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oB. J. ^aQc ^ QTo.'e Ocbucational ,Scri«0.

THE ELEMENTS

OF

Structural Botany

WITH SPECIAL REFERENCE TO THE STUDY

OF

CANADIAN PLANTS;

TO WHICH I» ADDED

A. SKIL.SCTIOM' OF EXAMINATION PAPERS.

BY

H. B. SPOTTON, M.A., F.L.S.,

HEAD UABTBR OF BARRIK COLIjEQIATK INSTITUTE.

REVISED EDITION.

With many Illustrations by the Author and others.

W. J. GAGE AND COMPANY,

TORONTO.

Kritered acx'ordiiijr to tliu Ai;t </f I'aiTiaiiieiit of Ciiiuula, in tlie Ollioe of

the Minister of AyrinilMiii', in the year 1888, 1)v

Vv. J. (.Saoe a C<»., Toroiiio.

^j^

PREFACE TO FIRST EDITION.

«; Odiec of

The work, of which the present little volume forms the
first part, has been undertaken, at the suggestion of several
eminent educationists, to supply a palpable want. The
works on Botany, many of them of great excellence, which
have found their way into this country, have been prepared
with reference to climates differing, in some cases, very
widely from our own. They consequently contain accounts
of many plants which are entirely foreign to Canada, thus
obstructing the search for descriptions of those which happen
to be common to our own and other countries ; and, on the
other hand, many of our Canadian species are not mentioned
at all in some of the Classifications which have been in use.
It is believed that the Classification which is to form the
second part of this work will be found to contain all the
commonly occurring species of the Provinces whose floras it
is denigned to illustrate, without being burdened with those
which are either extremely rare or which do not occur in
Canada at all.

The present part is designed to teach the Elements of
Structural Botany in accordance with a method which is
believed to be more rational than that commonly adopted;
and it will be found to supply all that is requisite for passing
the examinations for Teachers' Certificates of all grades, as
well as any others demanding an elementary knowledge oi
the subject. It contains familiar descriptions of common
plants, illustrating the chief variations in plant-structure,
with a view to laying a foundaticm for the intelligent study
of Systematic Botany with the aid of the second part ; then
follow a few lessons on Morphology ; and the Elements oi

i

III

PHEl'ACK TO I'IKHT EDITION.

Vegetable Histology are treated of in us simple and brief a
manner as was thought to be consistent with the nature of
the subject.

The Schedules, the use of which is very strongly recom-
mended, were devised by the late Professor Henslow, of
Cambridge University, to fix the attention of pupils upon the
salient points of structure. They will be found invaluable
to the teacher as tests of the accuracy of his pupils' knowl-
edge. The cost of striking ofi'a few hundred blanks of each
sort would be very trifling, and not worth considering in
view of the resulting advantages.

The wood-cuts are from drawings from living specimens,
except in two or three instances where assistance was derived
from cuts of well-known excellence in standard works on
Botany. It need hardly be said that the engravings are not
in any sense intended to take the place of the living plants.
They are designed chietiy to assist in the examination of the
latter ; and whilst it is hoped that they may be of service to
those who may desire to read the book in the winter season,
it is strongly urged upon teachers and students not to be
satisfied with them as long as the plants themselves are
available.

The works most frequently consulted in the preparation
of the text are those of Hooker, Gray, Bentley, and Oliver.

Finally, the Author looks for indulgence at the hands of
his fellow-teachers, and will be glad to receive suggestions
tending to increase the usefulness of the work, and to extend
;i taste for what must ever be regarded as one of tiie moat
refining as well as one of the most practically useful of
studies.

i^eptemher, 1879.

^^t5\g5^;®K"^

and brief a
10 nature of

i^A^y recom-
fenslow, of
ils upon the
invaluable
pil8' knowl-
nks of each
siderinw in

specimens,
vas derived
works on
igs are not
ng plants,
tion of the
' service to
ter season,
not to be
selves are

reparation

Oliver.

hands of
iggestions
to extend
the moat
useful of

PHEFACE TO REVISED EDITION.

The re-arrangement of the course of study in Botany for
Teachers' Certificates and for Junior Matriculation has
aflforded an opportunity for revising and, it is hoped, improv-
ing the present text-book, to which so kind a reception was
accorded on its first appearance some years ago.

The principal feature of the new curriculum is the addition
of certain Cryptogamous types. These are necessarily some-
what more difficult of study than the Phanerogams, because
their characteristics cannot be satisfactorily made out without
employing high powers of the microscope ; but it is hoped
that the numerous illustrations which accompany the text,
and which have been gathered from various sources, will
materially assist the student in this part of the work.

The chapter relating to minute structure has been re-
written, and, as will be seen, considerably extended. Though
it is still but a sketch, it is hoped that it will serve a useful
purpose in paving the way for the fuller study of the anatomy
and physiology of plants with the aid of advanced works.

Other changes and additions have also been made, chiefly
in the chapter on Morphology.

The writer need hardly add that in preparing this revision
he has laid under contribution the various text-books of
recognized merit which have come within his reach, and that
beyond the mere presentation of the subject he lays no claim
to originality.

Barriey August, 1887.

TAJJLF. -.:h' COM.MON PLANTS EXAMINED.

rHANKlIOnAMS.

BrTTKKCiTi', Hk^atiga, Maksii -

M.AimiOM) . . . ; rt'pic'seiiting RANnNcuLACEA:,

SlIKl'IIKllD's I'rusK " CRUCtFF.H.K.

ll0UN7)-LKAVi:iJ MVLI.OW " MaI-V A» K.i;.

(iAKIiK.V PkA " JjK(!1'.MIN(>S.1;.

OUKAT WlLLuW-lIKini '* 0NA<; JiACE/K.

S\vi:kt Bmikk, Strawiskkuv, Ci;au-

Al'lTJ-:, CllKRIiY, KasI'RKKKY *' KOSACK.K.

\Vatki:-1'\iisnip *' Umhki.i-ii'kk.i-;.

Danuklio.n " CoMi'osn.K.

Catnip '• Lahiat-i;.

CuCU.MJU'Ji " CutrKBITAOK.-K.

Oak ** CiJi'ULiKKH.E.

Willow *' Salicace^v-.

Maple " Sap[n i)A(^f:.e.

Doc's-TOOTII VtoLKT *' LiLIACK/K.

TrLS " IrI DAOE^K.

Orchis " ORruiDAt^E.E.

Indian Turnii', Calla '* Akack.e.

Timothy, Rkd-tot, Meadow -
Grass, Chess, Cott(;i[ (Jrass,
Old- witch Grass, Uarnyard

Grass, Foxtail " (Jramtne.*:.

White Pine, Ground Hemlock " Comfkr.e.

CRYPTOGAMS.

Polypody repicsenting Ferns.

Common Club- Moss '* IjYcopoos.

Common Horsktail " Horsetails.

Hair-Moss " Mossr.s.

MaRCIL\NTL\ T•OL^■M0KPIL\ " lilVERWORTS.

Parmelia parietina " Lichens.

Common Mcshroom •' MnsiiRooMs.

Chara frvuilis " The Charas.

MINED.

NriTLACEyl-,

•IKKK.K.

V.MK.V..

r.MlNos.i;.
;ha('e.k.

t'K.K.
OSITK.

\T/i:.

RMITAUK^K.

MKKK^E.

ACE.*:.

i>A(;e.k.

CE/K.

cE/i<;.

I)A(.'E,E.

t/E.

NE.I'-,.
CR.E.

CONTENTS.

• Its.
'A 1 1 S.

kOKTS.
S.

OOMS.
lARAS.

1

i'AOK.
I.NTIIOIJITCTIOX 1

Chai'I'ku I. Kxaiiiinatioii of a Hiittcrcup 2

ClfAi'TKK 11. — Functions of the Or^^an.s of the Flower 11

CiiAPTEii III. — Examination of Hepatica and Marsh-Mari-
gold— Reseinblanecs between their FioMers and tliat
of Buttercup 1 i

CllAPTEii IV. — Examination of other Common Plants with
Hypogynous Stamens -— Slieplierd's Purse — liound-
leaved Mallow 22

CiiArTEU V. — Examination of Common Plants with Perigy-

nous Stamens — Garden Pea — (jlreat Willow-herb 29

CriAPTBR VI. — Examination of Common Rosaceous Plants —
Sweet lii ier — Strawberry — Cherry — Crab- Apple —
Raspberry 35

Chapter VII. — Examination of a Plant with Epigynous

Stamens — Water Parsnip 41

CiiAri'KH VIII. — Examination of Conmion Plants with Epi-

petalous Stamens — Dandelion — Catnip 4.3

Chapter IX. — Examination of Plants with Mona}cious

Flowers — Cucumber — Oak 48

Chapter X. — Examination of Plants with Dioecious Flowers

—Willow— Maple 54

Chai'TEU XI. — Characteristics possessed in common by all
the Plants previously examined — Structure of the
Seed in Dicotyledons 59

Chapter XII. — Examination of Common Plants continued

— Dog's-Tooth Violet— Trillium— Iris- Orchis 61

Viii CONTKNTS.

Chai'Tkk XIII.— FiXnmiiiation of .Spadioeous Plants— Iiuliuii

Tmnip -Calla 7'-'

Cn/.iTi;i; \I\'. Mxiuniimtionof OliiniuoeouH IMaiits -TiMio-

thy and uthei' ( ! lassca 7S

CnArTi'.Fi XV. — Coimuon Characteristics of the IMants just

Kxiunined- Structure of the Seed in Monocotyledons.. 84

CiiArTKii .\VI. — K-xaniination of Coniferous IMants— White

I'ine — (Jronml Hemlock S7

CilAi'TKii XV n. — Morphology of Roots, Stems, and Foliage-
Leaves of Phanerogams {•H

CiiAi'TKU XVIIT. — Morpliology of Flower-Leaves — lidlor-
e-scenc(f The Calyx— The Corolla -The Stamens —
Tlic Pistil— The Fruit -The Seed— (Jermination. . . . Vl'l

CllAi'TKU XLX.— On the Mimito Structure of Plants — The
Cell -- Tissues — Tissutt- Systems — Exogenous and
Endogenous Stems 1 ."o

CiiAPTKH XX. — Food of Plants — Chemical Processes —

Movements of Water — Piienomena of Crowth 177

CiiAPTEu XXI. — Examination of a Fern — A Horsetail — A

Club Moss Ui4

('iiAPTKii XXII. — Examination of a Moss and a Liverwort. . . 1 90

CiiAi'TKK XXIII. — Examination of a Mushroom — A Lichen

-A Chara HKJ

CiiAi'TEii XXIV. — Classification of Plants according to the

Natural System 200

Index 210

-Iiuliuii

7'J

-'riiiio-

78

its just
edoiis.. 84

White

S7

FoHage-
.... m

Tiillor-
inciiH —
on !•::{

s-Tho
ts iind
1.",']

ases —

II-.-
lit

;:iil — A

184

wort... 100

Lichen

mi

to the

20G

21G

THE ELEMENTS

OF

STRUCTURAL BOTANY.

1. The study of Botany is commonly rendered unat-
tractive to the beginner by the order in which the parts
of the subject are presented to liim. His patience be-
comes exhausted by the lon*^ interval which must neces-
sarily elapse before he is in a position to do any practical
work for himself. In accordance with the usual plan,
some months are .spent in committing to memory a mass
of terms descriptive of the various modifications which
the organs of })]ants undergo ; and not until the student
has mastered these, and perhaps been initiated into the
mysteries of the fibro-vascular system, is he permitted to
examine a plant as a whole. In this little work, we
purpose, following the example of some recent writers,
to reverse this order of things, and at the outset to put
into the learner's iiands some common plants, at<d to
lead him, by his own examination of these, to a know-
ledge of their various organs — to cultivate, in short, not
merely his memory, but also, and chiefly, his powers of
observation.

Z ELEMEXTS OF STRUCTURAL BOTANY.

It is desirable that the beginner should provide him-
self with a magnifying glass of moderate power for
examining the more minute parts of specimens ; a sharp
penknife for dissecting ; and a cou} le of tine needles,
which he can himself insert in convenient handles, and
which will be found of great service in separating delicate
parts, and in impaling fine portions for examination
with the aid of the lens.

1

ul

li
b|

al

CHAPTER 1.

! ;li

EXA3I1NATI0X OF A BUTTERCUP.

2. To begin with, there is no plant quite so suitable
as our common Buttercup. This plant, which has con-
spicuous yellow flowers, may be found growing in almost
every moist meadow. Having found one, take up the
whole plant, loosening the soil a little, so as to obtain as
much of the E-oot as possible. Wash away the earth

adhering to the
Itvtter part, and
then proceed to
examine your
specimen, Begin-
ning with the
Root (Fig. l),the
first noticeable
Fig. 1 thing is that it is

not of the same colour as the rest of the plant. It is

Fiir. 1. — Fibrous Root of Buttercup.

I

:'ovide him-
power for
s ; a sharp
le needJes,
ndles. and
ng delicate
:aminatioii

b suitable
li'is con-
in almost
e up the
ahtain as
he earth
to the
^1% and
>ceed to
- your
Begin-
th the
g.l),the
ceable
fiat it is
It is

EXAMINATION OF A BUTTERCUP. 3

nearly white. Then it is not of the same forin as the
[>art of the plant above ground. It is made up of a num-
ber of thread-like parts which spread out in all directions,
and if you examine one of these threads through your
magnifying glass, you will find that from its surface are
given off many finer threads, called rootlets. These
latter are of great importance to the plant ; it is largely
by means of their tender extremities, and the parts
adjacent to these, that it imbibes the nutritious fluids
contained in the soil.

Whilst you are looking at these delicate rootlets, you
may perhaps wonder that they should be able to make
their way through the soil, but how they do this will be
apparent to you if you examine the tip of one of them
with a microscope of considerable power. Fig. 2 repre-
sents such a tip highly magnitied. It is to
be observed that the growth of the rootlet
does not take place at the very extremity,
but immediately behind it. The extreme
tip consists of harder and firmer matter than
that behind, and is in fact a sort of cap or
thimble to protect the growing part underneath. As
the rootlets grow, this little thimble is pushed on first
through the crevices of the soil, and, as you may sup-
pose, is soon worn away on the outside, but it is as
rapidly renewed by the rootlet itself on the inside.

Another difference between the root and the part
above ground you will scarcely have failed to discover :
the root has no leaves, nor has it any buds.

You may describe the root of the Buttercup a& fibrous.

V'\\i. 2. — Extremity of rootlet ; a, the harder tip ; />, the growing portion be-
hind the tip.

Fig. 2.

iSf.l

& >\

!/;

.\ .

ELEMENTS OP STRUCTURAL BOTANY.

' ill

3. Let us now look at the
Stem (Fig. 3). It is upright,
pretty firm, coloured green,
and leaves spring from it at
intervals. As there is scarcely
any appearance of wood in

it, we may describe it

as

herbaceous. At several points
along the main stem branches
are given off, and you will
observe that immediately be-
low the point from which every
branch springs there is a leaf
on the stem. The angle be-
tween the leaf and the stem,
on the upper side is called the
axil of the leaf {axilla^ an
armpit), and it is a rule to
which there are scarcely any
exceptions, that branches can
only spring from the axils of
leaves.

The stem and all the
branches of our plant termi-
nate, at their upper extremi-
ties, either in flowers or in flower-buds.

4. Let as now consider the Leaves. A glance will
show you that the leaves of this plant are not all alik«.
Those at the lower end of the stem have long stalks (Fig.
4), which we shall henceforward speak of as petioles. Those
a little higher up have petioles too, but they are not

h
tl

0

f

Fig. 8.— Stem of Buttercup.

EXAMINATION OF A BUTTERCUP.

ok at the
is upright,
ed green,
■rem it at
is scarcely

wood in
be it as
I'al points

branches
you will
lately be-
ich every

is a leaf
tngle be-
'he stem,
ailed the
villa^ an

rule to
'Q\y any
jhes can
axils of

11 the

termi-

ttremi-

Fig. 4.

quite so long as the lower ones, and the highest leaves
have no petioles at all. They appear to be sitting on
the stem, and hence are said to be sessile. The lowest
leaves of all, as they seem to spring from
the root, may be described as radical,
whilst the higher ones may be called
cauline {caul is, a stem). The broad part
of a leaf is its blade. In the plant we
are now examining, the blades of the
leaves are almost divided into distinct
pieces, which are called lobes, and each of
these again is more or less deeply cut.
Both petioles and blades of our leaves are
covered with minute hairs, and so are said
to be hairy.

Hold up one of these leaves to the light, and you will
observe that the veins run through it in all directions,
forming a sort of net-work. The leaves are therefore
net-veined.

The points along the stem from which the leaves
arise are called nodes, and the portions of stem between
the nodes are called internodes.

5. Let us next examine the PlowerS. Each flower in
our plant is at the end either of the stem or of a branch
of the stem. The upper portions of the stem and its
branches, upon which the flowers are raised,
are called the peduncles of the flowers.

Take now a flower which has just opened.
Beginning at the outside, you will find five
little spreading leaves, somewhat yellowish „.

Fi^. 4.— Radical leaf of Buttercup.

Fig. 5.— Flower of Buttercup, from the back.

I

6

ELEMKNTS OP STRUCTURAL BOTANY.

I!

m,

iii

in colour. Each of these is called a sepal, and the five
together form the calyx of the flower. If you look at
a flower which is a little older, you will probably not
find any sepals. They will have fallen off, and for this
reason they are said to be deciduous. So, in like manner,
the leaves of most of our trees are deciduous, because
they fall at the approach of winter. You will find that
you can pull off the sepals one at a time, without dis-
turbing those that remain. This shows that they are
not connected together. They are theiefore said to be
free, and the calyx is described as 2^olysepalous.

Inside the circle of sepals there is another circle of
leaves, usually five in number, bright yellow in colour,
and much larger than the sepals. Each of them is
called Q,]>etal, and the five together form the COroUa of
the flower. Observe carefully that each petal is not in-
serted in front of a sepal, but in front of the space be-
tween two sepals. The petals can be removed one at a
time like the sepals. They, too, are free, and the cor-
olla is imlyitetalous. If you compare the petals with one
another, you will see that they are, as nearly as possible,
alike in size and shape. The corolla is therefore leifular.

6. We have now examined, minutely enough for our
present purpose, the calyx and corolla. Though their
divisions are not coloured green, like the ordinary leaves
of the plant, still, from their general form, you will have
no difficulty in accepting the statement that the sepals
and petals are in reality leaves. It will not be quite so
apparent that the parts of the flower which still remain
are also only modifications of the same structure. But
there is good evidence that this is the case. Let us,
however, examine these parts that remain. There is

'.

M
■ff

p]XAMINATION OF A BUTTERCUP.

I the five
.\ look at
>al>ly not
i for tliis
I manner,
because
ind that
lout dis-
they are
id to be

circle of
L colour,
them is

rolla of

not in-

>ace be-

>ne at a

he cor-

ith one

ossible,

ei/ular.

or our

their

leaves

1 have

sepals

lite so

emain

But

Bt US,

sre is

Fig. G.

first a large number of little yellow bodies, each at the
top of a little thread-like stalk. Each of
these bodies, with its stalk, is called a
stamen. The little body itself is tlu;
anthiv, and the stalk is '\t% filament Your
magnifying glass will show you that each
anther consists of two oblong sacs, united lengthwise, the
filament being a continuation of the line of union (Fig. 7).

If you look at a stamen of a flower which
has been open some time, you will find that
each anther-cell has split open along its
outer edge, and has thus allowed a fine
yellowish dust to escape from it (Fig. 8).
This dust is called pollen. A powerful
magnifier will show this pollen to consist of Fig. 7. Fig. 8.
grains having a distinct form.

As the stamens are many in number, and free from
each other, they are said to be j^olijandrons.

7. On removing the stamens there is still left
a little raised mass (Fig. 9), which, with the aid
of your needle, you will be able to separate into
a number of distinct pieces, all exactly alike, and
looking something like unripe seeds. Fig. 10
shows one of them very much magnified, and cut
through lengthwise. These little bodies, taken
separately, are called carpels. Taken together,
they form the pistil. They are hollow, and
Fig. 10. each of them contains, as the figure shows, a

Fig. 6.— Section of a flower of Buttercup,

Fig. 7.— Stamen of Buttercup.

Fig. 8.— The same, showing longitudinal opening of the anther.

Fig, 9.— Head of carpels of Buttercup.

Fig. 10.— A single carpel cut through lengthwise to show the ovule.

Fig. 9.

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8

ELEMEJ^TS OP StnuCTUftAL BOTANY.

Fig. 11.

little grain-like substance attached to the lower end of
its cavity. This substance, in its present condition, is
the ovule, and later on becomes the seed.

You will notice that the carpel ends, at the top, in a
little bent point, and that the convex edge is more or
less rough and moist, so that in flowers
whose anthers have burst open, a quantity
of pollen will be found sticking there.
This rough upper part of the carpel is
called the stigma. Fig. 1 1 shows a stigma
greatly magnified. In many plants the
stigma is raised on a stalk above the ovary. Such a
stalk is called a st]/le. In the Buttercup the style is so
short as to be almost suppressed. When the style is
entirely absent, the stigma is said to be sessile. The
hollow part of the carpel is the ovary.

In our plant the pistil is not connected in any way
with the calyx, and is consequently said to be free or
superior^ and, as the carpels are not united together,
the pistil is said to be apocarpous.

8. Remove now all the carpels, and there
remains nothing but the swollen top of the
peduncle. This swollen top is the receptacle of
the flower. To it, in the case of the Butter-
cup, all four parts, calyx, corolla, stamens,
and pistil, are attached. When a flower has
all four of these parts it is said to be complete.

9. Let us now return to our statement that
Fig. 12. the structure of stamens and pistils is only a

modification of leaf-structure generally. The stamen

Fig. 11.— Stigma of Buttercup with adhering pollen-grains ; highly magnified.
Fig. 12. — Diagram to show leaf-structure of a stamen.

i

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J

KXAMINATION OF A liUTTERCUP.

9

looks less like a leaf than any other part of the Hower.
Fig. 12 will, however, serve to show us the plan upon
which the botanist considers a stamen to be formed. The
anth6r corresponds to the leaf-blade, and the filament to
the petiole. The two cells of the anther correspond to
the two halves of the leaf, and the cells burst open
along what answers to the margin of the leaf.

10. In the case of apocarpous pistils, as that of the
Buttercup, the botanist considers each carpel to be
formed by a leaf-blade doubled lengthwise until the edges
meet and unite, thus forming the ovary. Fig. 13 will
make this clear.

11. There are many facts which support this theory
as to the nature of the different parts of the flower.
Suffice it to mention here, that in the white Water-Lily,

in which there are several circles of sepals and
petals, it is difficult to say where the sepals end
and the petals begin, on account of the gradual
change from one set to the other. And not only
Fig. 13. is there a gradual transition from sepals to
petals, but there is likewise a similar transition from
petals to stamens, some parts occurring which are neither
altogether petals, nor altogether stamens, but a mixture
of both, being imperfect petals with imperfect anthers at
their summits. We can thus trace ordinary leaf-forms,
by gradual changes, to stamens.

We shall then distinguish the leaves of plants as
■foliage-leaves and floiver-leaves^ giving the latter name
exclusively to the parts which make up the flower, and
the former to the ordinary leaves which grow upon the
stem and its branches.

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Fig. 13.— Diagram to illustrate the Icaf-stiuuture of the carpel.

10

ELEMENTS OF STUUCTUUAL UOTANY.

si-

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Fig. 14.

1m-;-. 15.

12. You are now to try and procure a T3uttercup whose
Howers, or some of them, have withered away, leaving

only the head of carpels on tlie
receptacle. The carpels will have
swollen considerably, and will now
show themselves much moie dis-
tinctly than in the flower which
we have ])een examining. This is owing to the growth
of the ovules, which have now become seeds. Kemove
one of the carpels, and carefully cut it through the
middle lengthwise. You will find that the seed almost
entirely tills the cavity. (P'igs. l-i and 15.)

This seed consists mainly of a hard substance
called a//junif>n, enclosed in a thin covering. At
the lower end of the albumen is situated a very
small body, which is the onhyro. It is this
which developes into a new plant when the seed ^'ff- is*
germinates.

13. We have .seen, then, that our plant consists of
several parts :

(1). Th© Root. This penetrates the soil, avoiding
the light. It is nearly white, is made up of fibres, from
which numbers of much finer fibres are given off, and is
entirely destitute of buds and leaves.

(2). The Stem. This grows upward, is coloured,
bears foiiage-leaves at intervals, gives off branches from
the axils of these, and bears flowers at its upper end.

(3). The Leaves. These are of two sorts : Foliaqe-
leavcs and Flower-leaves. The former are sub-divided

Fijr. 14.— llipe carpel of Buttercup.

Fig. 1.").- Section of same.

Fig. 16.— Section of seed showing the small embryo. All much magnified.

■4

•n

rUN'CTIONS OK THK uliOANS UF THK FLOWKU.

11

into radical and caulwe, and the latter make up the
tlower, the. parts of which are four in number, viz.:

calyx, corolla, stamens, and pistil.

It is of great inipoi'tance that you should make your-
selves thoroughly familiar with the different parts of the
plant, as just descrihcd, before going furtlKjr, and to
that end it will bo desirable for you to review the pre-
sent chapter carefully, giving special attention to those
parts which were not perfectly plain to you on your tirst
reading.

In the next chapter, we shall give a very brief account
of the uaes of the ditferent parts of the flower. If found
too diliicult, the study of it may be deferred until further
progress has been made in plant-examination.

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CHAPTER II.

FUNCTIONS OF TJIE ORGANS OF THE FLOWER.

)ured,
from
d.

liaqe-
vided

14. The chief use of the calyx and corolla, ov floral
envelopes^ as they are collectively called, is to protect the
other 2)arts of the fltnccr. They enclose the stamens and
pistil in the bud, and they usually wither away and dis-
appear shortly after the anthers have shed their pollen,
that is, as we shall presently see, as soon as their services
as protectors are no longer required.

15. The corollas of flowers are usually bright-coloured,
and frequently sweet-scented. There is little doubt that
these qualities serve to attract insects, which, in search

12

ELKMKNTS OF HTHUCrPUKAL HOTANY.

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of honey, visit blossom after blossom, and, bringing their
hairy limbs and bodies into contact with the open cells
of the anthers, detach and carry away quantities of
pollen, some of whicli is sure to be rubbed ort' upon the
stigmas of other flowers of the same kind, subsequently
visited.

16. The essential part of the stamen is the anther,
and the purpose of this organ is to produce the pollen,
which, as you have already learned, consists of minute
(jrairis, having a delinite structure. These little grains
are usually alike in plants of the same kind. They are
furnished with two coats, tlie inner one extremely thin,
and the outer one much thictker by comparison. Tlie
interior of the pollen-<^rain is tilled with liquid matter.
When a pollen-grain falls upon the moist stigma it begins
to groio in a curious manner (Fig. 17). The inner coat
pushes its way throu<j[h the outer one, at some
weak point in the latter, thus forming the beginning
of a slender tube. This slowly penetrates the stigma,
and then extends itself downwartls through i\m
Fiff. 17. sty^Gj until it comes to the cavity of the ovary.
The liquid contents of the pollen-grain are carried down
through this tube, which remains closed at its lower end,
and the body of the grain on the stigma withers away.

The ovary contains an ovule, which is attached by on(3
end to the wall of the ovary. The ovule con-
sists of a kernel, called the nucleus^ which is
usually surrounded by two coats, through both
of which there is a minute opening to the nucleus.
This ojiening is called the micropyle, and is

Fig IS.

Fij:. 17.— Pollen-grain developing a tube.

Fig. 18 —Section of an ovule, showing central nucleus coats, and micropyle.

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always to \m foiiiid iil tlial and of tlu! oviiln wliicili is not
alta(;li(!(Uo the oviiry. (Fif,'. 18,///.)

About tlio timo the antliers dischargi! thiur poUun, a
little cavity, called the enihrijo-t<a<\ appears inside the
nucleus, near the micropyle. The pollen-tube, with its
liquid contents, enters the ovary, passes through the
micropyle, penetrates the nucleus, and attaches itself to
the outer surface of the euibryo-sac. Presently the tube
becomes empty, and then withers away, and, in the mean-
whilo, a minute body, which in time dovelopes into the
embryo, makes its appearance in the embryo-sac, and from
that time the ovule may properly bo called a seed.

17. In order that ovules may become seeds, it is always
essential that they should be fertilized in the manner just
described. If we prevent pollen from reaching the stigma
— by destroying the stamens, for instance — the ovules
simply shrivel up and come to nothing.

Now it is the business of the flower to produce seed,
and we have seen that the production of seed depends
mainly ui)on the stamens and the pistil. These organs
may consecjuently be called the essfmtial onians of the
flower. As the calyx and corolla do not play any direci
part in the production of seed, but only protect the
essential organs, and perhaps attract insects, we can under-
stand how it is that they, as a rule, disappear early.
Their work is done when fertilization has been accom-
plished.

Having noticed thus briefly the part played by each
set of floral organs, we shall now proceed to the exami-
nation of two other plants, with a view to comparing
their structure with that of the Buttercup.

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KLKMI.MS OK MTKlJCrLUAI. HOTANY.

CHAPTKK III.

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KXAMINATION oh' HK1»ATI(?A AND MAUHH-MAHIGOLD — IIRSRM-
UliANCKS UhTWF'lK.V TMIMIl I'l.OWMUS ANI> THAT oK

HUTTMUC.'Ul'.

18. Hepatica. You may prociiro specimens of the
Hepiitica uIiiKtst aiiywliero ill rich dry woods, but you
will not find it in ilower except in spring and early
summer. It is very desiral)le that you should have the

Fi-'. 19.

plant itself, but for those who are unable to obtain
specimens, the annexed engravings may serve as a
substitute.

Fig. 19. — Anemone Hepatica.

IIKI'ATICA.

15

C8KM-

f the

you

(iiirly

J the

btain
as a

licj^iiiniiig, th(!ti, at thn root of oiir ni^w pluut, you .s<oo
that it does not (lilleriu any great iiicii^urc from tliut of
tho ]>uttor(;u[). It may, in liko inaniicr, l.. (Iosci-IIkhI hh
jihroun.

The next point is tho stom. Yon will ronicniber tliat
in tho Ihittcrcni) tlio stem is thnt i)art of tho ])]ant
from which tlio leaves spring. Kxaniining onr llcpa-
lica in tho light of this fac-t, and following tho jiotiolcs
of tho leaves down to tiieir insertion, wo find that they
and the roots appear to spring from tho same place — •
that tliero is, aj)parently, 710 stem. Plants of this kind
aro theniforc; called aranfcHfrnt, that is, Ktenilrss, but it
must bo carefully borne in mind that the absence of the
stem is only apparent. In reality there is a stem, but it
is so short as to Ijo almost indistinguishable.

Tho leaves of tho llepatica aro, of course, all radical.
They will also bo found to be iiet-vcined.

19. Tho Flowers of tho llepatica aro all upon long
peduncles, which, like tho loaves, appear to spring from
the root. Naked peduncles of this kind, rising from tho
ground or near it, aro called ^cajtcs. Tho flower-stalks of
the Tulip and the Dandelion furnish other familiar
cxami)les.

Let us now proceed to examine tho flower itself. Just
beneath the coloured leaves there are three leaflets, which
you will be almost certain to regard, at first sij^ht, as sepals,
forming a calyx. It will not be dillicult, however, to con-
vince you that this conclusion would be incorrect. If,
with tho aid of your neiuUe, you turn l)ack these leaflets,
you will readily discover, between them and the coloured
portion of the flower, a verij ^hod hit of stem (Fig. 20),
the upper end of which is the reeeptacle. As these

1 ,

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16

ELEMENTS OF STRUCTURAL BOTANY.

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leaflets, then, are on tlie peduncle, below the r*^ceptacle,
they cannot be sepals. They arc simply small foliage
leaves, to which, as they are found beside the flower, the
name bracts is given. Our flower, then, is
apparently without a calyx, and in this re-
spect is difl'erent from the Buttercu}). The
whole four parts of the flower not being
present, it is said to be incomplete.

jii 20. It may be explained here that there is an under-

'|l standing among botanists, that if the calyx and corolla are

,ii not both present it is always the corolla which is wanting,

and so it happens that the coloured part of the flower

under consideration, though resembling a corolla, must be

regarded as a calyx, and the flower itself, therefore, as

% apetalous.

21. Remove now these coloured sepals, and what is left
of the flower very much resembles what was left of our
Buttercup, after the removal of the calyx and corolla. The
stamens are very numei-ous, and are inserted on the
receptacle. The carpels are also numer-
ous (Fig. 21), are inserted on tlie recep-
tacle, and are free from each other iJi
(apocarpous). And if you examine one ')
of the carpels (Fig. 22) you will And Fig. 2L
that it contains a single ovule. The flower, in short, so
much resembles that of the Buttercup that you will be
prepared to learn that the two belong to the same Order
or Family of plants, and you will i\o well to observe and
remember such resemblances as liave just been brought to
your notice, when you s(!t out to examine jdants for your

Fig. 20. — Flower of Hcpatica, with bracts below.
Fig. 2L— Carpels of llej)atica. Fig. 22.— Single carpel, enlarged.

Fig. 22.

MARSH-MAKlOOLn.

r

solves, bocuuse it is only in this way, and by slow steps,
tluit you can acquire a satisfactory knowledge of the
reasons which lie at the foundation of the classification of
plants.

22. Marsh-Marigold. This plant grows in wet
places almost everywhere, and is in flower in early summer.

Note the entire absence of h;urs on the surface of the
plant. It is therefore glahrnus.

The root, like that of the Buttercup and of the Hc-
patica, is Jihrons.

The stem is hollow and furrowed.

The foliage-leaves are of two kinds, as in the Butter-
cup. The raiUcal leaves spring ivom the base of the
stem, whilst the hi,i.',iu;r ones are cauline. The leaves
are not lobed, as in the other two plants, but are in-
dented on the edge. They are also net-veined.

23. Coming to the flower (Fig. 23)
we find a circle, or whorl, of bright
yellow leaves, looking a good deal
like the petals of the Buttercup, but
you will look in vain for the corres-
ponding sepals. In this case there
is no whorl of bracts to mislead you. \
Are we to say, then, that there is no
calyx? If we adhere to the under-
standing mentioned when describing
the liepatica, we must suppose the
corolla to be wanting, and then the
bright yellow leaves of our plant will pig.. 03.
be the sepaU, and will together constitute the calyx. As
to the number of the sepals, y,,i -will find, as in the

Fig. 23. — Flower and loaf of Marsh-Marl;,'old.

18

ELEMENTS OF STRUCTURAL J{(yrANY.

Ill

I:

Hepatica, some variation. AYliilst tlie normal number is
live, some llowers will l)o fouml to have as many as nine.
24. The stamens are next to l)e examined, but you
should first satisfy yourselves as to whether the calyx is
polysepalous or otherwise, and whether it is free from the
other floral leaves or not. If your examination be properly
made, it will show you that the calyx is free and poly-
sepalous.

The stamens are very much like those of the Buttercup
and Hepatica. They are numerous, they have both anthers
and filaments, and they shed their pollen tlnou^di slits on
the outer edges of the anthers. They are all separate from
each other (polyandrous), and are all inserted on the
receptacle. On this latter account they are saiil to hypogy-
nuus (below the jDistil).

25. Remove the stamens, and you hav(^ left, as before,
a head of carpels (Fig. 24). Examine one : there is the
lower broad ])art, which you recognize as the ovary,
the very short style, and the sticky stigma. To all
appearance the carpels are pretty much the same as
those of the two plants already examined. It will
not do, however, to trust altogether to appearances
Fig. 24. in this case. Cut open a carpel and you find that,
instead of a single ovule at the bottom of the ovary, th(!re
are several ovules in a row along that edge of the ovaiy
which is turned towards the centre of the flower.
The ovary is, in fact, a pod, and, when the seeds
ripen, splits open along its inner edge. If you can (^g
find one which has split in this way, you can hardly
fail to be struck with the resemblanrc^ which it
bears to a common leaf. (Fig. 25.)

Fig. 24. — Head of carpels of Marsli-Marigold.

Fig. 2r).— Siti^'le carpel, opened to show the two rows of seeds.

Fig. 25.

PLOWER-SCH KDULES.

19

On the whole tlie reseiiil)lani'e Lotweon the structure
of the Mai'sli-Marigold and that of the Hepatica and
Bnttorcuj) is sunicicutly great to justify us in placing it in
the same family with thorn.

26. Having now made yourselves familiar with the
diflerunt parts of these three plants, you are to write out
a tabular descrii»tion of them according to the following
form ; and, in like manner, whenever you examine a new
plant, do not consider your work done until you have
written out such a description of it.

BUTTERCUP.

ORGAN OU ]>AUT
OP FLOWKR.

NO.

COHESION.

APHESION.

RK MARKS.

Calyx.
Sepals.

5

L'olysei)alous. ' Inferior.

Corolla.
Petals.

Polypetalous.

ilypogynors

Each Petal
^vitU a pit at
llie base inside

Stamens.
Filaments.
Anthers.

X

rolyandrons.

Hypogynoiis.
Superior.

Pistil.
Carpels.
Ovary.

cc

Apocarpous.

Carpels
1 -seeded.

In the form the term colieslon relates to the union of
like parts ; for example, of sepals with sepals, or petals
with petals ; while the term adhesion relates to the union
of unlike parts; for example, of stamens with corolla, or
ovary with calyx. Neither cohesion nor adhesion takes
place in any of the three flowers we have examined, and
accordingly, under these headings in our schedule we
write down the terms polysepalous, polypetalous, &c., to
indicate this fact.

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KI-KMKNTS OP STKUCTUUAL HOTANY.
HEPATIC A.

OlUJAN.

Calyx.
Sepals.

Corolla.
Petals.

Stamens,

Filaments.

Anthers.

NO.

7-12

COHESION. .KDMKSION.

liKMAKKS.

Polynepalous.

Inferior.

Coloured like a
corolla.

Wantin

X

Polyandroiis.

Hyi)of,'ynniis.

Pistil.
Carpi'h.
Ovary.

Apocarpous.

Superior.

Carpels

1 -seeded.

MARSH-MARIGOLD,

OUGAN.

NO.

COHESION.

Polysepalous.

ADHKSION,

KKMAUKS.

Calyx.
Sepals.

5-9

Inferior.

Coloured like a
coro'la.

Corolla.
Petals.

Polyandrous.

Hypogynous.

Wanting.

Stamens.

Filaments.
Anthers.

00

Pistil.
Carpels.
Ovary.

00

Apocarpous.

Superior.

Carpels contain
several seeds.

CIlAliACTKRS OF RANUNCULACE.K.

21

KKS.

d like a

1 -seeded.

.lAllKS.

•o.A like a
'la.

ing.

Is contain
ral seeds.

The symbol oo mecans " indefinite," or " numerous," and
may be used when the parts of any organ exceed ten in
number.

Under the head " Remarks " you may describe any-
thing worthy of notice, for which provision is not made
elsewhere in the schedule.

If you use the exercise-book which has been prepared
to accompany the text-book, you will find also space for
drawing such parts as are not easy to describe in words.

27. The three plants upon which we have been en-
gaged up to this point are representatives or tfji^es of a
very large group, called by botanists Rauunculacete, that
is, Ranunculacjious 2>lants. All the members of it, whilst
they may differ in certain minor characteristics, agree in
all the more important respects. The minor differences,
such as we have observed in our examination of the
specimens, lead to the sub-division of the group into
several smaller groups, but any plant exhibiting the
peculiarities common to all three may be regarded as
typical of the Order, which is the name given to the
group as a wliole. These common peculiarities may be
summed up with sufficient accuracy for our present pur-
pose, as follows :

1. The circh'ti of Jlower-leaves, that is to sat/, the sepals,

petals, stamens, and car])els, are eutirely distinct,
and uncojmeried with each other.

2. The several members of each circle are also entirehj

separate fnmi each other.

3. It ))iai/ he atlded that the stamens are almost invari-

ably niunerous, and that the plants are acrid lo
the taste

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22 ELKMENTS Of WTKUCTUHAI. IJoTANY.

CHAPTER IV.

EXAMINATION OF OTHKK COMMON' PLANTS WITH IIYPOGY-
NOUS STAMENS — SHEPIIKKD's PUllSE — ROUND-
LEAVED iMALLOW.

28. We shall now proceed to examine some plants,
the flowers of which exhibit, in their structure, impor-
tant variations from the Buttercup, Hopatica, and
Marsh-Marigold.

Shepherd's Purse. This plant (Fi<,^ 26) is one of
the commonest of weeds. As in the Buttercup, the
foliage-leaves are of two kinds, radical and cauline, the
former being in a cluster around the base of the stem.
The cauline leaves are all sessile, and each of them, at
its base, projects backward on each side of the stem, so
that the leaf somewhat resembles the head cf an arrow.
Such leaves are, in fact, said to be sagittate, or arrow-
shaped. The flowers grow in a cluster at the top of the
stem, and, as the season advances, the peduncle gradu-
ally elongates, until, at the close of the summer, it forms
perhaps half of the entire length of the stem. You will
observe in this plant, that each separate flower is raised
on a little stalk of its own. Each of these little stalks
is 'A jtfdirel, and when pedicels are present,
the term peduncle is applied to the por-
tion of stem which supports the whole
cluster.

29. The flower.s ( Fig. 27) are rather small,
and .so will require more than ordinary care
in their examination. Tlie calyx is polyscpalous, and of

Fig. 27.

Fig. 27. — Flower of Shepherd's Purse, enlarged.

SHEPHERDS PURSE.

23

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Fijf. 26.— Shepherd's Pur^e.

24

ELEMENTS OF STRUCTURAL JJOTANY.

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four sepals. The corolla is polypctalous, and of four
petals. The stamens (Fig. 28) are six in number, and if
you examine them attentively, you will see that
two of them are shorter than the other four The
stamens are consequently said to be tetradynamous.
But if there had been only four stamens, in two
sets of two each, they would have been called pig. 28.
didijnamous. The stamens are inserted on the receptacle
(hypogynous). The pistil is separate from the other parts
of the flower (superior).

30. T(j examine the ovary, it will be better to select a
ripening pistil from the lower part of the peduncle.
It is a flat body, shaped something like a heart (Fig. 29),
and having the short style in the notch. A ridge divides
it lengthwise on each side. Carefully cut or pull away

the lobes, and this ridge will rsmain, pre-
senting now the appearance of a narrow
loop, with a very thin membranous parti-
tion stretched across it. Around the edge,
on both sides of the partition, seeds are
suspended from slender stalks (Fig. 30).

Fig. 29. Fig. 30. There are, then, two carpels united together^

and the pistil is, therefore, syncarpous.

31. Shepherd's Purse is a type of a large and important
Order, the Gruciferce, or Cress Family. Other common
examples, which should be studied and compared with
Shepherd's Purse, are the garden Stock (single flowers are
best for examination), Water-Cress, the yellow Mustard

Fig. 28. — The same, with calyx and corolla removed.

Fig. 29. —Ripened pistil of Shepherd's Purse.

Fig. 30. —The same, with one side removed to show the seeds.

liii,,
it|;i;

shepherd's PURdE.

of tlie wheat-fields, Radish, Sweet Alyssum of the gardens,
(^'c. All these plants, while dillering in unimportant par-
ticulars, such as the colour and size of the petals and the
shape of the pod, agree in presenting the following char-
acters :

1. The sepals and petals are each four in number.

2. Hie stamens are tetradynamous (and hypogynous).

3. The fruit is syncarixnis^ and is ^-celled by reason of

a thin p)artition stretched between the carpels.

Jf.. It may be added that the plants are generally pungent
to the tade^ and the ftoivers are almost invariably
in terminal clusters, like that of Shepherd's Purse.

m

.if;.

■'M
'' 'I

SHEPHERD'S PURSE.

OltUAN.

No.

4

4
C

2

CoHESIOK.

Adhesion.

Remarks.

Calyx.
Sepals.

PolysepalouH.

Inferior.

Corolla.
Petals.

Stamens.
Filaments.
Anthers.

Polypetalous.

Hypogynous

!

Tetradyna-
mous.

Hypogynous.

Two sepals
with a pair of
long stamens
opposite each ;
the other two
with one short
stamen opp.
each.

Pistil.
Carpels.
Ovary.

Syncarpous.

Superior.

The two cells
of the ovary
separated by a
thin partition.

■-J "1,

u

26

BLEMBNTS OP BTRUCTUItAL HOTANY.

'<'''^ Hi.

11. Mil'! !

32. Mallow. The rouml-leaved Mallow (Fig. 31)

grows along every
wayside, and ia
a very common
^ "W^ ^ .. weed in cultivat-

ed grounds. Pro-
cure, if possible,
a plant which has
ripened its seeds,
as well as one in
flower. The root
Fijf. 33. of this plant is of
of a different kind
from those of the
thiee plants first
examined. It
consists of a stout
tapering part, ds-
scending deep in-

Fig. 84.

Fig. 31.

!!■■ i

to the soil, from the surface of which fibres are given of!
irregularly. A stout root of this kind is called a tap-root.
The carrot is another example.

33. The leaves are long-petioled, net-veined, and in-
dented on the edges. On each side of the petiole, at its
junction with the stem, you will observe a little leaf-like
attachment, to which the name stipule is given. The
presence or absence of stipules is a point of some import-
ance in plant-structure, and you will do well to notice it
in your examinations. You have now made yourselves

Fig. 81.— Round-leaved Mallow. Fig. 32. --Section of the flower.

Fig. S3.— Flower with calyx and corolla removed.
Fig. 34. — A ripened pistil with the persistent calyx.

■ (''',, '-■

1

ROUND-I, RAVED MALLOW.

27

acquainted witli all the parts that any loaf has, viz., blade,
petiole^ and stipule>i.

34. Corainj^ to the flower, observe first that the parts
of the calyx are not entirely separate, as in the flowers
you have already examined. For about half their length
they are united together so as to form a cup. The upper
half of each sepal, however, is perfectly distinct, ami
forms a tooth of the calyx ; and the fact that there are
five of these teeth shows us unmistakably that the calyx
is made up of five sepals. We therefore speak of it as a
fjaiiiosepalous calyx, to indicate that the parts of it are
coherent.

As the calyx does not fall away when the other parts
of the flower disappear, it is said to be persistent. Fig.
31, «, shows a persistent calyx.

35. At the base of the calyx there are three minute
leaf -like teeth, looking almost like an outer calyx. A
circle of bracts of this kind is called an involucre. The
three bracts under the flower of the Hepatica also consti-
tute an involucre. As the bracts in the Mallow grow on
the calyx, some botanists speak of them as an epicalyx.

The corolla consists of five petals, separate from each
other, but united with the stamens at their base.

36. The stamens are numerous, and as their filaments
are united to form a tube, they are said to be monadelphous.
This tube springs from the receptacle^ and the stamens are
therefore hypocfynous. Fig. 32 will help you to an under-
standing of the relation between the petals and stamens.

Having removed the petals, split the tube of the stamens
with the point of your needle. A little care will then
enable you to remove the stamens without injuring the

'i

h

mA.

\ i

^il

m

28

Kf.KMENTS OF HTHUCTUnAL BOTANY.

M'', 'ii! ■!

jtistil. Tho liittor ov<*n\\ will thou l)o found to consist of
n ring of rolicicut ciirpels, i\ rather atout stylo, an<l nuni-
orous long stigmas (Fig. 3.'i). If you take the trouble to
count tho ctiipola and tho stigmas, you will find tho num-
bers to correspond. As the seeds ripen, the carpels separate
from each other (Fig. 34).

MALLOW.

Organ.

No.

00
X

Cohesion.

Gnmosepa-
lous.

Adkhion.

Hemakks.

Calyx.
Sepals.

Inferior.

Hypogynous.
Hypogynons.

Superior.

Three bracts
growing ou the
calyx.

Corolla.
Petals.

Polypetalous.

Monadelphous

One-celled.
Syncarpous.

Stamens.
Filaments.
Anthers.

Pistil.
Carpels.
Ovary.

Carpels as
many as the
stigmas.

37. Compare now the structure of tho Hollyhock (single
flowers should be selected) with that of the Mallow, and
write out a description. Musk-Mallow and Abutilon (a
common green-house plant) may also he examined with
advantage.

38. The Order (Malvacece) of which Mallow is a type
is very distinctly marked by the following characteristics :

1. The sP2)als are always placed edge to edge (valvafe)

in the hud, while the petals overlap and are rolled
together (convolute).

2. The stamens are numerous and monadelphovs, and

their anthers are 1-celled. Although united at the

Ex
of
One

the

the

strik

the

you

each

like

ufth

Fig.
Fig.
Fiff.

1,1' r
i i

GARDEN PEA.

29

base with the dawn o/fh' jfcfafs, thny are neverthe-
letfs imertf^d on the rerrpiac/e {InjpoyijnouH).

3, The carpeh are almost ah^'ays united in a ringy which
break's up at maturity.

Jf. It may be added that the leaves are furnished with
stipides^ and the juice of the plants is mucilayinous.

;;tl

\alvate)
rolled

its, and
at the

n

.•.»
■*

CHAPTER V.

EXAMINATION OP COMMON PLANTS WITH PERIGYNOUS
STAMENS — GARDEN PEA — GREAT WILLOW-HERB.

39. Garden Pea. In the fl(3wer of this phuit, the
calyx is constructed on the same plan as in the IVEullow.
Tl\ere are five sepals, coherent below, and spreading out
into distinct teeth above (Fig. 35). Tlie calyx is there-
fore gamosepalous.
Examine next the form
of the corolla (Fig. 36).
One difference between
the corolla and those of
the previous plants will
strike you at once. In
the flowers of the latter
you will remember that
each petal was precisely ^*^- 3^'

like its fellows in size and shape, and we therefore spoke
of tlie corolla as regidar. In the Pea, on the other hand,

Fig. 38

Fig. 30.

Fig. 35.— Flower of Garden Pea. Fig. 3G.— Front view of the same.

Fig. 37.— Diadelphous stamens of the same.

Fig. 38.— The pistil. Fig. 39.— The same cut through lengthwise.

30

ELEMENTS OF STRUCTURAL BOTANY.

;ir V

!'■ i

h ;

1"" i

i i

m

,1

one of the petals is large, broad, and open, whilst two
smaller ones, in the front of the flower, are united into a
kind of hood. We shall speak of this corolla, then, and
all others in which the petals are unlike each other in
size or shape, as irregidar.

As the Pea blossom bears some resemblance to a butter-
fly, it is said to be papilionaceous.

40. Remove now the calyx-teeth and the petals, being
very careful not to injure the stamens and the pistil, en-
veloped by those two which form the hood. Count the
stamens, and notice their form (Fig. 37). You will find
ten, one by itself, and the other nine with the lower halves
of their filaments joined together, or coherent. When
stamens occur in this way, in two distinct groups, they
are said to be diadelphous ; if in three groups, they would
be triadelplious ; if in several groups, polyadelphous. In
the Mallow, you will remember, they are united into one
group, and therefore we described them as monadelphous.

You will, perhaps, be a little puzzled in trying to
determine to what part of the flower the stamens are
attached. If you look closely, however, you will see
that the attachment, or insertion, is not quite the same
as in the Buttercup and the other flowers examined.
In the present instance they are inserted upon the lower
part of the calyx, and so they are described as perigijnous,
a term meaning " around the pistil."

41. But the pistil (Figs. 38, 39) is not attached to the
calyx. It is /ree, or supsrior. If you cut the ovary
across, you will observe there is but one cell, and if you
examine the stigma, you will find that it shows no sign
of division. You may therefore be certain that the pistil
is a single carpel.

(lARDEX PEA.

31

the
Dvary
you
sign
pistil

You are now prepared to fill up the schedule descrip-
tive of this flower.

GABDEN PEA.

ORGAN.

NO.

COHESION.

ADHESION.

RKMARKS.

Calyx.
Sepals.

Corolla.
Petals.

5

Gamosepalous

Papilionace-
ous. Irregular.

Inferior.

The two front
petals united.

5
10

Perigynous.

Stamens.
Filaments.
Anthers.

Diadelphous.

Perigynous.
Superior.

L _.

Pistil.
Carpels.
Ovary.

1

Apocarpous.

42. The beginner will be very likely to think, from its
appearance, that the largest of the petals is made up of
two coherent ones, hut the following considerations show
clearly that this is not the case. In the Buttercup, and
other flowers in which the number of sepals and petals is
the same, the petals do not stand before the sepals, but
before the spaces between them. In the Pea-blossom this
rule holds good if the large petal is considered as one,
but not otherwise. Again, the veining of this petal is
similar to that of a common leaf, tliere being a central rib
from which the veins spring on each side ; and lastly,
there are some flowers of the Pea kind — Cassia, for
example — in which this particular pet^l is of nearly the
same size and shape as the other four.

43. The Pea is a type of a highly important group of
plants — the Order Legiiminosoi. To it belong many plants

ill ill

32

ELEMENTS OP STRUCTURAL BOTANY.

11;:

I
11

iiflfering very widely in external appearance — the Locust-
Tree and the Clover, for example — but exhibiting in the
structure of their flowers so marked a similarity that their
relationship is beyond question. The characters by which
the Order is distinguished are chiefly these :

i. llie corolla is more or less papilionaceous, and is
inserted on the base of the calyx (perigynous).

2. The stamens^ almost invariably ten in number^ are

aho 2)erigynous^ and nearly always diadelphous.

3. The pistil is nearly ahoays a legume, that is to say,

it is a single carpel which splits into two pieces at
maturity, like the pod of the Pea or Bean.

Jf, The leaves have stipules, and are nearly always com-
pound, that is, of several distinct leaflets.

Plants which may be compared with the Pea are Red
Clover, White Clover, Sweet Clover, Medick, Locust-Tree,
Bean, Vetch, Lupine, Sweet Pea, &c.

44. Great Willow-herb. This plant is extremely
common in low grounds and newly-cleared land, and you
may easily recognize it by its tall stem
and bright purple flowers. \

Observe the position of the flowers.
In the three plants first examined we
found the flowers at the end of the
stem. In the Willow-herb, as in the
Mallow, they spring from the sides
of the stem, and immediately below
the point from which each flower Fig. 40.

springs you will find a small leaf or bract (Fig. 40). Flowers

Fig. 40.— Flower of Great Willow-herb.

„; tj;

GREAT WILLOW-HERB.

33

ocust-
Lii the
b their
which

and is

■)■

>er, are

lOUS.

to say,
ieces at

ys com-

are Ked
st-Tree,

iremely
and you

Flowers

which arise from the axils of bracts arc said to be axillary,
whilst those which are at the ends of stems are called
terminal, und you may remember that flowers can only bo
produced in the axils of leaves and at the ends of stems
and branches.

45. Coming to the flower itself, direct your attention,
first of all, to the position of the ovary. You will find it
apparently under the flower, in the form of a tube tinged
with purple. It is not in reality under the flower, because
its purplish covering is the calyx, or, more accurately, the
calyx-tube, which adheres to the whole surface of the
ovary, and expands above inco four long teeth. The ovary,
therefore, is inferior, and the calyx, of course, superior, in
this flower. As the sepals unite below to form the tube
the calyx is gamosepalous.

The corolla consists of four petals, free from each other,
and is consequently polypetalous. It is also regular, the

petals being alike in size and

V shape. Epch petal is narrowed

Pig_ 42. I M M,^^ '* ^^ ^^® base into what is called

the clatv of the petal, the broad
part, as in the ordinary foliage-
leaf, being the blade. The
stamens are eight in number
(octandrous), four short and
four long, and are attached to
the calyx (perigynous).
46. The pistil has its three
Fig. ii. parts — ovary, style,and stigma

— very distinctly marked. The stigma consists of four long
lobes, which curl outwards after the flower opens. The

m

■A

li.'

Fig. 41.— Ripened pistil of Willow-herb. Fig. 42.— Cross section of the same.

34

111

■T

ELEMENTS OP STRUCTURAL BOTANY.

style is long and slender. The examination of the ovary
requires much care ; you will get the best idea of its
structure by taking one which has just burst open and
begun to discharge its seeds (Fig. 41). The outside will
then be seen to consist of four pieces (valves)^ whilst the
centre is occupied by a slender four-winged column (Fig.
42), in the grooves of which the seeds are compactly
arranged. The pistil thus consists of four carpels united
together, and is therefore syncarpous. Every seed is
furnished with a tuft of silky hairs, which greatly facili-
tates its transportation by the wind.

47. The Willow-herb furnishes an excellent example
of what is called symmetry. We have seen that the calyx
and corolla are each made up of four parts ; the stamens
are in two sets of four each ; the stigma is four-lobed, and
the ovary has four seed-cells. A flower is symmetrical
when each set of floral leaves contains either the same
number of parts or a multiple of the same number.

Observe that the leaves of our plant are net-veined.

The schedule will be filled up as follows :

GREAT WILLOW-HERB.

ORGAN.

NO.

COHESION.

ADHESION.

ItEMAltKS.

Calyx.

Sepals.

■1

Garuosepalous

Superior.
Perigynous.

Perigyuoua.

Inferior.

Corolla.
Petals.

4

Polypetalous.

Pour short and'
four long, j

Seeds provided
witxi tufts of
hair.

Stameus.
Filatnents.
Anthers.

8
4

Octaudrous.

Syucarpoiis.

Pistil.
Carpels.
Ovary.

ROSACEOUS PLANTS.

35

Flowers to compare with Great Willow-herb are Fuchsia
and Evening Primrose. Either of these will serve as the
type if Willow-herb cannot be obtained.

CHAPTER VI.

EXAMINATION OF COMMON ROSACEOUS PLANTS — SWEET BRIER
— STRAWBERRY — CHERRY — CRAB-APPLE RASPBERRY.

48. Sweet Brier. As in the flowers examined in

the last chapter,
the sepal* of Sweet
Brier are not en-
tirely distinct;
their lower halves
cohere to form a
tube, and the calyx
is therefore gamo-
sepalous.

The corolla con-
sists of five sepa-
rate petals of the
same size and
shape, and is there-
fore both regular
and polypetalous.
F»er. 43- The stamens are

very numerous, and separate from each other. As in the
Pea and the Willow-herb, so in this flower they will be

Fig. 43.— Flower and leaves of Sweet Brier.

1'

i 1

m

■ "i

36

KLEMKNTS OF STUUCTUIIAL BOTANY.

m.

Ml

'"ill

!i; i

'' I

■3 •

iiij

l;i lii,'

found to be .ittiicheJ to tho calyx. They are, therefore,
perigi/noa-i.

49. To understand the construction of the pistil, you
must make a vertical section through the roundish green
mass which you will find on the under side of the flower.

You will til en have presented to
you some sue); appearance as that
in Fig. 44. The green mass, you
will observe, is hollow. Its outei
covering is simply the continua-
tion of the calyx-tube. The lin-
ing of this calyx-tube is the recep-
^^^' **• tacle of the Jiower ; to it are at-

tached the separate carpels which together constitute the
pistil (Fig. 45), just as the carpels of the Buttercup are
attached to the raised receptacle of that flower.

We must remind you again that whenever the ovary is
enclosed in the calyx-tube, and the calyx appears to spring
from the summit of the ovary, the latter is said to be
inferior, and the former superior.

In the case of Sweet Brier and similar forms,
where the pistil is strictly apocarpous, and the
other parts cohere at their base so as to form
a tube enclosing the really free carpels, the
pistil may be described as half -inferior, and
the calyx consequently as half -superior.

50. Strawberry. So far as calyx, corolla, and sta-
mens are concerned, the flower of Strawberry very
nearly resembles that of Sweet Brier. Alternating with
the five calyx-lobes, however, will be found five bractlets,

Fig. 45.

Fig. 44.— Vertical section through the pistil.

Fig. 45.— Vertical section through ripe fruit of Sweet Brier.

ROSACEOUS PLANTS.

sr

Fig. 40.

whicli constitute, as in Mallow, an eincalyx. The pistil
must be carefully examined. In this case there will be
found a conical elevation in the centre of the
flower, on the surface of which are inserted
many separate carpels, much in the same way
as in Buttercup. At maturity this elevated
receptacle will have become greatly enlarged
and pulpy, with the real fruit, the ripened
carpels, dotted over its surface (Fig. 46).

51. Cherry or Plum. Here also the calyx, corolla,
and stamens are all adherent, and a hollow cup is formed,
in the bottom of which
(but entirely free from
these parts) the pistil is / .
developed (Fig. 47). It
consists of a single carpel,
in which there are at first
two ovules, though gen-
erally but one seed is
ripened. The fruit is
called a drupe, the seed being surrounded by three distinct
layers: (1) a hard shell {i\\Q putamen\ (2) a mass of soft
pulp, and (3) the outer skin.

52. Crab- Apple. Here, as before, we have a gamo-
sepalous calyx, the lower part forming a tube. The five
petals are separate and inserted on the calyx, as are also
the numerous stamens. To understand the structure of
the pistil, make a vertical section through the centre of
the flower, and also a cross section. The cross section

Fig. 46. — Vertical section of Strawberry.

Fig. 47.— Vertical section through flower of Cherry. (Gray.)

I^i'

Fig. 47.

i

•I

38

ELEMENTS OP STRUCTURAL BOTANY.

m

WM

iiii,'

: ,,;!i

(Fig. 50) will show you that in this case we have a
syncarpous pistil of five carpels, and the vertical section
(Fig. 49) shows that the ovary is here truly inferior^ the

calyx-tube be-
ing completely
adherent or
adnate to it.
The style is
divided into
five parts, cor-
responding to
the five car-
Fig. 48. Fig. 49. P^^®'

63. At maturity, whilst the pistil or central organ has
enlarged considerably, it will be found that the calyx-
tube, which is adherent to it, has also grown very much.
It is, in fact, the largely developed calyx-tube which con-
stitutes the edible part of the apple, the true pistil forming
the core. It is not very easy to distin-
guish the line which separates these two
parts of the ripe fruit, but if a cross-
section be made through the apple a circle
of greenish dots may generally be made
out at the outer limit of the core, A fruit
of this sort is called a pome. The wither-
ed calyx-teeth may be found in the hollow
at the end opposite the stem, as also, generally, the
remains of the five styles.

Fig. 48.— Flower of Crab-Apple. Fig 49.— Vertical section of ovary.
Fig. 50.— Cross section of fruit of Crab- Apple.

Fig. 50.

iillll Cir
t;,jlii

ROSACKOUS PLANTS.

39

ive a
5ction
r, the
36 be-
)letely
nt or
to it.
yle is
i into
ts, cor-
ing to
e car-

gan has
calyx-
much,
ich con-
forming

f ovary.

54. Raspberry. Calyx, corolla, and stamens have
the same arrangement as in Strawberry, and tlio pistil is
likewise apocarpous, the numerous carpels covering the
surface of a raised receptacle. But here the carpels do not
produce achenes. Each of them at maturity forms a fruit
resembling a drupe, so that the- raspberry is a mass of
drupes heaped upon a common receptacle.

55. Let us now sum up our observations upon the repre-
sentatives of the great Order of Rosaceous plants. We
have found them to possess the following characters in
common:

1. TJie petals and the numerous stamens are inserted on

the calyx {perigynous).

2. The pistil^ except in the Apple^ is apocarpous and

free from the calyx.

3. It may he added that the leaves are furnished with

stipules.

56. The differences (which lead to the sub-division of
tlie Order into subordinate groups) are chiefly in the fruit.
In Sweet Brier, with which may ])e compared any wild
Rose, the achenes are enclosed in the calyx-tube. In Straw-
berry the receptacle is conical ; so also in Raspberry. In
the Cherry the carpel is single, forming a drupe. In the
Apple the ovary is syncarpous and combined with the
fleshy calyx. Compare with the Apple the Hawthorn and
the Mountain Ash or Rowan Tree.

57. The following are the schedules descriptive of
Sweet Brier and Crab-Apple. Those relating to Cherry,
Strawberry, and Raspberry should be carefully filled up
by the pupil.

\t

1 I ',:

40

ELEMEN'J'S OF STRUCTUUAL BOTANY.

SWEET BRIER.

OUGAN.

No.

Cohesion.

Adhesion.

Rk MARKS.

Calyx.
Sepals.

5

5

CO

00

Gamosepalous

Half superior.

Corolla.
Petals.

Polype talous.

Perigynous.

Stamens.

Polyandrous.

Perigyiious.

Pistil.
Oarpela.

Apocarpous.

Half-inferior.

The hollow re-
ceptacle lines
the calyx-tube

CRAB- APPLE.

Organ.

No.

')
5

00

Cohesion.

Adhesion.

Remarks.

Calyx.
Sepals.

Gamosepa-
lous.

Superior.

Corolla.
Petals.

Polypetalous.

Perigynous.

Stamens.

Polyandrous.
Syncarpoua.

Perigynous.

Pistil.
Carpels.

5

Inferior.

Fruit consiatK
chiefly of a
fleshy enlarge-
ment of the
calyx-tube.

m

EXAMINATION OF AN UMUELLIFER.

41

jnaiatK

of a I

f thel
be.

CHAPTER VII.

EXAMINATION OF A PLANT WITH EPIGYNOUS STAMENS —

WATER-P.AIiSNIP.

58. Water-Parsnip. This is a common swamp
plant in Canada ; but if any difficulty be experienced in
procuring specimens, the flower of the common Carrot or
Parsnip or of Parsley may be substituted for it, all these

plants being closely related, and dif-
fering but slightly in the structure
of their flowers.

Notice first the peculiar appearance
of the flower cluster ( Fig. 51). There
areseveral pedicels,nearly of the same
length, radiating from the end of tlie
peduncle, and from the end of each
pedicel radiate in like manner a num-
ber of smaller ones, each with a flower
at its extremity. Such a cluster is
known as an umbel. If, as in the
present case, there are groups of secondary pedicels, the
umbel is compound. As the flowers are very small we
shall be obliged to use the lens all through the examination.
Even with its aid you will have a little difficulty in making
out the calyx, the tube of which, in this flower, adheres to
tlie surface of the ovary, as in Willow-herb, and is reduced
above to a mere rim or border of five minute teeth. The
])etals are five in number, and free from each other.
Observe that each of them is incurved at its extremity

Fig. 51.— Compound umbel of VVatcr-Parsuip.
Fig. 52.— Single flower of same. Fii;. 53.— Vertical section of the ovary.

t'-1
I'

Fig. 52. Fig. 51.

I .:

m

42

KLKMKNTS OF 8TRUCTUUAL UOTANY.

If II

(Fig. 52). Tlioy .iro iiisnrtod on a dUk winch arowm the
(trat'i/, as aro also tlio five stainoiis, wliich aro honco said
to 1)0 epiffi/nous. In tho centre of the flower aro two short
styles projecting above tho disk, and a vertical section
through the ovary (Fig. 53) shows it to bo two-celled, with
a single seed suspended from the top of each cell.

WATER-PARSNIP.

OUOAN.

NO.

COHESION.

AnllKHION.

HEMAUK8. j

1

Calyx.
Sej)al8.

5

Gamosepalous

Superior.

Calyx-teeth al-
most obsolete.

Corolla.
Petals.

5

Polysepalous.

EpigyuoiiB.

Petala iu-
curved.

Stamens.

5

Pentandrous.

IJpigyuous.

Pistil.

Carpels.

Syncarpou3.

Inferior.

59. The Water-Parsnip is a type of the large Order
UinbellifercBf which is well marked by the following
characters :

1. Tlie flowers are clustered in umbels, and these are

generally coinpound.

2. The calyx is perfectly adherent to the ovary, so that

almost none of it projects above,

3. The petals and stamens {five each) are epigynous.

4. The ovary is two-celled, and is surmounted by two

styles. At maturity the pistil separates into two
dry carpels.

A COMPOSITE FLOWER.

43

the

hort
stion
with

IKS. i

ethal-j

solete.'

rved.

noits.
by two
nto two

Fig. 54.

are all radical.

CHAPTER VIII.

KXAMINATION OK COMMON PLAN I'H WITH KPIPETALOUS STA-
M HNH — DANDELION — CATNIP.

60. Dandelion. The oxamination of this llower will
be somewhat more difficult than that of any we have yet
undertaken.

Provide yourselves with specimens in
flower and in seed.

The root of the plant, like that of the
Mallow, is a tap-root.

The stem is almost suppressed, and,
as in the case of the Hepatica, the leaves
They are also net-veined.
The flowers are raised on scapes, which are hollow. At
first sight the flower appears to have a calyx of many
sepals, and a corolla of many petals. Both of these ap-
pearances, however, are contrary to facts. With a
sharp knife cut the flower through the middle from
top to bottom (Fig. 54). It will then appear that
the flower, or rather floiver-head, is made up of a
large number of distinct pieces. With the point of
your needle detach one of these pieces. At the
lower end of it you have a small body resembling
an unripe seed (Fig. 55). It is, in fact, an ovary.
Just above this there is a short bit of stalk, sur-
mounted by a circle of silky hairs, and above this a yellow
tube with one side greatly prolonged. This yellow tube
is a corolla, and a close examination of the extremity of

Fig. {i4.— Vertical section of Dandelion flower.
Fig. 66— Single floret.

Pig. 55.

11

41

ELEMENTS OF STRUCTURAL BOTANY.

its long side will show the existence of five minute points,
or teeth, from which we infer that the tube is made up of
five coherent petals. As the corolla is on the ovary,
it is said to be Epigynovs.

Out of the corolla protrudes the long style, divided
at its summit into two stigmas.

To discern the stamens will require the greatest
nicety of observation. Fig. 56 will help you in your
task. The stamens are five in number. They are
inserted on the tube of the corolla (epipetalous) and
Fifir.56. their anthers cohere (Fig. 57), and form a ring about
the style. When the anthers are united in this way, the
stamens are said to be syngenesious.

61. It appears, then, that the Dandelion, instead
of being a single flower, is in reality a compound of
a great many flowers upon a common receptacle, and
what seemed at first to be a calyx is, in
reality, an involucre^ made up of many Fig.57.
bracts.

But have the single flowers, or Jlorets, as
they are properly called, no calyx? The
theory is that they have one, but that it is
adherent to the surface of the ovary, and that
the tuft of silky hairs which we noticed is a
prolongation of it.
Fig. 58. Now turn to your specimen having the

seeds ready to blow away. The seeds are all single ; the
little bit of stalk at the top has grown into a long slender
thread, and the tuft of hairs has spread out like the rays
of an umbrella (Fig. 58). But though the seeds are

Fig. 56. — Corolla laid open to show epipetalous stamens.
Fig. 57.— Syngenesious anthers of Dandelion. Fig. 58.— Fruit of Pandelion.

m
th

St
Pi

6l
are
com
some
I)an(
into
In
roun(
whih
game
may
lar, 1:
mino]
dinat
chara

A COMPOSITE FI.OWER.

45

blion.

invariably single, it is inferred from the two-lobed stigma
that there are tivo carpels. The following is the schedule :

DANDELION.

ORGAN.

No.

Cohesion.

Adhesion.

Kem.uiks.

Calyx.
Sepals.

.5

Gamosepalous

Superior.

The number
of sepals is in-
ferred from
analogy to be
five.

Corolla.
Petals.

5

Gamopetalous

Epigynous.

Stamens.

5

Syngenesious.

Epipetalous.

Pistil.
Carpels.

2

Sjmcarpous.

Inferior.

Number of
carpels infer-
red from num-
ber of stigmas.

62. Flowers constructed on the plan of the Dandelion
are called Composite flowers. The Order (Compositse)
comprises an immense number of common plants, in
some of which all the corollas in the head are, as in the
Dandelion, of one sort, namely, with one side prolonged
into a strap, and hence called strap-shaped or ligulate.
In most cases, however, the ligulate corollas form a circle
round the margin of the head only, as in Sunflower,
while the central disk is filled up with small regular
gamopetalous corollas with a five-toothed border. Or it
may happen, as in Thistle, that all the flowers are regu-
lar, ligulate corollas being absent. These, however, are
minor points, and, while serving to distinguish subor-
dinate groups, do not interfere with the great and salient
characters which mark the Order as a whole. So, also,

i I

II H,

46

ELEMENTS OP STRUCTURAL BOTANY.

instead of the tuft of silky hairs (technically called the
pappus) which surmounts the ovary, there may be, as
in Sunflower, a few teeth-like projections, or scales, or
a mere rim hardly to be distinguished at all.

63. The Order is easily recognized by the following
characters :

i. The flowers^ or florets^ are in heads on a common re-
ceptacle^ and surrounded by an involucre.

2. The stamens are inserted on the corolla, and are

united by their anthers {syngenesions ).

3. The style is 2-lobed at the apex.

64. Representatives of this Family are so numerous
that it is needless to give a list. Specimens exhibiting
all the variations in regard to the corollas, pappus, &c.,
should be gathered and notes made of their structure.
In Part IT. will be found a very full account of all the
species likely to be met with, and the exercise book has
a number of blank schedules specially arranged for Com-
posites.

65 Catnip. Note carefully the appearance of the
stem. It is square.

The flowers are in axillary clusters. The calyx is a
tube (Fig. 59), terminating in five sharp
teeth, and you may observe that the tube is
a little longer on the upper side (that is, the
side towards the stem) than on the lower.
The corolla is somewhat peculiar. It has
somewhat the appearance of a wide-open
mouth, and is known as a labiate or two-lipped Fig. 59.
corolla. The upper lip is erect and notched at the apex.

t/

Fig. 59.— Flower of Catnip.

A LABIATE FLOWER.

47

The lower lip spreads outward, and consists of a large
central lobe and two small lateral ones. Altogether,
therefore, there are jive lobes constituting the gamopetal-
ouu corolla. Pull out the corolla, and with the point of
your needle split its tube in front. On laying it open,
the stamens will be found to be inserted upon it (epipet-
alous). They are four in number, two of them
longer than the other two. Hence they are
described as didynamous. The anthers are
peculiar in not having their lobes parallel (Fig.
60), these being wide apart at the base, in con-
sequence of the expansion of the connective^ the
Fig. 60. name given to that part of the anther v^hich
unites its two lobes c. -ells.

The pistil consists v . }wo-lobed stigma, a
long style, and an ovai^ vsrhich seems at first as
if made up of four distinct carpels (Fig. 61).
But the two-lobed stigma will warn you against
this supposition. The ovary really
consists of two carpels, each of two deep
lobes, and, as the seeds ripen, these
Fig. 62. lobes form four little nutlets (Fig. 62),
each containing a single seed.

66. The Catnip is a type of the Order Lahiatoe (Mint
Family), so called because the corollas are usually
labiate. It is marked by the following characters :

1, The stem is square, and the leaves are opposite and

generally aromatic.

2. The corolla is more or less labiate.
The stamens are mostly didynamous.

Fig. 61.

0

Fig. 60.— Front view of the same. Fig. 61.— Pistil of Catnip.

Fig. 62.— Ripe ovary of four separate nutlet*.

'A

i ■.41

i ''• L
i UA

■ill

t Is

iv.ifeiniHiit

m

y :."

48

ELEMENTS OP STRUCTURAL BOTANY.

4. The ovary is foitr-lobed, and at maturity breaks up
into four nutlets.

Other types are the various Mints, Sage, Thyme,

Summer Savory, Pennyroyal, Bergamot, Self-heal,

Horehound, &c., many of which are of very common

occurrence.

CATNIP.

Obgan.

No.

Cohesion.

Adhesion.

Eemarks.

Calyx.
Sepals.

5

Gamosepalous

Inferior.

Calyx- tube
nerved.

Corolla.
Petals.

5

GamopetaLius

Hypogynous.

Two-lipped.
Upper lip of
two, and lower
of three, lobes.

Stamens.
Anthers.

4
2

Didynamous.

Epipetalous.

Lobes of an-
thers not par-
allel.

Pistil.

Carpels.

Syncarpous.

Superior.

The ripe
ovary of four
nutlets.

CHAPTER IX.

EXAMINATION OF PLANTS WITH MONCECIOUS FLOWERS —

CUCUMBER — OAK.

67. Cucumber. You can hardly have failed to
notice that only a small proportion of the blossoms on
a Cucumber vine produce cucumbers. A great many

MONCECIOUS FLOWERS.

49

it

wither away and are apparently of no use. An atten-
tive inspection will show that some of the blossoms
have oblong fleshy protuber-
ances beneath them, whilst )p
others are destitute of these U
attachments. Select a flower
of each kind, and examine first
the one with the protuberance
(Fig. 63), which latter, from
its appearance, you will pro-
bably have rightly guessed to be
the ovary. The situation of the
ovary here, indeed, is the same
as in the Willow-herb. The pjj,^ 53.
calyx-tube adheres to its surface, and is prolonged to
some little distance above it, expanding finally into five
teeth. The corolla is gamopetalous, and is adherent to
the calyx. Remove now the calyx and the adherent
corolla, and there is left in the centre of the flower a
short column, terminating in three stigmas, each two.
lobed.

'ITiere are no stamens,

68. Now examine the other blossom (Fig. 64). Calyx

and corolla have almost exactly
^ I the same appearance as before.
Remove them, and you have left
three stamens growing on the
calyx-tube, and slightly united
by their anthers (syngenesious).

Fig. 64.

There is no 2^>^til'

Y\^. C3. -Pistillate flower of Cucumber.
Fig. 64.— Staminate fiower of Cucumber,

^c,'^or 01 B,

Cf ntrsii

t xi/enmt'ntdl (

^t'^u.r.. n^■^

■%

I Hi J

i^l

'%

Ml! •

50

ELEMENTS OF STRUCTURAL BOTANY.

You see now why some blossoms produce cucumbers
and others do not. Most of the blossoms have no pistil,
and are termed staminate or sterile flowers, whilst the
others are pistillate or feytUe. Flowers in which either
stamens or pistils are wanting are also called imperfect.
When staminate and pistillate flowers grow on the same
plant, as they do in the case of the Cucumber, they are
said to be monmeious.

69. In plants of this kind the pollen of one kind of
blossom is conveyed to the stigmas of the other kind,
chiefly by insects, which visit the flowers indiscrimin-
ately in search of honey. The pollen dust clings to
their hairy legs and bodies, and is presently rubbed off
upon the stigma of some fertile flower.

70. In order to describe monoecious flowers, our
schedule will require a slight modification. As given
below, the symbol ^ stands for "staminate flower,"
and the symbol ^ for "pistillate flower."

CTJCUMBEE.

Organ.

Calyx.

Sepals.

Corolla.
Petals.

No.
5

CoiIKSION.

Adhesion.

Remarks.

Gamosepalous

Superior.

5

GamopetaloLiH

Perigynons.

^ Stamens.

3

0

o

Syngenesious.

Perigynons,

Two anthers
are2-eelledand
one 1-celled.

^ Pistil.

Carpels.

9 Stamens.

? Pistil.
Carpels.

:-5

Syncarpous.

Inferior.

il'il

II !;^

CUPULIFKROUS PLANTS.

CI

71. Oa«k. The Oaks are among our finest and most
valuable forest-trees, and while everyone is familiar with

•r^^-^

Fig. 67. Piff. 65.

the appearance of the acorn, as tlie fruit of the Oak is

Fig. 66,— Twig of White Oak with sterile catkins.

Fig. 67.— Single staminate flower.

Fig. 68.— Fruit and leaf of Oak. (Wood and Steele.)

1

I.

52

KLKMENTS OP HTflUCTUriAL BOTANY.

called, the fact that the flowers are not to he ohtained
without effort on account of their distance from the ground,
as well as the circumstance of their heing rather incon-
spicuous, may lead to their heing overlooked unless special
attention is directed to them. The White Oak is perhaps
the best known species with us. It may be pretty well
distinguished from other species by its leaves, the lobes of
which (Fig. 65) are rounded. However, for the purposes
of this lesson, any other species may be used, if the White
Oak is not at hand. The flowers are monoecious, the
sterile ones forming long and slender drooping catkins,
which are either single or, more generally, several in a
cluster, from the same lateral bud (Fig. 66). Each sterile
flower (Fig. 67) consists of a perianth or calyx of a vari-
able number of sepals, mostly from four to six, and gen-
erally eight stamens. Tlie fertile flowers spring mostly
from the axils of the leaves of new shoots, and they occur
either singly or two or three in a cluster. Each flower
consists of a syncarpous pistil of three carpels. The ovary
is three-celled, or nearly so, and two ovules are formed
in each cell. The flower is surrounded at the base by a
scaly involucre, which, at maturity, has become quite
woody, and forms in fact the cup in which the acorn rests.
If you dissect an acorn you will observe that there is but
one seed in it. Although the ovary contains six ovules at
starting, it always happens that all but one disappear
before the fruit is matured.

The White Oak ripens its acorns the first year. The
Red Oak, on the other hand, does not ripen its fruit till
the autumn of the second year.

72. It will be a valuable exercise to compare flowers of
the Beech with those just described. They will be found

CUPULIFEROUSJ PLANTS.

53

to be monoecious also ; the sterile ones in small drooping
heads, with stamens and sepals variable in number, and thu
fertile ones from the axils of new leaves, usually two
together, surrounded by an involucre of many bristle-
pointed scales. These dev^elope into the familiar bristly
four-valved involucre which encloses the pair of three-
cornered nuts at maturity. Each nut is the product of
one flower, and contains but one seed, although at first
the ovary was (like that of the Oak) throe-celled, with two
ovules in each cell.

These resemblances lead us to the conclusion that the
Oak and the Beech are nearly related plants. They belong
to the same Order {Cupuliferai)^ as do also the Iron wood,
the Chestnut, and the Hazelnut, all of which should be
examined and compared, if within reach.

73. The following are the distinguishing characters of
the Order :

1, The flow&)'8 are moncecious, the sterile ones being in

catkins (or^ in Beech, in close heads), the fertile
single or in small clusters, with an involucre form-
ing at maturity a cup or covering for the 1 -seeded nut.

2. The ovary is at first several-celled, but at maturity is

1-celled and 1-seeded.

The pupil will write out descriptions of one or more
representatives of the Order, taking the description of
Cucumber for his model.

i

:t

m

^;!i

I

I.

'ill

n I

!!»;!

■! .'

I/:. :ii

l-il'

'

54 ELEMENTS OF STRUCTURAL BOTANY.

CHAPTER X.

EXAMINATION OF PLANTS WITH DICECIOUS FLOWERS —

WILLOW — MAPLE.

74. Willow. Tho flowers of most kinds of Willow
^l.ni,. appear in spring or early summer

before the leaves. They grow from
the axils in long, close clusters called
catldns or aments. Collect a few of
these from the same tree or shrub.
Fitj. 68. You will find them to be exactly

alike. If the tir.st one you examine is covered with yellow
stamens (Fig. 68), all the rest will likewise consist of
stamens, and you will search
in vain for any appearance
of a pistil. If, on the other
hand, one of your catkins is
evidently destitute of sta-
mens, and consists of oblong
pistils (Fig. 69), then all the
others will in like manner Fig. 69.

be found to be without stamens. Unlike our Cucumber
plant, the staminate and pistillate flowers of the
Willow are borne on different plants. These
flowers are therefore said to be diwcious. As a
general thing, staminate and pistillate catkins
will be found upon trees not far apart. Procure
one of each kind, and examine first the stami-
nate one. You will probably find the stamens
Fig. 70. in pairs. Follow any pair of filaments down to

Fig. 68.— staminate catkin of Willow. Fig. 69.— Fertile catkin.

Fig. 70.— Single staminate flower.

^^1

DICECIOUS flA)\VKH8.

55

tlieir insertion, and ohsorvo that they spring from the
axil of a minute bract (Fig. 70). These bracts are the
xralea of the calkin. There is no appearance of either
calyx or corolla, and the flowers are therefore said to be
achlanii/deous^ tliat is, without a covering. Now
look at the fertile catkin. Each pistil will, like
the stamens, be found to spring from the axil of
a scale (Fig. 71). The stigma is two-lobed, and,
on carefully opening the ovary, you observe that
though there is but one cell yet there are two
roivs of seeds. We therefore infer that the pistil
Fiy, 71. consists of two carpels. The pistillate flowers,
like the staminate, are achlamydeous. In dioecious plants

HEART-LEAVED WILLOW.

OBOAN.

Calyx.

No.

COHESION.

ADHESION.

UI.MARKS.

Corolla.

0

i

J

-r Stamens.
^ Pistil.

2
0

Diandrous.

U

!

Syncarpous.

.

Q Stamens.'

,, Pistil.
Carpels.

0
2

0

the process of fertilization is assisted by insects, especially
when the flowers are showy or odoriferous and nectar-
Fig. 71.— Single pistillate flower of Willow,

' ii

m

\:im

[i.!!!!!

56

KI.KMKNT.S OK MTUUCTUHAL IJOTANV.

Ill

boarin<,' ;

otliorwiflo t)u! wind is tlio i)rincipal nfiont.
Flowors wliic'h dupond on insects to ofFoct tho transfer of
pollen from the anther to the stigma are said to bo onto-
mophilous. Those which depend upon tho wind are
anemophilous. The Willow belongs to tho former class.

75. Maple. In oarly spring, while the branches are
us yet bare of leaves, our Red Maples are covered with
a profusion of scarlet and yellow blossoms, and the air
about them is alive with busy insects gathering honey for
themselves, and performing at the same time an impor-
tant service for the trees in return ; for it will be found
on examining a few of the trees that, like the Willow,

they do not all bear the same kind of
flowers. In some, the ends of the
reddish twigs will present the appear-
ance shown in Fig. 72,withnumerous
stamens protruding from the scaly
lateral buds. On looking into one
of these buds it will be found that
there are several flowers on short
pedicels, each like that shown in
Fig. 73, except that the number of
stamens will probably be found to
be somewhat variable. Observe
the fleshy disk in the bottom of
the calyx, upon which the stamens
are inserted. These flowers with
the projecting stamens are without
pistils. They produce nothing but
pollen, and the tree upon which you find them produces
no other kind.

Fis,'. 72. — Twig of Red Maple bearing staniiiiatc flowers.
Fig. 73.— Single staniinate flower. (Wood «& Steele).

Fig. 72.

Fij?. 73.

THE MAPLK8.

57

In other trees, tlio twigs will ho found to rosoiuhlo Fi^'.

74. The scaly buds uro present, and tlio clusters of flow-
ers within them as before, but the projecting fitamons
are wanting. If stamens are present at all, they are
short and almost concealed in the calyx, as shown in Fig.

75, where two anthers are just visible over the edge of

the calyx. The centre of the flower
is occupied by a syncarpous pistil,
having a two-celh^d ovary and two
long styles, as shown in the figure.

The flowers of tlie Maple, there-
fore, being sterile or staminate upon
one tree, and fertile or pistillate upon
another, are, as in Willow, said to bo
dioecious ; or, if we take into account
the fact that some of the flowers
have stamens as well as pistils, we
shall more accurately describe the
whole inflorescence ( or mode of
flowering) as polygamo-dioecinus.

In Maple, as in
Willow, the assist-
ance of insects is necessary to ensure
the transfer of the pollen to the stigma.
The flowers are, tlieref ore, entomophilous.
After fertilization, a ivimj is devel-
oped from the back of each of the two Fig. 76.
carpels, and the pedicels lengthen, so that as the fruit
ripens it presents the familiar aspect of hanging clusters of
double samarax, as these winged fruits are called (Fig. 76).

¥\g. 74— Twig of Red Maple bearing pistillate flowers.
Fig. 75. —Single pistillate flower. (Wood & Steele.)
Fig. 76.— Winged fruit or samara of Maple.

Fig. 74

Pig. 75.

(t

li

i^ii I

■I

58

ELEMENTS OF STRUCTURAL BOTANY.

ill If: ^^

m

The Red Maple ripens its seeds early in the summer,
and these, on falling, germinate immediately, so that by the
autumn of the same year a vigorous young tree, a foot or
more in height, is produced. The seeds will not germi-
nate if kept over till the following spring.

The Sugar Maple, on the other hand, flowers later, the
leaves and flowers appearing about the same time, and
the seeds do not ripen till the fall. If kept slightly moist
through the winter they will germinate the following
spring.

76. The several species of common occurrence should
be carefully studied and distinguished. Their character-
istics are given in the proper place in Part II.

The Maples form a subordinate group of the natural

Order Sapindacece. They are dist'nguished by the follow-
ing characters :

i. The flowers are dioecious (or polygamo-dioecious), and
commonly unsymmetrical.

2. The ovary is two-lobed and two-celled, with two

ovules in each cell, only on", of which, however, is
ripened.

3. The fruit is a double samara.
4* The leaves are opposite.

77. From this type there are important deviations in
other representatives of the Order. Horse-chestnut, for
instance, while its flowers are unsymmetrical and some-
what irregular, as in the Maples, produces a three-celled
ovary, with two ovules in each cell. Bui/ as in Maple,
again, only one ovule in each cell fcjrms a seed. The fruit,
however, is not a samara, but a leathery pod which splits
into three pieces at maturity, liberating the three large
shining seeds.

CHARACTERS COMMON TO DICOTYLEDONS.

59

Schedules descriptive of the Maple should be filled up,
taking that of Willow as the model.

1

i

■

! i I;

||i

and
two

CHAPTER XI.

CHARACTERISTICS POSSESSED IN COMMON BY ALL THE PLANTS

PREVIOUSLY EXAMINED — STRUCTURE OF THE SEED

IN DICOTYLEDONS.

78. Before proceeding further in our examination of
plants, we shall direct your attention to some characters
of those already examined, which they all possess in
common. The leaves of every one of them are net-veined.
Some leaves, at least, of each of them have distinct petioles
and blades. The parts of the flowers v/e found, as a gen-
eral thing, to be in fives. In one or two instances they
were in fours, that is four sepals, four petals, and so on.

79. Now, in addition to these resem-
blances, there are others which do not
so immediately strike the eye, but which,
nevertheless, are just as constant. One
of these is to be found in the structure
Fig. 77. Fig. 78. Fig. 79. of the embryo. Take a Cucumber or a
Pumpkin seed, and having soaked it for some time in
water, remove the outer coat. The body of the seed will
then readily split in two, except where the parts are joined
at one end (Figs. 77, 78, 79). The thick lobes are called
cotyledons, or seed-leaves, and as there are two, the embryo
is dicotijledonous. The pointed end where the cotyledons

Figs. 77, 78, 79.— Different views of Pumpkin seed, showing radicle,
cotyledons, and plumule.

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KLKMKNTS OF STRUCTURAL BOTANY.

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are attached, and from which the root is developed, is
called the radicle, a term meaning " little root." As it is
strictly, however, a rudimentary stenif and not a root, the
term cauHcle would be better. Between the cotyledons,
at the summit of tlie radicle, you will find a minute upward
projection. This is a bud, which is known as the plumule.
It developes into the stem.

80. If you treat a Pea or a Bean (Figs. 80, 81) in the
same manner as the Cucumber seed, you will find it to be
Fig. 80. constructed on the same plan. The em-

bryo of the Bean is dicotyledonous also.
But you will observe that in these cases
the embryo occupies the whole of the in-
terior of the seed. In describing the seed
of the Buttercup, it was pointed out that
the embryo occupies but a very small
space in the seed, the bulk of the latter
consisting of alhumen. Seeds like those of the Buttercu})
are therefore called albuminous seeds, while those of the
Bean and Pea are exalhuminous. But, notwithstanding
this difference in the structure of the seed, the embryo of
the Buttercup, when examined under a strong magnifier,
is found to be dicotyledonous like the others. In short,
the dicotyledonous embryo is a character common to all
the plants we have examined — common, as a rule, to
all plants possessing the other characters enumerated
above. From the general constancy of all these charac-
ters, plants possessing them are grouped together in a vast
Clf ss, called Dicotyledonous plants, or, shortly, DiCOty-

ledons.

Fig. 81.

Figs. 80 and 81.— Seed of the Bean.

LILIACEOUS PLANTS.

61

81. Besides the characters just mentioned, there is still
another one of great importance which Dicotyledons
possess in common. It is the manner of growth of tite
dem.. In the Willow, and all our trees and shrubs with-
out exception, there is an outer layer of bark on the stem,
and the stem increases in thickness, year by year, by form-
ing a new layer just inside the bark and outside the old
wood. These stems are therefore called exogenous, that is,
outside growers.

Now, in all Dicotyledonous plants, whether herbs,
shrubs, or trees, the stem thickens in this manner, so that

Dicotyledons are also Exogens.

#«

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! 1J5

CHAPTER XII.

EXAMINATION OP COMMON PLANTS CONTINUED — DOa'S-TOOTH
VIOLET — TRILLIUM — IRIS — ORCHIS.

82. Dog's-tooth Violet. This plant (Fig. 82), which
flowers in spring, may be pretty easily recognized by its
peculiar blotched leaves. It may be found in rich, moist
pasture lands and low copses. The name "Violet" is
somewhat unfortunate, because the plant is not in any
way related to the true Violets. To obtain a complete
specimen requires some trouble, owing to the fact that the
root is commonly six inches or so below the surface of the
ground ; you must therefore insert a spade or strong trowel
sufficiently deep to avoid cutting or breaking the tender
stem. Having cleared away the adhering earth, you will
find that the roots proceed from what appears to be the

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111

62

ELEMENTS OP STRUCTURAL BOTANY.

I

swollen end of the stem. This swollen mass is coated on
the outside with thin scales. A section across the middle
shows it to be more or less solid, with the stem growing

Fig. 82.

up through it from its base. It is, in fact, not easy to say
how much of this stem-like growth is in reality stem,

Fig. 82.— Dog's-tooth Violet.

1 » •

,1

LILIACEOUS PLANTS.

63

i on
ddle
fv'ing

because it merges gradually into the scape, which bears
the flower, and the petioles of the leaves, which sheathe
the scape. The swollen mass is called a bulb.

83. The leaves are two in number, gradually narrowing
at the base into sheaths. If you hold one of them up to
the light, you will observe that the veins do not, as in the
leaves of the Dicotyledonous plants, form a network, but
run only in one direction : namely, from
end to end of the leaves. Such leaves are
consequently called straight-veined.

84. In the flower there is no appearance
of a green calyx. There are six yellow
Fig. 83. leaves, nearly alike, arranged in two sets,
an outer and an inner, of three each. In such cases, we
shall speak of the coloured leaves collectively as the peri-
anth. If the leaves are free from each other we shall
speak of the perianth as polyphi/llous, but if they cohere
we shall describe it as gamophyllous. Stripping off the
leaves of the perianth, we find six stamens with long
upright anthers which open along their outer edges. If
the anthers be pulled off", the filaments will be found to
terminate in long, sharp points.

The pistil (Fig. 83) has its three parts —
ovary, style, and stigma — well marked. The
stigma is evidently formed by the union of
three into one. The ovary, when cut across,
is seen to be three-celled (Fig. 84), and is,
therefore, syncarpous.

Fig. 83.— Pistil of Dog'a-tooth Violet.
Fig. 84.— Cross section of the pistil.

Fig. 84.

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ELEMKNTH OP STRUCTURAL UOTANY.

DOG'S-TOOTH VIOLET.

I

Organ.

No.

Cohesion.

Adhesion.

Bemarks

Perianth.
Leaves.

6

Polyphyllous.

Inferior.

Stamens.

6

Hexandroua.

Hypogynous.

Filaments ter-
minating in
sharp points.

Pistil.
Carpels.

3

Synoarpons.

Superior.

!li

Fig. 85.

Figr. 87

85. Trillilim. This plant
(Fig. 85) may be found in
flower about the same time as
the one just described. The
perianth of Trillium consists
of six pieces in two sets, but
in this case the three outer
leaves are green, like a com-
mon calyx. The stamens are
six in number. There are
three styles, curving outwards,
the whole of the inner side of
each being stigmatic. The
ovary (Fig. 86) is six-angled,
and on being cut across is seen
to be three-celled.

Fig. 85.— Trillium. Fig. 86.— Cross section of the pistil.

Fig. 87.— Net-veined leaf of Trillium.

~;,i

LILIACEOUS PLANTS.

65

86. Comparing this flower with that of Dog's-tooth
Violet, we find the two to exhibit a striking resemb-
lance in structure. But in one respect the plants are
strikingly unlike : the leaves of the Trillium are net-
veined (Fig. 87), as in the Exogens. From this circum-
stance we learn that we cannot altogether rely on the
veining of the leaves as a constant characteristic of
plants whose parts are not in fives.

TRILLIUM.

Organ.

No.

Cohesion.

Adhesion.

Eemauki?.

Perianth.
Sepals,
Petals.

3
3

Polyphyllous.

Inferior.

Sepals persist-
ent.

Stamens.

6

Hexandrous.

Hypogynous.

Pistil.
Carpels.

3

Syncarpous.

Superior.

The iuner face
of each style
Btigmatic.

Leaves net- veined.

87. The two plants just examined are types of the
natural Order Liliacece. The distinguishing characters
are as follows :

1. The parts of the flower are almost invariably in sets

of three, the perianth being of two such sets, and
also the stamens. The flowers are therefore sym-
metrical ; they are also regular.

2. The stamens are opposite the divisions of the perianth.

3. The ovary is nearly always S-celled, and is superior.

I' 1 1

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66

ELEMENTS} OF STRUCTURAL BOTANY.

The representatives of this large Order are very nu-
merous. From the gardens may be had lilies of various
sorts, Asparagus, Star-of-Bethlehem, Tulip, Onion, Hya-
cinth, &c., whilst the fields and woods supply the Bell-
wort, Clintonia, Solomon's Seal, Smi-
lacina, and others. As a rule the plants
flower in spring and early summer.

88. Iris. For this lesson any variety
of the common garden Flag will answer
very well. In our marshes in early
summer abundant specimens of a wild
species may be obtained without much
trouble, but the cultivated plants will
probably be more accessible. Note first
the fleshy underground stem or root-
stock, with the fibrous roots below
(Fig. 88). If you have a sufficient
length of this root-
stock you will notice
the scars upon the'
older portions, show-
ing where the leaves
of former seasons
have been sent up.
The new buds ex-
pand into a crowded Fig. 88.
cluster of leaves, the shape and arrangement of which
should be carefully observed. Cut the whole cluster
across near the base, and the section will be as repre-
sented in Fig. 89, the section of each leaf being V-shaped,

Fig. 88.— Root-stock and leaves of Iris. (Gray.)
Fig. 89.— Cross section of cluster of equitant leaves.

(Gray.)

IRIS.

67

and astride the next one within. Leaves disposed in this
manner are consequently said to be equitaiit {eques^ a
horseman). As the leaf rises upward it alters in shape,
becoming fiat and sword-like. Besides being equitant,
these leaves, on account of their direction, are described
as vertical. You will observe, also, that they are straight-
veined.

From the centre of the cluster of leaves rises the scape
which bears the flower. If your specimen has a flower-
bud upon it, as is most likely, you will notice the way in
which its leaves are folded. The mode of folding here

exhibited is common to a great
many flowers, and is described
as convolute. In the full-blown
flower the perianth will be found
to consist of six pieces, in two
distinct sets of three each ; the
outer three are considerably
larger than the others, and are
bent backwards or refiexed; the
Fig. 90. inner ones are erect. There are

three stamens, each of them beneath and close against
an over-arching body, the nature of which is not at first
quite manifest. Cut away the perianth and the stamens,
and you will then have left the three radiating coloured
arches (Fig. 90), which will be seen to unite below into
a slender column. You have also left what is apparently
the swollen top of the scape. This, when cut across, is
found to be a three-celled ovary, which is thus, of course,
inferior. The slender column above is the style, and the

fig. 90.— Pistil of Iris. (Wood and Steele.)

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68

ELBMENTS OF STUUCTUUAL BOTANY.

three petal-like arches are its branches. Immediately
beneath the tip of each arch will be found a thin lip or
plate, which is the stigma.

The anthers open outwards to discharge the pollen,
and this fact, in addition to the peculiar situation of the
anther as regards the stigma, makes it almost impossible
that self-fertilization should take place in this flower.
As was the case with other flowers already examined,
the Iris is honey-bearing, and, besides, exceedingly showy.
The nectar is situated in a cavity at the bottom of the
flower, and cross-fertilization is accomplished by the aid
of insects. It will be remembered that flowers thus
fertilized are said to be entomophilous.

89. The Crocus and Gladiolus of the gardens and the
Blue-eyed Grass of our low meadows may be examined
and compared with the Iris. They are all types of the
natural Order /nt^acete, which you will observe differs from
Ldliacem chiefly in having flowers with only three stamens
and an inferior ovary.

I

■1

5

lEIS.

Ji

Organ.

No.

Cohesion.

Adhesion.

Bemarks.

Perianth.
Leaves.

6

Gamophyllous

Superior.

2 sets. Outer,
large aud re-
flexed ; inner,
erect.

Stamens.

3

Triandrous.

Perigynous.

Opposite the
stigmas.

Pistil.
Carpels,

3

Syncarpous.

Inferior.

Stigmas pet-
al-like, arching
over the ex-
trorse anthers.

yt

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ORCIIIH.

Gl)

90. Showy Orchis. The flowor of this plant ( Figs.
91, 92) is provided with floral envelopes, all coloured liko
a corolla. As in Dog's-tooth Violet, we shall call them
collectively the perianth, although they are not all alike.
One of them projects forward in front of the flower.

Fig. 91.

forming the lip, and bears underneath it a long, hollow
spur which, liko the spurs of Columbine, jis honey-bearing.
The remaining five converge together, forming a kind of

Fig. 91.— Showy Orchis.

70

ELKMKNTM OF .STRUCTUHAL BOTANY.

arch over the centre of the flower. Each flower springs
from the axil of a leaf-like bract, and is apparently
raised on a pedicel. What seerns to be a pedicel, how-
ever, will, if cut across, prove to bo the ovary,
which in this case is inferior. Its situation is
similar to the situation of the ovary in Willow-
herb, and, as in that flower, so in this the
calyx-tube adheres to the whole surface of the
ovary, and the three outer divisions of the
perianth are simply upward extensions of this
tube. Notice the peculiar twist in the ovary.
The effect of this twist is to turn the lip away
Fig. 92. from the scape, and so give it the appearance
of being the lower petal instead of the upper one, as it
really is.

91. The structure of the stamens and pistil remains
to be examined, and a glance at the flower shows you
that we have here something totally different from the
common arrangement of these organs. In the axis of the

flower, immediately behind the opening into tiie
spur, there is an upward projection known as the
columri. The face of this column is the stigma ;
on each side of the stigma, and adhering to it, is
an anther-cell. These cells, though separated by
the column, constitute but a siiigle stamen. The
stamen, then, in this case is united ivith the ^nstil^
Fig. 9S. a condition which is described as gynandrous.

92. If you have a flower in which the anther-cells are
bursting open, you will see that the pollen does not issue
from them in its usual dust-like form, but if you use the

Fig. 92.— Single flower of Orchis.

Fig. 93.— Pollen-mass of Orchis, greatly enlarged.

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point of your needle carefully you may remove the con-
tents of each cell in a manti. These pollen-masses are of
the form shown in Fig. 93. The grains are kept togtjthcr
by a fine tissue or web, and the slender stalk, upon which
each pollen-mass is raised, is attached by its lower end
to a sticky disk on the front of the stigma just above the
mouth of the spur. Insects, in their ertbrts to reach the
honey, bring their heads in contact with these disks, and,
when they fly away, carry the pollen-masses with them
and deposit them on the stigma of the next flower visited.
In fact, it is difficult to see how, without the aid of
insects, flowers of this sort could be fertilized at all.

SHOWY ORCHIS.

OUOAN.

No.

Cohesion.

Adhksion.

Bkmauks.

Perianth.

Leaves,

G

1

3

Ganiophyllous

Superior.

Stamens.

Monanclrous.

Gynandrous.

Pollen-grains
collected in

masses.

Pistil.
Carpels.

Syncarpous.

Inferior.

Ovary twisted.

93. Showy Orchis is a representative of the vast
Order Orchidacece, the members of which are chiefly
tropical. Some of our handsomest Canadian wild flow-
ers, however, belong to it, such as the Lady's Slipper,
the Rattlesnake Plantain, the beautiful little Calypso,
and the Habenarias. Most of our orchids will be found
in low and wet situations, and they flower rather early

m

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72

ELEMENTS OF STRUCTURAL BOTANY.

in the year. The most remarkable characteristics of the
Order are the gynandrous arrangement of the stamen or
stamens, and the cohesion of the pollen-grains, though
this latter peculiarity is exhibited also by other groups
— notably, the Milkweeds.

CHAPTER XIII.

EXAMINATION OP SPADICEOUS PLANTS — INDIAN TURNIP —

CALLA.

94. Indian Turnip. This plant may be easily met
with in our woods in early summer. If you are not
familiar with its appearance, the annexed cut (Fig. 94)
will help you to recognize it. Procure several speci-
mens : these will probably at first seem to you to be
alike in every respect, but out of a number some are
pretty sure to differ from the rest. Notice the bulb
from which the stem springs. It differs from that of
the Dog's-tooth Violet, and Lilies generally, in having a
much larger solid part. It is called a corm. Between
the pair of leaves you observe a curious striped sheath,
having an arching, hood-like top, and enclosing an up-
right stalk, the top of which almost touches the hood
(Fig. 95). Can this be a flower? It is certainly the
only thing about the plant which at all resembles a
flower, and yet how different it is from any we have
hitherto examined ! Carefully cut away the sheaths

I

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INDIAN TURNIP.

73

from all your specimens. Most, and perhaps all, of
them will then present an appearance like that in Fig.
96. If none of them be like Fig. 97 it will be well to
gather a few more plants. We shall suppose, however,

Vig. 94.

that you have been fortunate in obtaining both kinds,
and will proceed with our examination. Take first a
specimen corresponding with Fig. 96. Around the base
of the colujnn are compactly arranged many spherical
green bodies, each tipped with a little point. Separate

Fig. 94.— Indian Turnip.

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74

ELEMENTS OF STRUCTURAL BOTANY.

.|li;i

one of these from the rest and cut it across. It will be

found to contain several ovules, and
is, in fact, an ovary, the point at the
top being a stigma. In the autumn
a great change will have taken
place in the appearance of plants
like the one we are now examining.
The arched hood will have dis-
appeared, as also the long naked
top of the column, whilst the part
below, upon which we are now en-
gaged, will have vastly increased in
size, and become a compact ball of
red berries. There can be no doubt,
then, that we have
here a structure anal-
ogous to that found
in the Cucumber and
the Willow, the fertile, or pistillate,
flowers being clustered together separate-
ly. But in the Cucumber all the flowers
were observed tc be furnished with calyx
and corolla, and in the Willow catkins,
though floral envelopes were absent, each
pair of stamens and each pistil was sub-
tended by a bract. In the present plant
there are no floral envelopes, nor does
each pistil arise from a separate bract.

95. But, you will now ask, what is this sheathing
hood which we find wrapped about our column of pistils?

Fij;. 95.— Spathe of Indian Turnip.
Fig. 06.— Fertile spadix of the same. Fig. 97. —Sterile spadix.

Fig. 95.

Fig. 96. Fig. 97.

INDIAN TURNIP.

75

There is no doubt that we must look upon it as a brad^
because from its base the flower-cluster springs. So that,
whilst the flowers of Indian Turnip are, like those of
Willow, imperfect and dioecious, the clusters differ in
having but a single bract instead of a bract under each
flower.

96. We must now examine one of the other specimens ;
and we shall have no difficulty in determining the nature
of the bodies which, in this case, cover the base of the
column. They are evidently stamens, and your magni-
fying-glass will show you that they consist mostly of an-
thers, the filaments being extremely short, and that
some of the anthers are two-celled and some four-celled,
all discharging their pollen through little holes at the
top of the cells.

INDIAN TURNIP.

Organ.

No.

Cohesion.

Adhesion.

^ Stamens.

1

Monandrous.

0

Q Pistil.
Carpels.

1

Apocarpous.

0

Flowers crowded on a spadix, and surrounded by a spathe.
Leaves net- veined.

97. The column upon which, in plants like Indian
Turnip, the flowers are crowded, is known as a spadix,
and the surrounding bract as a spathe.

You will observe that the leaves of this plant are net-
veinedy as we found them in the Trillium.

iiil

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7G

ELEMENTS OF STRUCTURAL BOTANY.

98. Marsh Oalla. This plant must be looked for
in low, marshy grounds, where it will be found in flower
generally in the month of June. With the knowledge
which you have of the structure of Indian Turnip, you

Pig. 99.

will hardly doubt that the Calla is closely related to it.
You will easily recognize the spadix and the spathe
(Fig. 98), though in the present instance the spadix
bears flowers to the top, and the spathe is open instead
of enclosing the column. Observe, however, that the
veining of the leaf (Fig. 99) is different, that of Calla
being straight, like the Dog's-Tooth Violet. There is
also a difference in the flowers. Those of Indian Turnip
were found to be dioecious, but the spadix, in the present

Fig. 98.— Spadix and spathe of Marsh Calla.
Fig. 99.— Leaf of the same.

iMARSlI CALL A.

t i

case, bears both stamens and pistils, and most of the
lower flowers, if not all, are imrfect ;
sometimes the upper ones consist of sta-
mens only. Fig. 100 shows one of the
perfect flowers much enlarged. The sta-
mens, it will be observed, have two-celled

Fig. 100.

anthers, opening lengthwise.

MAKSH CALLA.

Organ.

No.

Cohesion.

Adhesion.

Perianth.

Wanting.

Stamens.

6

Hexandrons.

Hypogynons.

Pistil.
Carpels.

1

Apocarpous.

Superior.

99. These two plants, Indian Turnip and Marsh Calla,
are representatives of the Order Aracece. The characters
which distinguish it are very well displayed in the two
types we have selected for examination. The great feature
is the aggregation of the flowers on a spadix. Generally,
though not invariably, a spathe is also present. Among
wild plants the Skunk Cabbage and Sweet Flag (the latter
without a spathe) are common Araceous types, while the
familiar green-house and window plant, known as the
Calla-Lily, will serve very well for examination in winter.
It may be added that the plants of this Order have a very
acrid juice.

Fig. 100.— Perfect flower of Calla.

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7H

ELEMENTS OF STRUCTUKAL liOTANY.

CHAPTER XIV.

I II' i

EXAMINATION OF GI.UMACEOUS PLANTS-
OTHER C5RASSRS.

-TIMOTHY AND

100. Timothy. The top of a stalk of this well-
known grass is cylindrical in shape, and upon examina-
tion will be found to consist of a vast number of similar
pieces compactly arranged on very short pedicels about
the stalk as an axis. Carefully separate one of
these pieces from the rest, and if the grass has
not yet come into flower the piece will present
the appearance shown in Fig. 101. In this
Fig. the three points in the middle are the pro-
truding ends of stamens. The
piece which you have separated is, in
fact, a flower enclosed in a pair of bracts,
and all the other pieces which go to
make up the top are flowers also, and,
except perhaps a few at the very sum-
mit of the spike, precisely similar to this
one in their structure.

Fig. 101.

Fig. l()-2.

101. Fig. 102 is designed to help you in dissecting a
flower which has attained a greater degree of development
than the one shown in Fig. 101. Here the two bracts
which enclose the flower hrve been drawn asunder. To
these bracts the name glumes is applied. They are
present in all plants of the Grass Family, and are often

Fig. 101.— Closed flower of Timothy.
Fig. 102.— Expanded flower of the same.

j. t,i^

.iriiuti'ili

GRAH8E8.

79

found enclosing several flowers instead of one as in
Timothy. Inside the glumes will be found a second pair
of minute chaff-like bracts, which are known as palets or
pales. These enclose the flower proper.

102. The stamens are three in number, with the anthers
fixed by the middle to the long slender filament. The
anthers are therefore versatile. The styles are two in
number, bearing long, feathery stigmas. The ovary contains
a single ovule, and when ripe forms a seed-like grain,
technically known as a caryopsis.

TIMOTHY.

Obgan.

No.

Cohesion.

Adhesion.

Glumes.

2

Pftlets.

2

Stamens.

3

Triandroiis.

Hypogynous.

Pistil.
Carpels.

1

Apocarpous.

Superior.

\

I

■n

103. It will be observed that the stalk of Timothy is
hollow except at certain swollen knot-like joints. This
peculiar stem of the Grasses is called a culm. Occasionally,
however, it is not hollow. The leaves are long and narrow
and straight-veined, and each of them at its base surrounds
the culm with a split sheath. Observe also that at the

'•k

11

80

ELEMENTS OP STRUCTURAL BOTANY.

junction of tlio blade and the sheath there is a thin
appendage which is called a ligule.

104. In many grass-flowers, besides the parts described
above there will be found one or two minute scales below the

pistil. These are known as
lodiailesj and are analogous
to the perianth in ordinary
flowers. They are, on ac-
count of their minuteness,
very liable to be overlooked
in a superficial examination.
105. The immense Order
GraminecB (Grass Family)
includes all our valuable
grains, and is, on the whole,
the most important and
useful of all the Orders. Its
representatives are to be
found in every part of the
world, and they vary in size
from the stunted growths
of the polar regions to the
tree-like Bamboo of the
tropics. Wheat, Indian
Corn, Barley, Oats, Rye,
Sugar-cane, Rice, are all

Fig. 104.

Fig. 103.

Grasses, as well as the plants which make the verdure of
our meadows and pastures. The flowers of all are very
similar, but the Order is sub-divided on the basis of

Fig. 103.— Panicle of Red-top.
Fig. 104.— Single flower. (Gray.)

GRASHRS.

81

modifications which will Ix? ]>est iimlcrstood by studying

a few examples.

lOG. Procure specimens of the common
Red-top, and first compare the genei'al
aspect of tlie flower-cluster (Fig. 103)
with that of Timothy. Instead of a dense
spike we have here a loose, open inflor-

•aft.

^ ^ /^ escence ; it is technically known as a

Fig. 105

pariicle. You will see that
it is an irregular branched
raceme. As in Timothy,
each pah' of glumes encloses
Fig. 106. hit oiiejioicer (Fig. 104), and
we must observe that the
term s///kelet, so far as
Grasses are concerned, is
applied to the pair of glumes
and whatever is contained in
them, whether one flower, or
many, as is often the case.
In Red-top and Timothy, the
spikdets are 1-flowered. Ob-
serve the very thin texture
of the ^?aZe^s, and also that
one of them (the lower, e.e.,
the one farthest from the
stalk) is nearly twice as large
as the other, and is marked
with three nerves.

Fig. 105.— Common Meadow-Grass.

Fig. 106.— Spikelet enlarpred, siiowing the glumes at the base.

Fig. 107. — Single flower of same.

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ELEMENTS OP STRUCTURAL BOTANY.

107. Next let us inspect a specimen of the Common
Meadow-Grass. The inflorescence of this very common
grass (Fig. 105) is a greenish panicle. The spikelets (Fig.
106) contain from three to five flowers, and are laterally
compressed. The glumes are the lowest pair of scales, and
they are generally shorter than the flowers within them.
Observe the delicate whitish margin of the lower palet of
each flower (Fig. 107), and the thin texture of the upper
one. Count also, if you can, the five nerves on the lower
palet, and observe the two teeth at the apex of the upper
one. In this Grass the principal thing to notice is that
there are several flowers loithin each pair of glumes.

108. A common pest in wheat-fields is the Grass
known as Chess. It is comparatively easy of examination

on account of the size of the
spikelets (Fig. 108) and flow-
ers. The spikelets form a
spreading panicle, eachof them
being on a long, slender, nod-
ding pedicel, and containing
from eight to ten flowers. Of
the two glumes at the base of
each spikelot one is consider-

Fig.m Fig. 109. g^i^iy i^^.gg^ ^^^^ ^y^^ ^^^^^

The outer or lower palet of each flower is tipped with a
bristle or awn (Fig. 109), while the upper jmlet at length
becomes attached to the groove of the oblong grain.
Observe that the glumes are not awned.

109. The Couch Grass is another very common weed
in cultivated grounds. In this Grass the spikelets are

Fig. 108.— Spikelet of Chess.

Fig. 109.— Single flower. (Gray.)

GRASSES.

83

sessile on opposite sides of the zigzag peduncle, so that
the wliole forms a spike. Each spikelet is four- to eight-
flowered, and there is but one at each joint of the
peduncle, the side of the spikelet heing against the stalk.
The glumes are nearly equal in size, and the lower palet
of each flower closely resembles the glumes, but is sharp-
pointed or awned. The grass spreads rapidly by ?'unning
root-stocks, and is troublesome to eradicate.

110. Old-Witch Grass is to be found everywhere in
sandy soil and in cultivated grounds. The leaves are
very hairy, and the panicle very large, compound, and
loose, the pedicels being extremely slender. Of the two
glumes one is nmch larger than the other. Unless you
are careful you will regard the spikelets as l-Howerod ;
observe, however, that in addition to the one manifestly
perfect flower there is an extra palet below. This palet
(which is very much like the larger glume)is a rudimentary
or abortive second flower, and the spikelet may be
iescribed as IJ-flowered.

111. Barnyard Grass is a stout, coarse plant, common
in manured soil. It is from one to four feet in height,
and branches from the base. The spikelets form dense
spikes, and these are crowded in a dense panicle which is
rough with stiff hairs. The structure of the spikelets is
much the same as in Old- Witch Grass, but the palet of
the neutral flower is pointed with a rough awn or bristle.

112. In the common Foxtail the inflorescence is
apparently a dense, bristly, cylindrical spike. In reality,
however, it is a spiked panicle, the spikelets being much
the same as in Barnyard Grass, but their pedicels are
prolonged beyond them into awn-like bristles. In this

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ELEMENTS OP STRUCTURAL BOTANY.

plant the bristles are in clusters and are barbed upwards.

T?te spikes are tawny-yellow in colour.

113. These examples, if conscientiously studied with
the aid of the plants themselves, will give you a good
general idea of the kinds of variation which may be looked
for in the Grasses. They may be said, roughly, to consist
in the presence or absence of glumes, of awns, and of the
upper palet ; in the general aspect of the whole flower-
cluster ; in the number of flowers in the spikelets ; and
in the varying relative size of the glumes and of the palets.

114. The Order as a whole is distinguished by the
following characters :

1. The sheaths of the leaves are split on the side of the

culm opposite the blade.

2. The separate -flowers are enclosed in glumaceous bracts

called palets.
S. The perianth in represented by the lodicules.
4' The stamens are three in number , and the pistil is

syncarpous (two carpeL^J, ^'^'^li' ^ one-celled ovary

producing a single seed, which is always albuminous

with the embryo on one side.

CHAPTER XV

COMMON CHARACTERISTICS OF THE PLANTS JUST EXAMINED —
STRUCTURE OP THE SEED IN MONOCOTYLEDONS.

115. It is now to be pointed out that the plants
examined in the last three chapters, though differing iu
various particulars, yet have some characters common to
all of them, jmst as the group ending with Maple was

CHARACTERS COMMON TO MONOCOTYLEDONS.

85

found to be marked by characters possessed by all its
members. The flowers of Dicotyledons were found to
have their parts, as a rule, in fours or fives ; tliose of our
second group have them in threes or sixes^ never in fives.
116. Again, the leaves of these plants are straight-
veined, except in Trillium and Indian Turnip, which must
be regarded as exceptional, and they do not as a rule
axhibit the division into petiole and blade which was
found to characterize the Exogens.

117. We shall
now compare the
structure of a
grain of Indian
Corn with that of
the Cucumber or
Fig. no. Fiff.iia Fig. 111. Pumpkin seed

which we have already examined (page 59). It will
facilitate our task if we select a grain from an ear which
has been boiled. And, first of all, let us observe that the
grain consists of something more than the seed. The
grain is very much like the achene of the Buttercup, but
difiFers in this respect, that the outer covering of the
former is completely united with the seed-coat underneath
it, whilst in the latter the true seed easily separates from
its covering. Remove the coats of the grain, and what is
left is a whitish, starchy-looking substance, having a
yellowish body inserted in a hollow (Fig. 110) in the
middle of one side. This latter body is the embryo^ and
may be easily removed. All the rest is albumen. Fig.
Ill is a front view of the embryo, and Fig. 112 shows a
vertical section of the same. The greater part of the

Figs, no, 111, 112.— Sections of a grain of Indian Corn. (Gray.)

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ELEMENTS OP STRUCTURAL BOTANY.

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embryo consists of a sim/le cotyledon. The radicle is seen-
n(!ar the base, and the plumule above. Compare an Oat
(Fi^'. 113) with the grain of Corn and make out the corre-
sponding parts. In all essential particulars they are alike.

118. Comparing the result of our observations with what

wo have already learned about the Cucumber seed, we find

that whilst in the latter there are two cotyledons, in the

2)resent case there is but owe, and this peculiarity is

common to all the plants just examined, and

to a vast number of others besides, which are

consequently designated Monocotyledon-

OUS plants, or shortly MonOCOtyledonS.

The seeds of this great group may differ -as to

J^ the presence or absence of albumen, just as

the seeds of Dicotyledons do, but in the num-

ber of their cotyledons they are all alike.

The Orchids, however, are very peculiar from

having no cotyledons at all.

1 1 9. In addition to the points just mentioned,
viz : the number of floral leaves, the veining of
the foliage leaves, the usual absence of distinct petioles, and
the single cotyledon, which characterize our second great
group, there is still another, as constant as any of these,
and that is, the mode of growth of the stem, which is
quite at variance with that exhibited in Dicotyledonous
plants. In the present group the increase in the thickness
of the stem is accomplished not by the deposition of circle
after circle of new wood outside the old, but by the pro-
duction of new wood-fibres through the interior of the
stem generally. These stems are therefore said to be

Fig. 113. — Vertical section of Oat grain ; R, radicle ; G, plumule ; C,
cotyledon ; A, albumen (or endosperm) ; O, hairs ; T, testa. (ThomS.)

OHAEACTBRS OF MONOCOTYLEDONS.

87

nndogenous^ and the plants composing the group are called
Endogens, as well as Monocotyledons. The term

Endogen, however, is used in quite a different sense by
some recent botanists, and is discarded by them aa a
synonym for monocotyledon, as having been given originally
under a misconception as to the true mode of growth of
the wood in stems of this kind. We shall explain more
fully the structure of exogenous and endogenous stems
when we come to speak of the minute structure of plants
in a subsequent chapter.

120. The typical flower of the Monocotyledons is that
of the Lily ; it consists of five whorls, two belonging to the
perianth, two to the anthers, and one to the pistil Other
flowers of the group, as we have seen, exhibit departures
from the type, chiefly in the suppression of whorls or
parts of whorls. Thus in the Iris one whorl of stamens
is suppressed. In this plant, also, the ovary is inferior.
In the spadiceous plants the perianth is suppressed, and
in the Grasses there may be suppression in all the whorls.

iiil

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CHAPTER XVI.

EXAMINATION OF CONIFEROUS PLANTS -

GROUND-HEMLOCK.

-WHITE PINE —

121. The cone-bearing trees are so striking and important
a feature in Canadian vegetation that even an elementary
work like the present would be incomplete without a
notice of them. They form, besides, a very distinct group

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88

ELEMENTS OF STRUCTURAL BOTANY.

of plants, intermediate in structure, as we shall see,
between the groups upon which we have so far been

Fig. 114.

engaged and others to which we shall presently direct
attention.

122. As perhaps the commonest Canadian type of the
Coniferous Group, the White Pine first demands our
attention. This noble tree, in its general aspect, is
familiar to every one. It produces a straight trunk,
which is continued upward year after year by the develop-
ment of a strong terminal bud, the new branches of each
year being developed from a circle of lateral buds formed
behind the apex of the stem or old branch. The general
aspect of the tree, therefore, unless it is a very old one, is
that of a broad-based cone or spire. The leaves are straight

Fig. 114.— Leaves and cluster of staminate catkins of White Pine. (Wood
and Steele.)
Fig. 116.— Pollen-grain of Pine. (Wood and Steele.)

WHITE PINB.

89

-^^^Z

needles, and are produced in clusters of five each. In the
Red Pine, on the other hand, there are but two leaves in
the cluster. Other species have bundles of three each.
These leaves, as is well known, are evergreen^ that is to
say, they do not perish in the first autumn, but persist
through the winter and until the new leaves of the
following season are fully developed.

123. The flowers of the Pine must be looked for in
spring just before the new leaves are put forth. They are

monoecious or dioecious. The staminate flowers,
consisting of a single stamen each, are produced
around the bases of the new shoots, where they
form dense clusters of small catkins (Fig. 114).
Each anther is two-celled, and the pollen-grains
(Fig. 115) are rather peculiar in shape, having, in
fact, the appearance of three grains cohering
together. The two outer portions, however, are
only bladder-like developments of the outer coat
(extine) of the real grain, which occupies the
Fig. 116. centre.

124. The pistillate or fertile flowers are aggregated
together upon an elongated axis, forming in fact the well-
known cone of the Pine (Fig. 116). The young cones
will be found to occupy lateral positions on the branches ;
each of them is made up of many spirally arranged scales,
each scale being in the axil of a bract (Fig. 117). At the
base of each scale, on the inside, will be found two ovules
turned downwards (Fig. 118). Observe that these ovules
are not enclosed in an ovary. Because of this fact the
group of plants of which the Pine is a type is said to be

Fig. 116.— Cone of Pine. (Wood and Steele.)

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90

ELEMENTS OP STRUCTURAL BOTANY.

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Fig. 117.

gymnospermous^ that is, naked-seeded. All the plants
previously examined, on the other hand, have their seeds
enclosed in ovaries ; hence they are all angiospermous. The
scales of the cone are to be regarded as open
carpellary leaves, and each of them, with its
pair of ovules, constitutes a fertile flower.
The pollen is carried by the wind directly to
the micropyle of the ovule, there being no
intervening stigma; but, as the quantity of pollen produced
is immense, the chances of failure to reacli the ovules
are very slight. At the time of pollination, tlie air in a
pine forest is full of pollen. The yellow scum often
found on water after a summer shower is chiefly Pine
pollen. After fertilization the ovules develope into seeds,
and the scales of the cone, which are origin-
ally of rather soft texture, attain a woody
consistency. This process of maturing, how-
ever, in the Pine takes considerable time.
The cones do not ripen until the autumn of
the second year, after flowering. At this time the scales
diverge from the axis, and the seeds are allowed to
escape, each of them being now furnished with a wing,
which enables the wind more readily to waft it away.
The number of cotyledons in the embryo is variable,
but is always more than two ; sometimes there
are as manv as twelve.

The wood of the Gymnosperms is essentially
like that of the Dicotyledons, and the stem
thickens in the same way. Certain diflerences
Pig. 119. will be noticed in another place.

Fig. 117. — Single scale of Pine cone with its bract. (Wood and Steele.)
Pig. 118. — Inner side of the scale, showing the two naked ovules. (Wood
Fig. 119.— Starainate catkins of Ground Hemlock. [and Steele.)

Fig. 118.

GROUND HKMLOCK

91

125. It will be interesting' now to compare with the
structure of the Pine that of another member of the same
group — the Ground Hemlock, a low shrub common enough
in our Canadian woods. This, like the Pine, is evergreen.
The leaves, however, are not needle-shaped, but fiat ; and
they are not clustered, but project singly from tlie sides of
the stem.

126. The staminate flowers (Fig. 119) grow in small
catkins at the ends of very short lateral shoots which

bear about their bases
many scale-like
bracts. The stamens
are somewliat differ-
ent from those of
Pine, being umbrella-
shaped (peltate), and
bearing from three to
^'^- ^20- Fig. 121. gj„|,^ pollen-sacs upon

the under surface. The fertile flowers are also at the
extremities . of short, scaly-bracted branches, but in this
plant the flowers occur singly.^ and are not aggregated in
cones. Fig. 120 shows a section of a fertile branch with
its bracts and the single naked ovule at its extremitv
Around the base of the ovule there is a fleshy ring or disk
(shown in section at a in the figure). The pollen is conveyed
by the wind directly to the micropyle, and after fertiliza-
tion, and during the development of the seed, the fleshy
ring upon which it rests grows upward so as to surround
the seed and give the fruit a remarkable berry-like
appearance (Fig. 121). This fleshy covering (which is

Fig. 120.— Section of fertile branch of Ground Hemlock ; s, the apparently
terminal ovule ; i, its inteffument ; k, the nucellus ; in, the micropyle ; a a,
the rudiment of the aril, which finally surrounds the seed ; b h, bracts. (Prantl).

Fig. 121.— The same with mature fruit, /. (Prantl).

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ELEMENTS OF MTKUCTURAL BOTANY.

bright red at iimturity) ia a good examplcj of what is
(jailed an aril,

1 27. Wo find, then, that although there is at first sight
little in common, apparently, between the cone of the
Pine and the berry-like fruit of the Ground Hemlock
{Taxus haccata), yet they both have the characteristic
naked ovules.

128. Among our cone-bearing trees will readily be
recognized the Arbor Vitse (commonly called Cedar), the
Larch or Tamarack, which, however, is not evergreen,
and the various kinds of Spruce or Fir. The Juniper,
also, belongs to this group, but is marked by the
petiuliarity that the few scales of the cone cohere together
in ripening and become succulent, thus forming what
looks like a berry.

129. To sum up the results of our observations upon
plant-structure, we have found

(1) That all the plants to which our attention has so

far been directed produce fiowevH ; they are all,
therefore, flowering or 'phanerogamous plants, or,
briefly, phanerogams.

(2) That in a large number of the plants there are

ovaries enclosing the seeds. All such plants are
grouped as angiosperms.

(3) That in others the seeds are not enclosed in an

ovary. Hence we have a group known as gymno-
sperms.

(4) That the angiosperms are either dieotyledonous or

monocotyledonous.

MoltrHOLOOY OK UOOTS, hTEMH, AND FOLIAOE-LBAVES. 93

Tho«o conclusions nuiy be conveniently shown in a
tabular form as follows :

rHANKHOOAMS.

I

ANOIOBPKRMH.

I

OYMNOHPKBMI.

DICOTYLEDONS.

MONOCOTYLEDONS.

CHAPTER XVII.

MORPHOLOGY OP ROOTS, STEMS, AND FOLIAGE-LEAVES OF

PHANEROGAMS.

130. Before proceeding with the examination of other
selected plants illustrative of other divisions of the
vegetable kingdom, we shall present in a systematic way
the more important facts in connection with the Phanero-
gams, dealing in turn with the organs of vegetation —
the root, the stem, and the foliage-leaves — and then with
the organs of reproduction as displayed in the flower.
The various forms assumed by these organs, whether in
different plants or in different parts of the same plant,
will have our attention, as also their various modes of
arrangement. We shall consider, also, rather more
minutely than we have hitherto been able to do, the
development of the seed from the ovule, the process of
pollination and of fertilization, and the subsequent
germination of the seed and development of the new
plant. To this study of forms the name Morplioloyy
has been given. It need hardly be said that effective
morphological work can only be accomplished by actual

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KLKMKNIS OV H I'KUC IIJUAL HOTANY.

B li

contact with and inspection of the forms which are, for
the time being, the ohjocts of study. The young student
must provide himself with specimens, and learn to
associate the descriptive terms with the actual condition
which the terms describe. Only in this way can this
branch of botanical work be relieved of the element of
drudgery, and made what it ought to be — a means of
developing in a high degree those powers of observation
with which the young are so exceptionally endowed. It
is believed that with proper management even the
more difficult technical terms, which are derived from
Latin and Greek, and specially devised for botanical
purposes, will be learned without extraordinary effort. It
is the writer's experience that a term is insensibly
acquired and almost indelibly impressed upon the mind if
there isjird created the loaut of the term to describe what
is seen when some new form has been the subject of obser-
vation, and its peculiarities have been thoroughly grasped
through the medium of the eye. With a good many of
the terms there will bo found no difficulty whatever,
since they have the sanje meaning in their botanical
applications as they have in their e very-day use.

131. The Root. This organ is called the descending
axis of the plant, from its tendency to grow downward
into the soil from the very commencement of its develop,
ment. Its chief use is to imbibe liquid nourishment,
and transmit it to the stem, from which it is well distin-
guished by the presence of the root-cap (Fig. 122, a) and
the absence of leaves. The absorbing surface of a young
root or rootlet is largely increased by the development of
root-hairsy the nature of which will be explained later on
when we come to treat of trichomes or hair-like growths

HOOTS.

on

of

generally. It must l)o UHMitioiied hero, also, tluit there are
some exceptions to the ^oiioml staUjUKMit that roots do
not produce buds. It is \v«»ll known that n(!vv stems are
s('nt up hy the roots of Poplars and ot Apple trees, for
example, espucially if the roots havo \men injured. These
cases must he regarded as abnormal.

132. You will remember that in our examination of
some common seeds, such as those of the
[ Pumpkin and nean(Kigs, 7 7-81), wo found
at the junction of the cotyledons a small
pointed projection called the radicle. Now,
when such a seed is put into the ground,
under favorable circumstances of warmth
and moisture, it begins to grow or (/frnii-
vat<>, and the radicle, which in reality is a
^n minute stem, not only lengthens, in most
Fig. 122. cases, so as to push the cotyledons
upwards, but developes a roitt from its lower
extremity. All seeds, in short, when they
germinate, produce roots from the extremity
of the radicle, and in a direct line with it^ and
roots so produced are called jtriinai'fj roots. In
Monocotyledons the primary root is but very
slightly developed, the fibrous roots character- /
istic of these plants bursting forth from the
sides oi the radicle at an early period of growth.
In other plants the primary root either assumes Fig. i2.i.
the form of a distinct central axis larger than any of its
branches, and called a tap-root (Fig. 123), examples of
which are furnished by the Mallow, the Carrot, and the

Fig. 122.— Magnified tip of Hyacintli root ; a, tiie root-cap. (Hoolcer.)
Fig. 123.— Tap-root of Dandelion.

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96

ELEMENTS OF STRUCTURAL BOTANY.

Bean, or it may branch at an early stage into numerous
similar threads, and so form a fibrous root, as in Buttercup.

133. Tap-roots receive different names according to
the particular shape they happen to assume.
Thus, the Carrot (Fig. ] 24) is conical^ because
from a broad top it tapers gradually and regularly
to a point. The Radish, being somewhat thicker
at the middle than at* either end, is spindle-
shajied. The Turnip, and roots of similar shape,
are napiform {napus, a turnip).

These fleshy tap-roots belong, as a rule, to
biennial plants, and are designed as storehouses
^' ' of food for the plant's use during its second year's
growth. Occasionally fibrous roots also thicken in the
same manner, as in the Peony, and then they are said to
be fascicled or clustered.
(Fig. 125).

1 34. But you must have
observed that plants some-
times put forth roots in
addition to those develop-
ed from the embryo of the
seed. The Verbena of our
gardens, for example, will
take root at every joint if
the stem be laid upon the ground (Fig. 126). The
runners of the Strawberry take root at their extremities;
and nothing is more familiar than that cuttings from
various plants will make roots for themselves if put into
proper soil, and supplied with warmth and moisture.

Fig. 125.

Fig. 124.— Tap-root of Carr.it.

V\%. 125.— Fascicled roots of Peony.

ROOTS.

97

All such roots, not developed from the end of the radicle
and in a straight line with it, are called secondary or
adventitious roots. Under this head should, of course, be
placed the fibrous roots of all Monocotyledonous plants,
the true primary roots of which are but very feebly

developed. So,
also, all branches
of primary roots
should be re-
garded as adven-
titious. When
such roots are
developed from
parts of the stem
which are not in
contact with the
ground, they are

Fig. 126.

aerialf as, for example, the roots developed from the
lower joints of the stem of Indian Corn.

135. There are a few curious plants whose roots never
reach the ground at all, and which depend altogether
upon the air for food. These are called epiphytes. There
are others whose roots penetrate the stems and roots of
other living plants, and thus receive their nourishment
as it were at second-hand. These are parasitic plants.
The Dodder and Beech-drops, of Canadian woods, are
well-known examples. Others, again, subsist upon
decomposing animal or vegetable matter, and are lence
known as saprophytes. Indian Pipe and Coral-root are
good examples of saprophytic plants. Both parasites
and saprophytes are usually destitute of green leaves,

Fig. 126.— Adventitious roots of Verbena.

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98

ELEMENTS OP STRUCTURAL BOTANY.

being either pale or brownish. The Mistletoe, however,
is a green parasite.

136. As to duration, roots (and, consequently, the
plants themselves) are either annual^ or biennial, or
perennial. The plant is called an annual if its whole life,
from the germination of the seed, is limited to one
season. It is biennial if it flowers and ripens its seed
in the second season. Between these two classes it is
difficult to draw a sharp line, because, with proper care,
some annuals may be induced to live for two years ; and,
on the other hand, some plants, as the Radish, which
are properly biennial if the seed is sown in the fall, will
flower and produce seed in one season if sown in the
spring. Something, also, depends upon the climate in
which the plant is grown, its life, in some cases, being
prolonged in a more favourable situation. Perennials
live on year after year, as is the case with all our shrubs
and trees, and also with some herbaceous plants, as Peony
and Dahlia, which only die down to the surface of the
ground in the autumn.

137. The Stem. As the root is developed from the
lower end of the radicle of the embryo, so the stem is
developed from the upper end, but with this important
diflerence, that a hud always precedes the formation of
the stem or any part of it or its branches. If a bud, such
as that of the Lilac, be jjicked to pieces, it will be found
to consist mostly of minute leaves closely packed together
on a short bit of stem. A bud, in fact, is only a special
condition of the extremity of the stem, and is not to be
regarded as an organ distinct from it. As the bud unfolds,
the stem may lengthen so as to exhibit the internodes, or

^ ■'!■

STEMS.

99

it may remain short, in which case the expanded leaves
form a cluster or rosette, aa in Dandelion. The tender
leaves of the bud are not uncommonly protected from the
weather by coverings in the form of tough scales, with the
additional safeguard sometimes of a wax-like coating on
the surface of the latter, as seen in the conspicuous buds
of the Horse-Chestnut, and the cap-like coverings of those
of the Spruce.

138. Between the cotyledons of the Bean (Fig. 81), at
the top of the radicle, we found a minute bud called the
plumule. Out of this bud the first bit of stem is developed
(leaving out of consideration the radicle itself), and during
the subsequent growth of the plant, wherever a branch is
to be formed or a main stem to be prolonged, there a bud
will invariably be found. The branch buds are always in
the axils of leaves, and so are called axillaryy and it not
uncommonly happens that several buds are found together
in this situation.

1 39. Adventitious buds, however, are sometimes produced
in plants like the Willow, particularly if the stem, has
been wounded. As already mentioned, they are also
occasionally produced upon roots, as, for example, upon
those of the Poplars.

140. The bud from which the main stem is developed,
or a branch continued, is of course at the end of the stem
or branch, and so is terminal.

141. Branching or Ramification. By a branch

is meant an off-shoot similar in structure to the member
from which it springs. Hence the side-shoots of roots
are root-branches ; so, also, the lateral out-growths of the
stem which resemble the stem itself in structure are

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100

ELEMENTS OF STKUCTUUAL BOTANY.

stem-branches. It is found that the branching of stems
proceeds upon two well defined plans.

142. Monopodial BraucMmj. This system is distin-
guished by the circumstance that all the branches are the
result of the development of strictly lateral buds. In
other "words, there is invariably a terminal bud at the
apex of the stem distinct from the lateral buds produced
behind the apex. Of this system there are several

Fig. 130.

Fig. 127.

Fig. 128.

modifications. If the terminal bud develops regularly, as
well as the lateral ones, it is clear that we shall have a
straight and well-defined trunk, easily distinguished by
its vigorous growth from the branches. The Pine or
the Spruce is an excellent example of this effect.

Figs. 127, 128, 130.— Diagrams of various forma of monopodial branching.
(Sachs.)

MONOPODIAL BRANCHING.

101

But if the terminal bud, though produced, ceases
to grow, while the lateral buds are vigorously developed,
as is well exhibited in the spring by the annual shoots
of the Lilac, then it is clear that the
6 branches will overtop the original stem,
' and the latter will finally become unrecog-
nizable.

143. The Pine and the kSpruce and
similar forms are said to be racemose or
botryose, and the Lilac, in the development
of its annual shoots, is said to be eymose.
Fig. 127 is a representation of the latter
mode. Here 1 is the extremity of the
main stem, but the terminal bud at that
point has failed to grow, while two vigor-
ous branches have been produced. The
terminal buds of these branches (2 and 2),
have in their turn failed, and the laterals
immediately behind them have, as before,
given rise to new shoots. This is the result, then, when
both the lateral buds grow with equal vigour, and it is
known as a forlted cyme.

144. But sometimes one member of each pair of buds
is developed far more strongly than the other. If tlie
strong buds are developed in succession on the same side
of the stem an effect will be produced like that represented
in Fig. 128. This is known as a helicoid cyme. If,
however, the strong buds are developed alternately on
both sides of the stem, we get the form shown in Fig.
129, which is then called a scnrpioid cyme. Not-un»

' III ■—■■.■■III I — ■ , — I I ■ -I. , ■■1^.^^^

Fig. 129.— Diagram to illustrate acorpioid oyme. (Sachs.)

Fig. 129.

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102

ELEMENTS OP STRUCTURAL BOTANT.

commonly this latter form becomes straightened out, as in
Fig. 130, so that the successive branches are in the same
line, and look like a stem developed from the terminal

bud. As tlie foot or
support is not in this
case the continuation
of a single axis, but
is made up of a num-
ber of successive
branches superposed,
these forms are said
to be sympodial, the
prefix in this term
having the same sig-
nificance as in " syn-
carpous" and the lik(^,
and implying that the
foot is composed of
several coherent parts.
In these cases, then,
we have a sympodial
monopodium.

145. Dichotomous Branching. In this system the
growing point at the apex of the stem divides into tioo new
growing points^ both of which are, therefore, terminal and
not lateral, as in the first mode. The growing points of
the branches, in their turn, are each converted into two
new ones, as shown in Fig. 131. As in the monopodial
mode, there may be helicoid and scorpioid dichotomy,
due to the superior development of the growing points on

Figs. 131, 132, and 133.— Diagrams to illustrate dichotomous branching.
(Sachs.)

Fig. 133.

Fig. 132.

DiCnoTOMOUa BUANCHINO.

103

one side, or on alternate sides of the stem, as shown in
Figs. 132 and 133. These forms are, of course, synipodial.

146. A comparison of Figs. 127 and 131 will show
that there is a superficial resemblance between the forms.
On this account the forked cyme is sometimes referred to
as a dichasium or false dicliotoimj.

147. Dichotomous branching is rare, but occurs in the
roots of Club-Mosses, and* in Lichens. In the phanero-
gams, monopodial branching is the almost invariable rule.
The flowering stems, which afford the best illustrations,
will be referred to hereafter.

148. If you examine a few stems of plants at random,
you will probably find some of them quite soft and easily
compressible, while others will be firm and will resist
compression. The stem of a Beech or a Currant is an
instance of the latter kind, and any weed will serve to
illustrate the former. The Beech and the Currant have
woody stems, while the weeds are herbaceous. Between
the Beech and the Currant the chief difference is in size.
The Beech is a tree, the Currant a ,'ihriib. But you are
not to suppose that there is a hard and fast line between
shrubs and trees, or between herbs and shrubs. A series
of plants could be constructed, commencing with an
unquestiona])le herb and ending with an unquestionable
tree, but embracing plants exhibiting such a gradual
transition from herbs to shrubs and from shrubs to trees,
that you could not say at what precise point in the series
the changes occurred.

149. The forms assumed by stems above ground are
numerous, and they are described mostly by terms in
common use. For instance, if a stem is weak and trails

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104

BLEMKNTS OP STRUCTURAL BOTANY.

along tlie ground, it is trailing or prostrate ; and if, as in
the runners of the Strawberry, it takes root on the lower

side, then it is
creeping. Such a
shoot as the run-
ner of the Straw-
berry, which takes
root at a distance
from the parent
Pj J34 plant, is commonly

called a stolon.

150. Many weak stems raise themselves by clinging to
any support that may happen to be within their reach.
In some instances the stem itself winds
round the support, assuming a spiral
form, as in the Morning-Glory, the
Hop, and the Bean, and is therefore
distinguished as tivining. In other
cases the stem puts forth thread-like
leafless brnnches called tendrils (Fig.
134), which grasp the support, as in
the Virginia Creeper and the Grape.
In the Pea, the end of the extended
mid-rib of the leaf is transformed into a
tendril (Fig. 135). Sometimes the leaf-
stalks themselves serve the same purpose, as in the
Clematis or Virgin's Bower. In these cases the stems
are said to climb. Our Poison Ivy climbs over logs, &c.,
by the aid of its aerial roots.

The stems of wlieat and grasses generally are known as

Fig. 134. — Loaf and tendril of Grape-vine.
Fig. 135— Tendril of the Fea.

Fig. 135.

!i'

UNDEUGROUNK STKMS.

105

rulms. They are jointed, and usually hollow except at
the joints.

151. Besides the stems which grow above ground,
there are varieties to be found below the surface. Pull
up a Potato plant, and examine the underground portion
(Fig. 136). It is not improbable that you will regard the
whole as a mass of roots, but a very little trouble will
undeceive you. Many of the fibres arc unquestionably

Pig. 136.

roots, but an inspection of those having potatoes at the
ends of them will show you that they are quite different
from those which have not. The former will be found to
be furnished with little scales, answering to leaves, eacli
with a minute bud in the axil ; and the potatoes them-
selves exhibit buds of the same kind. The potato, in
short, is only the sioollen end of an underground stem.
Such swollen extremities are known iis tubers, whilst the

Fig. 136.— Tubers of ih; Potato.

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106

KLKMJiNT.S OF HTItUCTLUAL JUJTANY.

Fig. 137.

underground stem is called a ruut-'^tnrjc or rhizome^ and may
almost always bo distinf,'uislied from a true root by the
presence of buds. The Solomon's Seal and Toothwort of

Canadian woods, and
the Canada Thistle,
are common instances
of plants producing
these stems. Fig. 137
shows a rhizome.

152. Take now an
_ Onion, and compare
it with a Potato. You
will not find any such
outside appearances upon the former as are presented by
the latter. The Onion is smooth, and has no buds upon
its surface. From the under side there spring roots, and
this circumstance will probably suggest that the Onion
must be a stem of some sort. Cut
the Onion through from top to bot-
tom (Fig. 138). It will then be
seen to be made up of a number of
coats. Strip off one or two, and ob-
serve that whilst they are somewhat
fleshy where the Onion is broadest,
they gradually become thinner to-
wards the top. The long, green tubes
which project from the top of the '*''"

Onion during its growth are, in fact, the prolongations of
these coats. But the tubes are the leaves of the
plant itself. The mass of our Onion, therefore, consists

Fig. 137.— A rhizome.

Fig. 138.— Vertical section of bulb of the Onion.

M

UNDKHOIIOUNP HTKMS.

107

of iho JlesJty hascii of the. learcx. But you will observo
that at the bottom there is a ratlier ihit, solid part
upon which these coats or leaves are
inserted, and Avhich must consequently
be a stem. Such a stem as this, with its
fleshy leaves, is called a bulb. If tin-
leaves form coats, as in the Onion, the
bulb is coated or tunicated; if they do
^^«- ^^^' not, as in the Lilies (Fig. 139), it is srnhj.

153. Tubers and bulbs, then, consist chiefly of masses
of nourishing matter ; but there is this difference, that
in the latter the nourishment is contained in the fleshy
leaves themselves, whilst in the former it forms a mass
more or less distinct from the buds.

154. The thickened mass at the base of the stem of
our Indian Turnip (Fig. 94) is more like a tuber than a
bulb in its construction. It is called a corm or solid
bulb. The Crocus and Gladiolus of the gardens are
other examples. The chief difference between the corm
and the ordinary bulb is in the relative space occupied
by the stem or solid part. In the former it is very much
greater than in the latter. The student should dissect
specimens of Indian Turnip, Crocus, Tulip, Hyacinth,
(fee, when these differences will be readily apprehended.

155. In the axils of the leaves of the Tiger Lily are
produced small, black, rounded bodies, which, on
examination, prove to be of bulbous structure. They
are, in fact, bulblets, and new plants may be grown from
them.

156. Foliage-Leaves. These organs are usually
more or less flat, and of a green colour. In some plants,

Fijf. 139.— Bulb of a Lily.

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108

KLKMKNTH OF STIlUCTURAFi HoTANY.

however, they are extremely thick and succulent ; and
in the case of parasites and saprophytes, such as Indian
Pipe and Jieecli-drops, they are usually either white or
brown, or of some colour other than green. The scaly
leaves of underground stems are also, of course, destitute
of colour. The green colour is due to the presence of
granular particles of a substance called chlorophyll. It
is formed, as a rule, only in those parts which are
exposed to tJie action of sunlight, and it is intimately
connected with the process of assimilating nutritious
matter for the plant's use during growth. Further
reference will be made to it later on.

157. As a general thing, leaves are
extended horizontally from the stem or
branch, and turn one side towards the
sky and the other towards the ground.
But some leaves are vertical^ and in the
case of the common Iris (Figs. 88 and 89)
each leaf is doubled lengthwise at the
base,and sits astride the next one within.
Such leaves are called eqnitant,

158. Phyllotaxis or Leaf- Arrangement. As to

their arrangement on the stem, leaves are alternate when
only one arises from each node (Fig. 3). If two are formed
at each node, they are sure to be on opposite sides of the
stem, and so are described as opposite. If, as in Mint
and Maple, each pair of opposite leaves stands at right
angles to the next pair above, then the arrangement is
decussate. Sometimes there are several leaves at the same
node,in whichcase they aveivhorled or verticillate(Fi^.l4iO).

Fig. 140.— Whorled leaves of Galium.

Fig. 140.

I'UYLLOTAXIM.

109

159. Even if tlie loaves iin; placeJ singly and apparently
irregularly at intervals along tlio atmn, it will bo found on
examination that their arrani^onicnt is g(»vtM'nod hy dt^finite
laws. Take, for instance, a bram )i of i^ojildr with a
number of leaves upon it. Fix upon any one loaf nuav
the lower end of the branch, and then from its point of
insertion draw a line, hij tha iicarext wat/y to the insertion
of the next higher leaf, and from this to the noxt, ami so
on till you reach a loaf whicli is exactly over tlie first one*
If the branch itself has not been twisted out of its normal
shape, it will be found that the tii.dh leaf is always
precisely over the first, the seventh over the second, the
dghth over the third, and so on, and that the line joining
the points of insertion of successive leaves forms a spiral
round the stcmi. It will also be found that this spiral
goes twifr round the stem before passing through the
sixth leaf. The sixth loaf, as standing exactly over the
first, begins a new sot, which lasts in a similar manner till
we reach the eleventh. The leaves are therefore in sots or
cycles of five each, and the phyllotaxis in this case is
conveniently described by the fraction g, tlie denominator
of which gives the number of leaves in the cycle, and the
numerator the number of turns in the spiral.

160. Nowjif through the insertions of the leaves which are
vertically over each other — that is, through those numbered
I, C, 11, 16, etc., and then through those numbered 2, 7,
12, 17, and so on — lines be drawn, it is evident we shall
have five such vertical lines on the stem. These linen
mark the ranks of leaves, or orthostichies. The numbei
of orthostichies in any case always corresponds to the
number of leaves in the cycle.

III

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ELEMENTS OP STRUCTURAL BOTANV.

w

H ff

161. In the Elm, the phyllotaxis is much simpler.
Here, starting with any given leaf, it will be found that
tlie next one is exactly half way round the circumference
of the stem, and the third one exactly over the first, and
so on. So that the sj)iral completes the circuit in one
turn, and the number of orthostichies is only two, the
phyllotaxis being therefore described as ^. The ^ arrange-
ment is also common. The Poplar, as we see, has a f
arrangement ; this is extremely common.

162. If we set down these fractions in order, thus : |^,
i, I, it will be noticed that the sum of the first two
numerators gives the third numerator ; so also with the
denominators. If we proceed to make other fractions in
this way, the series would read }, I,, f , ^> T-ri} /i > M » and these
are, as it happens, the actual cases of phyllotaxy which we
commonly meet with. The cone of the White Pine
furnishes a very good exercise. In this case the scales
(which, of course, are leaf-forms) have a -^;j arrangement.

163. The conclusion come to from a close examination
of the incipient buds is, that the newer leaves are produced
over the widest intervals between those next below. In
short, the arrangement is that which secures to the leaves
the most advantageous conditions for exposure to the light,
and at the same time economizes space. As has been aptly
said, the growth of the new leaves follows the " lines of
least resistance."

164. When leaves are in whorls instead of in spirals,
the members of any whorl stand over the spaces of the
whorl below, as might be expected. As to leaves which
are clustered or fascicled, like those of the Pine and Larch,
it may be pointed out that the clustering is due simply to

if " -

FORMS OF FOLIAGE-LEAVES.

Ill

the non-development of internodes. The clusters when
carefully examined, show in some cases an alternate, and
in others a whorled, arrangement.

165. As branches are produced in the axils of leaves, it
is clear that the arrangement of branches will be the same
as that of the leaves. It rarely happens, however, that
all the buds develope into branches. Many of them fail,
so that generally branches appear to have no very definite
arrangement.

166. Vernation or Praefoliation. These terms have
reference to the mode in which the new leaves are folded
in the bud. Very commonly the leaf is simply doubled
lengthwise, the upper side of the leaf within ; then its
vernation is said to be conduplicate. In the Maple and
Mallow the folding is fan-like, and is described as plaited.
In the Cherry the leaf is coiled in a single coil beginning
with one edge : this is convolute vernation ; but if the
coiling is from both edges to the mid rib, it is said to be
involute ; if both edges are rolled backward, it is revoliite.
The vernation is circinate when the leaf is coiled from the
tip, as in Ferns.

167. Forms of Foliage-Leaves. Leaves present
an almost endless variety in their forms, and accuracy
in describing any given leaf depends a good deal upon
the ingenuity of the student in selecting and combining
terms. The chief terms in use will be given here.

Compare a leaf of the Round-leaved Mallow with one
of Red Clover (Figs. 141, U2). Each of them is
furnished with a long petiole and a pair of stipules. In
the blade, however, there is a difference. The blade of
the former consists of a &'iw^/ej;/ecc / that of the latter

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112

BLEMENT8 OF STRUCTURAL BOTANY.

is in three separate pieces, each of which is • called a
leafiet, but all of which, taken collectively, constitute the
blade of the leaf. The leaf of the Mallow is simple ;
that of the Clover is COmpound. Between the simple
and the compound form there is every possible shade of
gradation. In the Mallow leaf the lohes are not very
clearly defined. In the Maple (Fig. 143) they are well

Fipr. 141.

Fig. 142.

marked. In other cases, again, the lobes are so nearly
separate that the leaves appear at first sight to be really
compound.

168. You will remember that in our examinations of
dicotyledonous plants, we found the leaves to be invariably
net- veined. But, though they have this general character
in common, they differ considerably in the details of
their veining, or venation, as it is called. The two
leaves employed as illustrations in the last section will

Fig. 141.— Simple palmately-vuined leaf of Mallow.
Fig. 142.— Compoutid leaf of Clover.

jailed a
tute the

mple ;

5 simple
hade of
lOt very
ire well

nearly
B really

lions of
ariably
aracter
tails of
he two
on will

FORMS OF FOLIAGE-LEAVES.

113

serve to illustrate our meaning here

In the Mallow,
there are several ribs of
about the same size, radiat-
ing from the end of the
petiole, something like the
spread-out fingers of a hand.
The veining in this case is
therefore described as digi-
tate, or radiate, or palmate.
The leajiet of the Clover, on
the other hand, is divided
exactly in the middle by a
^^- 1*5' single rib (the mid-rib), and

from this the veins are given oflf on each side, so that
the veining, on the whole, presents the appearance of a
feather, and is, therefore, described as pinnate ^penna, a
feather).

169. Both simple and compound leaves exhibit these
two modes of venation. Of simple pinnately-veined
leaves, the Beech, Mullein, and
Willow supply familiar instances.
The Mallow, Maple, Grape, Cur-
rant, and Gooseberry have simple
radiate - veined leaves. Sweet-
Brier (Fig. 43), Mountain Ash,
and E/Ose have compound pinnate
leaves, whilst those of Virginia-
Creeper (Fig. 144), Horse-Chest-nut
compound digitate.

Fiy. 143.— Palmately-loheo leaf of Maple.
Fig. 144.— Palmate leaf of Virginia Creeper.

Fier. 144.

and Hemp

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114

ELEMENTS OP STRUCTURAL BOTANY.

As lias already been pointed out, the leaves of Mono-
cotyledonous plants are almost invariably straight-veined.

170. In addition to the venation, the description of a

Linear
Oblong
Oval
Orbicular

Fig. 146.

Fig. 146.

simple leaf includes particulars concerning : (1) the gen-
eral outline, (2) the edge or margin, (3) the point
or apex, (4) the base.

171. Outline. As to outline, it will be convenient to
consider first the forms assumed by leaves without lobes,

if

Lanceolate

Ovate

Deltoid

Fig. 147. Fitr. 148.

and whose margins aro therefore more or less continuous.
Such leaves are of three sorts, viz.: those in which both
ends of the leaf are alike, those in which the apex is

Fip-s. 145 to 148 —Various forms of foliage-leaves.

»i!

F()L1AGI>LEAVES.

115

narrower than the base, and those in which the apex is
broader than the base.

172. In the first of these three classes it is evident that
any variation in the outline will depend altogether on the

Fig. 152. Fig. 153. Fig. 149. Fig. 150. Fig. 151.

relation between the length and the breadth of the leaf.

When the leaf is extremely narrow in comparison with its

length, as in the Pine, it is acicular or

needle-shaped {¥\g. 145). As the width

increases, "we pass through the forms

known as linear^ oblong^ oval, and

finally 07'hicular, in which the width

and length are nearly or quite equal

(Fig. 146).

Fig. 154.

173. In the second class the different
forms arise from the varying width of
the base of the leaf, and we thus have subulate or awl-
shaped (Fig. 147), lanceolate, ovate, and deltoid leaves

(Fig- U8)-

Figs. 149 to 154. — Variotjs forms of foliage-leaves.

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116

ELEMENTS OP STRUCTURAL BOTANY.

174. In the third class, as the apex expands, we have
the forms spathulate (Fig. 149), ohlanceolate — that is, the
reverse of lanceolate (Fig. 150), and obovate (Fig. 151).

175. In leaves of the second kind we frequently find
the base indented, and then the leaf is cordate or heart-

\\

Fig. 155.

Fig. 156.

Fig. 157.

shaped (Fig. 152). The reverse of this — that is, when the
indentation is at the apex — is ohi'ort'!ate (Fig. 153). The
hastate or spear-shaped (Fig. 1-^4), sagittate or arrow-
shaped (Fig. 155), and reniform or kidney-shaped (Fig.
156) forms are modifications of the second
class, and will be readily understood from
the annexed figures.

If the petiole is attached to any part of
the under surface of the leaf, instead of to
the edge, the leaf is peltate (shield-shaped)
(Fig. 158).

Fig. 158.

176. Leaves which are lobed are usually described by
stating whether they are palmately or pinnately veined ; and

Figs. 155 to 158.— Various forms of foliage-leaves.

FOLIAGE-LEAVES.

117

if the former, the number of lobes is generally given. If the
leaves are very deeply cut, they are said to be palmatijid
or J) hmatifid J according to the veining (Fig. 1 59). if the leaf
is pinnatitid and the lobes point backwards
towards the base, as in Dandelion, the leaf
is said to be ramiinatG. If the leaf is palniately
lobed, and the lobes at the base are them-
selves lobed, the leaf is pedate (Fig. 160),
because it looks something like a bird's foot.
If the lobes of a pinnatifid leaf are them-
^ selves lobed, the leaf is hipiunatifid. If the
leaf is cut up into line segments, as in
Dicentra, it is said to be multijid.

177. Apex. The principal forms of the
Fig. 159. apex are the mucronate (Fig. 157), when
the leaf is tipped with a sharp
point, as though the mid-rib were
projecting beyond the blade;
eu^idatey when the leaf ends
abruptly in a very short, but
distinctly tapering, point (Fig.
Vv 161); acide, or sharp;
' ' and obtuse, or blunt.

It may happen that the apex does not end in
a point of any kind. If it looks as though the
end had been cut off square, it is truncate. If
Fig. 161. the end is slightly notched, but not sufficiently
so to warrant the description obcordate, it is emarginate.

178. Margin. If the margin is not indented in any
way, it is said to be entire. If it lias sharp U^.Qih, pointing

Figs. 159 to 161. — Various forms of foliage-leavea.

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118

ELEMKNTS OF STRUCTUKAL BOTANY,

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Fig. 162.

in the direction of the apeXf it is serrate, and will he
coarsely or finely serrate, according to the size of the
teeth. Sometimes the edtfes of lar^e teeth are themselves

finely serrated, and in that case the
leaf is doubly serrate (Fig. 162). If
the teeth point outwards, that is,
if the two edges of each tooth are of
the same length, the leaf is dentate;
but if the teeth, instead of being
sharp, are rounded, the leaf is crcnate
(Fig. 163). The term icavy explains
itself.

179. Base. There are two or three peculiar modifica-
tions of the bases of simple sessile leaves which are of
considerable importance in distinguishing plants. Some-
times a pair of lobes project backwards and
cohere on the other side of the stem, so that the
stem appears to pass through the leaf. This is
the case in our common Bell wort, the leaves of
which are accordingly described as ^;er/6>//a^c
(Fig. 164). Sometimes two opposite
sessile leaves grow together at the base
and clasp the stem, as in the upper
leaves of Honeysuckle, in the Triosteum, and in
one of our species of Eupatoriurn. Such leaves
are said to be connate or connate-perfoliate (Fig.
165). In one of our Everlastings the margin
of the leaf is continued on each side below the
point of insertion, and the lobes grow fast to the sides of
the stem, giving rise to what is called the decurrent form
(Fig. 166).

Figs. 162 to 164. — Various forms of foliage-leaves.

Fig. 163.

Fig. 164.

FOLIAGE-LEAVES.

119

The terms by which simple leaves are described are
applicable also to the leaflets of compound leaves, to the
sepals and petals of llowors, and, in short, to any flat forma.

Fig. 165.

Fig. 160.

180. We have already explained that compound leaves
are of two forms, j^innate and palmate. In the former the
leaflets are arranged on each side of the mid-rib. There may
be a leaflet at the end, in which case the loaf is odd-pinnate;
or the terminal leaflet may be wanting, and then the leaf is

Fig. 167.

abruptly pinnate. In the Pea, the leaf is pinnate and
terminates in a tendril (Fig. 135). Very frequently the
primary divisions of a pinnate leaf are themselves pinnate,
and the whole leaf is then twice-pinnate (Fig. 167). If

Figs. 165 to 167. — Various forms of foliage-leaves.

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120

ELEMENTS OK HTUUCIUHAL JJOTANV.

♦'^ij

the sulxlivision is continued through another stage, th(!
leaf is thrice-pinnate, and so on. Soinotinies, as in the
leaves of the Tomato, very small leaflets are found between

the larger ones, and this form is
described as interruptedly pinnate
(Fig. 168).

In the palmate or digitate forms
the leaflets spread out from the end
of the petiole, and, in describing
them, it is usual to mention the
number of divisions. If there are
three, the leaf is tri-foliolate ; if there
are five, it is quinque-foliolate.

181. In the examination of the
Mallow we found a couple of small
leaf-like attachments on the petiole
**' ■ of each leaf, just at the junction

with the stem. To these the name
stipules was given. Leaves which
have not these appendages are
exstipulate.

182. Besides the characters of
leaves mentioned above, there re-
main a few otliers to be noticed.
With regard to their surface,
leaves present every gradation from
perfect smoothness, as in Winter-
green, to extreme roughness or
woolliness, as in the Mullein. If hairs are entirely absent.

Fig. 168.— Interruptedly pinnate leaf.
Fig. 169.— Leaf of Pitcher-Plant.

Fig. 169

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I'DLIAUK-LKAVES.

1-21

the leaf is (jlahrom ; if present, tlie degree of hairiness is
described by an appropriate adverb ; if tlio leaf is eoni-
))letely covered, it is villoiis uv villoi^e ; and if the hairs ant
on the margin only, as in our Clintonia, it is cJliatf.
Some leaves, like those of the Cabbage, have a kind of
V)loom on the surface, which may be rubbed off with the
fingers ; this condition is described as glaucous.

183. A few plants liave anomaloUS leaves. Those
of the Onion are fillforin. The Pitcher-Plant of our
northern swamps has very curious leaves (Fig. 1G9),
apparently formed by the turning in and cohesion of the
outer edges of an ordinary leaf so as to form a tube,
closed except at the top, and armed on the inner surface
with bristles pointing towards the base of the leaf.

184. Finally, as leaves present an almost infinite
variety in their forms, it will often be necessary in
describing them to combine the terms explained above
For instance, a leaf may not be exactly linear, nor exactly
lance-shaped, but may approximate to both forms. In
such a case the leaf is described as lance-linear, and so
with other forms.

The following form of schedule may be used with
advantage in writing out descriptions of leaves. Two
leaves — one of Maple and one of Sweet Brier — are
described by way of illustration. If a leaf is compound,
the particulars as to outline, margin, apex, base, and surface
will have reference to the leaflets.

The exercise-book prepared to accompany this work
contains a supply of blank schedules for leaf-description,
with space for drawings.

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ULEMUNTli OF iTHUt^lt'KAL UOTAMY.

LEAF SCHEDULE.

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LKAf OF

Mai'lk.

SWKKT BllIKH.

1. PoBitiun.

Cauline.

Cauline.

2. Arrangement.

Opfiositt'.
Potiolatf-.
Exstipulatt'.

Altt'nuiU'.

3. luHertion.

Petiolate.

4. Stipulation.

Stipulate.

5. Division.

Simple.

Odd pinnate, 7 leaflets.

6. Venation.

Palmate.

7. Outline.

Roundish or oval.

8. Margin.

Deeply lobed.

Doubly serrate.

9. Apex.

Pointed.

Aeute.

10. Base.

Cordate.

Hardly indented.

11. Surface.

Glabrous above ;
wliitish beneath.

Downy above ; eoverod
with glands Ijeiieath.

INlKLOUEaCENCK.

1-23

CHAPTKH XVIII.

MORPHOLOGY OP FLOW KUhKA VMS — INFLOKKSCKNCE — TIIK

CALYX — THE CORilLf-.\ — THE STAMENS — THE PISTIL —

THE FRUIT — rilE SEED — OERMINATION.

185. From an examination of the various forms
presented by foliage-leaves, we pt'ocoed now to those oi
the floral ones, ami we shall first consider the chief
modifications in the arminjnment of Jfo/vrrs aft a ir/iolc,
to which the term infloreSCence is applied.

As the organs of which flowers are made up are strictly
leaf-forms, the special stalks upon which they are
produced (peduncles and pedicels) are true branches, and
their development is in strict accordance with the
principles enunciated in sections 141-144. As there
stated, the almost invariable mode of branching in phan-
erogams is monopodial, either after the botryone type oi*
after the cymose type. So inflorescence is found to
proceed upon one or other of these two plans.

186. To understand these let us recur to our specimens
of Shepherd's Purse and Buttercup. You wiW remember
that in the former the peduncle continues to lengthen
as long as the summer lasts, and new flowers continue
to be produced at the upper end. Observe, however,
that every one of the flowers is produced on the side of the
stem, that as the stem lengthens new lateral buds appear,
and that there is no Jiower on tha end of the stem. The
production of the flowering branches (pedicels) and the
continuation of the main axis are, in fact, exactly
analogous to the growth of the Spruce, as explained in
section 142.

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124

KLKMHNTS OF STRUCTURAL BOTANY.

:m.nv

You will easily uiidefstand, then, that the production
of flowers in such a plant is only limited by the close of
the season or by the exhaustion of the plant. Such

inflorescence is, therefore, called indefinite, or inde-
terminate, or axillary. It is sometimes also called
('putripetal^ because if the flowers happen to be in a close
cluster, as are the upper ones in Shepherd's Purse, the
order of development is from the outside towards the
centre.

187. If you now look at your Buttercup you will be
at once struck with the difference of plan exhibited.
The main axis or stem has a flower on the end of it, and
its further growth is therefore checked. And so, in like
manner, from the top downwards, the growth of the
branches is checked by the production of flowers at their
extremities. The mode of inflorescence here displayed

is definite, or determinate, or terminal. It is

also called cpntrifnrjal, because the development of the
flowers is the reverse of that exhibited in the first mode.
The upper, or, in the case of close clusters, the central,
flowers open first.

188. In either mode the flowers are said to l)e solitary,
if (1) single flowers are produced in the axils of the
ordinary foliage-leaves (botryose), or (2) if a single flower
terminates the stem, as in Tulip (terminal).

189. Of indeterminate or botryose inflores-
cence there are several varieties. In Shepherd's Purse
we have an instance of the raceivo, which may be described
as a cluster in ^vhich each flower is supported on a
lateral pedicel of its own, usually in the axil of a bract.
If the pedicels are absent and the flowers consequently

INFLORESCENCE.

125

sessile in the axils, the cluster becomes a spike, of which
the common Plantain and the Mullein furnish good
examples. The catkins of the Willow (Figs. 68 and 69)
and Birch and the spadix of the Indian Turnip (Figs.
96 and 97) are also spikes, the former having scaly
Vjracts and the latter a fleshy axis. If you suppose the

Fig. 170.

Fig. 171.

internodes of a spike to be suppressed so that the flowers
are densely crowded, you will have a Jiead, of which
Cover and Button-bush supply instances. If the lower
pedicels of a raceme are considerably longer than the

Fig. 170.— Plan of the simple corymb.
Fig. 171.— Compound raceme. (Gray.)

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126

ELEMENTS OF STRUCTURAL BOTANY.

/ ;

upper ones, so that all the blossoms are nearly on the
same level, the cluster is a corymb (Fig. 170). If the
flowers in a head were elevated on separate pedicels of
the same length, radiating like the ribs of an umbrella,
we should have an umhel^ of which the flowers of
Geranium and Parsnip (Fig. 51) are examples. A
raceme will be compound (Fig. 171) if, instead of a
solitary flower, there is a raceme in each axil, and a
similar remark will apply in the case of the spike, the
corymb, and the umbel.

190. The inflorescence of most Grasses is what is
called a panicle. This is a compound form, and is

%

Vy£. 172.

usually a kind of raceme having its primary divisions
branched in some irregular manner.

191. Of determinate inflorescence the chief

modification is the cyme. Tliis is a rather flat-topped

Fig. 172 — A cyme. (Gray.)

INFLORESCENCE,

12:

cluster, having something the appearance of a compound
corymb, but easily distinguished by this peculiarity : that
the central blossom ojicns Ji^'st, then those at the ends of
the first set of branches of the cluster, then those on the
secondary branches, and so on until the outer buds are
reached. The Elder, Dogwood, and St. John's Wort
furnish good examples of the cymose structure. Fig.
172 shows a loose, open cyme.

Helicoid and Scorpioid cymes have already been
described in section 144.

192. Besides the two distinct modes of inflorescence
just described, forms are met with which exhibit the
peculiarities of both modes. For example, the flower-
cluster of the Lilac is botryose or racemose as to the
production of its primary branches, but the development
of the flowers on the branches is according to the cymose
type. On the other hand it sometimes happens, in many
of the Composites for example, that the primary
branches are cymose while the secondary are botryose.
In the Lilac and the Horse-Chestnut the compact mixed
cluster is called a thyrse. Panicles, also, instead of being
altogether botryose, may be of a similar mixed character.

193. In many plants of the Mint Family the flowers
appear to form dense whorls at intervals about the stem.
Each of these whorls, when analysed, is found to consist
of two cymose clusters on opposite sides of the stem.
Such whorls are, therefore, mixed, and are often spoken
of as verticillasters.

194. It has already been pointed out that cauline
leaves tend to diminish in size towards the upper part
of the stem where the flowers are found. Such reduced

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128

ELKMRNTS OF STIUICTUUAL HOTANY.

leaves, containing flowers in their axils, are called bracts.
In the case of compound flovver-clusters this term is
limited to the leaves on the peduncle or main stem, the
term hradlet being then applied to those occurring on
the pedicels or subordinate stems. In the case of the
umbel and the head^ it generally happens that a circle of
bracts surrounds the base of the cluster. They are then
called, collectively, an involucre, and in the case of
compound clusters a circle of bractlets is called an
involucel. Bracts are often so minute as to be reduced
to mere scales. On the other hand they are occasionally
very conspicuous and showy, as, for instance, in the
four white bracts resembling a flower in the Bunchberry.
From our definition it will be evident, also, that the
spathe surrounding the spadix in Indian Turnip is merely
a bract.

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195. Floral symmetry. Before dealing with the mor-
phology of the separate leaf -forms which go to make up
the flower, a few words are necessary in regard to the
relations of the different sets of floral organs, both as to
number and as to position. The leaves which constitute
the flower are arranged about the axis either in whorls,
when the flowers are said to be cyclic; or in spirals, after
the manner of most foliage-leaves, in which case the
flowers are acyclic. Occasionally the outer sets (the
perianth) are in whorls, while the stamens are spirally
arranged ; then the flowers are said to be JiP.micydic.
The spiral arrangement prevails, as a rule, where the
floral organs are very numerous, as, for instance, in the
Water Lily and in Buttercup ; though Columbine, with
very numerous stamens, has cyclic flowers.

ii )!

FLORAL DIAGRAMS.

129

196. In cyclic flowers, whilst there is usually one
whorl each of sepals, petals, and carpels, there are not
unfrequently two whorls of stamens. If each whorl is
made up of the same number of members the flower is
uomerous, and will, at the same time, be mojiomeroii^,
dimerous, trimerous, tetramernns, or pmtamerous, accord-
ing as each whorl contains one, two, three, four, or five
members. If the numbers of the members in the whorls
do not correspond, the flowers are heteromerous.

197. The relations of the whorls to each other in any
particular case may be very conveniently exhibited by a

diagram. Fig. 173, for example,
shows the plan of a Lily. The dot at
the top of the figure represents the
position of the axis of the plant, and
should always be shown in a floral
diagram. The side of the flower
Fig. 173. towards the stem is the posterior side,

the opposite one being anterior^ and a plane passing
through the centre of the flower and also through the
stem or axis is called the median plane. We have in the
flower of the Lily an outer whorl of three members ; then
alternately with these (and this is the usual plan in
cyclic flo yers) a second whorl of three members ; then
the outer whorl of stamens, also three in number ; then
the three inner stamens ; and, finally, the three carpels.

198. The composition of this flower may also be
expressed by a formula, as follows : Kg, Cy, A3+3, G(^),
where K stands for calyx, C for corolla, A for anthers,
G for gynoecium. The brackets enclosing the figure

Fig. 173.— Diagram of Lily flower. (Prantl.)

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130

ELEMENTS OF STUUCTURAL BOTANY.

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which follows G show the carpels to be united, and the
placing of the figure ahuve the short line indicates that
the ovary is superior ; if inferior, the figure would be
• written below the line. Fig. 174 shows

the plan of a Grass-flower. Here parts
which are suppressed, and the position
of which can in general be easily
inferred from that of those which are
present, are represented by dots. The
Fip. 174. formula would be : Kq, C2, A34.0, G(^\

199. The gynoecium is very frequently made up of
fewer members (carpels) than the other whorls, and in
all such cases the position of the carpels is more or less
irregular.

200. Fig. 175 gives the plan of Shepherd's Purse.
This shows the four sepals to be in two whorls of two
sepals each ; the four petals, however, are arranged
alternately with the four sepals, as if
the latter were all in one whorl ; the
position of the stamens indicates that
the ttm posterior ones, as well as the
two anterior ones, occupy the place of
single stamens, and have, therefore,
probably arisen from the early division
of single stamens into pairs. The
formula would be : K2+2J G4, Aa+a", G(-); the expression
2"^ indicating the reduplication of the inner stamens.

201. If there is no clear distinction between the calyx
and corolla, the letter P (for perianth) may be used to
include both ; and, finally, if the members of any whorl

F\g. 174. — Diagram of a Grass-flower. (Prantl.)

Fig. 175.— Diagram of flower of Shepherd's Purse. (Prantl.)

Fig. 175.

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THE CALYX.

131

stand opposite those of the one exterior to it, a vertical
line may be placed between the symbols, thus : C, | A^.

202. Other methods of indicatinj,' symbolically the
relations of the parts of the flower are in vogue ; the one
just given is recommended by Prantl, and is sufficiently
convenient.

203. It has already been mentioned that flowers arc
said to be irregular when the members of any whorl are
of different sizes or shapes, as, for example, in the Pea ;
and regular, when the opposite is true. Fig. 173 repre-
sents one of these regular flowers. A moment's reflection
will show that any line whatever drawn across the centre
of this diagram will divide it into two exactly similiar
halves. The term actinomorphiG^ as well as "regular," is
applied to all such flowers. Flowers, on the other hand,
which can be cut symmetrically in one vertical plane only
are zygomorphic.

204. In this book, as in most English books, the term
" symmetrical " is employed to indicate that the whorls
consist of the same number of members each, and it is, in
fact, the same in meaning as " isomerous." The later
German botanists define a symmetrical flower as "one
which can be divided vertically into two halves resembling
each other like an object and its reflected image."

"We shall now proceed to consider in detail the variations
in form assumed by the floral organs individually.

205. The Calyx. As you are now well aware, this
term is applied to the outer circle of floral leaves. These
are usually green, but not necessarily so ; in some Exogens,
and in nearly all Endogens, they are of some other colour.
Each division of a calyx is called a sepaly and if the sepals

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ICLKMEST.S OF STIIUOTURAL DoTANY.

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are entirely distinct from each otlier, the calyx is poly-
sepalous ; if tlioy are united in any degree, it is gamo-
sepalous. A calyx i.s rtyjnlat' or itretju/ar according as the
petals are of the same or different shape and size

206. In a gamosepalous calyx, if the sepals are not
united to the very to}), the free portions are known as
calyx-teeth^ or, taken collectively, as the limb of the calyx.
The united portion, especially if long, as in Willow-herb,
is called the calyx-tube, and the entrance to the tube its
throat. In many plants, particularly those of the Com-
posite Family, the limb of the calyx consists merely of a
circle of bristles or soft hairs, and is then described as
pappose. In other cases the limb is quite inconspicuous,
and so is said to be obsolete. A calyx which remains after
the corolla has disappeared, as in Mallow (Fig. 31), is
persistent. If it disappears when the flower opens, as in
our Bloodroot, it is caducous; and if it falls away with the
corolla, it is deciduous.

We must repeat here, that when calyx and corolla are
not both present, the circle which is present is considered
to be the calyx, whether green or not.

207. The Oorolla. The calyx and corolla, taken
together, are called the Jloi'al envelopes. When both
envelopes are present, the corolla is the inner one ; it is
usually, though not invariably, of some other colour than
green. Each division of a corolla is called a j^Btctl, and the
corolla is polypetalous when the petals are completely
disconnected ; but gamopetalous if thoy are united in any
degree, however slight. The terms regular and irregular,
applied to the calyx, are applicable also to the corolla, and
the terms used in the description of leaves are applicable

it 1 ■

THE COROLLA.

[:\:\

to petals. If, however, a petal is narrowed into a long iin<l
slender portion towards the base, that portion is known
as the claw, whilst the broader upper |i:iit is
called the liinb (Fig. 17G). The leaf-terms
are then applicable to the limb.

208. Gamopetalous corollas assume various
forms, most of which are described by terms
Figf. 176. easily understood. The forms assumed

depend almost entirely on the shape of the petals
which, when united, make up the corolla. If
these, taken separately, are linear, and are united
to the top, or nearly so, the corolla will be tubular
(Fig. 177). If the petals are wedge-shaped, they
will, by their union, produce a funnel-shaped
corolla (Fig. 178). In the campanulate or bell-
shaped form, the enlargement from base to sum-
mit is more gradual. If the petals are narrowed Figr- 177.
abruptly into long claws, the union of the claws into a

tube and the spreading of the limb at
C'^" MM^^ right angles to the tube will produce the

salver-shaped form, as in Phlox (Fig. 179).

The rotate corolla differs from this in

having a very short tube. The corolla of

the Potato is rotate.

209. The most important irregular
gamopetalous corollas are the Uaulate,
which has been fully described in the
examination of the Dandelion, and the

labiate, of which we found an example in Catnip (Fig.

59). The corolla of Turtle-head (Fig. 180) is another

Fig. 176.— Single petal of a Pink. Fig. 177.— Tubular corolla of a Honeysuckle.
Fig. 178.— Funnel-shaped corolla of Calystegia.

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134

ELEMENTS OF STRUCTURAL BOTANY.

II

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example. When a labiate corolla presents a wide opening
between the upper and lower lips, it is said to bo rimjent ,
if the opening is closed by an upward projection of th«j
lower lip, as in Toadflax (Fig. 181), it is said to be
personate^ and the projection in this case is known as the
palate. A good many corollas, such as those of Toadflax,
Dicentra, Snapdragon, Columbine, and Violet, have
protuberances or spurs at the base. In Violet one petal
only is spurred ; in Columbine the whole five are so.

Fig. 179. Fig. isa Fig. 181.

210. Estivation. This is the term applied to the
mode in which the sepals and petals are folded in the
bud. In general, the members of a calyx or of a corolla
overlap in the bud, or they do not. If they stand edge
to edge, as in the calyx of Mallow, the a3stivation is
vdlvate. If there is overlapping, and one or more of
the members have hotJi edges covered, the aestivation is
imbricate; and if each member has one edge covered
and the other uncovered, as in the corolla of Mallow»
Evening Primrose, Phlox, tfec, it is then said to be con-
volute. Gamopetalous corollas are frequently plaited in
the bud, and the plaits may be convolute, as in Morning
Glory.

Fig. 179.— Salver-shaped corolla of Phlox.
Fig. 180.— Labiate corolla of Turtle-head.
Fig. 181.— Personate corolla of Toadflax.

THE WTAMENS.

135

211. The Stamens. As calyx and corolla aro called
collectively the floral envelopes, so stamens and pistil are
spoken of collectively as the es.^ential organs of tlu; llovvci*.
The circle of stamens alone is sometimes calhul the
andrmdum. A complete stamen consists of a slender
stalk known as the filament, and one or more small sacs
called collectively the anther. The filament, howcjver, is
not uncommonly absent, in which case the anther is sesnile.
As a general thing, the anther consists of two oblong cells
with a sort of rib between them called the connective, and
that side of the anther which presents a distinctly r//7;oyef?
appearance is the face, the opposite side being the back.

t 11;

Fig. 182.

Fig. 183.

Fig. 184.

The filament is invariably attached to the connective, and
may adhere through the entire length of the latter, in
which case the anther is adnate (Fig. 182); or the base of
the connective may rest on the end of the filament, a
condition described a^ innate (Fig. 183); or the extremity
of the filament may be attached to the middle of the back
of the connective, so that the anther swings about : it is
then said to be versatile (Fig. 184). In all these cases, if
the face of the anther is turned towards the centre of the
flower, it is said to be introrse ; if turned outwards,
ext7'07'se.

Figs. 182, 183, 184.
ments of the anther.

-Stamens showing adnate, innate, and versatile attach-

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KLKMKMS OK STUUClUHAL BOTANV.

Tho cells of anthers conmionly open alonj^ their outer
(idges to c'ischtir^'e their pollen (Fi;,'. 185). In most of tlio
Heaths, however, the pollen is disci uu'i^'ecl throu<j;h u
minute aperture at tin; top of each ctjU (Fi<,'. 186), and in
our lilue Cohosh each cell is provided with a lid or valve
near the top, which opens on a kind of hinge (Fig. 187).
Occasionally, examples of barren or abortive stamens are
met with, as the fifth stamen in Turtle Head and
Pentstemon. These are filaments without anthers, and are
known as stamlnodes.

212 Stamens may be either entirely distinct from each
other — in which ciso they are described as diandrouti,
jtfutanilronsj odandwus^ &c., according to their number
(or, if more than twenty, as indefinite) — or
they may be united in various ways. If
their anthers are united in a circle, while
the filaments are separate (Fig. 57), they
are said to be syngeiipsious ; but if the
filaments unite to form a tube, while the
Flgfs. isf). 187. 186. anthers remain distinct, they are said to be
monaddphous (Fig. 32) ; if they are in two groups they
are diadelphous (Fig. 37) ; if in three, triadelphous ; if in
more than three, polyadelplioua.

213. As to insertion, when stamens are inserted on
the receptacle they are hypo(jynovs ; when borne on the
calyx, perigynous ; when borne on the ovary, epigynnus ;
and if inserted on the corolla, epipetalous. They may,
however, be borne even on the style, as in Orchis, and
then they are described as gynandrous.

214. If tho stamens are four in number, and in two

Figs. 185, ISO, 187.— Antlu'i's exhibiting: different modes of dehiseence.

TIIK I'lSTIK.

137

jiairs of (litfcnMiL Icngtlis, tlioy unj Huid to hn tfii/i/unnionK
(Fig. GO); if six in miiubor, four lon^ iind two short, tlu!y
ure tcti'aihjnaiauufi (Fi;^'. 'JH) ; and, linally, if thcj Ptiinions
are liiddun in tlio tube of ii yiinio})etulous corolla they an!
said to be included^ but if they protrude beyond the tube
they are exufivtad (Fig. 177).

215. The Pistil. This is the name given to the
central organ of the flower. It is sometimes also called the
gyncecimn. As in the case of the stamens, the structure
of the pistil must be regarded as a modification of the
structure of leaves generally. The pistil may be formed
by the folding of a single carpeilary loaf, as in the Bean
(Fig. 188), in which case it issivipfe ; or it may consist
of a number of carpels, either entirely separate from each
other or united together
in various ways, in which
case it is conipound. By
some botanists, however,
the term compound is
restricted to the case of Fig. iss.

united carpels. If the carpels are entirely distinct, as in
Buttercup, the pistil is ajxfrarpous ; if they are united in
any degree, it is syncarpous. A pistil of one carpel is
monocarpellarij ; of two, dicarpeUary ; and so on, to
poly carpeilary.

216. The terms inferior and superior j as applied to the
pistil, describe its situation upon the axis relative to
that of the calyx, corolla, and stamens. It will be
remembered that the end of the peduncle is usually
enlarged, forming what is called the forns oi receptacle.
Usually the i-eceptaele is a little highei in the centre

Fig. 188.— Legume of the Bean.

' 111

:Httii

11

138

ELEMENTS OF STRUCTURAL BOTANY.

than at its margin, and as the gynoecium occupies this
central part, its position is above that of the other floral
leaves, as shown in Fig. 189. Here the pistil is superior,
and the stamens and petals hypogynous. But frequently
the outer part of the receptacle grows more vigorously
than the centre, forming, in fact, a cup with the pistil
in the bottom of it, and the stamens and petals around

Fig. 189.

Fig. 190.

Fig. 191.

its margin (Fig. 190). In this case the pistil may be
described as half-inferior, and the stamens and petals as
perigynous. Often the cup-shaped receptacle grows fast
to the ovary all round. In other cases, the carpels,
instead of being developed from the bottom of the cup,
spring from the margin, thus forming a roof-like disk,
around the edge of which the stamens are attached
(Fig. 191). Here the stamens are epigynous, and the
ovary is truly inferior. Other cases of epigyny and
perigyny arise from the adnation (growing together) of
the floral whorls without exceptional development of the

Figs. 189, 190, 191.— Diagrams illustrating hypogynous (/i), perigynous (P),
am', epigynous (E) flowers ; a, axis ; k, calyx ; c, corolla ; «, stamens ; /,
carpels ; n, stigma ; sk, ovule. (Prantl.)

! ; i

THE PISTIL.

1313

receptacle. The cases of the Rose, Cherry, and Apple
li'ave already been referred to (Chapter VI.).

217. In our examination of the Marsh Marigold (Figs.
24 and 25) we found an apocarpous pistil of several
carpels. We found also that each carpel contained a
number of seeds, and that in every case the seeds were
attached to that edge of the carpel wMcJi ivas turned
toivards the centre of the floioer^ and that, as the carpels
ripened, they invariably split open along that edge, but
not along the other, so that the carpel when opened out
presented the appearance of a leaf with seeds attached to
the margins. The inner edge of a simple carpel, to
which the seeds are thus attached, is called the ventral
suture, the opposite edge, corresponding to the mid-rib
of a leaf, being the doi'sal suture.

218. If we suppose a number of simple carpels to
approach each other and unite in the centre of a flower,
it is evident that the pistil so formed would contain as
many cells as there were carpels, the cells being separated
from each other by a double tvall, and that the seeds
would be found arranged about the centre or axis of the
pistil ; and this is the actual state of things in the Tulip,
whose pistil is formed by the union of three carpels.
When the pistil ripens, the double walls separating the
cells split asunder. To these separating walls the name
dissepiment or partition is given.

219. The cells are technically known as loculi. An
ovary with one cell is unilocular ; with two, bilocidar ;
with several, multilocidar. Between the unilocular and
multilocular forms there are all shades of gradation. In
some cases, as, for example, in Saxifrage, the carpels

■ !

i'tll

' A I

1 'It
f IS

■ I :

i, 1 ■.

J ■ ' I ■

Ml

140

ELEMKNTS OF STRUCTURAL BOTANY.

are united below but separate above. Sometimes, also,
false partitions are formed across the loculi in the course
of growth. In the Mints, for instance, there are at
first but two loculi ; eventually, however, there are four,
which completely separate at the time of ripening.

220. But it often happens that though several carpels
unite to form a compound pistil, there is but one cell in

the ovary. This is because the separ-
ate carpellary leaves have not been
folded before uniting, but have been
joined edge to edge, or rather with
Fig. 193. Fig. 192. their edges slightly turned inwards.
In these cases the seeds cannot, of course, be in the
centre of the ovary, but will be found on the wallsj at
the junction of the carpels (Figs. 192 and 193). In
some plants the ovar;^' is one-celled, and the seeds are
arranged round a column which rises from the bottom of
the cell (Figs. 194 and 195). This case is
explained by the early obliteration of the
partitions, which must at first have met in
the centre of the cell. Special cases, how-
ever, are found in which no trace of parti-
tions has been observed, and these must
consequently be explained by the actual '^" ' '^
upward growth of the axis into the centre of the ovary.

221. In all cases the line or projection to which the
seeds are attached is called the placenta, and the term
plaiCeilta<tioil has refei-ence to the manner in which
the placentas are arranged. In the simple pistil the

acentation

pi

margi i

syncarpoui!

Figs. 192, 193. — Compound one-ocllcd ovary of Mignonette.
Figs. 194, 195.— Sections of ovary of a Pinl<, showing free central pla-
centatlOD.

y.^/

PHYLLOMK ANO TRICIIOME.

141

^igs. 197, 198.

pistil, if the dissepiments meet in the centre of the ovary,
thus dividing it in^c separate cells, the placentation is
central or axile ; if the ovary is one-celled and bears the
seeds on its walls, the placentation is parietal ; and if
the seeds are attached to a central column it is free
central.

222. Besides the union of the ovaries there may also
be a union of the styles, and even of the stigmas.

223. A very exceptional pistil is found in plants of
the Pine Family. Here the ovules, instead of being

enclosed in an ovary, are
usually simply attached to
the inner surface of an open
carpellary leaf or scale, the
scales forming what is known
!96, 197, and 198). The plants of this
family are hcuce called gymnospermoits^ or naked-seeded.

224. Nectaries. This name is given to that part of a
flower which has been specially formed for the secretion
Df honey. The nectaries need not, however, be looked
upon as separate or independent organs. Sometimes
they are to be found at the base of the petals, as in
Buttercup \ sometimes at the base of the stamens, as in
the Grape. Very commonly they are at the bottom of
deep spurs formed on one or more divisions of the
perianth, as in Violet, many Orchids, and in Columbine.

225. Phyllome and Trichome. To all leaf-forms,
whether ordinary foliage-leaves or those special modifica-
tions which make up the flower — sepals, petals, stamens^

Fiff. 196. —A cone.

Fig. 197.— Single scale showing position of the two seeds on the inner face.

Fig. 198.— One of the winged seeds removed.

Fig. 196

as a cone >.

m

\ vi^

w

>\

i ^t'

142

ELEMENTS OF STRUCTURAL BOTANY

and carpels — the general term phi/Uome is applicable.
The. characteristic of the phyllome is that it is a lateral
outgrowth of the stem or its branches.

226. The terra trichome, on the other hand, is applic-
able to any hair-like appendage on the surface of the
plant generally, whether of root, stem, or leaf. The
commonest form of trichome is the hair. The root-
hairs which generally clothe the surface of young roots
are of great importance as absorbing agents. Each
root-hair consists of a single, delicate, tube-like cell with
extremely thin '/alls. Other hairs may consist of several
such cells placed end to end. Others, again, may branch
extensively. It sometimes happens that the terminal
cell of a hair produces a gummy substance which comes
away with the slightest touch. The sticky surfaces of
many common plants are due to the presence of such
hairs, which are then described as glandular. Gummy
matters are also secreted by glarids close to the surface
of the plant. Peltate hairs are occasionally met with,
as in the leaves of Shepherdia. They give a scurfy
appearance to the surface upon which they grow. Then
there are hairs which secrete odorous fluids, as, for
example, those upon the surface of the Sweet Brier-
These probably serve to attract insects. Stinging hairs
are also common. They contain an irritating fluid.
When the point of the hair pierces the skin it is broken
off', and the fluid then escapes into the wound.

227. Besides the trichome forms just mentioned, there
are also bristles, formed from hairs by the gradual thick-
ening and hardening of their walls, and prickles, such as
those of Sweet Brier (Fig. 199), which consist of many

Fig.

THE FRUIT.

143

Fig. 200.

Fig. 199.

hard- walled woody cells closely packed together. That

prickles are really trichomes is shown by the fact that

when the bark is stripped off they

come away along with it. SpineSy on

the other hand (Fig. 200), are lateral
outgrowths of the stem.
They are, in fac^, gener-
ally stunted branches, and
will be found to spring
originally from the axils
of leaves. Occasionally
the petiole of a leaf is
converted into a spine, which then becomes a
true phyllome. Ovules are generally regarded
as trichomes since they arise from the inner
surface of the carpels.

228. The Fr.uit. In coming to the consideration of
the fruit, you must for the present lay aside any popular
ideas you may lave acquired as to the meaning of this
term. You will find that, in a strict botanical sense,
many things are fruits which, in the language of common
life, are not so designated. For instance, we hardly speak
of a pumpkin or a cucumber as fruit, and yet they are
clearly so, according to the botanist's definition of that
term. A fruit may be defined to be the ripened pistil
together with any other organ, such as the calyx or
receptacle^ which may he adherent to it. This definition
will, perhaps, be more clearly understood after a few speci-
mens have been attentively examined.

229. For an example of the simplest kind of fruit let

Fig. 199.— Prickles of Sweet Brier. Fig. 200.— Spines of the Hawthorn.

■'•

5 1

t- \\

■i

144

ELEMENTS OF STKUCTURAL BOTANY.

jif:

US revert to our Buttercup. As the carpels ripen, the
style and stigma are reduced to a mere point. On cutting
open one of these carpels when fully ripe, we find it
contains a single seed, not quite filling the cavity, but
attached at one point to the wall of the latter. "What you
have to guard against, in this instance, is the mistake of
considering the entire carpel to be merely a seed. It is a
seed enveloped in an outer covering which we called the
ovary in the early stages of the flower, but which, now
that it is ripe, we shall call the pericarp. This pericarp,
with the seed which it contains, is the fruit. The
principal difference between the fruit of Marsh Marigold
and that of Buttercup is that, in the former, the pericarp
envelopes several seeds, and, when ripe, splits open down
one side. The fruit of Buttercup does not thus split open.
In the Pea, again, the pericarp encloses several seeds, but
splits open along both margins. The fruits just mentioned
all result from the ripening of apocarpous pistils, and they
are consequently spoken of as apocarpous fruits.

230. In Willow-herb, you will recollect that the calyx-
tube adheres to the whole surface of the ovary. The
fruit in this case, then, must include the calyx. When
the ovary ripens, it splits longitudinally into four pieces
(Fig. 41), and, as the pistil was s//7icarpous, so also is the
fruit.

231. In the Peach, Plum, Cherry, and stone-fruits or
drupes generally, the seed is enclosed in a hard shell
called a imtaiuen. Outside the putamen is a thick layer
of pulp, and outside this, enclosing the whole, is a skin-
like covering. In these fruits all outside the seeds is the
pericarp. In one respect these stone-fruits resemble the

are said

TTIF- TRUIT.

145

fruit of the Buttercup : tln^y do not split open in ordcu-
to discharge their seeds. All fruits hiiviug this peculiarity
are said to he indehiscent, whilst those in which the
pericarp opens, or separates into pieces, are dehiscent-

232. In the Apple (Fig. 50) and Pear, the seeds are
contained in five cells in the middle of the fruit, and
these cells are surrounded by a firm fleshy mass, which is
mainly an enlargement of the calyx. In fact, the remains
of the five calyx-teeth may be readily detected at the end
of the apple opposite the stem. As in Willow-herb, the
calyx is adherent to the ovary, and therefore calyx and
ovary together constitute the pericarp. These feahy fruits,
or pomes, as they are sometimes called, are of course
indehiscent,

233. In the Currant, as in the Apple, you will find the
remains of a calyx at the top, so that this fruit, too, is
inferior, but the seeds, instead of being separated from the
mass of the fruit by tough cartilaginous cell-walls, as in the
Apple, lie imbedded in the soft, juicy pulp. Such a fruit as
this is a herry. The Gooseberry and the Grape are other
examples. The Pumpkin and otlier gourds are similar in
structure to the berry ; but, besides the soft inner pulp, they
have also a firm outer layer and a hard rind.
The name pepo is generally given to fruits of
this sort.

234. A Raspberry or Blackberry (Fig. 201)
proves, on examination, to be made up of a
large number of juicy little drupes, aggregated F'?- 201.
upon a central axis. It cannot, therefore, be a true berry,
but may be called an arfrjregated fruit. ^_^

If

m

I :;:■

! '■ \

Fig.

201.-

-Agg

regaled

ruit of the

Raspberry.

i

— ^" ■

nt

•nt

146

KLKMENTS OP STRUCTURAL UOTANY.

D'ti

'

235. A strawberry (Fig. 202) is ii fruit consisting chiefly
of a mass of pulp, having its surface dotted all ovor
with little carpels (achenos), similar to
those of the Buttercup. The flesh of the
Strawberry is simply an enlarged recep-
tacle ; so that this fruit, also, is not a true
berry.

236. The fruit of Sweet Brier (Fig. 45)
Fig. 202. consists of a red fleshy calyx, lined with
a hollow receptacle which bears a number of achenes. This
fruit is, therefore, analogous to that of the Strawberry.
In the latter the achenes are on the outer surface of a
raised receptacle, while in the former they are on the
inner surface of a hollow receptacle.

When other parts of the flower are combined with the
ovary in fruit, as in Apple, Rose, and Strawberry, the
result is sometimes described as a pseudocarp, or spurious
fruit.

237. The cone of the Pine (Fig. 116) is a fruit which
differs in an important respect from all those yet mentioned,
inasmuch as it is the product, not of a single flower, but
of as many flowers as there are scales. It may, therefore,
be called a cnUective or multii^le fruit. The Pine Apple
is another instance of the same thing.

238. Of dehiscent fruits there are some varieties which
receive special names. The fruit of the Pea or Bean
(Fig. 188), whose pericarp splits open along both margins,
is called a legume; that of Marsh Marigold (Fig. 25),
which opens down one side onlyj is a follicle. Both of
these are apocarpous.

Fijf. 202.— Section of a Strawberry.

I UK lUL'lT.

14:

239. Any syncarpoiis fruit having a dry dahisemt
pericarp is called a capsule. The dehiscence of syncarpous
or polycarpellary fruits is of several kinds. If the rujiturc!

takes place along the partitions the
fruit will be split up into its original
carpels ; this form of dehiscence is
septicidal (Fig. 203). But the
dehiscence may take place along the
dorsal suture of each carpel, half-
way between the partitions, so that
the opening is into the loculus ; this
^'^' ^^- mode is known as loculiddal (Fig.

204). Or .again, the valves (separate

pieces of the pericarp) may fall away,

leaving the partitions standing ; this

dehiscence is septifragal (Fig. 205).

240. A long and slender capsule
having two cells separated by a
membranous partition bearing the
seed, and from which, when ripe,

the valves fall away on each side,
is called a dlique (Fig. 206). If,
as in Shepherd's Purse (Fig. 29),
the capsule is short and broad, it is
called a silicle. If the capsule
opens horizontally, so that the top
comes off like a lid, as in Purslane
Fig. 205. (Fig. 207), itisa^i!/.^i9.

241. Any dry, one-seeded, indehiscpnt fruit is called an
achene, of which the fruit of Buttercup (Fig. 14) is an

Figs. 203, 204, 205.— Diagrams illustrating septicidal, loculicidal, andgepti-
taafpX dehiscence.

Fig. 204.

M I

i: !

Ill,

•i

mj

■\ : III;

i I

1 48

Rf.KMKNT.S OP HTRUOTUIIAL UoTANY.

I

I'Xiiinidc. In Wheat tlic, fruit dilFors from that of Buttercui)
ill liJiviiij,' a closely fitting and adlwrent |)(M'icai'p. 8ucli a

fruit ia call(Ml a carijiypsu or (/rain. A nut is

usually syncarpous, with a liard, dry pericarp.

A iriiifipd fruit, sucli as that of the Maple (Fi^.

208), is called a samara or key.

242. A fruit wliich splits up when ripe into
several one-seeded pieces is called a schizocarji.
The samara of the Maple is a good example ;
also the fruit of Catnip, which splits up
at maturity into four one-seeded portions.
Fi{!r.20G. The fruit of Mallow is another common ^'^•2"'-
instance. The separate portions in these cases are called
mericarps. In some leguminous plants
the pod breaks up transversely into one-
seeded portions, giving rise
to the form called a loraent.

243. A special P'^ln'zocarp
is that of UniheliiiV'iOus
plants (Fig. 209). Here the Fig.208.

fruit splits into two mericarps, each attached,
however, by a fibre to the axis. Such a fruit
Fig. 209. is called a en mocarp.

244. The Seed. The seed has already been described
as the fertilized omdo. During the formation of the
carpels, the ovules arise as outgrowths from the inner
surface of the ovary, mostly, as has been pointed out,
upon the margins of the carpellary leaves, but occasion-
ally also upon the surface generally. At first tlu; ovule

Fig. 206.— Sillcle of Stock. Fig. 207. -Pyxis of Purslane.

Fig. 208.— Samara of Maple.

Fig. 209.— Cremocarp of an Umbellifer ; a, the fibre attaching the merioarp
totheaxia. (Thome.)

THE SEED.

UU

is a simple, .soft mass with no indication whatovcr of
the covering so manifest in ripe seeds of all kinds. Very
soon, however, after the appearance of the body of the
ovule, a circular ridge is developed upon it, and tliis
gradually extends upwards over the surface so as to form
a coat, which at length entirely covers it except at the
very apex, where a minute opening is left. Very
commonly, but not always, a second coat is developed
exactly in the same manner, outside the first, and an
opening is left in this coat also, precisely over the other.
This minute passage through both coats to the ovule body
has already been named the micropyle. The two coats
are known as the j>'n?/«'/?e (generally, though not always,
applied to the outer) and the seeundine, and the central
body is the nucleus.

245. If the ovule appears to arise directly from the
placenta without the intervention of a stalk, it is sessile ;
but if a stalk is present, this is known as the funiculus.
In the accompanying diagram (Fig. 210) which represents
a section of the complete ovule, k is the nucleus ; ai^ the
primine ; m, the seeundine ; ?«, the micropyle ; /, the
funiculus. The point (c) where the two coats and the
nucleus are blended together is called the chalaza. The
portion of the nucleus marked em is the cavity called
the embryo-sac, already referred to in Chapter II.

246. It must now be pointed out that though the ovules
at the commencement of their growth are straight, as in
the diagram just described, yet they do not commonly
remain so. Very often the ovule bends over so as to appear
completely inverted, in which case the funiculus grows
fast to one side of the primine, becoming completely fused

J

' X

m

m

150

ELKMENTH OF HTIIUCTUKAL HOTANT.

'iff"

with it, and forming what is then called tho raphe. Fig.
211 ropresonts this condition, r being tho raphe, « the
chalaza, and tiio oth(ir letters corresponding to those in

Fig. 210.

Sometimes tiie curving of the ovule upon itself is not
carried to this extreme, and an intermediate form is
presented, as in Fig. 212.

Fig. 210.

If the ovule remains straight it is said to be orthotro-
pous ; if completely inverted, anatropous ; if half bent
over, campy lot ropous.

247. Pollination. The process of fertilization, by
which the ovule is converted into the seed, has been
briefly described in Chapter II. A few words may be
added here upon pollination — the process of supplying
pollen to the stigma. In very many flowers which have
both stamens and pistil (and hence called hermaphrodite),
the process is very simple. Either the anthers and
stigma are so close together that the pollen cannot fail to
be deposited upon the stigma immediately upon the
opening of tlie anther, or the stigma is upon a lower level,
so that the pollen drops upon it, or, in special cases, as in

Figs. 210, 211, 212.— Diagrams of orthotropous, anatropous, and campylo-
tropous ovules. (Prantl.)

Tuipfitic
llowcr.s,
mom 11

Culi^ pi'li

tliiil ill
flower 1
some 0
against
limes tl
in the ?
Soniutii;
tho aiitl
receive
develop
the lint
said to
fertiliza'
pollen f
ways. "^
the win
said to
citlicr b
(|uest of
pollen,
and arc;
lioiiey n
stigmn,
anther c
another,
referred

248.
as exliil

roiJ.INATION'.

151

Tia|ifititMis iiiii] Wonil Sftircl, Itcsidos tli<^ ordinary larj^o
flowers, there mo .-jcfiiil : mall ones (known as r/risffiija-
iiiKilt^ flowers) wliose lloral envelopes do Jiot open, tliu.s
ci'iniii'lliiKi self-fertil zation. I'lit it is well otablislied
tlial in a vast nuinlx-'r of cases the ovules in any given
llower liavo to depend for feiLilization upon tho pollen of
some olluu" flower. Nature seems to have provided
iu;ainst self-fertilization by varicms contrivances. Some-
times the relative positions of the antluM's and tho sti;^'ma
in the same flower are such as to render it impossible.
Sometimes the })ollen couk^s to maturity and is shed from
tho anthers l)efoie tho stii^nna is in a suitable condition to
receive it ; whilst, on the othcn' hand, the stigma is often
developed first and has wither(Ml l)eforo tho opening of
the unther.s. (Flowers showing these peculiarities are
said to be (Uchogamoux ) WIkmi for any reason cross-
fertilization has become a necessity, the conveyance of the
pollen from one llower to another is ensured in various
ways. When the flowers are inconsi)ieuous, as in Grasses,
tho wind is tho great agent, and flowers so fertilized are
said to bo ancinojt/n/o/tn. In otlier cases the flowers,
either by their brightness or their odour, attract insects in
(juest of honey, and these then become the carriers of the
pollen. Flowers of this sort are said to bo entomophilou)^,
and are usually so constructed as to tho situation of their
honey rece[)tacl(!s, and the relative p )sition of anthers and
stigma, as to ensure the transfer of tho pollen from tho
anther of one flower to its destiu'ition upon the stigma of
another. The case of tho Orchids has already been
referred to in section 92.

248. After fertilization, the embryo, or young plantlet,
as exhibited in the seed, begins its growth in that end of

5

"^\

U\

y ,,..

i !

■"ui

<n

', . I

'ii

iff

152

ELKMENTS OF STRUCTURAL BOTANY.

the embryo-sac •which is next the micropyle, and about
the same time, in the other end of the embryo-sac, there
begins a deposit of matter intended for the nourishment
of the embryo during the germination of the seed. This
deposit has been already referred to under tlie name of
albumen. It is also known as endosperm. As the embryo
developes, this endosperm or albumen may be completely
absorbed by it, so that at m iturity the embryo will occupy
the whole space within the seed-coats, as in the Bean. In
this case the seed is exalbuminous. In other cases, as in
Indian Corn, the endosperm remains as a distinct mass
with the embryo embedded in it, or sometimes wrapped
round it. Seeds of this kind are albuminous. Rarely
this nourishing material is deposited outside the embryo-
sac, in the body of the ovule. It is then known as
perisperm.

249. The ripened seed presents very different aspects
in dilferent plants. It may be resolved, however, into the
nucleus and the integument (the s2)ermoderm of some
botanists). The former is made up of the embryo,
together with the endosperm or perisperm, if present,
while the latter consists of two layers: an outer, known
as the testa, and an inner, the tegmen. The scar showing
where the seed has been attached to the placenta is called
the hilum ; it is very distinct in the Bean.

250. Besides the integument just mentioned, occasionally
an additional outer coat is formed, to which the term ai'il
is applied. The fleshy red covering of the seed in our
Ground Hemlock is a good example.

251. The seeds of Willow-herb, Milkweed, ami many
other plants are fiiniished with tufts of hair-like bristles

CEKMINATION.

ir>:{

which faciUtate tlieir dispersion ])y the wind. These
tufts grow from the testa of tlie seed, and arc not to be
confounded with the pappus of the Thistle, DandeUon,
&c.; the latter, it will be remembered, is an outgrowth
of the calyx.

252. The embryo, as already explained, generally
consists of an axis or stem called the radicle (or, more
properly, the caulicley because it is in all respects a true
stem and not a root), and one or more leaves called
cotyledons, with sometimes, also, a bud known as the
plumule. As to the number of cotyledons, it may be
repeated here that seeds are, as a rule, either dicotyle-
donous or monocotyledonous. Some plants of the Pine
Family, however, have six cotyledons, whilst, on the
other hand, in the Orchids and a few other plants, these
organs are altogether wanting.

253. The cotyledons vary greatly in thickness. In the
Maple, for example, they are very thin, while in the Pea,
the Bean, and the Oak they are extremely thick and
fleshy.

254. Germination. If a seed is supplied with
proper warmth and moisture it soon begins to swell and
sofien by absorption of water, with the effect of bursting
the seed-coats to a greater or less degree. At the same
time the process of growth is begun. This early growth
of the embryo is (jennination. Tlie details of tlie process
vary somewhat according to the structure of the seed. In
dicotyledons, if the seed-leaves are thin and leaf-like,
containing within themselves but scanty store of nourish-
ment, the radicle will grow throughout its length so as to
raise the cotyledons above the soil, where they at once

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ELKMI.NTS OF STFlUCTUltAL llOTANY.

expiinJ and boconio the uailicst loaves of the new phxnt;
and during this upward ext(Mision of tlie radicle a root
also is being rajtidly developed from its lower end. It is
important, also, to notice hero that the mode of growth of
the root portion is at variance with that of the radicle or
stem proper, for while the latter grows throur/hout its
length, the former grows hy the addition of successive new
portions to its extremity. (The protection of the growing
root by a root-caj) has already 1)een refcncd to.) As soon
as the root is prepared to absorb nouiishm(n:t from the
soil, then, and not till then, the development of the next
bit of stem commences between the first pair of leaves.

255. But when the cotyledons are loaded with nour-
ishment, as in the Bean, it will generally be found that
the elements of additional bits of stem (the plunmle) are
already present in the embryo, and although the radicle
may lengthen so as to lift the cotyledons above the
surface, yet these do not. as in the thin-leaved embi-yos,
fully perform the office of foliage-leaves ; their true
function is to supply the newly developing parts with
nourishment, and when this duty is performed they
usually drop off. In fact, it is not uncommon for such
extremely fleshy cotyledons to remain under the surface
altogether, as in the case of the Pea and the Acorn. In
these cases the growth of the radicle is but slight. The
plumule and the end of the radicle are liberated from
the seed, and the former at once grows vigorously upward,
being practically independent of the root as long as the
stock of nourishment in the cotyledons holds out.
Simultaneously with the development of the stem, the root
is strongly developed from the end of the short radicle.

GERMINATION.

155

256. In the monocotyledons the process of germination
is much the same as that just described, with the
important difference, liowever, tliat the primary root
from the end of tlie radicle can scarcely be said to develope
at all, a cluster of fibrous roots burst in^:, out almost at
once from its sides. Indian Corn answers very well as
an illustration. Here the seed, largely made up of
endosperm or albumen, remains in the ground. The
single cotyledon is wrapped round the plumule and
adheres by its back to the endosperm, acting thus as a
medium through which nourishment is absorbed, and of
course not being carried up to the surface. The plumule
is rapidly carried upward, developing alternate leaves,
and the numerous fibrous roots are given off from the
sides of the short radicle.

'a

257. The young student is strongly recommended to
investigate for himself the phenomena of germination as
exhibited in common seeds. For this purpose he may
place a few Windsor beans and grains of Indian Corn
between layers of moist flannel or coarse paper in a
shallow dish. If kept damp, germination will begin in a
day or two, and if sufEcient specimens have been provided
the process may be observed at various stages. Trial
should also be made of the length of time during which
seeds will retain their vitality. Many seeds, such as
^■hose of Elm and Poplar, will be found to germinate
only if they have been kept fresh and not permitted to
dry up, whilst others, such as Indian Corn and Wheat,
and in general those containinijf stiirch, may be kept for
a very long time without losing their germinating power.

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156 ELEMENTS OP STRUCTURAL BOTANY.

CHAPTER XIX.

ON THE MINUTE STRUCTURE OP PLANTS — THE CELL

TISSUES — TISSU E-S YSTEMS — EXOGENOUS AND
ENDOGENOUS STEMS.

258. Up to this point we have been engaged in observ-
ing such particulars of structure in plants as are manifest
to the naked eye. It is now time to encj^uire a little more
closely, and find out what we can about the efementar/j
structure of the different organs. We have all observed
how tender and delicate is a little plantlet of any kind
just sprouting from the seed ; but as time elapses, and the
plant developes itself and acquires strength, its substance
will, as we know, assume a texture varying with the
nature of tlie plant, either becoming hard and firm and
woody, if it is to be a tree or a shrub, or continuing to be
soft and compressible as long as it lives, if it is to be an
herb. Then, as a rule, tlie leaves of plants are of quite a
different consistency from the stems, and the ribs and
veins and petioles of foliage-leaves are of a firmer texture
than the remaining part of them. In all plants, also, the
newest portions, both of stem and root, are extremely soft
compared with the older parts. It will be our object in
this chapter to ascertain, as far as we can, the reason of
such differences as these ; and to accomplish this we
shall have to call in the aid of a microscope of much
higher power than that which has hitherto served our
purpose.

259. First let us examine under our microscope a very
thin slice of the pith of the Elder. You see at once that

THE CELL.

157

the whole slice is made up of more or less rounded,
nearly transpfireut bodies, rather loosely thrown together,
as shown in Fig. 213. Next let us examine, in the same
way, a thin slice of the tuber of the Potato. Here,
again, it is evident that the object under
examination is wholly composed of en-
closed spaces, not so much rounded, how-
ever, as those of the Elder pith, because
they are more closely packed together.
Fig. 214 is a representation of two of
Fig. 213. these spaces. Now look at the leaf of a
Moss, and you see again that we have an aggregation of
enclosed spaces as before (Fig. 215). So, also, if we
examine a hair from the surface of a Petunia or a
Geranium, we have some such appearance presented to
us as that shown in Figs. 216 and 217, the hairs
manifestly consisting of several enclosed spaces placed
end to end. In short, the microscope reveals to us the
fact that every part of a plant is made up of such
enclosed spaces, varying greatly in shape and size and
general aspect, it is true, but always
(except in some of the very lowest
plants) clearly exhibiting bound-
aries ; and since these boundaries
are visible, no matter in what direc-
tion we make our cutting, it is clear
that the spaces must be shut i„ on all sides. These
enclosed spaces are called cells, and their boundaries are
known as the cell-walls.

Fig. 214.

Fig. 213.— Loosely packed cells of Elder-pith.

Fig. 214.— Two cells of I'otato tuber coiitainiiig stareh -granules and crys-
talloids. (Gray.)

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ELK.MKXT.S OF STRUCTURAL RoTANY.

200. AVhilst looking at the parts of plants just sub-
mitted to examination, it must liavo strnck v<.u tiiat the

interior of the cell
presents a very dif-
ferent appearance in
dift'erent cases. The
Potato section, for
example, is not at all
like the Moss-lenf
section in the matter
of rpll-contfuts, and
the cells of the Elder-
pith appear to be
quite empty. We
shall discuss these
differences presently.
In the meantime let
us study the appear-
Pj„ 215. ance of some cells

taken fresh from some part of a plant where growth is
actually j^oing on — say the point of a new rootlet. If our
section is taken sr>

near enough to ^

the point we shall ^^^^^^^^^^^^^^c::::^ X V

get cells which ^^^:::;-^x^ X^'^

have just been ^ ^ \

formed. Such a ^'^'^^^- Fig. 2i7.

section is very well shown in Fig. 218. Here the cells
are seen to be completely filled with liquid having a

Fig. 215.— Cells from leaf of a Moss coiifcaiiiing i)rotoi)lasiii and chlorophyll-
granules.

Fig. 216.— Hair from Petunia leaf. Fig. 217.— Hairs from Geranium leaf.

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TIIK CKLL.

1 59

\mg a

granular appearance, and in tlie centre of each a rounded
denser portion may be made out, each of these again
enclosing one or more smaller bodies. Tliis licjuid which

thus fills the newly-formed cells is
csi\\ed2^rotoplatS7}i; the large rounded
central mass is the nucleus^ consist-
ing of denser protoplasm, and the
smaller enclosed masses are the
nucleoli.

*

Now let us consider Fig. 219.
This is a representation of a section
of the same rootlet, taken a little
farther back from the point, so
that the cells now in view are a
little older than the first ones.
They are manifestly larger ; that
is to say, they have grown. The
nucleus and the nucleoli can still
be made out in some of them, but
the protoplasm no longer entirely
fills the cell. There are now
transparent spaces (vacuoles)
which are filled with water, and
between these the piotoplasni is
seen in the form of strings or
bands, as well as lining the cell.
The water has been absorbed through the cell-wall, and
after saturating the protoplasm the excess has formed the
\ acuoles.

Fig. 218.— Yoiinj,' cells filled with protoplasm (i>) ; b, coll wall ; h, nucleus ;
IcJc, nucleolus. (Sachs.)

Fig. 219.— Cells a little older, exhibitingf vacuoles («). (Sachs.)

Fi<'. 219.

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KLEMKN'I'H OK STHlTCTUUAL UOTANY.

Fig. 220 sliows sorae cells from the same rootlet taken
still farther back. It is clear that the change olserved
in Fig. 219 has been carried to a still greater extent.

In some of these cellc tlie proto-
plasm is restricted to the lining
of the cell and the nucleus.

261. It is now to be observed
that the protoplasm is the es-
ential part of every living cell.
Through its agency all the vital
processes of the plant are carried
on. Every cell of every plant
at some time or other contains
this substance, and when at
length it disappears the cells
which are deprived of it no
^ longer take any active part in
the growth of the plant, but serve
merely mechanical purposes, such
as that of support or conduction,
and are in that stage of their
history filled usually with air or
water. The pith of the Elder
is made up of such dead cells,

fas is also the greater part of the
wood and bark and older parts
generally of all plants.

262. The most marked feature of the living protoplasm
is its activity. We may observe this property by

Fl5,^ 220. — Cells still older ; h, the wall ; s, vacuoles ; p, protoplasm ; A:,
nucleus ; xy, swelling of nucleus caused by water used in preparation of the
section. (Sachs.)

Fig-. 220.

THE CELL.

IGl

examining plant-hairs and other parts unclor high powers
of the microscope, when it will be seen that there are
movements of two kinds. The wliole mass of protoplasm
has a rotary motion, sliding upon the cell-wall, down-
wards on one side and upwards on the other. This is
the mass-movement. Also, currents may be traced passing
across the protoplasm in different directions. This is
the streaming-movement.

In some of the very lowest plants, where there is no
cell-wall, and the whole is a mass of naked protoplasm,
these movements may be observed more readily because
they are less restricted.

263. There is some doubt as to the exact chemical
composition of protoplasm. It is, however, a very complex
substance belonging to a group of bodies known as
albuminoids^ of which nitrogen is an important con-
stituent.

The consistence of protoplasm depends upon
the amount of water it contains. In dry seeds,
for example, it is tough and hard, but when
the same seeds are soaked in water it becomes
partially liquid.

264. Forms of Oells. As cells become
older they tend as a rule to change their form, |f ^
though sometimes we find them differing but
little from their original conformation. Com-
monly a cell grows more rapidly in some one
direction, thus giving rise to long forms, as is *'*&• 221.
the case in stems generally, and in the petioles and veins
of leaves, the superior toughness and strength of which

Fig. 221.— Prosenchyma of the wood. (Gray.)

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KLKMKNTS OF STRUCIUKAL HOTANY.

i

.nro (liio to tho loiiijtlieiiiii^' and luirilLMiiuy of tlio cells
of which they are composed (Fig 221),

205. The Oell-wall. In the portions of plants just
selected for microscopic examination Me have seen that
the protoplasm is in every instance bounded by a wall.
It has been ascertained that the wall is a cliemical com-
pound of carbon, hydro'^en, and oxygen, and to this
compound the name celhilo.w has been given.

We have said tliiit the protoplasm is the active principle
through the agency of which all tho vital processes of
the plant are carried on. It contains at some time or
other every constituent of the plant. The cell-wall is
itself, therefore, a product or sfcretion of the protoplasm,
and is at first an extremely thin film, whicii, however,
' gradually increases in thickness by the addition of further
material. This new material is deposited h''tir>'i'n. the
molecules of the original film, and so extends not only
the surface of the wall, but, by deeper deposits, the
thickness also. This process of acquisition of new
material is known as iutusi^Ufiception.

266. As the wall between two cells increases in thick-
ness, a distinct middle layer is discernible in it, known as
the iniddle lamella. This portion of the common wall is
different in chemical composition from the rest, so that it
may, under proper treatment, be dissolved and the cells
thereby separated.

267. It is in the earlier stages of their history, while
the walls are comparatively thin, that the cells possess
the greatest activity. By these alone is carried on tiie
process of growth, which consists in the multiplication
and enlargement of cells.

!

THE CKLL

1G3

208. It IS soldoni the caso tliiit the wall is thickened
uniformly. Often nunieious round thm spots are left, so
that the cell has a doftnl ajjpearance (Fij^. 222). When

^^

the thin spots in ailjacent cells are contiguous,

=S?-

[.y^Tt as they commonly are, a ready means of inter-
communication is allbrded. Sometimes the spots,
instead of beinf? round, are oblong, so that tiie
cell under the microscope presents a ladder-like
appearance, and so is said to be scalan/orm. Then
again, the thickening may take the form of spiral
hands upon the inner surface; or, instead of a
continuous si)iral band, we may find a series of
Fig 222. isolated rings^ when the marking is said to be

annular. Reticulated cells are also found, in which the

markings, as the name implies, form a sort

of network on the walls. Several of these

forms are shown in Figs. 223 and 224.

209. Soiiietinjes round thm spots wiii
be left in tiie wall, and over each of these
a thick-walled dome with an opening at
the top will be formed. At thcisame time
a similar dome is raised at exactly the ^
same spot on the other side of the wall in IP
the next cell ; and, finally, the thin par-
tition between the opposite domes breaks
away, permitting free communication.
Thus are formed what are called bordered Fig 223. Fig. 224
pits, which abound in the wood of Conifers.

270. When cells stand end to end, and thin spots are

Fig. 222.— Dotted duct. (Gray.)

Fig. 223.— Spiral and aiimilar markings on cell-wall. (Gray.)

Fig. 224.— Various markings on cell-wall. (Gray.)

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ELKMENTa OF STRUCTURAL IJOTANY.

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l<'ft in the cross-partitions between them, sinve-cella are
formed. Here, agiiin, tiio tliin spots finaiiy ilisappoar,
thus practically unitin*^ adjacent wWa.

271. It sometimes liaj)pens tiiat the thickening takes
l)hico throughout tlio length of a cell but in its antjlen
only. Cells of this kind, which are often found im-
mediately under the surface of. the stem in the higher
plants, are called coIlencJiipna cells.

272. Besides the mark nigs on the inside, cells often
show markings on the outside. The pollen-grains of the
Mallow, for instance, are seen under the microscope to be
covered ■with pointed projections. Other pollen-grains,
also, exhibit outside markings of dilFerent sorts.

273 The thickening deposit may be so excessive in
some cases as to almost completely fill up
the cavity of the cell (Fig. 225). The
shells of nuts and the tough coatings of
seeds consist of cells of this kind ; but even
in these cases the wall may bo seen to be
traversed by slender pores or canals, either

simple or branched, radiating from the centre of the cell.

To these hardened cells the name sdcrenchyma is applied.

274. The Contents of Oells. If you look at Fig.

215, or, better still, if you have the opportunity of
viewing a Moss-leaf through a good microscope, you will
see that in the protoplasmic lining of the cells there
are numerous greenish, rounded granules. These are
the bodies to which the green parts of plants owe
their colour. They are called chlowphj/ II -granules j and
consist of protoplasmic matter in which particles of green

Fig. 226-

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THE CKLli.

IC5

Tlie colounuj,' mtittcr

colouring matter aro oiuImmMocI.
itself is chloropliyll, and may l)o dissolvi'd out of the
granules, leaving the latter as onlinury protoplasm.
Almost without exception chlorophyll re([unes the action
of sunlight for its production, and the chlorophyll dis-
appears from green parts when sunlight is withdrawn, as
is well seen in the process of bleaching celery. In many
of our brightly coloured foliage-plants the chlorophyll is
concealed from view by other colouring matttus. In
flowers various colours are found in the protoplasu), but
these, unlike chlorophyll, are produced in darkness as
well as in sunlight.

275. Chlorophyll is of the utmost importance to the
plant, seeing that only in the cells which contain it, and
in the presence of sunlight, can the materials which the
plant imbibes from the soil and the air be asdmilated^
that is, converted into matter which the plant can use for
the purposes of growth.

276. Now consider Fig. 214. Here are exhibited cell-
contents of an entirely diilerent aspect. The rounded
bodies here visible are starch-f/7'a7iule.% as may be easily
demonstrated by adding a drop of iodine solution to the
Potato section under the microscope, a characteristic blue
colour being at once produced. Such granules, differing
somewhat in shape in different cases, abound in the cells
of tubers and in grains of all sorts, where they have been
stored up for use during the process of germination.
They are originally formed during sunlight in the chloro-
phyll granules of the green parts. When the light is
withdrawn, as at night, they are dissolved and carried in
solution to other parts to promote growth or to be
stored up.

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ELEMENTS OF STltUCTUIlAL BOTANY.

277. If grains of wheat are macticated for u time it
will be found that a portion remains in the nioutli un-
dissolved. This is because the starcli of wliicli the grain
is so largely made up consists of two distinct parts : (1)
a more soluble portion which is known as granidose, and
(2) a less soluble part called starch-cellulose.

278. Crystals. These are of common occurrence in
many plants, not only in the cell - cavities, but also
imbedded in the substance of the cell-wall. They are
also of various shapes, and may either occur separately or
be massed together in clusters. The needle-shaped forms
are known as raplddes. These crystals consist for the
most part of calcium oxalate, but calcium carbonate
is also found, and may be readily distinguished from the
former by tiie effervescence occasioned on the addition of
hydrochloric acid. The c lalate dissolves in this acid
without effervescence.

Crystals may be readily observed under the microscope
in thin sections of scales from the Onion bulb, Rhubarb,
Indian Turnip, and many other plants.

279. In the leaves of plants of the Nettle Family it
frequently happens that a wart-like growth of cellulose
takes place on the inside of the cell-wall, tlie inwardly
projecting mass being attached to the wall by a slender
stalk, and having multitudes of small crystals imbedded
in it. Such inward growths are called ct/stolifhs ; tl;ey
may be readily seen in cross-sections of the Nettle leaf.

280. Crystalloids. Seeds, especially those of an
oily nature, as they approacli maturity and become dry,
develope in their cells multitudes of small rounded bodies
of an albuminous nature known as aleurone-grains, and

FORMATION OF NEW VKIA.H.

ig;

these often envelope niinuto substances of crystalline
aspect, Avliicli, however, under the action of potash and
other re-agents, undergo such changes of form as to lead
to the belief that they are not true crystals. They are
called crystalloids, and are to be regarded as forms of
protoplasm.

Occasionally crystalloids are observed without the
albuminous envelope, as, for example, in the tuber of the
Potato. Fig. 214 shows a cell having two or three such
crystalloids of a cubical shape.

The aleurone-grains in seeds containing starch fill the
spaces between the starch-granules. In oily seeds, such
as the Brazil-nut, they replace the starch.

281. Other cell-contents. Besides the important
substances already enumerated as products of the proto-
plasm, many others are found, such as sugar, inuline (a
substance nearly related to starch, and found in a few
special plants), fixed oils (castor, olive, linseed, &c., chiefly
in seeds), essential oils (turpentine, oil of lemons, and
essences of different kinds), gums, resins, and various
acids.

282. How new cells are formed. There are

several methods by which new cells are produced, but in
the higher plants the common method is that of cell-
division. We have already stated that only the newer
thin-walled cells are capable of exercising this function.
The process is briefly as follows : in the cell about to
divide, the protoplasm first separates into two portions,
each containing part of the nucleus ; then a partition-wall
of cellulose is developed between the two portions, thus
forming two cells out of the original one. Each part then

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KLKMKN'TS OB' STRUCTUKAL ilUTAW.

enlarges ami divides again, a.id so the process goes on.
When cell-division takes place in one d.'rection only,
filamerds or threads are formed ; if in two directions,
surfaces are formed ; while division in three directions
gives rise to masses.

It is evident that every part of a plant, however much
altered in its later history, must in its earlier stages have
consisted of this thin-walled cellular substance, or
iiiensteni^ as it is called from its power of dividing.

283. Cell-division, then, is the method of new cell
formation which prevails in the vegetative parts of the
higher plants. In the production of pollen, however, and
of the spores of vascular cryptogams, four new nuclei are
formed in the cell, and the protoplasm collects about
these, eventually secreting walls, so that four new and
complete cells are formed wWdn the original one, and
these sooner or later make their escape. This mode is known
as free cell-formation. In tlie proiluction of the endo-
sperm cells in the embryo-sac and the spores of many of the
lower plants a similar process goes on ; but here the
division of the nucleus is not limited to four portions, as
in the cases just mentioned, but may be carried on to an
indefinite extent.

284. In some lower plants the entire ^.ontents of two
adjacent cells may coalesce to form a single new cell.
This mode is known as conjugation. Also, the contents
of a cell may contract and develops a new cell-wall, a
process known as the rejuvenescence or renewal of a cell.

285. Tissues. An aggregation of similar cells is
called a tissue. Originally, every part of a plant consists
of meristem^ that is, of cells capable of dividing. But

TISSL'KS.

IGO

cljiinges set in, as we liave seen, at a very early stage, and
eventually all the c(}lls assume 'permanent forms, some
develoj)ing in one way, others in quite a different way,
according to the function of each particular part. So that
in any given plant we find tissues, or groups of cells, of
very various kinds, and very different arrangements of
these tissues in different cases. By examining sections
taken in succession from the growing point backwards,
every degree of change from meristem to permanent tissue
may be made out.

286. In the growing parts of all plants, in the pulp of
fruits, in the pith, in the green parts of leaves, and in
the entire substance of many plants of low organization,
we find tissue composed of short and comparatively thin-
walled cells, to which the name parencliyma has been
given. On the other hand, in the substance of wood, in
the inner bark, in the petioles and veins of leaves, tkc,
we meet with tissue consisting of long, pointed, and
overlapping cells, and known as prosenchyma. That of
the wood \^ fibrous tissue, and that of the inner bark is
the hast, specially characterized by the extraordinary
length and flexibility of the cells. Sclerenchijma and
collenchiima have already been referred to. In the
former the cells are commonly, though not always, short;
while in the latter they are usually long, but the ends
are not pointed.

287. Cells have been described which are characterized
by peculiar markings on their walls. When such cells
stand end to end, the cross-partitions conmionly dis-
appear, with the effect of forming long tubes, generally
of larger diameter than the other cells with which thev

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170

ELEMENTS OF STIIUCTUKAL IJtriANV.

are associated. Such large cells are known as vessels,
and tissue formed of them is called vascular or tracliearij
tissue. Hence we have spiral, scalar i/orm, annular,
reticulated, and Jotted vessels. These different kinds of
vessels are usually found associated with fibrous tissue,
and the combination of the two is known as the fittro-
vascular system.

288. Many plants, such as Dandelion, Blood-root,
Milkweed, and Spurge, emit a coloured or milky juice
when wounded. This juice is technically called the latex.
It is contained in a special tissue which is peculiar to
such plants, known as latici/ernus tissue. Its form
differs in different cases. In some instances it consists
of long tubes which may or may not branch. In others,
the cells composing it form a net-work. As in the case
of vessels, the latex tubes are connnonly formed by the
coalescence of cells originally separate, but sometimes by
the continued apical growth of single cells.

289. Sieve-tissue has been already noticed. The
cells are usually rather wide, and the walls are not
hardened, but the cross-partitions between the cells are
thickened and perforated.

290. It may be added that siiKjle cells which resemble
vessels in their markings are often spoken of as tracheids.

291. Tissue-Systems. While groups of similar
ceils are designated tissues, we may have also diff(;re:it
combinations of these tissues in different plants, or in
different parts of the same plant, and these various
combinations are known as t/ss>i(> .^i/sfp))is. These are no'v
usually ranged under three lunids : (1) 77f,e Efiid-mi: :
System, including those combinations of tissue which go tsj

TISSUE-SYSTEMS.

171

form the coverings of young stems, roots, and leaves ;
(2) The Fibro-vascalar S//>^feni, including such combina-
tions as form the stringy masses which abound in the
substance of the higher plants ; and (3) IVie Fundamental
System, including the combinations of cells which have
undergone little or no change of form ; in short, all the
rest of the plant except the two systems first mentioned.
292. The epidermal system is most highly devel-
oped in Phanerogams. Fig. 226 shows a section through

the thickness of a leaf. Here
it will be observed that there
is a closely-packed layer of
cells forming the uppei- sur-
face, and a similar layer form-
inef the lower surface. These

Z30C3DCQPCZ:

Fig-. 226.

layers constitute the e/ndcrniis
or skin of the leaf. The outer
part of the epidermis is usu-
ally a continuous layer, and
is known as the cuticle. It
will be seen that the walls of these cells are much
thicker than those of the cells in the body of the lo if,
and also that tlie epidermal cells, unlike the interior
ones, have been emptied of their protoplasmic contents
and are rectangular in shape. It sometimes happens
that the epidermis consists of two or three layers instead
of one.

The outgrowths of the epidermis, included under the
general term tnchonies, have already been referred to ;
they must be regarded as part of the epidermal system.

Fijjf. 22(i. — Cross-soctioii of a leaf, showiiijj opidcrinis above and below,
palisade cells under the upper epidermis, and loose tissue witli intercellular
spaces below the palisaile cells, (Gray.)

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ELEMENTS OF STIIUCTUIIAL BOTANY.

203. An examination of the under surface of almost
any leaf will show the presence of large numbers of oval
openings, somewhat similar to that shown in Fig. 227.
These are stomata. They are formed by two epidermal
crescent-shaped cells with a space between them, and
these have the power of separating or closing together
according to circumstances ; separating in the light, in
moist weather, and closing in dry. The
openings communicate with intercellular
spaces in the body of the leaf, a number of
which are seen in Fig. 226. In ordinary
leaves with an upper and a lower surface,
the stomata are far more numerous on the
lower side ; indeed, many such leaves are
'*^\ entirely without stomata on the upper sur-
Fig. 227. face. Vertical leaves have them rather
equally distributed on both surfaces. Immersed leaves
and underground stems have hardly any at all, and they
are never found on roots. The use of the stomata will
be referred to presently.

294. The stems of Dicotyledons lose their epidermis at
a comparatively early period, and a tissue consisting of
cells of corh^ filled with air, takes its place. These cork-
cells are modifications of the cells beneath the epidermis,
and they form an effectual protection to the tissues
within. The skin of the Potato-tuber exhibits this corky
layer very clearly. The special tissue from which the
cork is developed is called iihellogen.

295. In the fibrO-vaSCUlar system ditierent plants
exhibit a very different arran<::jt!ineiit of the component

Fig. 227. — Stoma from the iirface of a leaf, showing the crescent-shaped
guard -cells.

TISSUK-SV«Ti;.Ms.

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tissues. As ji rule, these tissues are Ctii)able of division
into two groups, in one of wliich the 'vvood is developed,
and in the other the bast. To the former of these groups
the general term xylem is applicable, and to the latter the
terra 2^Moem. The xylem is made np of the elongated
woody cells with pointed and overlapping ends, already
referred to as fibrous tissue, the wide tubes (vessels)
with variously marked walls, formed by the disappearance
of the cross-partitions between cells placed end to end,
and more or less short-celled tissue or parenchyma. The
pldoem is likewise made up of three constituents : the
long, thick-walled, flexible cells called bast-cells, which
correspond to the fibrous tissue of the xylem ; the wide
thin-walled sieve-cells, corresponding to the vessels; and a
certain amount of thin-walled, parenchyma.

296. The fibro-vascular bundles, as they are called,
have their origin in the meristem of the growing point.
This meristem is at first uniform, but soon groups of long

cells arise in it, and these are then
known as procamhium, to disti)iguish
them from the surrounding ground-
tissue. This procambium is gradually
converted into the fibro- vascular
bundles.

Fig. 228.

297. In dicotyledonous plants, the
fibro-vascular Ijundles are more or less
wedge-shaped, as shown in Fig. 228. The inner part of
each bundle consists of xylem and the outer of phloem,
and between the xylem and the phloem there is a layer
of meristem, known as the camhium. The soft cells of

«

Fig. 228. — Cross-section of ayoungdicotyledonousstem, sliowingsixbundles.

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174

KLEMKNTS OF HTRUCTUUAI. JiOTANY.

T'

tlie caiiibimn iliviilu, and tlio lu'w cells thus continually
being formed become modilied on the one luind into tissues
which increase the thickness of the xylein, and, on tho
other, into tissues ■which are added to tho phloem. Later
on cambium cells are formed in the ground-tissue between
the bundles, thus linking together tho cambium-layers of
the various bundles, and forming a continuous ring. Tho
links are then known a^ iiderfascicAiIar cambium, that of
the bundles themselves being the fascicidar. Ihmdles of
this kind, characterized by the cambium-layer, and so
capable of continuous enlargement, are called o^jcm bundles.

298. In monocotyledons, on the other hand, there is no
caml)ium-layer, and consequently the bundle when onco

formed is incapable of further in-
crease, and so is said to be dosed.
Fig. 229 is a representation of the
cross-section of an endogenous stem
in which many of these closed bumlles
are visible. Of course in such stems
no bark is formed.

299. It has been explained that
in the exogenous stem the xylem occupies one side of the
fibro- vascular bundle, while the phloem occupies the other.
In the closed bundles of Ferns and Club-Mosses, as well
as of some monocotyledons, however, a different arrange-
ment prevails, the xylem occupying the central part of
the bundle, and the phloem forming a circle around it.
The former arrangement is described as collateral, while
the latter is concentric. In many of the monocotyledons,
as well as in the exogens, the bundles are collateral.

Fig. 229. — Cross-section of monocotyledonous stem, showing closed bundles.

TISSUE-SYSTEM.S.

175

m^^ \

Fi<?. 230.

300. Fig. 2130 shows a section of an exogenous stem
somewhat older than that shown in Fig. 228. Here new
buntlles have been formed between the earlier ones, so
that the whoh; centre of tlie stem, except the^ytYAand the

lines radiating from it, is occupied by
the wood. This cylinder of wood is
now encircled by a ring of cambium,
l)eyond which are the tissues of the
[)hloem.

301. The appearance presented by
the cross-section of an exogenous stem
is that of a series of concentric rings,
each ring showing tlie limit of a year's gr-wth. The
portions of wood formed late in the sunmier are more
compressed by the outlying tissue than those formed in
spring, and hence the outer part of each year's ring appears
denser, and is sharply marked off from the ring of the
following year. No growth of the cambium takes plact;
in winter. The rays which intersect these rings as tine
lines consist of portions of the ground or fundamental
tissue which have been squeezed into their present form
by the increasing fibro-vascular bundles on each side of
them ; they are called medullary rays, and, as the stem
grows, new ones are formed from the cambium. Only the
primary ones, however, extend from the })ith to the bark;
those formed later are shorter.

302. In roots a special arrangement of the tissues of
the bundles prevails, the xyleni and phloem forming
alternate ray?^ This is the radial arrangement.

303. The fundamental or ground tissue com-
prises all the parts of the plant not already included in

Fig. 2;J0.— Section of an older dicotyledon, the bundles now forming

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parencnyina generally. in
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it embraces the pith, the medullary rays, and

collenchyma found just
y ma occurring indifferent
parts, and laticiferous tissue are also constituents of th(5
fundamental system, as well as the cork cells already
referred to. In tlie monocotyl* dons ground-tissue in the
form of parenchyma lills the space between the closed
bundles of the stem ; while in many plants in which
Rbro-vascular bundles are not produced, the ground-
tissue constitutes the whole of the interior.

304. In exogenous stems the wood developed from
the cambium is often different from that of the primary
bundle as developed from the procambium. Pines, for
example, have vessels in the primary xylem, but none in
the secondary, the latter being almost entirely made up
of the cells with bordered 'pit. % already described.

305. The bundles of the leaves are continuous with
bundles in the stem. Leaves appear at first as protuber-
ances on the side of the stem close to the growing point,
and the upper ends of the primary bundles almost at
the very beginning bend outwards towards the new
leaves, the lower part being continued down the stem
In the monocotyledons these bundles first arch inwards
towards the centre of the stem, and then outwards and
downwards, thinning out as they descend. Hence, in a
cross-section (Fig. 229) the bundles appear more crowded
towards the circumference, and also smaller. Such a
stem is, therefore, found to be harder at the outside than
at the centre.

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OONHTITUKNTS or IM.ANTM.

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CAWPTVAi XX.

rOOD OP PLANTS — CIIKMICAL 1M{0(.'KSHI:S — MOVKMKNTS OK
WATER — PHENOMENA OF GROWTH.

306. The materials of which the substance of a plant
is made up are various, and some of them occur in far
larger quantities than others. Water forms a very
considerable percentage of the whole weight, but is
present to a greater extent in some poi'tions of a plant
than in others. Fleshy roots, for example, may contain
as much as 90 per cent, of water, while dry seeds contain
only about 12 per cent.

307. The water may be expelled by careful drying,
and if what is left is then burnt, what is called the
otyaniG part of the plant disappears, and a small (quantity
of atih remains behind. The organic part is found to
consist mainly of carbon, hydrogen, oxygen, nitrogen,
and sulphur ; while the inorganic part (or ash) contains
very small quantities of phosphorus, iron, calcium, mag-
nesium, and potassium. All these materials are obtained
from the air or the soil. There is constantly present in
the air carbonic acid gas, a compound of carbon and
oxygen, which is exhaled from the lungs of animals, and
which is always found wherever wood or coal, or carbon
in any form, is being burned. This gas is carried down
into the soil dissolved in rain-water, and the solution is
then absorbed by the roots and transmitted by the stem
to the leaves, where, in the presence of chlorophyll and
in sunlight, the gas is decomposed into its carbon and
oxygen. The excess of oxygen is then exhaled and the
carbon chemically combined with the other elements to

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Photographic

Sciences
Corporation

73 WEST MAIN STREET

WEBSTER, N.Y. 14580

(716) 872-4503

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178

KLRMKNTS OF STRUCTURAL ROTANY.

t'onii starch foi* purposes of growtli. The oxygen
r('(|uired by the plant is derived chielly f roni the carbonic
acid gas and fi-oni water. Hydrogen is obtained by the
decomposition of water, and nitr'ogen from the ammonia,
which^ like the carbon dioxide, is carried down from the
air by rain, and also from nitrates contained in the soil.
Sulphur is obtained from salts (such as calcic sulphate)
found in the soil, as are also, of course, all the inorganic
elements.

Of all thesv. constituents of the drf/ plant, carbon is
the most abundant, amounting to about half of the entire
weight.

308. The inorganic elements, though small in quantity,
are, nevertheless, essential. If, for example, a plant be
altogether deprived of iron it will produce no chlorophyll;
while, if potassium is withheld, it will not produce starch.
These facts are proved by causing seeds to grow under
conditions which enable us to accurately control the
supply of nutrition in the form of carefully prepared
solutions of the different ingredients. Several substances
of common occurrence in the ash of plants, as silica,
sodium, and some others, are in this way shown not to
be essential to healthy growth.

309. The process by which the carbon, obtained from
the carbon dioxide, is combined with the elements of
water to form starch is called assimilafcon. As already
explained, the particles of starch which are formed by
the chlorophyll granules in sunlight are converted by
combination with oxygen into soluble forms, and carried
away, when the light is withdrawn, to other parts where
growth is going on, or to storehouses such as tubers and
seeds. This oxidising and converting process is metastasis.

RESPIRATION*.

179

In consequence of having such a store of material,
tubers can gjow in the dark as long as th(; material holds
out, but will not, of course, produce green leaves.

Besides starch, oil is a common form of reserve material,
particularly in seeds. Sugar, also, is found; as, for
example, in the Sugar-Beet.

310. Parasites and saprophytes, which are as a rule
without chlorophyll, do not assimilate, but obtain their
nourishment from the stores of other plants or from
decomposing organic matter.

311. The so-called carnivorous plants, such as the
Bladder-wort and the Pitcher-plant, obtain a portion of
their nitrogen by entrapping insects and other small
animal organisms, and absorbing them as they decompose.
Some such plants appear to cover their prey with an acid
secretion, and to go through a digestive process not
altogether unlike that performed by animals.

312. Respiration. Plants, like animals, are continu-
ally inhaling oxygen, and the presence of this gas is
essential to their existence. The oxygen so inhaled is
combined with carbon to form carbon dioxide, and this in
the day-time is at once decomposed and the carbon
assimilated. The absorption of oxygen and its subse(pient
combination with oi'ganic matters in the plant is accom-
panied by evolution of heat, a fact well illustrated in the
process of malting, where damp barley is heaped together.
As soon as the grain begins to sprout, oxygen is rapidly
absorbed, and a vt.'ry decided rise of temperature takes
place. The starch of the gi'ain is oxidised and converted
into sugar, and the growth is then stopped by rapid drying.
The sugar, on fermenting, produces alcohol.

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ELEMKNT8 OF STRUCTUKAL HOTANY.

313. Transpiration. The oiH'uings in the epidermis,
called iittniiata, have alieady been described. Through
these the excess of water-vapoiir in the plant is exhaled,
it may often be observed, in hot, bright weather, that the
leaves of plants droop if exposed to the sun. This is
because the rate of evai)oration through the stomata is
greater than the rate of supply at the roots. At night,
however, the stomata close and the balance being restored
the plant recovers. The water which is thus supplied to
the leaves appears to be conveyed through the stem by
means of the cdl-ivalls of the wood-prosenchyma, since the
supply is not diminished if a ring of bark and the under-
lying bast and cambium be removed.

314. But water is also supplied to the growing points,
and in a different way. It is well known that if two
liquids (or gases) of different density are separated by a
porous diaphragm they will tend to change places, the
fluid of less density passing through the diaphragm more
rapidly than tlie other. This is the principle of osmose,
and wherever in a plant a cell-wall separates cell-contents
of dili'<Ment density it is found to apply. Hence, water is
absorbed by freshly-formed cells, containing dense proto-
j)lasm, from neighboring cells which are a little older and
in which the protoplasm lias been diluted. These absorb
from the older cells behind them, and so on. Such water
is transmitted, not through the prosenchyma of the wood,
but through the parenchyma and the meristem.

315. It is a matter of common observation that the
stems of many plants " bleed " if cut in the spring. This
is due to the upward pressure of the water with which the
roots are charged at that time, and it takes place in the

GROWTH.

181

the
I This
\i the

the

ubsunce uf transpiration. When the leaves are formoil
and transpiration sets in actively, the root-pressure i>
reUeved and the stems will no longer bleed immediately
on being wounded. In some plants the excessive root-
pressure even causes drops of water to exude from the
leaves.

316. "We may observe, then, three distinct movements of
water in the plant: (1) the rapid movement to make up
for the loss by transpiration, (2) the slow movement to
supply the growing cells with requisite moisture, and (3)
the movement due to root-pressure.

317. Growth. Growth has already been referred to
as consisting in the formation and subsequent enlargement
of new cells, accompanied in many cases by change of
form. It has also been mentioned that the enlargement
is the result of the introduction of new particles of
vegetable material into the spaces between the molecules
of the parts already formed — a process known as intussus-
ception. It is now generally admitted that each of the
molecules of which the plant-body is made up is enveloped
in a sheath of water. We know that the presence of
water is essential to growth ; when it is absorbed by a
growing cell the immediate effect is to stretch the cell, as
it were, to its utmost capacity ; in other words, to separate
the molecules as far as possible and so increase the amount
of water between them, thus making it possible to inter-
pose new molecules of solid matter. The use of the water,
also, as a vehicle for conveying the new material is obvious.
This new material, the presence of which is essential to
growth, is commonly supplied to the growing points from
older parts which serve the purpose of storehouses, as seeds
and tubers, or of manufactories, as the leave?.

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i;m:mi:nts uf stuuctl'ua!. jjotany.

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318. Stonis and roots, as a rule, exliibit three distinct
regions according to the stage of devcJojmioiit at which
they liave arrived. There is, first, tlie growing point,
the chief characteristic of which is the raj)id formation of
new cells by division ; secondly, the elongating part,
chiefly characterized by the growth of the cells in length,
there being practically no further division here ; and,
thirdly, the fully developed part, in which there is no
further division or enlargement, though the cells may
continue to discharge various important functions.

319. Growth, whilst dependent upon an adequate supply
of water and of new material, is also largely affected by
external conditions, such as temperature and light. Growth
may be stopped altogether by either too low or too high a
temperature, and between the limits within wliich any
given plant is found to be capable of growth there will be
found a particular degree of temperature more favourable
to growth than any other either above it or below it.
This may be called the optimum. The effect of tempera-
ture differs considerably according to the amount of water
present in the part affected, dry seeds, for instance, resist-
ing a temperature, either high or low, to which soaked
seeds would at once succumb.

320. Light is essential to assimilation, but seeds and
tubers, as well as many of the lower plants which are
without chlorophyll, such as Mushrooms, will grow in the
absence of light as long as th^) stock of assimilated
material upon which they draw is not exhausted. The
growth which takes place in the cambium-layer of
dicotyledons and in roots is another examj)le of increase
in size in the absence of light. The assimilated material

ii i

(;i{t)WTii.

183

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in all these cases, Ijowever, has been previously elaborated
elsewhere.

321. Light is found to exercise a retarding influence
upon growth. A plant, for instance, in a window will
bend towards the light, because the cells on the side
nearest the window grow more slowly than those which
are shaded, tluis causing curvature of the stem and
petioles.

322. Gravitation also affects growth, as we know that
the stem and root, or axis of the plant, are usually in the
line of the radius of the earth at the place of growth. If
a seedling plantlet be laid with the stem and root
horizontal, the stem will curve upward and the root
downward in the endeavour to restore the vertical direction.

323. The twining movement of the stems of many
plants is due to inequality of growth at successive points
in the sides of the stems. Leaves unfold from the bud
because the growth on the upi)er side at the time of
unfolding is more rapid than on the under side. These
movements are called nutations, and are not due to the
external action of light, but entirely to internal causes.
The movements of tendrils, however, are affected by
contact with the object which they grasp.

*■•>:■

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184 ELEMENTS OF STKUCTUKAL BOTANV.

CHAPTER XXI.

EXAMINATION OF A FERN — A HORSETAIL — A CLUB-MOSS.

324. We shall now proceed to tlio examination of some
common plants which will be found to be typical of groups
differing in important respects from the piianerogams.

Ferns. Fig. 231 is a representation of our com-
mon Polypody, You may find it in almost any shaded
rocky place. Running horizontally beneath the surface
you will find the stem of the plant, which in this case is,
therefore, a rhizome. A portion of the rhizome is shown
in the lower part of the figure, with fibrous roots on the
under side. From the upper side are developed the
leaves, which, as you see, have long petioles, and if you
find one which is still in the bud you will observe that it
is rolled up lengthwise, as shown in Fig. 232. The
vernation is, tlierefore, circinate^ and this is the case in
nearly all the Ferns. On examining the back of the leaf
(Fig. 231 shows the back) we observo rows of brownish
dots on each side of the middle veins of the upper lobes.
Fig. 233 is an enlarged view showing the position of these
dots at the extremities of the veinlets. When we put one
of these dots under the microscope it is seen to be a
cluster of minute, stalked bodies, such as that shown ii.i
Fig. 234. These bodies are further found to be sacs filled
with extremely fine dust, and the dust consists of multi-
tudes of rounded particles ail exactly alike. They are, in
short, spores, and the sacs in which they are contained
are the spore-cases, or sporangia ; while the clusters of
sporangia are the fruit-dots, or sorL Around each spor-
angium there is an elastic jointed ring which breaks at

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Pt-:i{Ns.

185

maturity, and by its elasticity ruptures the spore-case,

"•vhich then discharges its
spores, as shown in Fig.
234. The leaf of the Fern,
then, is something more
than an ordinary foliage-
leaf, and is known as the
frond. The petiole is
called the dipe^ while the
mid-rib is the rhachis.

325. A spore under
proper conditions developes
a slender thread-like cell
which eventually gives
rise to a thin, flat, green
expansion, resembling that
shown in Fig.
235. This is
called the pro-
thalliwn. From
the U; Jlt sur-
face root-hairs
are produced as
sliown in the
figure. On the
same surface,
among the root-
hairs, arise mi-
nute projections

Fig. 232.

Fi-'. 231.

Fig. 231. Root-stock and frond of Polypody.

Fig. 232. -Ciicinat.e vernation of the frond.

Fig. 233 -" Magnified view of the sori.

Fig. 234.— Sporangium discharging spores ; greatly magnified.

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of tissiit! ill wliicli aro (l<'vel()|Hul cuUm corrnsjmnding toth?
polk'ii-giaiiis of phaner(».L,'!iius. Tluisu jirojcctions are the
anthcrldia; tliov contain cells in which aro fertilizing bodies
known as ant/ierowith. Also on the under surface of the

prothalliuni, near the notch,
we lind structures analogous
to the embryo-sac of the
phanerogamous ovule. These
are the arrhfr/o/iia. They
are mostly ftiisk-shaped bod-
ies, having a gcrm-cell — the
o()X})1ifr«' — in the lower end.
The autherozoids, on escap-
ing from the antheridia,
make their way down the

necks of the archegonia, and
Figr. 235. • . , i. -ii i.u

coming in conlait with the
oospheres fertilize them. As a result of this fertilization,
a plant is developed in all respects like the one which
originally bore the spores on its fronds.

326. It is manifest, then, that we have hero two distinct
generations : first, the sporo produces tlie prothalliuni
which bears the antheridia and archegonia ; secondly, the
interaction of these gives rise to a plant which bears the
spores. Til is phenomenon is sp(jken of as the alternation
of generations.

327. The stems and roots of Ferns are found to contain
vascular bundles which, like those of monocotyledons, are
closed.

Fig. 235. — Prothalliuni of a Fern, under side ; h, root-hairs; an, antheridia;
ar, archegonia. Magnified 10 tinies. (Prantl.)

I

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TIIK HOHSKTAHA

187

328. From tlio account licro j^ivcn of tho mode of
reproduction in tlm Ferns, it wiil Ijo evident that the
(iynin(xs|)errna occupy an intermediate position between
th(5m and tin; An.L,'iospornis.

For a description of otlier common Ferns dirtering in
detail from tho Poly[)ody, the student is referred to Part
IL, pa«,'o 146.

329. The Horsetails. At i)a,i,^e lOO, Pnrt TT., will
be found a description of tho common Horsetail, with an
illustration of the fcn-tile stem, or ratlicr brancli, because
botli tho i)alo spore-beariuf,' branch and tho later green
shoots with whorled branches are sent up from an under-
ground stem or rhizome. The spores, upon germination,
give rise to prothallia bearing anthoridia and arcliegonia
[)recisely as in tho Ferns. The prothallium is usually
small, flat, and irregularly branclied or lobed, developing
the anthoridia at tho projecting ends of tiio lobes, and the
archegonia in the angles biitween them ; or, in other cases,
the prothallia may 1)0 dionnous. Fertilization of the germ-
cell, which occuj)ies a cavity at the l)aso of the archegonium,
takes place exactly as in the Ferns, and, as a result of
f(>rtilization, the germ-cell developes into a sjiore-boaring
plant similar to tho original one. Here, tlierefore, we
have again exhibited an alternation of generations.

Other species of Equisetum of common occurrence,

instead of producing a special fertile branch, develope

' sporangia at the extremities of the ordinary leafy stems.

330. These plants, like the Ferns, exhibit fibro-vascular
bundles, and the ej)idermis is especially characterized by
the excessive amount of silica contained in it, some of the
species being used for scouring or polishing by reason of
this property.

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KF.KMKN'TM OF' .STIIUCTURAL HOTANY.

Ml

Fiff. 23G.

.I.n. The curioiis r/nfrrn (Fig. 23G) attached to the
spores doulttless assist thoiii to csciiiio from
the. Hpons-cases, and siil)S('(|ii('iitly aid in
dis|)<'isiiiL( them.

:i:52. The Olub-Mosses. i'ij,'. 2;i7 is

a icpiesc'ntatioii of a brand)
of Li/f(}/iO(ftu7ii clarataiHy one of our coiu-
ninii Cinb-Mosst's. The creeping stem lies
flat upon the ground, and often attains a
great lengtli, sending up at intervals erect
branches Avith crowded linear-awl-shaped
leaves, some of wliich, like tiio one shown
in tlie figure, are terminated by a slender
peduncle bearing one or more cylindrical
spikes. These are the fertile branches,
and the leaves u})on them, or at all events
upon the slender upper part, are very much
smaller than upon the ordinary sterile
branches.

It is to be o])served that the stems and
ro'^ts of these jjlants branch (licliotomouslij
(145,.

333. The sporangia are produced in the
axils of the leavers of the terminal spike.
One of these leaves, greatly magnified,
with its attached sporangium, is shown in
Fig. 238. The sporangium opens by a
slit at the top to discharge the spores.

334. It is only quite recently that the
prothalliuin has ]»een detected. It is

Kig. 237.

described in the case observed as a " yellowish-white

Fig. 236.— Spore of Equisetuni with elaters; iiigiily majjfnificd.

Fig. 237.— Branch of Lycopodiam davatum; natural size. (Thom^.)

I

id to the

ig. '230.

our coin-

Htoni lies

jittiiins a

vals oroct

kVl-slui[)('tl

no sliowii
a slcii(l(M'
yliiKlrifiil
hraiichos,
all events
ery much
y sterile

;ems and
tomoudy

;ed in the
lal spike,
lagnified,
shown in
ms by ii
)ores.

that the
It is
ish-white

I-MAUACIKHS OK I'lKICl UOPII Y I KS.

S9

irregular lohed body, sj)iirin;.(iy liirnislKMl o\\ its und«!r sur-
face with small rooi-hairs." Tiuj authiu'idia and archcj^'imii
ai)|u'ar to be ])r()duc('d on the uinusr sur-
face, and tliesc l)y tiieir interaction, ;_;ive
rise to the new plant which Ix'ars the
spores, just as in the Kerns and ll^ rsu-
tails ; so that M<,'ain there is an alternation
of generations.

335. It is a fact of great interest that
Fif,'. 238, in some pliints nearly related to the Club-

Mosses, tirt) liiud)^ of spores — largo and small — are producod
in acparato sporangia. Tlie largo ones developo prothallia
upon which arehegonia are formed, and the smaller others
upon which antheridia ai)pear.

33G. The three plants just considered, while evidently
differing in certain details of structure and in general
asj.ect, nevertheless have a number of characters in
common :

1, Then agree in their niodr. of reprodiidi'm, which is
hy 82X)re.% these bodies heinrj quite unlilce the si;f<;ds
with which wc are now familiar., and which, t/ou wilt
recollect, always contain the embryo of the new
plant.
They all exhibit an alternation of generations.
They all have true roots.
4-. The three tissne-systenis — tlie epidermal, the fihro-
vasculary and the fundamental — though not all
developed to so ^'igh a degree as in tlie Phanerogams,
still can be very clearly made out in both roots arid
stems. The fihro-vascnlar bundles are always closed,
as in monocotyledons, and are, as a general rale,
coneen t ric (209 ).

Fiff. 238. — Leaf of Lycopodiuin buarinj;^ sporangium ; greatly magnified.
^Thomd.)

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190

ELKMKNTS OF STRUCTURAL BOTANY.

337. PJants with these coniiiion characteristics constitute

a group called Pteridophytes or Vascular Crypto-
gams, " cryptogam " being a general term applicable
to all plants which do not produce true flowers, as
" phanerogam " applies to all those which do.

th(

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hi fi

CHAPTER XXII.

EXAMINATION OF A MOSS AND A LIVERWORT.

338. Mosses. Fig. 239 is a representation of the
common Hair-Moss {Polijtrichum commune)^ which may
be found in early summer almost anywhere. It grows in
dense masses, and upon examination it will be found
that while many of the stems resemble that shown in
Fig. 239, the upper extremities of othei's form rosettes,
as in Fig. 240, whilst others again terminate in ordinary
vegetative buds.

339. Let us first examine a specimen as represented
in Fig. 239. There is, it will be observed, a well-marked
stem, or leaf-bearing axis, upon which the crowded
minute leaves are sessile. In the Mosses they always
are so, and they are found, upon examination with a
good microscope, to consist as a rule of only one layer of
cells, being therefore much simpler in structure than
those of the plants we have so far been engaged upon.
It is also to be noticed that the leaves of Mosses are
without stomata.

340. Observe now that our Moss has no true roots.
It is, however, fixed to tlie soil upon which it grows by
numerous root-hairs or rliizoids,

m

Jill

EXAMINATION OP A MOSS.

191

■upon,
is are

roots.
rshy

341. The ^lender scape-like stalk which rises above
the leaves is technically called the seta, or bristle ; in the
left-hand part of the figure («) the upper end of the seta

is covered by a hairy cap, the
calyptra. In the right-hand por-
tion the calyptra has been re-
moved, disclosing a little pod,
variously spoken of as the tlieca,
or urn^ or capsule, or s])oran<jiwn.
Fig. 241 is an enlarged view.
This capsule is closed at the top
by a circular lid, the operculum,
which falls away when the cap-
sule is mature, thus allowing the
escape of the sj^ores, which are
produced in it. The spores are
developed upon the surface of a
central column which rises from
the bottom of the capsule, and
which is known as the columella.
The opening through which the
spores escape is called the stoma,
and a good lens reveals the fact
that around the stoma there is a
circle (sometimes two) of minute
teeth, known collectively as the
peristome. In tlie Moss now be-
fore us the peristome consists of sixty -four teeth. In
other Mosses the number varies, })eing always, however,
some power of 2 ; either 4, or 8, or 16, or 32, or 64.
Occasionally the teeth are altogether absent.

Fip. 230. — Two fertile stems of a Moss (Pohftricliaiii commune) of the
natural size ; at c the calyptra is seen enveloping the capsule. (Wood and
Steele).

Fig. 239.

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192

ELKMENTS OF .STllUCTUIiAL BOTANY.

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It'"''''-?' ;

342. We shall now consider the mode of reproduction
in the Mosses. Let us commence with the spore. This,
upon meeting with proper conditions, bursts its outer

coat (tlie pxospon'), and the inner
coat (the endospore) is then pro-
truded as a slender tube. This
continues to grow by repeated divi-
sion, until at length, iu most cases,
a tangled thread-like uimss of vege-
tation is produced, to which the
name ])roto?iema has been given.
After the lapse of seveivil days
Fig. 240. minute buds are developed at ditt'er-

Bnt points upon the protonema, and these are found to
consist of whorls of scaly leaves. This is the beginning
of the development of the ordinary Moss-plant. Upon
the plants thus arising from the buds are developed
anther idia and archegonia,
the former in the axils of
the leaves forming the
rosettes shown in Fig. 240,
and the latter at the apex
Df other stems, as shown in
Fig. 239. The antheridia
ire seen under the microscope
bo be club-shaped bodies, containing a mass of cells in
which the antherozoids are formed. The archegonia are
flask-shaped bodies, with a lower expanded portion and a

Fig. 242 shows the apex of a fertile

Fiff. 241.

long neck above.

Fig. 240. — Apex of sterile .stem, showing rosette of perigonial leaves, in tlie
ixils of wiiicli are tlie antheridia ; greatly enlarged.

Fig. 241.— Enlarged view of capsule, showing peristome and det^vshed oper-
3ulum. (Wood and Steele.)

)roduction
)re. This,

its outer
the inner
then pro-
be. This
eated divi-
nost cases,
ss of vege-
which the
een civen.
veral days
3d at diti'er-
re found to
3 beginning
nt. Upon

developed

of cells in
legonia are
'tion and a
)f a fertile

leaves, in the
Idetached oper-

EXAMINATIOX OF A MOSS.

193

stem with several archegonia in the centre, and Fig. 243
shows a single archegoniuin very highly magnitied. The

antherozoids upon being set free
make their way down the necks
of the archegonia, and unite
their substance with that of
special cells in the lower end
(one in each archegonium). These
cells, as a consequence of being
thus fertilized, become sur-
rounded by a thin coat and
immediately begin to grow up-
wards, developing the slender
stalks (seta3) with the capsules
at the summit, and surmounted
by the calyptra, which is, in
fact, nothing but the wall of the
Fig. 24i. archegonium wliich is torn away
at its base and carried upwards. Then the
spores are developed around the columella,
and the round of life of the plant is com-
pleted.

As in the Ferns, we have here also

exhibited an alternation of generations, the

one generation being that arising from the

Fig. 243. development of the spore and resulting in

the production of the antheridia and the archegonia ; the

other being that arising from the fertilization of the

Fig. 242.— Enlarged view of apex of the fertile stem of a Moss; o, archegonia;
b, leaves.

Fig. 243. —Very highly magnified view of an archegonium; b, the base;
h, the necli ; vi, the mouth ; the germ-cell is seen at the bottom of the flask*
shaped cavity. (Sachs.)

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194

ELEMENTS OF STRUCTUUAL IJOTANY.

special cells in the archegonia, and resulting in the
production of spores.

343. Liverworts. Figs. 244 and 245 are representa-
tions of portions of a very common Liveiwort, Mair.haufia
liolijntorpha. It may be found growing along the borders
of marshes and in wet places generally, often "vith inter-
mingled moss. It is of a deep green colour, and usually

spreads over a consid-
erable extent of sur-
face. There is no ap-
pearance of leaves, the
plant-body lying flat
upon the surface upon
which it grows, and
putting forth root-hairs
on the under side.
Fig. 244. From tlie upper side

arise peculiar stalked bodies of two sorts, as shown in
the figures ; the one consisting of flattened or slightly
convex disks, and the other being star-shaped. These
stalked bodies contain the reproductive organs. In
cavities on the upper surface of the flattened disks are
produced the antheridia, from the cells of which are
liberated the antherozoids. On the under surface of the
rays of the star-shaped bodies are produced clusters of
flask-shaped archegonia, each with a germ-cell at its
base, and fertilization takes place in the manner already
described in the account of the Moss. As a result of
fertilization a capsule is developed which pioduces spores,

Fig. 244. — Portion of a Liverwort (MitrcJututia polipnofjilia', showing the
tliallus and several stalked disks which hoar the antheridia ; natural size.
(Thome.)

■'! J

the

In

:s are
li are
)f the

!rs of
Lt its
I'eady
lit of

)ores,

Itij^ the
il size.

KXAMIXATION OF A LIVKKWORT.

195

pretty much as in the Mosses, though in Marcliantia
the stalk of the capsule is very short, and the whole is

surrounded Iiy a loose sheath
which grows up from the base
and at length completely encloses
it. The spores on germinating
develope into plant -bodies such
as we have described, so that the
alternation of generations is here
also well marked.

344. Other Liverworts more
nearly resemble the Mosses in
form, having leafy stems, from
the summit of which arise slender
stalks with capsules at the upper
^l^^"^^^:; ^^. end. Tlieso capsules, however, do
M <\^ - ,- __/ not open by a stoma, but are four-
Fig. 245. valved, and at maturity the valves
split asunder, allowing the escape of the spores. In the
leaves of these latter forms there are no veins of any kind.
Forms in which the plant-body is a flat expansion, as in
Marchantia, are distinguished as t/ialloid, while the leafy
forms are said to be foliose.

345. It remains to be added that Marchantia and other
Liverworts reproduce themselves by buds as well as by
spores. These buds (gemmce) are formed in little cup-
shajjcd rec('})tacles which appear on the up[)er surface of
the plant-body. They consist of simple masses of tissue,
which fall away when fully grown, and immediately
develope into new plants.

Fig. 245.— Thallus with star-shaped receptaclo bearing archegonia ; natural
size. (Thom6.)

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19o

ELKMEXT.S OP HTRUCTUUAL BOTxVNY.

346. TliB Mosses and Liverworts constitute a distinct
group of plants called Bryophytes. It will be evident
from the preceding descriptions that in the matter of
reproduction they do not differ materially from the Pteri-
dophytes. They are, however, distinctly sei)arated from
them by the sim^der ortjauization of their tissues. The
Bryophytes have no true roots, but only root-hairs or
rhizoids. The whole plant-body is, as a rule, composed
of thin-walled parenchyma, and only in a few cases is
there any appearance of a development of a fibr'^ vascular
system, and that only of the vaguest possible kind. There
is, however, a well-defined epidermal system, and stomata
are not uncommon.

■If ;: '1.

CHAPTER XXIII.

EXAMINATION OF A MUSHROOM — A LICHEN — A OHARA.

347. Mushroom. Fig. 246 is a representation of
the Common Mushroom of the natural size, while Fig.
247 shows the several stages of its growth. At A is seen
a matted fibrous mass, which is the underground portion
of the plant. It is called the mycelium; at several
places on it rounded outgrowths of different sizes are
visible. These eventually develope into the overground
part of the Mushroom. At // is shown a vertical section
through one of these outgrowths at an early stage ; at I
in this figure you will observe two dark dots ; these are
the open ends of a channel which forms a complete ring

seen
tion
'^eral
are
und
tion
at/
are
ring

KXAMINATION OF A MUSIIROOAI.

I'j;

in the interior. At /// they are much more distinct, and
here is also manifest a difference between the upper and
lower sections, which is still more marked at IV and V.
The upper spreading portion is called the pileus ; at V
the lower edge of the pileus is still attached by a circular
membrane to the stalk. In this stage the membrane is

Fig. 246.

called the veil ; later on, as seen in Fig. 246, it is torn
away from the pileus and now forms the anmdus, or ring,
about the stalk. Upon the under side of the pileus are
produced a great many vertical, thin plates, called lamellm
or gills. If we make a vertical section through the pileus
so as to cut across a number of the lamella?, they will

Fig. 246. — The Common Mushroom (Afjaricus campestris) ; a, the pileus;
b, the lamellae ; c, the annuliis. (Thom6.)

♦ i1

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198

ELEMENTS OP STItUCTURAL BOTANY.

present the appearance shown at A, Fig. 248, and if we
magnify one of these cross sections it will appear as at B,

Pig. 247.

where there is seen an outer layer of cells standing on
end. The whole of both surfaces of the lamellae is
covered with such cells, and this special layer is the

Fijf. 247.— Various stages in the development of a Mushroom. (Sacha.)

1 (•!

on

is

the

I)

EXAMINATION OF A MUHHIlooM.

lUi)

hymenium. At C, the left hand portion of the figuro
shows a number of these long cells much more highly

Fig. 248.

magnified, some of them narrowed in at the top so as to
form slender points, upon each of which is a rounded body.

Fig. 248.— Greatly enlarged views of sections of the lamellse of a Muahroom.
(Sachs.)

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200

KLEMENTH OF 8TUUCTUFIAL BOTANY.

These rounded bodies are tlu) spurns ; the narrowed ends
of tlie cells are callctl sferiymata, and the projecting cells
which bear them are speciiaily known as hasidia. The
spores are formed by tlio simple narrowing in of the outer
ends of the basidia.

The mycelium is, therefore, the vegetative part of the
Mushroom, while the stalked pileus above the surface is
the fructification. The mycelium is developed directly
from the spore, but so far there have not been dis-
covered any indications of the interaction of sperm-
cells and germ-cells such as characterize the Bryophytes
and Pteridophytes

348. You will note the entire absence of green colouring-
matter. The Mushrooms produce no chlorophyll, and,
consequently, are incapable of assimilation. They are
always found growing upon decaying organic matter, as
the leaf-soil of forests and meadows, &c.

349. The Mushrooms are representatives of a large class
of plants called Fungi, all the members of which are
destitute of chlorophyll. The cells of which they are
made up are generally in rows so as to form long threads
which are known as hypha', and these may be either
loosely interwoven, as in ordinary Moulds, or firmly
compacted together, as in the Mushroom.

350. As just mentioned, Mushrooms are saproohytic in
their habits ; but there are also Fungi which are parasitic,
such as Rust and Smut. To the Fungi belong such
organisms as tlie Yeast-plant, and the Bacteria which are
found in putrefying matter, and are the cause of, or are
associated with, diseases of various kinds.

KXAMINAIIUN l»F A l,l» HKN.

•JOl

ed ends
ing cells
a. The
he outer

t of the
urface is
directly
teen dis-
sperm-
f^ophytes

)loiiring-
'11, and,
hey are
itter, as

^e class

lich are

ley are

ih reads

either

firmly

ytic in
rasitic,
? such
ch are
or are

.5>*'

Fij,'. 241).

351. Lichens. Tln-so plimts may 1h5 found growing
on the bark of trees, on old fences, on rooks, (jr on the

gioiuid. Tliey diller widely in cxturnid
j»ppeiiriinc<', sonicLime.s growing erect and
imitating a stem and ])ianches, us in Fig.
249 ; sometimes forming flat expansions
which adlieio to the surface upon which
they grow, as in Fig. 2r)0. Borne species
are yellow, others red, others grey. A
very common one is that rejjresented in
Fig. 250. It may bo found upon many
tree-trunks, and will be easily recognized

by the yellow disks which dot its

surface.

352. Tlie flat part of the Lichen is
the thallus, or vegetative portion,
while the yellow, cu[)-shaped disks
(the ajmthecia) con^iin the fructifica-
tion. Fig. 251 shows a section of the
apothecium, and also the lobing of
the margin of the thallus. Fig. 252
is a very highly magnified view of a section of a thallus,

showing it to be largely made up
\ of cells, or liiipluv, similar to those
y of the Mushroom. But in the
Fig. 251. Lichen there are visible, in addi-

tion, large numbers of spherical green cells (r/ g in the.
Fig.) known as gojiidia, which either occupy well-marked

Fig. 249. — A fruticose Lichen (Cladonia d'niitata) of the Datural size ; h, the
(•ni> ; c, the thallus ; the rounded bodies at the siuninit are the apothecia.
lThoni6.)

Fig. 250. — A foliaceoug Lichen growing on a stone ; natural size. (Gray.)

Fig. 251. —Section of an apothecium. (Gray.)

Fig. 250.

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-UJ KI.KMIINT.S Ol- .sTUL'CTlMlAr, UoTANY.

laycMs, as in the inrsoiit instance, or ate .scattered tlnon"ii
tlmlxxlyof tho tliaiius. Tiiu prcsenc.) of tl,e.so gonidi.i
may bo said to ))c tliu distin;^niisliin^' filature of tiic
Li(;lH3ns. Their true relation and function were for a Ion--
timo ilimblful, wiiloly clill'('iviit opinions Iicing held, Imt

Virr

l■(•■

Fig. 252.

it is now generally admitted that the goniiiia are them-
selves chlorojthjll-heanag plants^ and that the remainder
of the Lich(m is a true Fungus, paradtin upon the fjonidia.

Fig. 252.— Very hisrhly magnified view of sc(;tlon of tlie thallus of a Lichen ;
r, rhizoids; w, spurious tissue of hypiue ; ,/, jrreen gonidia ; o, boundary
cells of upper side ; n, Ijoiuidary cells of ini<ier side. (Sachs.)

(L'llAHA.

'2o:\

Tlif (jiicsiioii 118 to tliu origin of tho i^onidia is not yot
settit'd.

.'553. Till! structure of n • apotiircifiiii is vfry woU
siiowik ill Vi'^. 253. From ilu' hvpli.i' aii! (Icvolopod
hiV'ffi', clulj-siiapcMl, vertical ceils (tho r<^v•/) wliioli penetratn
butwecn tiio narrower vortical brunches of tlie iiypluu (the
parajilnjxvs). In tlu; asci arise the spores (technically,
asrntijiorcn)^ usually eight in each, and these when mature
are discharged from tho asci, and give rise to \m\x [tlaiils.
Tho ascospores are formed in the asci by the process
known as free cell-formation (283). The protoplasm in
the asci collects about as many dilforent points as there

are spores to be formed, and a wall is then secreted about
each. This mode, which is characteristic of a large
number of Fungi, is quite distinct from that which
))revails in the Mushrooms, where, as we have seen, the
spores are formed by ahstriction.

354. Ohara. Fig. 254 represents a Chara of the
natural size. It grows almost everywhere in fresh waters,
and is quite readily distinguished from other thread-like

Fij;. 253. — Very liif{hl y inai.'iiifled view of section o an apothecium, showing
the elub-shapcd asci. (Thome.)

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204

Fifr. 254.

ELEMENTS OF STRUCTURAL BOTANY.

aquatics by tlie whorls of so-called
leaves which encircle the stem, and
also by the general gritty nature of
the plant. A very offensive odour
is emitted by the jilant in the course
of decay. Its green colour shows at
once the presence of chlorophyll. On
the branches you may observe num-
bers of minute, more or less rounded,
bodies ; Fig. 255 is an enlarged view
of one of them. Here, at b, is shown
a liirge central nucleus (the nucule)
enclosed in a spiral covering. This
spiral consists of five long cells side
by side, all of which wind about the
central body, and have their ends
projecting above it. The nucule is a
row of cells of which the highest is
the germ-cell, and the whole answers,
in fact, to the archegoniura of the
Bryophytes and Pteridophytes. It
is, in this plant, called the carpo-
goniuin. Just below it is a globular
body made up of eight triangular
shield - shaped segments arranged
about a central cavity. From the
inner end of each segment several
coiled filaments of many cells each
project into the cavity. At maturity
the shields separate, and the fila-
ments eventually break up into their

Fig. 254.— CAam/ra(/iiis; natural size, (Thom^.)

CIlAlU.

205

constituent cells, each of which then liberates an anthero-
zoid. The antherozoids make their way down the necks
of the carpogonia and fertilize the germ-cells. The spiral
cells then harden, and form a firm coat for the spore
within. As the plant decays in the autumn, these seed-
like sporocarps, as they are now called, drop off and fall
to the bottom of the water, where they eventually ger-
minate. On germination, they first
produce a sim[)le form to which the
name jiro-emhryo has been given,
and from which arises the plant-
body which bears the antheridia
and carpogonia.

There is, therefore, displayed in
this case an alternation of genera-
tions.

355. Chara belongs to a group of
Fig. 255. plants known as AlgSB. They

grow either in the water or upon damp surfaces. They
differ from the Fungi principally in developing chlorophyll,
so that they are able to assimilate. In colour, the Algse
are often gieen, but in other cases the chlorophyll is
obscured by the presence of other colours, such as brown
and red. In the lowest forms of both AlgaB and Fungi
reproduction takes place by simple division of the cells.
In higher forms the entire contents of two similar adjacent
cells coalesce to form a new one, from which the new
plant springs. This is the process of conjugation (284).
In still higher forms, as in Chara, reproduction takes place
by fertilization"

5: :'

■1=

I ■ i'

I

Fig. 255.
(Thoni6.)

-Highly magnified view of part of the fertile thallus of Chara.

ill

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iiS,

^'itli.

20G

i:lkmknts of stkuctuhal ijotaxy.

356. The Algae, Fungi, and Lichens together constitute
a great group cilled ThallophyteS. Tlie Lichens from
their peculiar constitution may be regarded as transitional
between the Algic and the Fungi, and by some the Charas
are looked upon as links between the Algae and the
Bryophytes.

Some further reference will be made to the Thallophytes
in the next chapter, in which is given a brief outline of
the classification of plants generally.

CHAPTER XXIV.

CLASSIFICATION OP PLANTS ACCORDING TO THE NATURAL

SYSTEM.

357. Hitherto our examination of plants has been
confined to a few selected specimens, and we have
examined these chiefly in order to become acquainted
with some variations in the details of growth, as exem-
plified by them. Thus we have found plants which agree
in exhibiting two cotyledons in the embryo, and others,
again, which are monocotyledonous. Some members of
the former group were found to exhibit two sets of floral
envelopes, other only one, and others, again, were entirely
without these organs. And so on through the various
details. We now set out with the vegetable world before
us — a world populated by forms almost infinite in number
and variety. If, therefore, our study of these forms is
to be carried on to advantage, we shall have to resolve
upon some definite plan or system upon which to proceed ;
otherwise we shall merely dissipate our energies, and our
results will be without meaning. Just as, in our study

CLAS8IFICATI0X.

207

of language, we find it convenient to classify words into
what we call parts of speech, and to divide and sub-divide
these again, in order to draw finer distinctions, so, in our
study of plants, it will l>e necessary to arrange them
first of all in comprehensive groups, on the ground of
some characteristic possessed by every member of each
group. Just as, in Latin, every noun whose genitive
case is found to end in m is classed with nouns of the
first declension, so in Botany every plant presenting
certain peculiarities will be placed in a group along with
all the other plants presenting the same peculiarities.

358. Some hints have already been given you as to
the kind of resemblances upon which classification is
based. For instance, an immense number of plants are
found to produce seeds with a dicotyledonous embryo,
while an immense number of others have monocotyledon-
ous embryos. This distinction, therefore, is so pro-
nounced, that it forms the basis of a division into two
very large groupG. Again, a very large number of
dicotyledonous plants have their corollas in separate
petals ; many others have them united, whilst others
again have no petals at all. Here, then, is an opportunity
to sub-divide the Dicotyledons into polypstalous, gamo-
petalous, and apetalous groups. And so we go on, always
on the plan that the more widely spread a peculiarity is
found to be, the more comprehensive must be the group
based on that peculiarity ; and so it happens, that the
smallest groups of all come to depend upon distinctions
which are, in many cases, by no means evident, and upon
which botanists often find themselves unable to agree.

359. As our divisions and sub-divisions will necessarily
be somewhat numerous, we shall have to devise a special

V^M

I

208

ELEMENTS OF STHUCTUKAL BOTANY.

Vt

> ?

name for each kind of group, in order to avoid confusion
of ideas. We shall, then, to begin with, draw a broad
line of distinction between those plants which produce
flowers of some kind, and those wbich ilo not, and to each
of these great groups we shall give the name Series.
We thus have the Flowering, or, to use the Greek

term, Phanerogamous, Series, and the Flowerless

or CryptOgamOUS Series ; or we may speak of

them briefly as Phanerogams and Cryptogams.

Then, leaving the Cryptogams aside for the moment, we
may break up the Phanerogams into two great OlaSSeS,

Dicotyledons and Monocotyledons, for reasons

already explained. By far the greater number of
Dicotyledons produce seeds which are enclosed in a
pericarp of some kind ; but there is a remarkable group
of plants (represented in Canada only by the Pines and
their immediate relatives) which dispense with the
pericarp altogether, and whose seeds are consequently
naked. So that we can make two Sub-claSSeS of the
Dicotyledons on the basis of this difference, and these

we shall call the Angiospermous Sub-class and
the Gymnospermous (naked-seeded) Sub-class.

The first of these may be grouped in three Divisions,
the Polijpetalout^, Gamopetalou.^, and Apctalous, and the
Monocotyledons also in three, the Spadiceous, the
Pf'taloideous, and the Glinvaceouti, types of which we have
already examined in the Marsh Calla (spadiceous),
Trillium (petaloideous), and Timothy (glumaceous), and
the distinctions between which ara sufficiently obvious.

The Cryptogams are divided into three great
Classes, viz.: Pteridophytes, embracing Ferns,
Horsetails, and Club-mosses ; Bryophytes, embracing

CLASSIFICATION.

200

Mosses and Liverworts ; and ThallophyteS, embracing
Lichens, Seaweeds (Algae), and Mushrooms (Fungi).

360. So far, then, our classification is as follows :

o

O
>

Series I.

Phanero-
gams.

Class I.— Dicotyle-
dons

Class II.— Mono-
cotyledons . .

'Sub-clasS l-An<,MOspernis.

Polypetaloas Division.
■{ Gamopetnloits do.

Apetalous do.

VSub-class2-Gymnospemi3

''Spadiceous Division.

Petaloideous do.

{Ghimaceous do.

Series II.
Cryptogams.

o
»
o

M

>^
n
<•,

H

W

o
w

Group I.
Phanerogams.

Group II.
Pteridophytes.

Group III.
Bryophytes.

Group IV.
Thallophytes.

C Class III.— Pteridophytes.
( Class IV.-Bryophytes.
I Class, v.- -Thallophytes.

361. The above is very nearly the arrangement adopted
by Gray, but many botanists prefer another arrangement
as follows :

f Class 1.— Dicotyledons.
il.— Angiosperms. ■<

\ Class II.— Monocotyledons.

B.— Gymnosperms. Class 111. -Oytnnosperms.

^ Class IV.— Ferns.

■s Class Y. -Uorsetails.

V Class VI. -Club- Mosses.
f Class Yll.— Mosses.
\ Class YllL—Livertvorts.

y Class IX.— Fungi.

V Class X.—Alijcu.

In this arrangement the last three Groups constitute
the Cryptogams, and the Gymnosperms are raised to the
rank of a sub-division of the PhaneKoganis, instead of

il

■■1

■i Y:

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^1%

1

^11

■ 'i%

*

m

lili

210

ELKMKNTS OF STKUC'lURAL HOTANY.

|li^:)

being a sub-division of the Dicotyledons. The Lichens,
also, are incliulod in the Fungi.

362. The wliolo qu»istion of botanical classification is
still in an unsettled state. For further information in
regard to the various modes that have been put forward,
the student must consult larijer works. In the second
part of this book, whilst the classification of Gray (who
follows Hentham and Hooker) is followed in a general
way, those who prefer the second arrangement of the
Phanerogams as given above may easily make the
requisite change.

3G) Each of the IHclfftonx is sub-divided into a number
of Families oi- Orders ; each Order into a number of
Genera. ; and each Genus into SpecieS.

The names of the Orders as a rule have the ending
-acew, as : liaJiunculaceia, Rosarece. These names are
adjectives agreeing with the noun Plantw understood, so
that they mean " Rosaceous plants," " Ranunculaceous
plants," Sec.

364. A species is the sum of all the individual plants
whose resemblances in all essential respects are so great
as to warrant the belief that they have sprung from one
common stock. De Candolle has this statement : " We
unite under the designation of a .^/irric,^ all those indi-
viduals that mutually bear to oach other so close a
resemblance as to allow of our supposing that they may
have proceeded originally from a single being or a single
pair." We may also speak of each one of these individual
plants as a species. For example, you may say, after
finishing the first lesson of this book, that you have
examined a specJos of Buttercu}). Mere differences of

li'

are

iffle

CLAS8IFICATI0M.

211

colour or size are not sufficient to constitute different
species. The Balsams of our gardens, for instance, are
of various colours, and the plants vary greatly in size,
yet they all belong to one species. These minor differ-
ences, which are mainly the result of care and cultivation,
give rise to varii'llfs. These are of great interest to the
horticulturist, but the study of specie^ is the great end and
aim of the botanist.

365. Those Species which are considered to resemble
each other most nearly are grouped into Genera, and the
Genera, in like manner, into Orders ; but these particular
groupings are more or less artificial, and are subject to
continual alteration in consequence of our imperfect
knowledge. As year by year new facts are brought to
light, modifications in arrangement take place. In the
Classification of common plants which constitutes the
Second Part of this work, the Divisions spoken of above
are placed in the order named. In the Polypetalous
Division, those Orders are put first which embrace plants
with hypogiinou>i stamena and apocari'Oiis pistils^ the
parts of the flowers being consequently separate; then
those with similarly inserted stamens, but s/jncarpous
pistils; then those \v\i\\. perigyiious stamens; and, generally,
we proceed from plants whose flowers have all their parts
separate to those exhibiting more or less rohesion and
adhesion^ and finally to those having one or more parts of
the flower wanting.

366. In looking up the name of a plant, it will be your
object to determine the Genus to which it belongs, and
also the Species. The name of every plant consists of two
parts : its Genus first, and then its Species. The name of

■■ Si

1 1:

':i^:

I .

i n I

V\

2lL>

ELEMENTS OF STRUCTURAL UOTANY.

the Genus is a Latin noun, an<l that of the Species
generally a Latin adjective agreein',' witli the noun. The
Buttercup, for example, which we examined at the
outset, belongs to the (iijnus Uanunculiis. In this Genus
!ire included many Species. The particular one examined
hy us is known as acrix; so that tlie full name of the
plant is Itanuncuhis arris. In like manner, the nam«^
of the plant popularly called Marsh-Marigold is Caltha
jxilufitris.

3G7. The Key which is prefixed to the Classification
will enable you to determine without much difficulty tln^
Order to which a plant belongs, but notiiiiig more. Having
satisfied yourselves as to the Order, you must turn to the
page on which that Order is described, and, by carefully
comparing the descriptions there given with the characters
exhibited by your i»]ant, decide upon its Genus, and, in
the same manner, upon its Species.

.i I ■!

THE HERBARIUM.

368. Those who are anxious to make the most of their
botanical studies will find it of great advantage to gather
and preserve specimens for reference. A few hints,
therefore, on this subject will not be out of place. It will,
of course, be an object to collectors to have their specimens
exhibit as many of their natural characters as possible, so
that, although dried and pressed, there will be no difficulty
in recognizing them ; and to this end neatness and care
are the first requisites.

SpecimeiiR should be collected when the plants are in
flower, and, if possible, on a dry day, as the flowers are

THE HERBARIUM.

213

then in bettor condition than if wet. If the pUint is
small, the whole of it, root and all, should be taken up;
if too large to be treated in this way, a flower and one or
two of the leaves (radiciil as well as cauline, if these bo
different) may be gathered.

As many of your specimens will be collected at a
distance from home, a close tin box, which may be slung
over the shoulder by a strap, sliould 1)0 provided, in which
the plants may be kept fresli, [jaiticularly if a few dro[)S
of water be sj)rink]ed upon them. Perhaps a better way,
however, is to cany a portfolio of convenient size — say 15
inches by 10 inches — made of two pieces of stout paste
board or thin deal, and having a couple of straps with
buckles for fastening it together. Between the covers
should be placed sheets of blotting-paper or coarse
wrapping-paper, as many as will allow the specimens to
be separated by at least five or six sheets. The advantage
of the portfolio is, that the plants may be placed between
the sheets of blotting-paper and subjected to pressure by
means of the straps as soon as they are gathered. If carried
in a box, they should be transferred to paper as soon as pos-
sible. The specimens should be spread out with great care,
and the crumpling and doubling of leaves guarded against.
The only way to prevent moulding is to place plenty of
paper between the plants, and change the iia^^er freqnenilij;
the frequency depending on the amount of moisture con-
tained in the specimens. From ten days to a fortniglit
will be found sufficient for the thorough drying of almost
any plant you are likely to meet with. Having made a
pile of specimens with paper between them, as directed,
thev should be placed on a tabic; or floor, covered by a flat

I

I . d

•ill

■ ^

. ;!

> ;)

It

214

KLEAIENTS or STUUCTIRAI. HoTANV,

board, and subjected to pressure Ijy pliicing weights on
the top ; twenty bricks or so will answer very well.

3G9. It is of great importance that fin' sheft uf 2)aper
within inlncJi tite pUmt ia Jird placet I should not bo
interfered with during the drying process. The directions
as to fre((Uont changes refer only to the sheets not
iniuiediatcly in contact with the plant. These, to ensure
the liest I'esults, should be changed once a day for the
lii'st few days ; less frequently thereafter. Gray recom-
mends ironing with hot irons in order to remove more
lap idly the moisture from fleshy leaves, and in any case
to warm the driers in the sun before putting them
between the plants.

When the specimens are thoroughly dry, the next
thing is to mount them, and for this purpose you will
require sheets of strong white paper ; a good quality of
unruled foolscap or cheap drawing paper will be sriitable.
The most convenient way of attaching the specimen to
the paper is to take a sheet of the same size as your
paper, lay the specimen carefully in the centre, wrong
side up, and gum it thoroughly with a very soft brush.
Then take the paper to which the plant is to be attached,
and lay it carefully on the specimen. You can then lift
paper and specimen together, and, by pi-essing lightly
with a soft cloth, ensure complete adhesion. To render
plants with stout stems additionally secure, make a slit
with a penknife through the paper innnediately under-
neath the stem ; then pass a narrow band of paper round
the stem, and thrust both ends of the band thi'ough the
slit. The ends may then be gummed to the back of the
sheet,

11'

your

THK MKnH.MlIUM.

215

The specimen having l)een duly mounted, its l)otanical
name should he written neatly in the lower riy;ht-hand
corner, together with the date of its collection and the
locality were found. Of course only one Species should
he mounted on each sheet ; and when a suHicient numher
have been prepaied, the Species of the same (ienus should
he placed in a sheet of largei' and coarser paper than
that on which the specimens are mounted, and the name
of the Genus should he written outside on the lower
corner. Then the Genera of the same Order should be
collected in the same manner, and the name of the Order
written outside as before. The Orders may then be
arranged in accordance with the classification you may
be using, and carefully laid away in a dry place. If a
cabinet, with shelves or drawers, can be specially devoted
to storing the plants, so much the better.

!i

li!"

I'

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■ I

)rush.
iched,
n lift
htiy
ender
a slit
inder-
ound
h the
f the

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M I

'\P:-

M 1

I '11^

INDEX AND GLOSSARY.

The numbers refer to Sections, unlt'na Figures are specified.

Abruptly pinnate, 180.

AbHorptiou by roots, 2.

Abhtrictioii, 353.

Acaulescent; aj)parently without
a stem, 18.

AcceHHory fruits : such as consist
chiefly of an enlargement of
some orj^an, such as the calyx
or receptacle, not or^'.micaily
united with the pistil, 2i3.~).

Achenium or Achene, 64, OG, 241.

Achlamydeous : having neither
calyx nor corolla, 74.

Acicular, Fig. 145.

Acorn, 71.

Actinomorphio flowers, 203.

Acuminate: with a long tapering
point.

Acute: sharp-pointed, 177.

Acyclic flowers, 1!)5.

Adherent: a term applied to the
union of unlike parts, e. fj., sta-
mens with corolla, &c., 26.

Adnate, 52,211.

Adventitious: occurring out of the
natural position.

Adventitious roots, 134.

Adventitious buds, 139.

Aerial roots, 134.

^Estivation : the folding of the
floral envelopes in the bud, 210.

Aggregated fruits, 234.

Air-plants (epiphytes), 87.

Albumen (of the seed): solid nour-
ishing matter distinct from the
embryo, 12,80,117,248.

Albuminoids, 263.

Albuminous seeds, 80, 248.

Aleurone-grains, 280.

Algfe, 355.

Alternate (leaves), 158.

Alternation of generations, 326,
329, 334, 342, 343.

Ameut or Catkin, Figs. 68, 69.

Amplexicaul : clasping a stem.
Anatropous: a term applied to

ovules when inverted, ho that

the micropyle is dose to the

point of Htt:ichincnt, 246.
AndnDciuin : the circle of stamens

colle(!tivcly, 211.
Androus : an ending of adjectives

descri|)tive of stamens, e. g.,

monandrous, p()lyandrous,&c.
Anemopliilous, 74, 247.
Angiospcrnious : applied to plants

whose seeds are enclosed in au

ovary, 124, 129.
Annual : a plant whichlgrows from

the seecf, flowers, and dies in

the same season, 136.
Annular vessels, 2H8, 287.
Annulus, 347.
Anterior, 197.
Anther: tlie essential part of a

stamen containing the pollen,

6,211
Antheridiuni, 325.
Antherozoid, 325.
Apetalous: without a corolla; hav-
ing only one set of floral en-

veloiies, 20.
Apsx of leaves, 177.
Apocarpous: applied to pistils

when the carpels are free from

each other, 7, 21, 215, 229.
Apothecium, 352, 353.
Appendage: anything attached or

added.
Appressed : in contact, but not

united.
Aquatic : growing in the water,

whether completely or only

partially immersed.
Arborescent : resembling a tree.
Archegonium, 325.
Aril, 126, 250.
Arrow-shaped, Fig. 155.

cified.

I stem.

pplied to

I, HO that

^e to the

4().

if Htamens

adjectives
MiH, e. g.,
roua,&c.

d to plants
osed in an

;row8 from
id dies in

part of a
it> ]iollen,

rolla; hav-
ll(n-al en-

to pistils
free from
229.

ittached or

, but not

the water,
or only

ig a tree.

INDKX AND (. LOSS ART.

217

AHcendiii^ : ri>iiti|* upwards in a
Hlanting dirvctioii ; applied
chiefly to weak HteniH.

Ancending axiH: the stem of a plant.

AhcI, 853.

AHcitliuni : a pitcher-shaped leaf,
Fig. 1G9.

ABcospore, 353.

Ash of plantH, 307.

ABsiniilation, 275, 309.

Auriculate : same Asauricled, hav-
ing rounded loben at the base ;
applied mostly to leaves.

Awl-shaped, Fig. 147.

Awn: a bristle, such as is found
on the glumes of many Grasses,
Barley for example, 108.

Axil, 8.

Axile : relating to the axis, 221.

Axillary : proceeding from an axil,
44, 1.38.

Axillary buds, 138.

Axillary flowers, 186.

Axis : the stem and root, 131.

Baccate : like a berry.

Bark, 286.

Bases of leaves, 179.

Basidium, 847.

Bast, 286.

Bearded : furnished with hairs, like
the petals of some Violets, &c.

Bell-shaped, 208.

Berry, 233.

Biennial; a plant which grows
from seed in one season, but
produces its seed and dies in the
following season, 133, 136.

Bifoliolate: having two leaflets.

Bilabiate: two-lipped, Fig. 180.

Bilocular, 219.

Bipinnate : twice pinnate, Fig. 167.

Bipinnatifid : twice piunatifid,176.

Blade : the broad part of a leaf or
petal, 4, 45.

Bleeding of plants, 315.

Bordered pits, 269.

Botryose, 143.

Botryose inflorescence, 185, 189.

Bracts, 19, 44, 194.

Bracteate : 8u))tended by a bract.

Bractlets : secondary bracts grow-
ing on pedicels, 194.

Braudhes, 8, 132, 141.
Branching, Modes of, 141.
Breatliing-poren (stomates), 293,

313.
Bristles, 227.
Hryophytes, 346.
Bud: an undeveloped stem or

brancii, 137.
Buds on roots, 131, 139.
Bull., H2, 114, 152.
Bulliiferous : producing bulbs.
Bulblets, 155.

Bulbous : like a bulb in shape.
Bundles, 296.

Caducous, 206.

Calcium, 307.

Calcium carbonate, 278.

Calcium oxalate, 278.

Calyptra, 341.

Calyx, 5, 13, 205.

Calyx-teeth, 206.

Calyx-tube, 206.

Cambium layer, 297.

Campanulate, 208.

Campylotropous, 246.

Capi lary : hne and hair-like.

Capituluni : same as head, 189.

Capsule, 239, 341.

Carbon, 307.

Carbon dioxide, 307.

Carbonic acid, 307.

Carina, or keel : the two coherent

petals in the front of a flower of

the Pea kind. Fig. 36.
Carnivorous plants, 311.
Carpel 7.
Carpellary: relating to a carpel,

e.g., a carpellary leaf, &c.
Carpogonium, 354.
Cartilaginous : tough.
Caryopsis, 102, 241.
Catkin, 71, 74, 123, 189.
Caulescent: with an evident stem.
Caulicle : another name for the

radicle, 79, 252.
Cauliue: relating to the stem, e.^.,

cauline leaves, &c., 4, 13, 28.
Cell-contents, 260, 274.
Cell-division, 282.
Cell-formation, 282.
Cells, 259.
Cellulose. 265.

I

1 ;■'*

isi Jih|i II

218

INDEX AND GLOSSARY.

V ,-

i4^^

•If

■■■ii , ll

Cell-wall, 259, 265.
Centrifugal iuflorescencs, 187.
Centripetal inflorescence, 186.
Chalaza: tlie part of an ovule

where the coats are united to

the nucleus, 245.
Chlorophyll, 156, 274, 307.
Ciliate, 182.
Circiuate : curled up like the young

frond of a Fern, 166, 324.
Circulation in cells, 262.
Circunicissile : opening like a

pyxis. Fig. 207.
Classification, 357.
Claw (of a petal), 45, 207.
Cleistogamous flowers, 247.
Climbing stems, 150.
Closed bundles, 298.
Club-shaped : with the lower part

more slender than the upper, as

the style of Dog's-tooth Violet,

Fig. 82.
Clustered, 133, 164.
Coats of the ovule, 244.
Coherent: a term applied to the

union of like parts, 26.
Coliesion, 26.
Collateral bundles, 299.
Collective fruits, 237.
Collenchyma, 271, 286, 303.
Colour of flowers, 274.
Columella, 341.
Column, 91.
Coma : a tuft of hairs, such as that

on the seed of Dandelion, Fig. 68.
Complete, 8.
Compound or Composite flowers,

62.
Compound leaf, 43, 167.
Compound pistil, 215.
Compound spike, corymb, &c.,189.
Concentric bundles, 299.
Conduplicate vernation, 16G.
Cone, 124, 223.
Conical, 133.

Coniferous : bearing cones.
Conjugation, 284, 355.
Connate : grovu together.
Connate-perfoliate, Fig. 165.
Connective, 65, 211.
Convolute : rolled inward from one

edge, 38, 88, 166, 210.
Cordate, 175.

Cork, 294, 303.
Corm, 94, 154.
Corolla, 5, 13, 15, 207.
Corymb, 189.

Corymbose : like a coryml).
Cotyledons, 78, 117, 252.
Creeping, 149.
Cremocarp, 243.
Crenate, Fig. 163.
Cross-fertilization, 247.
Cruciform: cross-shaped, as the
flowers of Shepherd's Purse, &c.
Cryptogams, 369.
Crystalloids, 280.
Crystals, 278.
Culm, 103, 150.
Cuueate : wedge-shaped.
Currents of water, 315, 316.
Cuspidate, Fig. 161.
Cuticle, 292.
Cycle, 159.
Cyclic flowers, 195.
Cyme, 191.

Cymose : like a cyme, 143, 185.
Cystoliths, 279.

Decandrous : with ten separate
stamens.

Deciduous, 6, 206.

Decompound : applied t-^ leaves
whose blades are divided and
sub-divided.

Decumbent: applied to stems
which lie on the ground but turn
upward at the extremity.

Decurrent, Fig. 166.

Decussate : applied to the arrange-
ment of leaves, when successive
pairs of opposite leaves are at
right angles, as in the plants of
the Mint Family, 158.

Definite inflorescence, 187, 191.

Deflexed : bent down.

Dehiscence of anthers, Figs. 186,
186, 187.

Dehiscent, 231.

Deliquescent: applied to stems
which dissolve into branches.

Deltoid, Fig. 148.

Dentate, 178.

Depauperate : unnaturally small.

Depressed: flattened down.

as the
rae, &c.

INDEX AND GLOSSARY.

219

, 185.

separate

o leaves
ded and

stems
3ut turn

arrange-

iccessive

8 are at

plants of

191.

^igs. 185,

to stems
nches.

y small.

Descending axis : tlie root, 131.

Determinate inflorescence, 187, 101 .

Diadelphous : applied to stamens,
40, 212.

Diandrous : with two separate
stamens, 212.

Dicarpellary, 215.

Dichasium, 146.

Dichlamydeous ; having lioth sets
of floral envelopes.

Dichogamous, 247.

Dichotomous branching, 14.5, 332.

Dicotyledonous, 78.

Dicotyledons, 80.

Didynamous (stamens), 20, 65, 214.

Digitate, 168.

Dimerous flowers, 196.

Dioecious, 74.

Disk : in flowers of the Composite
Family, the centre of the head
as distinguished from the bor-
der, 62 ; a fleshy enlargement of
the receptacle of a flower, 58, 75,
126.

Dissected : finely cut.

Dissepiment, 218.

Distinct : not coherent, (see Cohe-
rent).

Divergent: separating from one
another.

Dodecandrous : with 12 distinct
stamens.

Dorsal suture, 217.

Dotted ducts, Figs. 222, 287.

Double flowers : abnormal flowers
in which stamens and carpels
have been transformed into
petals.

Downy : covered with soft hairs.

Drupe, 51, 231.

Drupelet : a little drupe.

Ducts, 287.

Earthy constituents of plants, 307.

Elater, 331.

Elementary constituents of plants,
307.

Elliptical : same as oval. Fig. 146.

Emarginate, 177.

Embryo, 12, 78, 117.

Embryo-sac, 16, 245.

Emersed: raised above the sur-
face of water.

Endocarp : " When the walls of a
pericarp form two or more lay-
ers of dissimilar texture, the
outer layer is called the Epicarp,
the middle one Mesocarpf and
the innermost Endcoarp." —
Gray.

Endogen, 119.

Endo<,'euou8 growth, 119.

Endospore, 342.

Endosperm, 248.

Enneandrous: with nine distinct
stfinit'iis.

Entire, 178.

Entomophilous, 74, 75, 88, 247.

Ephemeral : lasting one day only.

Epicalyx, 35, 50.

Epicarp : see Endocarp,

Epidermal system, 291, 292.

Epidermis, 292.

E p i gy n ou 8 : i n serted on the ovary,
58, 60, 213, 216.

Epipetalous : inserted on the cor-
olla, 60, 65, 213.

Epiphytes, 135.

Equitant (leaves), 88, 157.

Essential organs, 17, 211.

Evergreen : retaining foliage dur-
ing winter, 122, 125.

Exalbuminous, 80, 248.

Excurrent: said of main sterna
which are distinct and well-
marked to the top, as in the
Pine and Fir ; the reverse of
deliquescent.

Exogen, 81.

Exogenous growth, 81.

Exospore, 342.

Exserted : protruding, 214.

Exstipulate, 181.

Extine, 123.

Extrorse, 211.

False dichotomy, 146.

Families, 363.

Fascicle : a close bundle, either of

leaves or flowers.
Fascicled (roots), 133; (leaves), 164.
Fascicular cambium, 297.
Feather-veined: same as pinnately-

veined, 168.
Fertile-flower, 68.
Fertilization, 17.

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11

220

INDEX AND GLOSSARY.

Fibrous : thread-like, 2, 18, 22.

Fibrous tisHue, 286.

Fibro-vascular system, 287, 291,
296.

Filament, 6, 211.

Filiform, 183.

Fimbriate: fiiii<:fed.

Fleshy fruits, 232.

Flora: a description of the plants
of a district ; a collective nam'^
for the whole of *he species of a
district.

Floral difigram, 197.

Floral envelopes, 14, 207.

Floral formula, 198.

Floral symmetry, 195.

Floret, 61.

Flower: the part of a phanero-
gamous plant in which the sta-
mens and pistil are situated.

Flower-head, 60.

Flower-leaves, 11.

Flowering plants, 359.

Flowerless plants, 359.

Foliaceous : like a leaf in appear-
ance.

Foliage-leaves, 11, 156.

Foliolfite: having leaflets.

Foliose (Liverwort), 344.

Follicle, 238.

Foot, 144.

Forked cyme, 143.

Free, 5,7,41.

Free cell-formation, 283, 353.

Free-central placentation, 221.

Frond, 324.

Fruit, 228.

Fruit-dots, 324.

Fugacious : falling away early.

Fundamental tissue, 291, 303.

Funiculus, 245.

Funnel-shaped, Fig. 178.

Furcate: forked.

Fusiform : same as spindle-shaped,
133.

Galea: an arching petal or sepal,
as the two upper ones in Catnip,
Fig. 59.

Gamopetalous, 207.

Gamophyllous, 84.

Gamosepalous, 34, 205.

Gemmaa, 345.

Genera : plural of genus.

Genus, 363.

Germ : same as embryo.

Germ-cells, 347.

Germination, 132, 254.

Gibbous : swollen on one side.

Gills, 347.

Glabrous, 22, 182.

Gladiate : sword-shaped.

Glands : applied generally to cells
or hairs on the surfaces of plants,
in which resinous or oily mat-
ters are secreted; but the term in
also used to describe any pro
jection, the use of which is not
clear, 226

Glandular : bearing glands, 226.

Glaucous, 182.

Globose : like a globe or sphere.

Glumaceous : bearing or rt'semb-
ling glumes, 114, 359.

Glumes, 101

Gonidia, 352.

Gourd, 233.

Grain, 102, 117,241.

Granules : particles.

Granulose, 277.

Gravitation, 322.

Ground-tissue, 303.

Growing point, 145.

Growth, 317.

Gum, 281.

Gymnospcrmous, 124, 223.

Gynmosperms, 124, 129, 359.

Gynandrous, 91, 213.

Gynoecium, 199, 215.

Habitat : a term applied to the
region most favourable to the
growth of a plant: tlie place
where it grows naturally.

Hairs, 226.

Hairy, 4.

Halberd-shaped, Fig. 154.

Half-inferior, 49, 216.

Half-superior, 49.

Hastate, Fig. 154.

Head, 189.

Heart-shaped, 175.

Helicoid cyme, 144.

Heniicycli^ flowers, 195.

Heptandrous : with seven distinct
stamens.

'Mi

de.

to cells
plants,
ly mat-
term i>«
ly pro
1:1 is not

i, 22G.

)here.
resemb-

59.

to the
e to the
le place

ly-

distinct

IN HEX AND GLOSSARY.

L>-JI

Herl), 148.

Herbaceous, 3, 80, 136, 148.

Herbarium : a botanist's collection

of dried plants, 368.
Hermaphrodite, 247.
Heteromerous flowers, 196.
Hexandrous : with six distinct

stamens.
Hilum, 249.

Hirsute: rough with hairs.
Hispid : covered witii stiff hairs.
Hoary: densely covered with tine

grayisli hairs.
Hortus siccus: same as herbarium.
Hybrids : plants resulting from

the crossing of nearly related

species.
Hydrogen, 3C7.
Hymenium, 347.
HyphsB, 349, 352.
Hypogyuous, 24, 29, 213.

Imbricate : overlapping like the
shingles on a roof, 210.

Immersed : wholly under water.

Imperfect, 68.

Included, 214

Incomplete, 19.

Incurved (petals). Fig. 52.

Indefinite, 20, 212.

Indefinite inflorescence, 186, 189.

Indehiscent, 231.

Indeterminate inflorescence, 186,
189.

Indigenous : naturally growing in
a country.

Inferior : underneath ; farthest
from the axis ; the ovary is in-
ferior when the calyx adheres to
it throughout ; the calyx is in-
ferior when free from the ovary,
45, 49, 52, 88, 210.

Inflorescence, in, 185.

Innate, 211.

Inorganic elements, 307.

Inserted: attached to.

Insertion : tlie point or manner
of attachment, 40, 212.

Integument, 249.

Intercellular space, 293.

Interfascicular cambium, 297.

Internodes, 4.

Interruptedly pinnate, Fij;. 168.

Intine, 123.

Introrse, 211.

Intussusce|)Uon, 265, 317.

Inuline, 281.

Invohuel, 194.

Involucre, 35. 61, 71, 72, 194.

Involute : rolled inward from both

edges, 166.
Iron, 307, 308.
Irregular, 3i), 205, 207.
Isomerous : having the parts equal

in number, 196.

Joints : a name sometimes given
to the nodes of a stem.

Keel, see Carina.
Kernel, 16.
Key-fruit, 241.
Kidney-shaped, Fig. 156.

Labellum (or lip), 90.

Labiate, 65, 209.

Lamellae, 347.

Lanceolate, Fig. 148.

Latex. 288.

Laticiferous tissue, 288, 303.

Leaf, 4, 13.

Leaf-arrangement, 158.

Leaf-green, see Chlorophyll.

Leaflet, 167.

Leaf-schtdule, 184.

Leaf-stalk, 4

Leaf-tendril, 150.

Legume, 43, 238.

Leguminous : producing or relat-
ing to legumes.

Light, 320, 321.

Ligneous : woody.

Ligulate, 62, 209.

Ligule: a strap-shaped corolla; in
Grasses, a scale-like projection
between the blades of a leaf and
the sheath, 103.

Limb, 207.

Linear, Fig. 146.

Lip, 90.

Lobe, 4, 167.

Loculicidal (dehiscence) : splitting
midway between the partitions,
239.

Loculus, 219.

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Lodioule, 101.

Lornent : a jointed Icjjume, 24'2.

Lyrate : i)innately-lt>^Jfd, with tlu^

terminal lol)e much larger tliitii

tlie otliers.

Magnesium, 307.

Marcesoent: withering persistent.

Margin of leaves, 178.

Marginal : relating to the margin,

221.
Markings (on cells), 2()8.
Mass-movement of Protoplasm,

2t)2.
Median plane, 107.
Medullary rays, 301.
Membranous : thin, like a mem-

Ijrane.
Mericarp, 242.
Meristem, 2H2, 28.5.
Meaocarp : see Eudocarp.
Metastasis, 309.
Mieropyle, 16, 244.
Middle lamella, 266.
Mid-rib, 168.
Mixed infloresoence, 192.
Monadelphous, 36, 40, 212.
Monandrous : with a single stamen.
Monocarpellary. 215
Monochlamydeous : with only one

set of floral envelopes.
Monocotyledonous, 118.
Monocotyledons, 118.
Monoecious, 68, 71
Monomerous flowers, 196.
Monopodia! branching, 142.
Morphology, 130.
Mucronate, 177.
Multifid, 176.
Multilocular, 219.
Multiple fruits, 237.
Mycelium, 347.

Naked flowers : those which are
destitute of calyx and corolla.

Naked seeds : those not enclosed
in an ovary, 127.

Napifox'm, 133.

Natural system of classification,
857, &c.'

Naturalized: introduced from

other countries, but growing

s])ontaneously from seed.
Nectary : that in which nectar is

secreted, 88, 224.
Needle-shaped, 122.
Net-veined, 4, 18.
Neutral flowers : those having

neither stamens nor pistil.
Nitrogen, 307.
Nodding : hanging with the tojt

downward, like the flower in

!• ig. 82,
Node, 4.

Normal: regular ; according to nile.
Nucleolus, 260.
Nucleus (of an ovule), 16, 244, 249 :

(of a cell), 260.
Nucule, 354,
Nut, 241.
Nutations, 323.
Nutlet: a small nut or nut-like

body, 65.

Obcordate, 175.

Oi-lanceolate, 174.

01)lique: having the sides unequal.

Obliteration (of ])artitions), 220.

Oblong, Fig. 146.

Obovate, 174.

Obsolete, 206.

Obtuse, 177.

Ochrea : a tube formed by the
union of both edges of a pair of
stipiiles.

Ochreate : having ochreaB.

Octandrous : having eight separ-
ate stamens, 45.

Odd-])innate, 180.

Offset : a short, prostrate branch,
rooting at the end.

Oils, 281, 309.

Open bundles, 297.

Operculum, 341.

Opposite, 158.

Optimum temperature, 319.

Orbicular, Fig. 146.

Orders, 363.

Organic elements, 307.

Organs : the parts or members of
a living body.

Organs of Reproduction the parts
of the flower.

1^ . li-

IKDKX AM) ULOSSAin*,

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Organs of Vegetation : mot, stem,
and leaves.

Orthostirhiea, IGO.

Orthotropous : applied to ovnleH
when straight, so that tlie nii-
cropyle is as far as poasil)le from
the point of attachment, •24().

Osmose, 314.

Outline of loaves, 171.

Oval, Fig. Ui).

Ovarv, 7, 25.

Ovate, Fig. 148.

Ovoid: egg-shaped.

Ovule, 7, 16.

Oxygen, 307.

Palate, 209.

Palet, 101.

Palmate, 1(58.

Palmately-lohed, 176.

Palmatitid, 17(5.

Panicle, lOG, 190.

Papilionaceous, 39.

Pappose, 206.

Pappus : a ciirle of bristles or
hairs representing the Hml) of
the calvx in tloweis of the Com-
posite Family, 62.

Pai'allel- veined; same as straight-
veined, 83.

Paraphyses, 353.

Parasites, 135, 1,*0, 310.

Parenchyma, 286.

Parietal : on the walls, 221.

Parted : almost completely cut
through.

Pectinate: pinnatifid with lobes
"like the teeth of a comb.

Pedate, Fig. 160.

Pedicel, 28, 58.

Peduncle, 5, 28.

Peltate, 126, 175.

Pentamerous flowers, 196.

Peutandrous : with five distinct
stamens

Pepo, 233.

Perennial : a plant which con-
tinues to grow year after year,
136.

Perfect: having both stamens and
pistil.

Perfoliate, 170.

Perianth, 84. 9U.

Pericarj), 22'.'.

Perigynous, 40. 4S. 213, 216.

Perisperm, '2ix.

Peristome, 341.

Permanent tissue, 285.

Persistent, 34. 206.

Personate, 20'.).

Petal, ,5, 207.

Petaloideons, 35'.l.

Petiolate : having petioles.

Petiole, 4.

Phanerogamous or Pha?nogamous,
12<t, 359.

Phellogen, 294.

Phloem, 295.

Pliosphorus, 307.

Phyllome, 225.

Pliyllotaxis, 158.

Pileus, 347.

Pilose: having long, soft liairs.

Pinna: a primary division of a
pinnately-compound leaf.

Pinnate, 168.

Pinnately-lobed, 176.

Pinnatifid, 176.

Pinnule: a secondary division of
a pinnately-coniiKiund leaf.

Pistil, 7, 13.215.

Pistillate: having a pistil, 68, 70.

Pitcher-shaped (leaf), Fig. 169.

Pith, 300.

Placenta, 221.

Placentation, 221.

Plaited, 166, 210.

Plumose : featliery.

Plumule, 79, 117, i3S, 252.

Pod : a dehiscent fruit, 25.

Pollen, 6, 16.

Pollen-masses, 92.

Pollen-tube, 16

Pollination, 124. 247.

Pollinia : polien-niasses, Fig. 93.

Polyadelphous, 40, 212.

Polyandroiis : with numerous dis-
tinct stamens, 6, 24.

Polycarpellary, 21,5.

Polygamous: having perfect as
well as imperfect flowers.

Polygamo-dioBcious, 75.

Polypetalous : having separate
petals, 5, 207.

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224

INDEX AND GLOSSARY.

Polyphyllo\i8, 84.

Polysepalous : havint» separate

sepals, 5, 205.
Pome, 63, 232.

Posterior : next the axis, 197.
Potassium, 307, 308.
Pr»floratioii, see Estivation.
Pra'foliation : the disposition of

leaves in the bud, IGG.
Prickles, 227.
Primary roots, 132.
Priniine, 244.
Procambium, 296.
Procumbent: lying on llie t,'round.
Proembryo, 354.
Prosenchyma, 28G.
Prostrate, 149,
Prothallium, 325.
Protonema, 342.
Protoulasm, 2(50.
Ps(au{ocarp, 236.
Pteridophytes, 337.
Pubescent: covered with fine down.
Punctate: having transparent dots,

like the leaves of St. John's Wort.
Putamen, 51,231.
Pyxis. 240.

Quinquefoliolate : having five leaf-
lets, 180.

Raceme, 189.

Racemose : like a raceme, 143.

Radial bundles, 302.

Radiate, 168.

Radical: pertaining to tlie root,
4,13,18,60.

Radical leaves, 4, 28.

Radicle, 79, 117, 132, 252.

Ramification, 141.

Raphe, 240.

Raphides, 278.

Ray: the marginal florets of a
Composite flower,as distinguish-
ed from the disk.

Receptacle, 8.

Recurved : curved backwards.

Reduplication, 200.

Reflexed : bent backwards, 88.

Regular: with parts of the same
size and shape, 5, 205, 207.

Rejuvenescence, 284.

Reniform, Fig. 1.56.

Resin, 281.

Respiration, 812.

Reticulated cells, 268, 2H7.

Retuse: slightly notched at the
apex.

Revolute : rolled back, 166.

Rhachis : an axis, 324.

Rhizoid, 340.

Rhizome, 151.

Riugent, 209.

Root, 2, 13, 131.

Root-cap, 131.

Root-hairs, 131, 226.

Rootlet, 2.

Root-pressure, 316.

Root-stock, 88, 151.

Rotate, 208.

Rudimentary : imperfectly devel-
oped.

Rugose : wrinkled.

Runcinate : with teeth pointing
backwards, as in tlie leaf of
Dandelion, 176.

Runner, 134.

Sasittnte, 28, 175.
Salver-shaped, Fig. 179.
Saniar.,Figs. 76, 2t8.
Saprophytes, 135, 156, 310.
Sarcocarp: the flesh of a drupe.
Scabrous : rough.
Sciilariform cells, 268, 287.
Scales, 74, 124, 137, 194.
Scandent: climbing.
Scape, 19, 60, 88.
Scar, 88.
Schizocarp, 242.
Scion : a young shoot.
Sclerenchynia, 273, 286, 303.
Scorpioid cyme, 144
Secondary roots, 134.
Secundine, 244.
Seed, 12, 244
Seed-leaves, 78.
Seed-vessel, see Ovary.
Self-fertilization, 88.
Sepal, 6, 205.

Septicidal (dehiscence) : splittinj.
open along the partitions, 239.

INDBX AND GLOSSARY.

22:)

Septifragal, 239.

Siiptum : a partition.

Series, 359.

Serrate, 178.

Sessile, 4, 28, 211.

Seta, 341.

Setaceous : like a bristle.

Sheatli : a tube surrounding a

stem, 103.
Sheathing : surrounding like a

sheath.
Shield-shaped, see Peltate.
Shoot : a newly-formed bramh.
Shrub, 148.
Sieve-tubes, 270, 289.
Silica, 308, 330.
Silicle, 240,
Silique, 240.

Simple (leaves), 167; (pistil), 215.
Sinuate : wavy on the margin.
Sodium, 308.
Solitary, 188.
Sori, 324.
Spadiceoua, 359.
Spadix, 97, 98, 189.
Spathe, 97, 98, 194.
Spathulate, 174.
Species, 363, 364.
Sperm-cells, 347.
Spermoderm, 249.
Spike, 100, 189.

Spikelet, a secondary spike, 106.
Spindle-shaped, 133.
Spine, 227.

Spiral markings, 268, 287.
Spores : the reproductive bodies

inCryptogams which correspond

to the seeds of Phanern^'nins,

324, 341, 347.
Sporangium, 324,341.
Sporocarp, 354.
Spur, 90, 209.
Stamen, 6, 13,211.
Staminate (flower): having no

pistil, but only stamens, 68, 70.
Staminode, 211.
Standard: the broad upper petal

of a papilionaceous corolla.
Starch, 276.
Starch-cellulose, 277.
Stem, 3, 13, 137.
Stemless, 18.

Sterile (flower): having no piatil,68.

Sterigma, 347.

Stigma, 7.

Stigmatic : bearing the stigma.

Stinging-hairs, 226.

Stipe, 324.

Stipulate : having stipules.

Stipule, 33, 181.

Stolon: a short branch which

droops to the ground and takes

root, 149.
Stoma (of Moss), 341.
Stomata, 2i»;i, 313.
Stone, see Putamen.
Stone-fruit, see Drupe.
Straight- veined, 83.
Strap-shaped, see Ligulate.
Streaming of protoplasm, 262.
Striate: marked lengthwise with

lines or furrows.
Strobile : same as Cone.
Style, 7.

Subulate, Fig. 147.
Succulent: juicy; fleshy.
Sucker: an underground branch,

at length emerging and forming

a stem.
Sugar, 309.
Sulphur, 307.

Superior, 7, 41, 4.5, 40, 216.
Suppression : absence of parts.
Surface of leaves, 182.
Suspended ; hung from above.
Suture, 217.
Symmetrical, 47. 204.
Sympodial, 144, 145.
Syncarpous, 30, 215, 230.
Syngenesious, 60, 68, 212.

Tap-root, 32, 132.

Teeth(of calyx, 34.

Tegmen, 249.

Temperature, 319.

Tendril, 150.

Terete: cylindrical.

Terminal: at the end of a stem or

branch, 44, 122, 140, 187.
Teruate : in throes.
Testa, 249.

Tetradynamous, 29, 214.
Tetramerous floweru, 196.

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INDEX AND OLOaSARV.

Tetrandrous : haviuj,' four distinct
fitfimens.

Thalamiflorous: having the sta-
mens inserted on the receptacle.

Thahirnua : the receptadi-.

Thalloid (Liverwort), 344

I'hiillopliytes, 35(3.

Thallus, .852.

Theca, 341.

'Ihread-sliaped, see Filiform.

Throat (of calyx), 20G.

Thorn, see Spine.

Thyrse, 1<I2.

Tissue, 285.

Tissue-systems, 201.

Tomentose : woolly.

Toothed, see Dentate, 112.

Torus : same as receptacle, 21().

Traeheary tissue, 287.

Tracheids, 2!)0.

Trailing, 14it.

Transpiration, 313.

Tree, 148.

Triadelphons, 40,212.

Triandroiis: having three distinct
stamens.

Trichomes, 131, 226, 292.

Triennial : lasting three years.

Trifoliolate : having three le.iflet-,
180.

Trimeroua flowers, 196.

Truncate, 177.

Trunk: tlie main stem.

Tuhe, 34, 128.

Tuher, 1.51.

Tuherous : like a tuber.

Tul)ular, 208.

Tunicated, 92.

Twining, 150.

I wo-lipf)ed, see Labiate.

Types, 27.

Umbel, 58, 189.

Umbellet : a secondary umbel.

Ungiiiculate : having a claw.
Unilocular, 219,
Urn, 341.

Vacuoles, 260.

Valvate: edge to edge, but not

overlapping, 38, 210.
Valve, 4(5,

Valved : having valves.
Varieties, 3(54.
Vascular crj'ptogams, 337.
Vascular tissue, 287.
Veil, 347.
Veins : the finer parts of the

framework of a leaf.
Venation, 168.
Ventral suture, 217.
Vernation, same as Prsefoliation,

166.
Versatile, 102, 211.
Vertical leaves, 88, 157.
Verticillate, 158.
Verticillaster, 193.
Vessels, 287.
Villose, 182.
Volatile oils, 281.

Water in the plant, 306, 315, 316.
Wavy : with alternate rounded

hollows and projections, 178.
Wedge-shaped : like a wedge, the

broad part being the apex.
Wheel-shaped, see Botate.
Whorl : a circle of three or more

leaves at the same node, 23, 120,

158.
Wing, 75, 124, 241.
Woody stems, 148.

Xylem, 295.

Zygomorphic flowers, 203.

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APPEIS-DIX.

(Selectiono from examination Jpajjcrs.

UNIVERSITY OF TORONTO.

1. Define suckers, stolous, offsets, runners, tendrils, thorns, iiiid
prickles, describing their respective origins and uses, and giving
examples of plants in which they occur.

2. What are the functions of leaves ? Describe the different kinds
of compound leaves.

3. What is meant by inflorescencte ? Describe the different kinds
of flower-clusters, giving an example of each.

4. Mention and explain the terms applied to the various modes
of insertion of stamens.

5. How are fruits classified ? What are multiple or collective
fruits ? Give examples.

6. Relate the differences in structure between endogenous and
exogenous stems. Describe their respective modes of growth.

7. What is the food of plants ? how do they obtain it ? and how
do they make use of it ?

8. Describe the component parts of a simple flower. How ia
I'eproduction effected ?

9. Describe the anatomical structure of a leaf, and the formation
and office of leaf-stomata.

10. Explain the consequences of flowering upon the health of a
plant, and show how these effects are remedied in different climates.
What practical bearing has this upon horticulture ?

11. Trace tlie development of a carpel from a leaf. Describe tiie
different forms assumed by placentae in compound ovaries, and
explain the origin of these variations.

12. Mention the principal modes in which pollen gains access to
the stigma. What are hybrid plants, and how are they perpetuated ?

13. Describe the anatomy of a leaf. What are stomata?

14. What is the placenta in a seed-vessel ? Describe the different
modes of placentation. Show how the varieties of placentation
agree with the " altered-leaf theory" of the pistil.

15. Give the characters of the Compositse. How is the ordn-
sub-divided? Describe the composite flower, and mention some of
the common Canadian examples of this order.

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■ZAMINATION PAPERS.

10. Give tliti peculiarities of Endo{,'enrt in seed-leaf, leaf, and stem.
Sub-divide tlie ilass. Describe shortly the orders AraceaD and
Graniiiicnn.

17. Describe the wall of a seed-vessel, and notice its varieties of
form.

18. "What is meant by the dehiscence of a capsule? Show the
different modes in which pods dehisce, and give examples of each.

19. Give the characters and orders of Gymnospermous Exogens.

20. Give the characters of Ranunculaceie. Describe shortly some
(if the principal plants of the order.

21. Give some account of the special forms which the leaves of
plants assume.

22. What are stipules ? What their size and shape ?

2.3. What is meant by Imperfect, Incomplete, and Unsymmetricol
riowers respectively ? *

24. Describe Papilicmaceous and Labiate corollas.

2'). Write notes on Abortive Organs, Gymnospermous Pistil, and
Pollen Granule.

20. Distinguish between the essential and non-essential materials
found in plants, and notice the non-essential.

27. What is vegetable growth ? Illustrate by a reference to the
pollen granule in its fertilization of the ovary.

28. What is an axil ? What is the pappus ?

29. What are the cotyledons ? What is their function, and what
their value in systematic Botany ?

30. Distinguish between Epiphytes and Parasites. Describe their
respective modes of growth, and give examples of each.

31. What is the difference betwe. i roots and subterranean
branches ? Define rhizoma, tuber, corni, and bulb, giving examples
of each. How does a potato differ botanically from a sweet-potato ?

32. Describe the calyx and corolla. What modifications of parts
take place in double flowers ?

33. What is a fruit in Botany ? Explain the structure of an apple,
grape, almond, strawberry, fig, and pine-apple.

34. What organs appear in the more perfect plants ? In what two
divisions are they comprised ?

36. Weak climbing stems distinguished according to the mode in
which they support themselves, the direction of their growth, the
nature of their clasping organs.

36. Structure and parts of a leaf: What is most important in
their study ? Give the leading divisions, and mention what
secondary distinctions are required in specific description ?

37. Function of the flower : its origin : its essential and accessory
parts : name of the circles and their component organs: circumstances
which explain the differences among flowers.

38. Parts of the fully formed ovule and distinctions founded oo
their relative position.

KXAMINATION PAPERS.

it<^v

30. SuV)-kiug(l<)ins and classes of tlio vo^'etablc kiu^'dom.

40. What iH iiu'aiit by h ((inipoHitt' fiower ? Illurttnite your annwor
by refercMco to tliii dniKlolioii, mid joint out in what rt'sjiect its
flower-head differs from tliat r)f the eonuuon (•h)ver.

•U. Define what is »ne;int by the terms Exoyvn and Endoijrti.

42. Exphiin v.liat is meant l)y the followinf,' : Stamens and pelnls
are, from a morpliolof^'ieal point of view, leaves.

What is tlie morphologieal nature of onion bulbs, and potato
tubers ?

43. Name and deseribe the different ])arts of stamens and jtistils.
Why are these two sets of or}^ans called the essential parts of a
flower? State what is meant by a staminatc^ flower, and what by a
pistillate flower? How is fertilization accomplished in the ease of
the latter?

44. What is meant by the terms, berry, drupe, and poTTW ? Why
caimot a raspberry or a strawberry be termed a true berry ?

45. Draw outlines of the following forms of leaves: ovate, deltoid,
lanceolate, reniform, peltate, sagittate, hastate, cordate, obcordate.

46. Define the following terms : involucre, glume, gynoDcium,
micropyle, pappus, spadix, tendril, cyme.

don

SECOND AND THIRD CLASS TEACHEES' CERTIFICATES,
PROVINCE OF ONTARIO.

1. Name the parts of the pistil and stamens of a flower and give
their uses.

2. What are Perennial plants ? Describe their mode of life.

3. " There are two great classes of stems, which differ in the way
the woody part is arranged in the cellular tissue." Fully explain this.

4. Describe the functions of leaves. How are leaves classified as
to their veining.

5. Name and describe the organic constituents of plants.

6. Name the organs of reproduction in plants, and describe their
functions.

7. Give, and fully describe, the principal parts of the flower.

8. What are the different parts of a plant ? Describe the functions
of each part.

9. State all the ways by which an Exogenous stem may bo
distinguished from an Endogenous.

10. Describe the functions of leaves. What is the cause of their
fall in autumn ? Draw and describe a maple leaf.

11. Name the different parts of a flower, and describe the use of
each part. Draw a diagram showing a stamen and a pistil and the
parts of each.

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KXAMINATION I'APKHS.

12. Wli.it i^. llif fruit.? Why do hoiiir fruits fall from the Bttnii
inoro oii-ily tlmii otlifrN ''

]>]. Of will 1, does lilt' food (if pi iiits coii.sisl ? In wliat forms and
by wliat orf,'aiis is it tuKtii ii|i, .iiid how is it assimjl.itt'd ? Naiiic
the 8uli-.taii('('S iuliah'd ,iiid liiusc rxhiih'd hy plants, and the uses of
♦ Mcli ill tlui t'conoiiiy of nulni'c.

14. Dfscriho fully (Vl Ihr plant in N'ct^i.'tation ; (2) tho plaint in
Kcpiodiiction.

1."). J)i>scril)e Fibrous roots, Fleshy roots, and different kiuds of
Taproot.
](). Describe tlu) Htructur*' and vfininj,' of leavoa.

17. "'1'Ih' noiii islmii'iit which the mother plant ))rovides in the
seed is not always stored up in tlu; emijryo." Explain and illustrate.

IH. Describe th»^ various modes in which Perennials "provide a
stock of nourishment to beLMii tlie new growth."

I!). Describe fully tiie organs of re[)roduction in a plant. Deacribe
tile process of germination.

'20. What are the parts of a flower ? Give illustrations by diagram,
with a full description.

21. Name and describe tho principal sorts of flowers.

22. What elementary substances should the soil contain for the
nourishment of ])liints?

2;j. How are plants nourished before and after appearing above
ground ?

24. Tell what you know about the various forms of the calyx and
the corolla.

2'). Explain the terms Cotyledon, Pinnate, Root-stock, Filament,
and Radicle.

26. Explain the tenns Papilionaceous, Cruciferous, Silique, and
Syngenesious ; and in each case name a family in the description of
which the term under consideration may be properly applied.

27. Give the characters of the Rose family.

28. Describe the various inod<>s in which biennials store up
nourishment during their first season.

29. Exi)lain the meaning of the terms Sepal, Bract, llacemt\ and
Stipule. Describe minutely the Stamen and the Pistil, and give
the names applied to their parts.

30. Are the portions of the onion, the ])otato, and the turnip which
are ca])able of preservation tlu'ough the winter, equally entitled to
the name of roots ? Give reasons for your answer.

31. Describe briefly a vegetable cell in regard to its form, size,
contents, &c.

What differences usually exist between cells found in pith and
those found in wt)od ?

32. Name two kinds of underground stems.
How do we know that they are not roots?

State any uses of these stems (a) to the plant, (6) to man.

EXAMINATION PAPERS.

231

and

■ 'ive

83. What aro the functions of the leaf in plant life ?

Btato any differencuB between leuvea which uro surrouudoi by air
and leaves which float upon water.

Give auy laws according to which heaves are arranged upon the
Htem.

34. Give the uaiuert and relative ponitious of the parts of a com*
plete flower.

Cau you name a flower which itj perfect but not complete /

35. When a pea is soaked in water it Hplitt) into two parts, united
by a small ligament, but a grain of corn docs uot. Explain the
meauiug of this difference.

3G. Is an apple a Botanical fruit? If not, what is it?

37. Name any plants belonging to tiie following natural orders : —
Cruciferte, Caropuyllaceo), Composita>, Labiatoj.

38. From what does the root of an exogenous plant originate?
What are the chief functions of rootH? How may roots be distin*
guished from underground stems ?

39. From what do stems originate? Compare in appearance
transverHe sections of the stem of an elm and of a stalk of maize.
Uow do these stems differ iu their modes of growth ?

40. What are the functions of foliage-leaves? Describe briefly
the general structure and appearance of the leaf of (a) the Sugar
Maple (Acer aaccharinum) ; [b) the Indian Turnip {Aria(Bma
triphijllum).

41. Name the parts of a complete flower, and briefly describe the
chief modifications due to cohesion, adhesion, and suppression of
parts. (Name illustrative examples of each modification you
describe.)

42. Contrast a strawberry, a raspberry, and an apple, and compare
a gooseberry, a lemon, and a melon.

43. What are tlie general characters of the Cruciferoe, the Legu-
minoste, the Liliacero, and the Gramiueo) ?

44. Wliat are the morphological characters of roots ? How do
adventitious roots differ from normal roots as respects their origin?
Briefly describe the normal mode of growth of the roots of Gym-
nosperms and Dicotyledons.

45. Describe briefly the structure of the stem ot the Sunflower
(Helianthus annuus). Mention the chief differences iu the structure
and the mode of growth of the bark in diffeivnt dicotyledououa
trees ?

46. What is meant by an inflorescence? l^istinguish between
definite and .Indefinite inflorescence, and brietly lescribe the chief
kinds of indefinite inflorescence, giving an exam{>le of each.

47. Describe the structure and the process of germination of the
following named seeds : bean, buckwheat, marsh- marigold, oat.

48. What are stomata ? On what plants and parts of plantp. '.re
they found ? What are their functions ?

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EXAMINATION PAPERS.

49. Give the distinguishing characters of the Sapindacese, the
BosacesB, the Goniferse, and t)ie Iridaceso. Name a Canadian plant
belonging to each of these orders, and mention any uses made of it
or of any part of it.

60. Define the following terms : bract, scale, involucre, spathe,
Bcape, pedicel, asepalous, monoecious, monadelphous, perianth,
stamen, pistil, pome, thallus, drupe.

51. Describe briefly the structure, the mode of growth, and the
use to the plant of roots. Name an example of a plant with aerial
roots.

52. Name the enveloping and the essential organs of the flower,
and give a morphological comparison of foliage-leaves, floral en-
velopes, stamens, and carpels.

63. Describe briefly the general process of plant-nutrition, and
name the essential elements in the food of plants.

54. Give the chief distinctive characters of the Cruciferae, the
Leguminosse, the Umbellifern;, and the Liliaceae. Name three
common examples of each of these families.

65. Describe the modes by which the fertilization of a flower is
accomplished.

66. Distitguish between " definite " and " indefinite " inflorescence.

67. Which are the nutritive and which the reproductive organs
of plants ?

Briefly describe the principal ones of each kind.

68. Describe the structure of a "follicle," a "siliqua" and a
"legume."

59. When is a flower said to be " complete," *' regular," and
"symmetrical? "

60. Fill the accompanying Floral Schedule with an accurate
description of the specimen before you, referring it to its proper
order, &c.

61. Distinguish between (the series): Phanerogams and Crypto-
gams. State their divisions and note the distinctions of those of
tlio first (series).

62. What is the foundation of all vegetable tissue? and of its
elements which is essential for its growth and development ?

63. Describe the functions of the roots, stems, and foliage-leaves
of plants. State the kinds and sources of their nourishment.
Mention the changes the nutritive elements undergo in their passage
through them and the agencie •; by which these changes are effected.

04. Name, describe, and give the functions of the several parts of
a typical flower. State which are essential and why.

65. Give the general characteristics of the Leguminosae, Bosaceae
and ConiferaB.

66. Eefer to their botanical orders, genera, etc.; the plum, pear,
orange, pumpkin, cucumber, carrot.

67. Describe the structure and mode of growth of exogenous and
•udogenous stems.

idacesB, the
adian plant
s made of it

ere, spathe,
, perianth,

th, and the
with aerial

the flower,
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!Tame three

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ifloreflcence.
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its proper

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and of its

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>urishment.
leir passage
ire effected.

ral parts of
8d, BosacesB
)lum, pear,
euoua and

EXAMINATION PAPERS.

233

68. Give the meanings of apocarpous and syncarpous, aud name
two allied genera which may be distinguished by the difference
these terms express.

. 69. Where, in plants, are stomata most abundant? What is their
chief function ? Describe chlorophyll and explain its physiological
importance.

70. By what means is fei-tilization effected (1) in Phanerogams,
and (2) in Cryptogams ?

71. How would you distinguish a root from a stem ? Enumerate
the most important varieties of roots, giving examples.

72. Make a drawinj^ of the leaf of the sugar maple (i4cer Sacchari-
num) and of the beech {Ftujusferruginea), and describe them with
special reference to form, parts, aud venation.

73. Fill the accompanying Floral Schedule with an exact descrip-
tion of the specimen before you. Classify, if you can.

FIRST CLASS CERTIFICATES.

1. What are the cotyledons ? Describe their functions, &c. State
their value in systematic botany.

2. Describe the difference in structure aud modes of growth of
exogenous and endogenous stems.

3. Describe the circulation in plants. " In the act of making
vegetable matter, plants purify the air for animals." Explain this
fully.

4. What are Phaiuogamous plauts ? Defhie Hacenie, Corymb,
Head, Panicle, Ameut.

5. Give the characters of («) the classes Exogens and Endogens;
(6) the Mint aud Lily families.

6. To wnat family do the Cedar, Clover, Mustard, aud Dandelion
respectively belong?

7. Why does a botanist consider the tuber of the potato an under-
ground stem.

8. Give the philosophical explanation of the nature of a flower
considered as to the origin and correspondence of its different parts.

9. Draw a spathulate, an obcordate, a truncate, a palmately-
divided and an odd-pinnate leaf.

10. Explain the constitution of a pome or apple-fruit.

11. What organs appear in the more perfect plants, and in what
divisions are thev comprised ?

12. Give the function of the flower, its origin, and its essential
and accessory parts.

13. Describe the nature and chief varieties of roots, and distinguish
between them and underground stems.

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EXAMINATION PAPERS.

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14. " Ah to the Apex or Point leaves are Pointed, Acute, Obtuse,
Truncate, Retuse, Emarginate, Obcordate, Cuspidate, Mucronate."
Sketch these difEereut forms.

15. " There is no separate set of vessels, and no open tubes for the
sap to rise through in an unbroken stream, in the way people
generally suppose." Comment on this passage.

16. The great series of Flowering Plants is divided into two
classes. Describe these classes.

17. Give the cniet characterintics of the order Cruciferce (Cress
Family), and name some commou examples of this order.

18. State the difference between definite and indefinite inflores-
cence, and give examples of the latter.

v.). Of wnat does the food of plants consist? In what form is it
found in the soil? How is it introduced into the plant? What
inference may be drawn respecting the culture of the plant?

20. Distinguish weak climbing stems according to the mode in
which thny support themselves, the direction of their growth, and
the nature of their clasping organs.

21. Name the three classes of Flowerless Plants, and give an
example of each.

22. Explain the terms Spore, Capsule, Bract, Stipule, Albumen,
and Epiphyte.

23. What are tendrils, and of what organs are they supposed to
be modifications ?

24. Give the characters of the Cress Family, and name as many
plants belonging to it as you can.

25. Tell what you know about the minute structure and the
chemical composition of vegetal)le tissue.

26. Describe the origin of tlie different kinds of placentas; and
of the different parts of the ^ruit of the plum, the oak, and the maple.

27. Describe fully the ])rocess by which it is supposed that water
is carried up from the roots of plants.

28. Give the meaning of the terms stomate, indehisceni, thyrae,
glume, pyxis. Distinguish epi2>hyte3 Ixoni ^^ciTasites,

29. Describe any plant you have examined; if you can, tabulate
your description.

30. Name all the families of monopetalous dicotyledons which you
remeniber, and give the characters of any one of them,

31. Describe the following: primordial cell (utricle), protoplasm,
cyclosis, mode of plant growth.

32. Describe the process of reproduction in a phanerogamic plant.

33. How are the pulse family — order Legumiuosae — distinguished?
Show the utility of the plants of this order.

34. What is .^^stivation ? Describe the different kinds, and men-
tion a natural order of which each is characteristic.

35. Describe the course of tlie sap through the root and trunk of
an exogenous tree.

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EXAMINATION PAPERS

235

36. Enumerate vhe chief nitrogenous and non-nitrogenouB sub-
stances which are found in plantH.

37. Fill in the accompanying Floral Schedule with a full and
accurate description of the specimen under observation.

McGILL UNIVERSITY.

1. Describe the germination of a plant.

2. Explain the differences in the structure of the embryo.
8. Explain the functions of the Root.

4. Describe the structures in a leaf, and explain their action on
the air.

5. Mention tlie several parts of bhe stamen and the pistil, and
explain their uses.

6. Describe an Acheue, a Samara, a Drupe, and a Silique.

7. Describe the differences in the stems of Exogens and Endogens,
and the relations of these to the other parts of the plant and to
classificp'Jon.

8. Eip'-r • the terms Genera, Species, Order.

9. W .1 excurrent stem, an axillary bud, bud scales ?

10. Exi..la,ia the terms primordial utricle, parenchyma, proto-
plasm, as used in Botany.

11. What are the functions of the nucleus in a living cell ?

12. Explain the movements of the sap in plants.

13. Describe the appearance under the microscope of raphides,
Kpiral vessels, and disc-bearing wood-cells.

14. Describe the structure of the bark of an Exogen.

15. Describe freely the anatomy of a leaf.

16. Describe shortly the parts and structures denoted by the
f«>llowing terms : spine, aerial root, phyll odium, cam,bium, stipule,
yliizoma.

17. Give examples of ■phcenogams, cryptogams, exogens, and
^•ndogens,^^vo^ev\y arranged.

18. Describe the i)rincipal forms of indeterminate inflorescence.

19. In what natural families do we find siliqiies, didynamoiis
stamens, labiate corollas, or pappus-bearing achenes. Describe
tliese structures.

20. State the characters of any Canadian exogenous order, with
examples.

21. Describe the cell-wails in a living i)arenchymatous cell.

22. Describe the ftbro-vas(!ular tissues in an Exogenous stem.

23. Describe the appearance of stomata and glandular hairs under
the microscope.

24. T>ehne prosenchytna, corm, cyclosia, thallus.

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EXAMINATION PAPERS.

2o. Explaiu the sources of the Carbon and Nitrogeu of the plant,
and the mode of their assiuiilatioii.

26. Describe the pericarp, stating its normal structure, and naming
Bome of itn modifications.

27. Explain tlie natural system in Botany, and state the gradation
of groups from the species upward, with examples.

ONTAEIO COLLEGE OF PHARMACY.

1. What do plants feed upon ?

2. What do you understand by the terms Acaulescent, Apetalous,
Suffrutescent, Culm ?

3. Name some of the different forms of Primary, Secondary, and
Aerial Roots, giving examples.

4. Explain the following terms descx'iptive of forms of leaves,
giving sketch: — Ovate, Peltate, Crenate, Serrate, Cleft, Entire,
Cuspidate, Perfoliate.

5. Explain difference between Determinate and Indeterminate
inflorescence, giving three examples of each.

(5. What organs are deficient in a sterile and a fertile flower ?

7. Give the parts of a perfect flower, with their relative position.

8. Give the difference between simple and compound Pistil, with
examples of each.

9. Name the principal sorts of buds, and explain how the position
of these affects the arrangement of branches.

10. Give description of multiple and primary roots, with two
examples of same; also explain the difference between these and
secondary roots.

U. Name the principal kinds of subterranean stems and branches,
and explain bow you would distinguish between these and roots.

12. In the classification of plants explaiu difference between
classes and orders : f eiius and species.

13. Name three principal kinds of simple fruits.

14. Wlien roots stop growing does tlie absorption of moisture
increase or decrease ? Give reason for it.

15. Upon what do plants live ? Indicate how you would prove
your answer correct.

16. In what part of the plant, and when, is the work of assimila-
tion carried on ?

17. Name three ])rincipal kinds of determinate, and some of
indeterminate, inflorescence ; name the essential organs of a flower.

18. In what respects do plants differ from inorganic matter ? And
from animals ?

19. Describe a Rhizome, Tuber, Bulb ; and say if they belong
to the root or stem. Which are Rheum, Jalapa, Sweet Potato, Onion ?

EXAMINATION PAPERS.

237

20. Define the difference between natural and special forms of
leaves; between simple and o()mi)ouud leaves. Give example of
each. Sketch a conuate-perfoliate leaf.

21. Mention the parts of au embryo. Of a leaf. Of a pistil. Of a
stamen. Of a seed.

22. What is meant by an albuminous seed ? By dioecious flowers ?
By a compound ovary ?

23. What is the difference between determinate and indeterminate
inflorescence? How do they influence growth of the stem. Give
three princii)al kinds of eacli.

24. Name the parts of a flower. What office is performed by the
ovule ? Name two kinds.

25. Name the parts of a vegetable cell. What are spiral ducts ?

20. In what parts of the plant is the work of absorption carried
on ? In what part the work of assimilation ? How do the plants
purify the air for animals ?

27. Explain the natural system of classification in Botany? Name
and characterize the classes of plants.

28. Explain the structure and functions of the Leaf, Bud, Hoot.

29. Give some of the terms used in describing the shape of a
simple leaf as (ioncerns (a) its general contour, (6) its base, (c) its
margin, (r?) its apex.

30. Name the organs in a perfect flower; describe fully the
structure of the anther and pollen. What is coalescence and adna-
tion of the parts of a flower?

31. Explain the terms Raceme, Pappus, Coma, Rhizome, Pentas-
tichous.

32. State ti;e distinction between Exogens and Endogens.

33. What are cellular structures as distinguished from vascidar?
What is chlorophyll ?

84. Mention the organs of fructification, and explain the process
of fertilization in a flower-ing plant.

3.5. Explain the structure of a seed, and describe in a few words
the process of germination.

86. Define what is meant by the following terms : Morphology,
Polycotyledonous, Epiphyte, Peduncle, Stipules

37. Describe briefly the root, stem, leaf, and flower of the common
dandelion, giving the functions or office of each.

38. Name some of the most common forms of leaves, giving a
few rough outlines.

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