apology for reproducing here the substance of this interesting
communication. In describing the structure of Naias graminea on
page 13, I mentioned that there were two forms of the plant; one,
possessing peculiar libriform cells near the margin of the leaf; the
other, destitute of these bast-cells. This latter form Dr. Magnus
names the var. Delilei, and he states that the English specimens
belong to this variety, and indubitabty prove their Egyptian
source. The following are some extracts from the paper of
Dr. Magnus, published in the ‘ Berichte der deutsch. Botanischen
Gesellschaft,’ Jahrg. 1883, Band i., Heft 10 :—

“T have examined the specimens of Najas graminea collected by
Delile in the rice-fields near Rosetta, as also those obtained by
Schweinfurth near Benha-el-assl in the Nile Delta, and have found
them to be without bast-nerves. They are also wanting in a
specimen collected by Gaillardet, near Saida in Syria, which has
been kindly communicated.to me by M. Boissier. I was further
enabled, through the kind communication of Professor Ascherson,
to examine specimens of Najas graminea Del., collected by him
during his travels in the Libyan Desert, in the Oasis of Dachl, as
also specimens collected by Schweinfurth in the Great Oasis
Chargeh). From this it would appear that the Najas graminea

el., collected in a brook at Ain-Scherif near Kasr Dachl, as well
as those collected by Ascherson near El Chargeh, likewise have
leaves without libriform cells, like the plants of Lower Egypt. On
the other hand, the N. graminea collected some weeks later in the
same ditches in Ain-Scherif by Ascherson, as well as from a warm
spring-hole in Kasr Dachl, as also the specimens collected by
Schweinfurth near Chargeh, have all well-developed bast-nerves,
similar to the plants of Cordofan, Djur, Algeria, Celebes, &. ...

“The absence of these bast-nerves in a variety of Najas
graminea is the more peculiar, as through the construction of the
male flower of N. tenuifolia R. Br. [see fig. 15, Plate 251], from
Australia, which differs so materially, has precisely the same bast-
nerves in exactly the same shaped libriform cells on the leaves ;
consequently these bast-nerves represent the distinctive character
of a group of allied species, but still subject to variations.

‘‘T have mentioned above that the one set of specimens from
Kasr-Dachl and Chargeh had leaves without bast-nerves, and
28 ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS.

that another set had them; that is, that the one set belong to the
var. Delilei, while the other agrees with the form which appears in
Cordofan, Djur, Algiers, &c. This would appear to be a clear
proof that the oases of the Libyan Desert have received their flora
from Egypt as well as from Central Africa. This agrees with the
results of the investigations which Ascherson furnished to the
‘ Botanische Zeitung ’ for 1874, pages 641 to 644.

“These explanations would, however, seem to be somewhat
contradictory, seeing that the English specimens are remarkable
for their great length of leaf, whereas the leaves of N. graminea
from Cairo and Damietta are very short. But a minute examina-
tion of form teaches us that we must not attach much importance
to the question of the length of leaves, which is influenced, as in
most water-plants, by the depth, current, bed, and temperature of
the water. Thus we find that the specimens collected by Professor
Ascherson in the Dachl Oasis, from the deeper pools (half a metre
deep), have long leaves as well as bast-nerves, and yet the English
specimens have longer leaves without bast-nerves; while the
Egyptian specimens have shorter leaves without bast-nerves.
Thus, again, we find the N. graminea Del., growing in the shallow
ditches of the rice-fields of the plains of Lombardy, has short
leaves with bast-nerves, whereas the Najas graminea from Celebes
has very long leaves with bast-nerves. Im short, we see that
the length or shortness of the leaves has nothing whatever to do
with the formation of the variety, and nothing to do with the
histological formation of the leaf-tissue.

‘Tt is nevertheless possible that the var. Delile’, deprived of the
bast-nerves, has been developed in the quiet stagnant waters of the
overflowed Nile, as in these stagnant waters the mechanical cells
would become deprived of their functions. Thus we find Schwen-
dener, in his exhaustive work, ‘ The Mechanical Principle in the
Anatomical Construction of Monocotyledons,’ Leipzig, 1874, page
122, remarking that Potamogeton fluitans in its customary habitat
of running water has a developed system of bark-bundles, whereas
the var. 6 stagnalis Koch is completely deprived of same.

“The var. Delile, found in the stagnant waters of the
overflowed Nile, is a most persistent and constant one, as during a
period of a hundred years it has been indubitably collected by
Delile, Schweinfurth, and Ehrenberg, in Lower Egypt. Its
unaltered appearance in England and in the oases shows its
constancy and total independence of habitats, whilst its formation:
has probably been caused by the same.”

It now only remains to me to tender my ackn
Mr. Ridley, Mr. Arthur Bennett, Dr. Magan, a
Mr. Beeby, and to the Editor of this Journal, for ‘help rendered.
The delay which has occurred in completing this paper has bean
ene it has had to take its turn in the intervals of a busy
ife.
ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS. 29

XX.—EXpLaNaTION OF THE FIGURES

Prats 249.

Fig. 1. The upper portion of a branch of N. graminea, from Reddish ; nat.
size.
2. Two of the leaves from same, drawn rather broader than the natural
size, the sheaths and auricles flattened out.

Puate 250.

8. Upper portion of a branch of N. graminea from Lower Egypt. Copied
from Delile’s drawing in his ‘ Flore de ’ Egypte,’ but reduced to two-
thirds original size.

4, Base of a leaf-fascicle, showing leaf-auricles, fruits, &c.; slightly
enlarged. From Delile’s ‘Flore de l’Egypte.’

5. Section of fruit; enlarged. From Delile’s ‘Flore de l’Egypte.’

Prats 251.

6—8. Arrangement of the cells of the marginal spines on the leaf of (6),
N. flexilis; (7), N. graminea; (8), N. minor and N. arguta. From
Dr. Alexander Braun’s sketches in ‘ Journal of Botany,’ 1864, vol ii.,

p. 275.

9. Form of sheath at base of leaf of N. minor; from ‘Compendio della
Flora Italiana,’ of Cesati, Passerini, and Gibelli, tav. xxviii, fig. 1n.

10—14. Form of sheath at base of leaf of (10), N. flexilis; (11), N. minor ;
(12), N. minor, var. setacea; (13), N. falciculata: and (14), N.
graminea. All copied from Dr. A. Braun’s woodcuts in ‘Journal
of Botany,’ 1864, vol. ii., p. 274. rd

15. Male flower of N. tenuifolia R. Br. Enlarged 1s. From Magnus’s
‘Beitrage,’ plate iv., fig. 5.

16. Anther of N. major, with the perianth reflexed; enlarged. From
‘Genera Plantarum Flore Germanic#,’ Th. Fr. Lud. Nees ab Esen-
beck, Fasc. vi., Naias, fig. 5.

17. Male flower of N. minor; enlarged. Nees ab Esenbeck, l. c., fig. 24.

18. Transverse section of male flower of N. major. Nees ab Esenbeck, J.c.,

fig. 7.

19. Pollea of N. major; enlarged. Nees ab Esenbeck, J. c., fig. 8.

20. Male flower of N. major, with the perianth drawn back; enlarged.
From ‘Iconographia familiarum naturalium regni vegetabilis,’
Dr. Adalbert Schnizlein, Heft v., pl. 71, fig. 4.

21. Vertical section of male flower of N. major: enlarged. Schnizlein,
l. ¢., fig. 6. y

22. Male flower of N. major, showing the separation of the perianth from
the anther; enlarged. Schnizlein, J. c. fig. 7.

23. Vertical section of a male flower of N. major. From ‘ Compendio della
Flora Italiana,’ l. ¢., fig. 1b.

24-25. Dehiscence of the perianth of N. major, after the observations
of Braun; enlarged. Nees ab Esenbeck, I. c., figs. 9 and 10.

26. Grains of pollen of N. major, with fovilla; enlarged 22°. From

~¢Compend. Fl. It.,’ l. c., fig. 1d.

2%. Vertical section of a male fiower of N. minor All. ; enlarged. ‘ Compend.
Fl. It.,’ l.c., fig. Le.

28. Male flower of N. major; enlarged ¢. ‘Compend. FI. It.,’ l, c., fig. 1a.

29. Base of leaf of N. major with the sheath opened. Intravaginal scales
at the base of the sheath, one on each side; enlarged 2. ‘Compend.
FI. It.,’ Uc. fig. 1m.

30. Intravaginal scale of N. major; enlarged . ‘Compend. FI. It.,’ . c.,
fig. Lo.

= Prate 252.

81. Transverse section of the middle of the leaf of N. graminea, Del.;
enlarged 142. Magnus, ‘ Beitrage,’ pl. vi., fig. 3.

32. Transverse section of the side of the leaf of N. graminea, Del., from
Celebes; enlarged #35, Magnus, ‘ Beitrage,’ pl. vi., fig. 2.
30 ON NAIAS GRAMINEA DEL., VAR. DELILEI MAGNUS.

Fig. 38. Transverse section of the leaf of N. graminea Del., from Celebes ;
enlarged 12°. Magnus, ‘ Beitrage,’ pl. vi., fig. 1. ’
In Figs. 81—38 the leading bundles are drawn schematically :
i= intercellular spaces, b = bast-cells.
34. Isolated bast-cell from the leaf of N. graminea from Celebes; enlarged
182, Magnus, ‘ Beitrage,’ pl. vi., fig. 4d. ; ze
35. Male flower of N.graminea; enlarged 3%. Magnus, ‘ Beitrage,’ pl. iii.,
fig. 6. :
36. Transverse section of the stem of Caulinia alaganensis. From
‘Tavole per una Anatomia delle piante aquatiche,’ Parlatore, pl. vi.,
fig. 3.
37. Surtive vise of the outer cell-layer of the unripe seed of N. flewilis ;
193, Magnus, ‘Beitrage,’ pl. v., fig. 9.
38. Diagonal section of the nearly ripe seed-shell of N. flexilis : enlarged
198, Magnus, ‘ Beitrage,’ pl. v., fig. 8.
39—40. Diagonal sections of the still (?if not always) unripe seed-shell of
N. graminea from Cairo; enlarged 14°.
41. Diagonal section of the quite ripe seed-shell of N. graminea from
Cairo; enlarged 12®. Magnus, ‘ Beitrage,’ pl. v., fig. 12. ©

Fieurres In THE LETTERPRESS.

All the figures are drawn from Reddish specimens of Naias graminea
Del., var. Delilei Magnus, except when stated otherwise.

42. N. graminea.—Transverse section of stem, drawn diagrammatically ;
enlarged 42.

43 and 44. N. graminea.—Ends of leaves, showing dentition; enlarged +.

45 and 46. N. flexilis—Spines on margins of leaves, from specimens
collected by Dr. Boswell, in Loch Cluny, near Blairgowrie, Perth-
shire; enlarged 14%. See ‘Journal of Botany,’ No. 154, 1875,
p. 297.

47 to 49. N. graminea.—Spines on margin of middle portion of leaf;
enlarged 14°.

50. N. minor.—Tooth of leaf from one of Archbishop Haynald’s speci-
mens from ponds in his park at Kalocsa, Hungary ; enlarged 14°.

51. N. major.—Tooth of leaf from plant collected near Coblentz, by Dr.
Ph. Wirtgen; enlarged 14°.

52. N. graminea.—Large leaf-sheaf from leaf of first pair; enlarged +t.

53. N. graminea.—Usual form of leaf-sheaf from leaf of first pair; en-
larged 3.

54. N. graminea.—Usual form of leaf-sheaf from leaf of first pair, with
irregular-sized auricles ; enlarged +4.

55. N. graminea.—Leaf-sheat from leaf of second pair; enlarged 1.

56 and 57. N. flexilis.—Leaf-sheath from Scotch specimens; enlarged ¥*.

58. N. graminea—Spines on margin of auricles; enlarged 14°, =

59. N. flexilis.—Spines on margin of auricles from Loch Cluny. They are
the first four which occur on the left shoulder of Fig. 57, above the
minute spine, nearest the base of the sheath; enlarged 146,

60 to 65. N. graminea.—Transverse sections of leaves, beginning near the
summit; enlarged 4. ‘ =

66. N. alaganensis.—Libriform cells in margin of leaf, from Malinverni’s
Italian specimens ; enlarged 14%. The libriform cells are the long
cells without cell: contents.

67. N. graminea.—Young autheriferous and pistillifer i
side by side ; enlarged +3. B ust Homers rowing

68. N. graminea.—Older antheriferous and pistilliferous flowers growin,
side by side; enlarged +3. 8

69. N. graminea.—Portion of central infloresence ; enlarged 38,

70. N. graminea.—Pistilliferous flower with contiguous bracts; enlarged 15

71. N. graminea.—Young pistilliferous flower ; enlarged 43. , 2

72 and 73. N. graminea.—Young pistilliferous flowers, showing the stig-
matoid appendages; enlarged 1. 6

a and 75.—N. ee ae flowers ; enlarged as

76. N. graminea.—Young antheriferous flower, showing i i 3
eta ws, g immature pollen ;
ON NAIAS GRAMINEA DEL., VAR. DELILE] MAGNUS. 31

Fig. 77. N. graminea.—Antheriferous flower not fully ripe; enlarged 33.

78. WN. graminea—Mature antheriferous flower ; enlarged +.

79. N. graminea.—Globose pollen ; enlarged 148,

80. N. graminea.—Elliptico-cylindrical pollen; enlarged 14°.

81. N. graminea.—Fruit, with immature pistilliferous flower im the same
bract; enlarged 48.

82 and 83. N. graminea—Fruits nearly mature; enlarged 1.

84. N. graminea.—Supposed ridges and pits, of hexagonal outline, on
surface of fruit; as seen’ with a ,4, objective, Lieberkuhn and
Kelner B eye-piece.

85. N. flexilis.— Ridges and pits, of quadrangular outline, on surface
of fruit; as seen with a 4, objective, Lieberkuhn, and a Kelner
B eye-piece.

86. N. graminea.—Three mature fruits and an immature pistilliferous
flower in the same verticil; enlarged 1.

87. N. flexilis—Mature fruit from Loch Cluny specimen; enlarged 14.

88. N. graminea.—Perianth removed from fruit; enlarged 44.

89. N. graminea.—Transverse section of the root; enlarged &.

PRINTED BY WEST, NEWMAN AND CO., HATTON GARDEN, LONDON, E.c.
Tab, 251.

Journal of Botany.

 

Organography of Naias.
Jo ILLUSTRATE PAPER BY MR..CHARLES BAILEY.
Journal of Botany. Tab. 252.

 

 

 

 

 

 

Organography of Naias.

Jo ILLUSTRATE PAPER BY MR. CHARLES PalILey.