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TEE STOKY OF THE PLANTS.

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THE STOEY OF

THE PLANTS.

GEANT ALLEN.

—•3

M

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3^

WITH ILLUSTRATIONS.

LONDON: GEORGE NEWNES, LTD.

SOUTHAMPTON STREET, STRAND

1895

The rights of translation and of reproduction are reserved.

PREFACE.

IN this little volume I have endeavoured to give
a short and succinct account of the principal
phenomena of plant life, in language suited to
the comprehension of unscientific readers. As
far as possible I have avoided technical terms
and minute detail, while I have tried to adopt a
more philosophical tone than is usually employed
in elementary works. I have treated my readers,
not as children, but as men and women, endowed
with the average amount of intelligence and
insight, and anxious to obtain some sensible
information about the world of plants which
exists all round them. Acting upon this basis,
I have freely admitted the main results of the
latest investigations, accepting throughout the
evolutionary theory, and making the study of
plants a first introduction to the great modern
principles of heredity, variation, natural selec-
tion, and adaptation to the environment. Hence
I have wasted comparatively little space on
mere structural detail, and have dwelt as much
as possible on those more interesting features
in the interrelation of the plant and animal
worlds which have vivified for us of late years
the dry bones of the old technical botany.

My principle has been to unfold my subject
by gradual stages, telling the reader one thing
at a time, and building up by degrees his know-

i

D PREFACE.

ledge of the subject. My treatment is, therefore,
to some extent diagrammatic, especially in the
earlier chapters ; but I endeavour as I proceed
to correct the generalisations and fill in the
gaps of the first crude statement. I trust that
advanced students who may glance at this little
book will forgive me for such concessions to the
weaker brethren, especially when they see that
at the same time I have ventured to lay before
untechnical readers all the latest results of the
most advanced botanical research, as far as
could be done in so small a compass. I have
even made bold to speak at times of "carbonic
acid," where I ought strictly to have said
"Carbon dioxide." and to glide gently over the
distinction between hydro-carbons and carbo-
hydrates, which could interest none but chemical
students. I have been well content to make
these trivial sacrifices of formal accuracy in
order to find room for fuller exposition of the
delightful relations between flowers and insects,
birds and fruits, soil and pla*it, climate and
foliage. In one word, I have dwelt more on
the functions and habits of plants than on their
structure and classification. At the same time
I have tried to lead on my reader by gradual
stages to the further study of plants in the
concrete ; and I shall be disappointed if my
little book does not induce a considerable pro-
portion of those into whose hands it may fall
to pursue the subject further in our fields and
woods by the aid of a Flora.

G. A.

THE CROFT, HINDHEAD.
April, 1895.

CONTENTS.

CHAP. PAGE

I. INTRODUCTORY ..... 9

II. HOW PLANTS BEGAN TO BE . . . 14

III. HOW PLANTS CAME TO DIFFER FROM ONE ANOTHER 26

IV. HOW PLANTS EAT .... 35
V. HOW PLANTS DRINK . . . ,57

VI. HOW PLANTS MARRY . . . 78

VII. VARIOUS MARRIAGE CUSTOMS . . .93

VIII. MORE MARRIAGE CUSTOMS . . . 113

IX. THE WIND AS CARRIER .... 135

X. HOW FLOWERS CLUB TOGETHER . . 147

XI. WHAT PLANTS DO FOR THEIR YOUNG . . 162

XII. THE STEM AND BRANCHES . . - 176

XIII. SOME PLANT BIOGRAPHIES . . . 198

XIV. THE PAST HISTORY OF PLANTS . . 221

CHAPTEE I.

INTRODUCTORY.

I PROPOSE in this volume to write in brief the
history of plants, their origin and their develop-
ment. I shall deal with them all, both big and
little, from the cedar that is in Lebanon to the
hyssop that springeth out of the wall. I shall
endeavour to show how they first came into
existence, and by what slow degrees they have
been altered and moulded into the immense
variety of tree, shrub, and herb, palm, mush-
room, and sea- weed we now behold before us.
In short, I shall treat the history of plants much
as one treats the history of a nation, beginning
with their simple and unobtrusive origin, and
tracing them up through varying stages to their
highest point of beauty and efficiency.

Plants are living things. That is the first
idea we must clearly form about them. They
are living in just the same sense that you and
I are. They were born from a seed, the joint
product of two previous individuals, their father
and mother. Plants likewise live by eating ;
they have mouths and stomachs, which devour,
digest, and assimilate the food supplied to them.
These mouths and stomachs exist in the shape of
leaves, whose business it is to catch floating

10 THE STORY OF THE PLANTS.

particles of carbonic acid in the air around, to
suck such particles in by means of countless
lips, and to extract from them the carbon which
is the principal food and raw material of plant
life. Plants also drink, but, unlike ourselves,
they have quite different mouths to eat with and
to drink with. They take in their more solid
constituent, carbon, with their leaves from the
air ; but they take in their liquid constituent,
water, with their roots and rootlets from the soil
beneath them. " More solid," I say, because
the greater part of the wood and harder tissues
of plants is made up of carbon, in combination
with other less important materials ; though,
when the plants eat this carbon, it is not in the
solid form, but in the shape of a gas, carbonic
acid, as I shall more fully explain when we come
to consider this subject in detail, For the
present, it will be enough to remember that
Plants are living things, which eat and drink
exactly as we ourselves do.

Plants also marry and rear families. They
have two distinct sexes, male and female —
sometimes separated on different plants, but
more often united on the same stem, or even
combined in the same flower. For flowers are
the reproductive parts of plants ; they are there
for the purpose of producing the seeds, from
which new plants spring, and by means of which
each kind is perpetuated. The male portions of
plants of the higher types are known as stamens ,
they shed a yellow powder which we call pollen,
and this powder has a fertilising influence on
the young seeds or ovules. The female portion

INTRODUCTORY. 11

of plants of the higher types is known as the
pistil ; it contains tiny undeveloped knobs or
ovules, which can only swell out and grow into
fruitful seeds provided they have been fertilised
by pollen from the stamens of their own or some
other flower. The ovules thus answer very
closely to the eggs of animals. After they have
been fertilised, the pistil begins to mature into
what we call a fruit, which is sometimes a sweet
and juicy berry, as in the gr,ape or the currant,
but more often a dry capsule, as in the poppy or
the violet.

Plants, however, unlike animals, are usually
fixed and rooted to one spot. This makes it
practically impossible for them to go in search
of mates, like birds or butterflies, squirrels or
weasels. So they are obliged to depend upon
outside agencies, not themselves, for the con-
veyance of pollen from one flower to another.
Sometimes, in particular plants, such as the
hazels and grasses, it is the wind that carries
the pollen on its wings from one blossom to its
neighbour ; and, in this case, the stamens which
shed the pollen hang out freely to the breeze,
while the pistil, which is to catch it, is provided
with numberless little feathery tails to receive
the passing grains of fertilising powder. But
oftener still, it is insects that perform this kind
office for the plant, as in the dog-rose, the holly-
hock, and the greater part of our beautiful garden
flowers. In such cases the plant usually makes
its blossom very attractive with bright-coloured
petals, so as to allure the insect, while it repays
.him for his trouble in carrying a\vay the pollen

12 THE STOKY OF THE PLANTS.

by giving him in return a drop of honey. The
bee or butterfly goes there, of course, for the
honey alone, unconscious that he is aiding the
plant to set its seeds; but the plant puts the
honey there in order to entice him against his
will to transport the fertilising powder from
flower to flower. There is no more fascinating
chapter in the great book of life than that which
deals with these marriage relations of the flowers
and insects, and I shall explain at some detail in
later portions of this little work some of the most
curious and interesting of such devices.

Again, after the plant has had its flower
fertilised, and has set its seed, it has to place
its young ones out in the world to the greatest
advantage. If it merely drops them under its
own branches, they may not thrive at all; it
may have impoverished the soil already of certain
things which are necessary for that particular
kind, owing to causes to be explained hereafter ;
and even where this is not the case, the sur-
rounding soil may be so fully occupied by other
plants that the poor little seedlings get no
chance of establishing themselves. To meet
such emergencies, plants have invented all sorts
of clever dodges for dispersing their seeds, into
the nature of which we will go in full in the
sequel. Thus, some of them put feathery tops
to their seeds or fruits, like the thistle and the
dandelion, the willow and the cotton-bush, by
means of which they float lightly on the air, and
are wafted by the wind to new and favourable
situations. Others, again, bribe animals to dis-
perse them, by the allurement of sweet and pulpy

INTRODUCTORY. 13

fruits, like the strawberry or the orange ; and in
all these instances, though the fruit or outer coat
is edible, the actual seed itself is hard and indi-
gestible, like the orange -pip, or is covered with a
solid envelope like the cherry-stone. Numerous
other examples we shall see by and by in their
proper place. For the present, we have only to
remember that plants to some extent provide
beforehand for their children, and in many cases
take care to set them out in life to the best
possible advantage.

Most of these points to which I am here
briefly calling your attention are true only of
the higher plants, and especially of land-plants.
For we must not forget that plants, like animals,
differ immensely from one another in dignity,
rank, and relative development. There are
higher and lower orders. We shall have to
consider, therefore, their grades and classes —
to find out why some are big, some small ; some
annual, some perennial ; why some are rooted in
dry land, while some float freely about in water ;
why some have soft stems like spinach and
celery, while others have hard trunks like the
oak and the chestnut. We shall also have to
ask ourselves what were the causes which made
them differ at first from one another, and to
what agencies they owe the various steps in
their upward development. In short, we must
not rest content with merely saying that the
rose is like this and the cabbage like that ; we
must try to find out what gave to each of them
its main distinctive features. We must " con-
sider the lilies, how they grow," and must seek

14 THE STOEY OF THE PLANTS.

to account for their growth and their peculiari-
ties.

And now let me sum up again these central
ideas of our future reading on plants and their
history.

Plants are living things ; they eat with their
leaves, and drink with their rootlets. They take
up carbon from the air, and water from the soil,
and build the materials so derived into their own
bodies. Plants also marry and are given in
marriage. They have often two sexes, male and
female. Each seed is thus the product of a
separate father and mother. Plants are of many
kinds, and we must inquire by and by how they
came to be so. Plants live on sea and land, and
have varieties specially fitted for almost every
situation. Plants have very varied ways of
securing the fertilisation of their flowers, and
look after the future of their young, like good
parents tha* they are, in many different man-
ners. Plants are higher and lower, exactly like
animals.

These are some of the points we must proceed
to consider at greater length in the following
pages.

CHAPTER II.

HOW PLANTS BEGAN TO BE.

WHICH came first — the plant or the animal ?

That question is almost as absurd as if one
were to ask, Which came first — the beast of
prey, or the animals it preys upon ? Clearly,

HOW PLANTS BEGAN TO BE. 15

the earliest animals could not possibly have been
lions and tigers; for lions and tigers could not
begin to exist till after there were deer and
antelopes for them to hunt and devour. Now
the general connection between animals and
plants is somewhat the same in this respect as
the general connection between beasts of prey
and the creatures they feed upon. For all
animals feed, directly or indirectly, upon
plants and their products. Even carnivorous
animals eat sheep and rabbits, let us say ; but
then, the sheep and the rabbits eat grass and
clover. In the last resort, plants are self-
supporting ; animals feed upon what the plants
have laid by for their own uses. Every animal
gets all its material (except water) directly or
indirectly from plants. In one word, plants are .
the only things that Jcnoiv how to manufacture j
living material. ? •"*' y

Eoughly speaking, plants are the producers
and animals the consumers. Plants are like
the pine-tree that makes the wood ; animals are
like the fire that burns it up and reduces it to
its previous unorganised condition.

It is a little difficult really to understand the
true relation of plants and animals without
some small mental effort; yet the point is so
important, and will help us so much in our after
inquiries that I will venture upon asking you to
make that effort, here at the very outset.

If you take a piece of wood or coal, you have
in it a quantity of hydrogen and carbon, almost
unmixed with oxygen, or at least combined with
far less oxygen than they are capable of uniting

(t d •.tus&St""'

16 THE STOKY OF THE PLANTS.

with. Now put a light to the wood or coal, and
what happens ? They catch fire, as we say, and
burn till they are consumed. And what is the
meaning of this burning ? Why, the carbon and
hydrogen are rushing together with oxygen —
taking up all the oxygen they can unite with,
and forming with it carbonic acid and water.
The carbon joins the oxygen in a very close
embrace, and becomes carbonic acid gas, which
goes up the chimney and mixes with the
atmosphere ; the hydrogen joins the oxygen in
an equally intimate union, and similarly goes off
into the air in the form of steam or watery
vapour. Burning, in fact, is nothing more than
the union of the carbon and hydrogen in wood or
coal with the oxygen of the atmosphere. But
observe that, as the carbon and hydrogen burn,
/ they give off Alight and heat. This light and
Jf , heat they held^ktored up before in their separate
' \ form ; it was, so to speak, dormant or""*!&t!£ht

{within them. Free carbon and free hydrogen
contain an amount of energy, that is to say of
latent lighted fln^arji-. h^, which they yield
tTjJ wjiejX-they unite with free oxygen. A*ncl
thou^Iithe^carb(5r^jid hydrogen in wood and
coal are not quite free, they may be regarded as
free for our present purpose.

Now, -sdifice did this light and heat come
from? Well, the wood, we know, is part of a
tree which has grown in the open air, by the aid
of sunshine. The coal is just equally part of
certain very ancient plants, long pressed beneath
the earth and crushed and hardened, but still
possessing the plant-like property of burning

iiOW PLANTS fcEGAH TO BE. 1?

when lighted. In both cases the light and heatj
as we shall see more fully hereafter, are derived
from the sun, our great storehouse of energy. •'
The sunshine fell upon the leaves of the nlodern
oak-tree, or of the very antique club -mosses
which constitute coal, and separated^in them the
carbon from the oxygen oT caT'bo^mc^acid , and
trie* hydrogen from the oxygen of tfe^^ii^" m ,'
the sap? In each case the oxygen was turned
loose upon the air in its free form, while the
carbon and the hydrogen (with a very little
oxygen and a few other materials) were lelTln

in the leaves

and wood of the^oak or tEe club-mos.s. But the
point to which I wish now specially to direct
your attention is this — the sunlight was actually
used up for the time being in effecting this
separation between the oxygen 611 the one hand,
and' the carbon and hydrogen on the other. As
long as the plant remained unburnt, the light
and heat it received from the sun lay dormant
within it, not as actual light and heat, but as
ggl^yajiprL between the oxygen and the hydrogen
or carbon. Coal, indeed, has been well described
as " bottled sunshine."

More than this ; it took just as much light anal
heat from the sun "to builcf lip ltEe~pTaht as you*
can get out of the plant in the end by bum-j
ing it.

Now, let us burn .our piece of wood or coal,
and what happens ? Why, particles of oxygen
rush together with particles of carbon in the
fuel, and form carbonic acid. How much
carbonic acid ? Just as much as it took

18 THE STOKY OP THE PLANTS.

oi4iginally to build that part of the plant from.
Simultaneously, other particles of oxygen in the
air rush together with particles of hydrogen in
the fuel, and form water, in the shape of steam.
How much water ? Just as much as it took
originally to build thaT^paf¥~bT^the plant from.
As they unite, they give out their dormant heat
and light. How much heat and light ? Just as
rryicjj as they absorbed in the act of building up
those parts of the plant from the sunshine that
fell upon them.

/ In other words, the same quantity of oxygen
\that was first separated from the carbon and
/ hydrogen reunites with them in the act of burn-
| ing, and the same amount of heat and lights, that
(were requIEecL'lib effect' "ffieir separation is yielded
up again in the act of reunion.

Let us put this point numerically, and I will
simplify it exceedingly, so as to make my
meaning clearer. Suppose we -begin with a
particle of carbonic acid and a particle of water
in the interior of a green leaf — the carbonic acid
swallowed from the air by the leaf, the water
brought to it as sap from the roots. Now, under
the influence of sunlight, these materials are
separated into their component parts. The
particle of carbonic acid consists of one atom of
carbon, closely locked up with two "'atoms of
oxygen. It takes an amount of sunlight, which
we will call A, to unlocKTffis union, and separate
the atoms. The oxygen goes off free into the
air, and the carbon remains in the leaf as
material for building the plant up. Again, the
particle of water consists of two atoms of

HOW PLANTS BEGAN TO BE. 19

hydrogen, closely locked up with one atom of
oxygen. If iaJTes aEraTn75unT of sunlight, which
we will call B, to unlock this union and separate
the atoms. The oxygen once more goes^ofF'freir '
into the air, and the hydrogen joins in a loose ^
union with the carbon already spoken of. Islow,
burn the material resulting from these two acts,
and what happens? Two atoms of oxygen
once more unite with the one atom of carbon, to
form a particle of carbonic acid ; one atom of
oxygen once more unites with the two atoms of
hydrogen £o form a particle of water, and there
is given out injhe^act of union an amount of
light and heat exacfly^ n equal 'to_ the A and B
originally locked^ up7m tne act °f separating
them.

I have now made it clear, I hope, what plant
life really is in its final essence. In nature at
large, the elements which chiefly compose it —
namely, carbon and hydrogen — exist only in very
close union with oxygen ; the plant is a machineA
for separating these elements Irom oxygen under f
the influence of sunlight, and building them up
into fresh forms, whose great peculiarity is that |
they possess energy or dormant motion. }

Now the animal is the exact opposite of all
this. He is essentially a destroyer, as the plant
is a builder. The plant produces ; the animal 1
consumes ; the plant makes living matter, the A
animal breaks it down again. He is, in fact, /
a slowjire, where plant products like grasses,
fruits, nuts, or grains, are consumed by degrees
and reduced once more to their original condition.

The animal eats what the plant laid by. He

20 THE STOEY OF THE PLANTS.

also breathes — that is to say, takes oxygen into
his lungs. Within his body that oxygen once
more unites with the carbon and the hydrogen,
and is given out again in union with them as
carbonic acid and water. Andythe energy tin the
plant food, thus set free within hfs' body, takeg
the jorm of^anirnal hfeat and animal motion—
/jipF^a^TKeerlergy seE free iii tne locomotive
takes the form oi heat and visible movement.
Animals are thus the absolute converse of
plants ; all that the plants did, the animal
undoes again.

Briefly to recapitulate this rather dry subject,
— the plant is a mechanism for scparajing^oxygen
from carbon and iiy drogen , and ior^storing up
sun-energy. The animal is a mechanism for
uniting oxygen with carbon and hydrogen, and
for usinjr the stored-up sun-energy as heat and
motton.

And now you can see why it is so absurd to

ask, Which came first, the plant or the animal ?

You might as well ask, Which came first, the

coal or the fire ? All the living material in the

world was first macle and laid up by plants.

; They alone have fop, pnwp.r t,n taak^ living or-

rncrgyj-yielding stuff out of deadancl inert

\ water or carbon!*1, acid. Thejfare the origin

and foundation of liie. Without them there

could be no living thing in the universe. It

i is in their green parts alone that the wonderful

! transformation of dead matter into living bodies

^ takes place ; they alone know how to store up

and utilise the sunshine that falls upon them.

HOW PLANTS BEGAN TO BE. 21

All the animal can do is to take the living
material the plant has made for him, and to
consume it slowly in his own body. He
destroys it (as living matter) just as truly as a
fire does, and turns it loose on the air again in
the dead and inert forms of water and carbonic
acid.

It is clear, then, that plants must have come
first, and animals afterward. The earliest living
beings must needs have been plants — very
simple plants ; yet essentially plants in this —
that they were green, and that they separated
carbon and hydrogen from oxygen under tne
influence of sunlight. It is that above every -
thing that makes true plants ; • though^ some
degenerate plants have now given up their
ancestral habit, and behave in this respect much
like animals.

How did the first plant of all come into
being ?

About that, at present, we know very little.
We can only guess that, in the early ages of
the world, when matter was fresher and more
plastic than now, certain combinations were set
up between atoms under the influence of sun-
light, which formed the earliest living body.
This would be what is called " spontaneous
generation." Whether such spontaneous genera-
tion ever took place is much disputed ; though
some people competent to form an opinion
incline to believe that it probably did take place
in remote times and under special conditions.
But it is certain, or almost certain, that in our

22 THE STOKY OF THE PLANTS.

own days at least spontaneous generation does

not take place — perhaps because all the available

material is otherwise employed, perhaps because

the conditions are no longer favourable. At any

/rate, we have every reason to suppose that at the

' present day every living being, whether plant or

\animal, is the product of a previous living being,

its parent, or of two previous living beings, its

father and mother.

Why should this be so? Well, if you think
for a moment, you will see that it results almost
naturally from the other facts we have so far
considered. For the plant is a machine for. \
making living ma^tey m\t pf water anH carbonic
acI37~under the influence of sunlight. As long
as sunlight, direct or reflected, in sun or shade,
falls upon a green plant, the plant goes on
taking up carbonic acid from the air by means
of its leaves, and water from the earth by means
of its roots, and continues to manufacture from
them |resh living material. Thus it must be
always groiving, as we say ; in other words, the
mass of living material must be constantly
increasing. Now, it results from this that the
plant would grow in time unwieldily large ; and
/in simple types, when it grows very large, it
\ splits or divides into two portions. That is the
real origin of what we call KEPKODUCTION. In
its simplest forms, reproduction means no more
than this — that a rather large body, which cannot
easily hold together, divides in two, and that
each part of it then continues to live and grow
exactly as the whole did.

This seems odd and unfamiliar to you, because

\

HOW PLANTS BEGAN TO BE. 23

you are thinking of large and very advanced
plants, like a sweet-pea or a potato. But you
must remember that we are dealing here with
very early and simple plants, and that these
early and simple plants consist for the most part
of tiny greeT? pij,tftsf floating free in water. They
are generally invisible to the naked eye, and are
in point of fact mere specks of green jelly. Yet
it is from such insignificant atoms as these that
the great forest trees derive their origin, through
a long line of ancestors ; and if we wish to
understand the larger and more developed
plants, we must begin by understanding these
their simple relations.

Very early plants, then, floated free in water ;
and there is reason to believe that for a con-
siderable period in the beginnings of our world
there was no dry land at all ; the whole surface
of the globe was covered by one boundless ocean.
At any rate, most of the simplest and earliest
forms of life now remaining to us inhabit the
water, either fresh or salt ; while almost all the
higher and nobler plants and animals are dwellers
on land. Hence it is not unreasonable to con-
clude that life began in the sea, and only
gradually spread itself over the islands and
continents.

Floating jelly-like plants would readily reach
a size at which it would be convenient for them
to split in two — or rather, at which it would be
difficult for them to hold together ; and most

:very small floating plants do^to this, jj^Y continue \
to grow, up to a certain point, and then divide ']
into two similar and equal portions. This is the |

24 THE STORY OF THE PLANTS.

simplest known form of what we call reproduc-
tion. Of course, the two halves into which the
plant thus divides itself are exactly like one
another ; and that gives us the basis for what
i we call HEREDITY — that is to say, the general
similarity between parent and offspring. This
similarity depends upon the fact that the two
were once ono, and when they split or divide
each part continues to possess all the qualities
of the original mass of which it once formed a
portion.

You will observe that I here use the words,
parent and offspring. I do so, partly from
custom, and partly to show where this reasoning
leads us. But in reality, in such very simple
plants, neither part of the divided whole can
claim to be either parent or child ; they are
equal and similar. In higher plants, however
(as in higher animals), we find that the main
portion of the plant continues to live and grow,
and sends off smaller portions, known as spores
or seeds, to reproduce its species. Here, we
may fairly speak of the larger plant as the
parent, and of the smaller ones which it de-
taches from itself as its children or offspring.

The truth is, every gradation exists in nature
between these two extreme cases. The different
types glide imperceptibly into one another.
There is no one point at which we can definitely
say, "Here reproduction by splitting or division
ceases, and reproduction by eggs, or by spores
or seeds begins."

Again, all the earlier and simpler plants are
sexless ; they simply grow till they divide, and

HOW PLANTS BEGAN TO BE. 25

then the two halves continue to exist inde-
pendently. No two distinct plants or parts of
plants are concerned in producing each new
individual. But the higher plants, like the
higher animals, are male and female. In such
cases two distinct individuals combine to form
a new one. They are its father and mother, so
to speak, and the young one is their offspring.
A little grain of pollen produced by the male
plant unites with a little ovule or seedlet pro-
duced by the female ; and from the union of the
two springs a fresh young plant, deriving its
peculiarities about equally from each of them.
How and why this great change in the mode
of reproduction takes place is another of the
questions we must discuss hereafter ; I will
only anticipate now the result of this discussion
by saying briefly beforehand that plants gain in
this way, because greater variety is secured in
the offspring, and because the weak points of 9
one parent are likely to be reinforced and made *
good by the other.

Let us sum up our conclusions in this pre-
liminary chapter : —

Plants are an older type of life than animals.
They are the first and mosif original form of
living beings, and wjthrmt, J^e.m, yp Jifa nf^a.ny
sort would be possible. All living matter is
manufactured by plants out of material found
floating in the air, under the influence of sun-
light. How plants first came into existence we
do not yet know ; but we may suspect that they
grew, in very simple and small forms, at &

26 THE STORY OF THE PLANTS.

remote period, under conditions which now no
longer exist. It is almost certain that the first
plants were jelly-like specks, floating freely in
water. They must have been green, and must
also have possessed the essential plant-power of
building up fresh living material when sunlight
fell upon them. This power implies the other
power of reproduction, that is to say of splitting
up into two or more similar parts, each of which
continues to live and grow like the original body.
From such simple and very primordial plants
all other and higher forms are most likely
descended.

CHAPTEE III.

HOW PLANTS CAME TO DIFFER FKOM ONE ANOTHER.

ALL plants are not now alike. Some are trees,
some herbs ; some are roses, some buttercups.
Yet we have a certain amount of reason to
believe that they are all descended from one and
the same original ancestor ; and we shall see by
and by that we can often trace the various
stages in their long development. They differ
immensely. Some of them are more advanced
and more complex than their neighbours ; some
are small and low, while others are tall and
strong; some, like nettles and grasses, have
simple and inconspicuous flowers, while others,
like lilies and orchids, have beautiful and very
complicated blossoms, highly arranged in such
ways as to attract and entice particular insects
to visit and fertilise them. Again, some havq

HOW PLANTS CAME TO DIFFEE. 27

tiny dry fruits, with small round seeds, which
fall on the ground unheeded ; while others have
brilliant red or yellow berries, or winged or
feathery seeds, especially fitted for special modes
of dispersion. In short, there are plants which
seem, as it were, very low and uncivilised, while
there are others which display, so to speak, all
the latest modern inventions and improvements.

The question is, How did they thus come to
differ from one another ? What made them
vary in such diverse ways from the primitive
pattern ?

In order to understand the answer which
modern science gives to this question, we must
first glance briefly at certain early steps in the
history of the process which we call creation or
evolution.

The earliest plants, we saw, were in all pro-
bability mere tiny green jelly- specks, floating
free in water, and taking from it small quantities
of dissolved carbonic acid, which they manu-
factured for themselves into green living material
when sunlight fell upon them. Now we shall
have to consider another peculiarity of plants
(and of animals as well) before we can
thoroughly understand the first stage in the
upward process which leads at last to the pine
and the lily, the palm and the apple.

Plants are made up of separate parts or
elements, known as cells, each of which consists
of a thin cell- wall, usually containing living
material. The very simplest and earliest plants,
however, consist of a single such cell apiece ;

28 THE STORY OF THE PLANTS.

they are specks of green jelly, enclosed by a
cell-wall, alone and isolated. In such cases,
when the cell grows big and divides in two, each
half floats off as a separate cell, or a separate
plant, and continues to divide again and again,
as long as it can get a sufficient amount of
carbonic acid and sunlight. But in some
instances it happens that the new cells, when
budded out from the old ones, do not float off
in water, but remain hanging together in long
strings or threads, in single file, as you may see
in certain simple forms of hair-like pond- weeds.
These weeds consist of rows of cells, stuck one
after another, not unlike rows of pearls in a
necklace. Of course the individual cells are too
small to see with one's unaided eye ; but under
a microscope you can see them, joined end to
end, so as to form a sort of thread or long line
of plant-cells. This is the beginning of the
formation of the higher plants, which consist,
I indeed, of collections of cells, arranged either
I in rows or in flattened blades, or many deep
| together in complicated order.

However, the higher plants differ from the
lower ones in something more than the number
and complexity of the cells which compose them.
They are very varied ; and their variety adapts
them to their special circumstances. For
example, desert plants, like the cactuses, have
thick and fleshy leaves (or, rather, jointed stems)
to store up water, with a very tough skin to
prevent evaporation. The flowers of each
country, again, are exactly adapted to the
insects of that country; and so are the fruits

ItOW PkANtfS CAME TO DlFFEli. 29

to the birds that swallow and disperse them.
How did this all come about ? What made the
adaptation ? It is a result of two great under- )
lying principles known as The Struggle for Life,\
and Natural Selection.

Since each early plant goes on growing and
dividing, again and again, as fast as it can, it
must follow in time that a great number of
plants will soon be produced, each righting with
the others for air and sunlight. Now, some of
them must, by pure accident of situation, get
better placed than others ; and these will pro-
duce greater numbers of descendants. Again,
unless all of them remained utterly uninfluenced
by circumstances (which is not likely) it must
necessarily happen that slight differences will
come to exist between them. These differences
of outline, or shape, or cell- wall, may happen to
make it easier or harder for the plant to get
access to carbonic acid and sunlight, or to
disperse its young, or to fix itself favourably.
Those plants, therefore, which happened to vary
in the right directions would most easily go on
living and produce most descendants, whilA\
those which happened to vary in the wrong
directions would soonest die out and leave
fewest descendants.

Well, the world around us, both of plants and
animals, is full of creatures all struggling against
one another, and all competing for food and air?
and sunshine. Moreover, each individual pro-*
duces (as a rule) a 'vast number of young ; some-
times, like the poppy, many thousand seeds on
a single flower-stem. Now suppose only ten of

'60 THE STOKY OF THE PLANTS.

those seeds succeed in growing each year. In
the first year, that poppy will have produced ten
new poppy plants ; the year after, each of those
ten will have produced ten more, making the
total 100 ; in the third year, they will be 1,000 ;
in the fourth, 10,000 ; and so on in the same
progression till in a very few years the whole
world would simply be full of poppies. And
similarly with animals. If every egg in a cod's
roe developed into a mature fish, the sea would
soon be one solid and compact mass of cod-fish.

Why doesn't this happen ? Because every
other kind is producing seeds or eggs at about
the same rate, and every one of them is fighting
against the other for its share of light and food
and soil and water. The stronger or better-
adapted survive, while the weaker or less-
adapted go to the wall, and are starved out of
existence. At first, to be sure, it sounds odd
to talk of a Struggle for Life among plants, which
seem too fixed and inert to battle against one
another. But they do battle for all that. Each
root is striving with all its might to fix itself
underground in the best position ; each leaf and
stem is struggling hard to overtop its neighbour,
and secure its fair share of carbon and of sun-
shine. When a garden is abandoned, you can
very soon see the result of this struggle ; for the
flowers, which we only keep alive by weeding —
that is to say, by uprooting the sturdier com-
petitors— are soon overgrown and killed out by
the weeds — that is to say, by the stronger and
better-adapted native plants of the district.

This, then, is the nature and meaning of these

HOW PLANTS CAME TO DIFFEK. 31

two great principles. The Struggle for Life
means that more creatures are produced than
there is room in the world for. Natural Selec-
tion (or Survival of the Fittest) means that among
them all, those which happen to be best adapted
to their particular circumstances oftenest suc-
ceed and leave most offspring.

By the action of the two great principles in
question (which affect all life, animal or vege-
table) the world has been gradually filled with
an immense variety of wonderful and beautiful
creatures, all ultimately descended (as modern
thinkers hold) from the selfsame ancestors.
The simple little green jelly-speck, which is the
primitive plant, has given rise " in time to the
sea- weeds and liverworts, then to the mosses
and ferns, then to the simplest flowering plants,
thence to the shrubs and trees, and finally to
all the immense wealth and variety of fruits,
flowers, and foliage we now see around us.

The rest of this book will consist mainly of an
exposition of the results brought about among
plants by Variation, the Struggle for Life, and
Survival of the Fittest. But before we go on to
examine them in detail, I shall give just a few
characteristic instances which show the mode of
action of these important principles.

There is a pretty wild flower in our hedges
called a red campion, or " Eobin Hood/' Now,
a single red campion produces in a year three
thousand seeds. But there are not three thou-
sand times as many red campions this year as
last, nor will there be three thousand times as

32 THE STORY OF THE PLANTS*

many more again next season. Indeed, if an
annual plant had only two seeds, each of which
lived and produced two more, and so on con-
tinually, in twenty years its descendants would
amount to no less than a million. From all this
it necessarily results that a Struggle for Exis-
tence must take place among plants ; they fight
with one another for the soil, the rain, the
carbon, the sunshine.

Again, take such a wild flower as this very red
campion. Why has it light pink petals? The
reason is, to attract the insects which fertilise
it. Flowers, in which the pollen is carried by
the wind, never have brilliant or conspicuous
blossoms ; but flowers which are fertilised by
insects have almost always coloured petals to tell
the insects where to find the honey. How did
this come about? In this way, I imagine : Many
plants produce a sweet juice on their leaves — for
example, the common laurel. This juice, which
is probably of no particular use to them, is very
greedily eaten by insects. Now suppose some
flower, by accident at first, happened to produce
such sweet juice near its stamens, which (as we
saw) are the organs for making pollen, and also
near its pistil, which contains its young seeds or
ovules. Then insects would naturally visit it to
eat this sweet juice, which we commonly call
honey. In eating it, they would dust themselves
over with the floury pollen, by pure accident, and
they would carry som,e of it away with them on
their heads and legs to the next flower they
visited. Chance would make them often rub off
the pollen and fertilise the flower ; and as such

HOW PLANTS CAME TO tUFFEft. 33

cross-fertilisation, as it is called, is good' for the
plants, producing very strong and vigorous
seedlings, the young ones so set would have
the best chance of flourishing and surviving in
the Struggle for Existence. Thus the flowers
which made most honey would be oftenest
visited and crossed, so that they would soon
become very numerous. Again, if they hap-
pened to have bright leaves near the honey,
they would be most readily discriminated, and
oftenest visited. So, in the long run, it has
come about that almost all the flowers fertilised
by insects produce honey to allure them, and
have brilliant petals to guide their allies to the
honey. That, in fact, is what beautiful flowers
are for — to attract the fertilising bees and
butterflies to visit and impregnate the various
blossoms.

Take one more case — or, rather, the same
case, extended a little further. The red cam-
pion flowers by day, and is fertilised by butter-
flies; therefore it is pink, because pink is an
attractive colour in the daylight ; and it is scent-
less, because its colour alone is quite enough to
attract sufficient insects. But it has a close
relation, the white campion, which flowers by
night only, and lays itself out to be visited by
moths in the twilight. Why is this kind white ?
Because no other colour is seen so well in the
dusk ; a red or pink blossom would then be
almost invisible. Moreover, the white cam-
pion is heavily scented, as are almost all other
night-flowering blossoms, like the jasmine, the
tuberose, the stephanotis, and the gardenia.
3

34 THE STOEY OF THE PLANTS.

Observe the numerous points of similarity : all
these are white ; all are sweet-scented ; all are
moth-fertilised. Why is this? Because the
scent helps to show the moth the way to the
flower when there is hardly enough light for him
to see the white petals. Thus every plant is
adapted to its particular station in life, and its
adaptation is the result of the Struggle for
Existence, and Survival of the Fittest.

Briefly put, whatever variation helps the plant
in any way in any particular place, or at any
particular time, is likely to give it an extra
chance in the fight, and is therefore reproduced
in all its descendants.

So that is how plants began to vary.

To sum up. Plants grow, because they keep
on continually taking in carbon and hydrogen
from the world outside them, under the in-
fluence of sunlight. They multiply, because
when they have attained a certain size they
split up to form two or more individuals. They
struggle for life with one another, because more
are produced than can find means of livelihood.
And the struggle results in Survival of the Fittest.

Or, looked at in another light. Plants
multiply, and as they multiply by division the
new ones on the whole resemble their parents ;

Jthis is the law of PifftfflJT-fy But they do not
exactly resemble them in every detail ; this is
the law of Variation. And as some variations
are to the good7and some to the bad, the better
survive and produce young like themselves
oftener than the worse do ; this is the law of
Natural Selection.

CHAPTEK IV.

HOW PLANTS EAT.

WE saw in the last chapter how and why plants
came to differ from one another, but not why
they came to be divided into well-marked groups
or kinds, such as primroses, daisies, cabbages,
oaks, and willows. In the world around us we
observe a great many different sorts of plants,
not all mixed up together, so to speak, nor
merging into one another by endless gradations,
but often clearly marked off by definite lines into
groups or families. Thus a primrose is quite
distinct from a crocus, and an oak from a maple.
For the present, however, I do not propose to go
into the question of how they came to be divided
into such natural groups. I will begin by telling
you briefly how plants eat and drink, marry and
rear families, and then will return later on to
this problem of the Origin of Species, as it is
called, and the pedigrees and relationships of the
leading plant families.

First of all, then, we will inquire, How Plants
Eat. And in this inquiry I will neglect for the
most part the very early and simple plants we
have already spoken about, and will chiefly
deal with those more advanced and complicated
types, the flowering plants, with which every-
body is familiar.

Plants Eat with their Leaves. The leaves are,
in fact, their mouths and stomachs.

36 THE STOHY OF THE

Now, what is a leaf ? It is usually a rather
thin, flat body, often with two parts, a stalk and
a blade, as in the oak or the beech ; though
sometimes the stalk is suppressed, as in grass
and the teasel. Almost always, however, the
leaf is green : it is broad and flat, with a large
expanded surface, and this surface is spread out
horizontally, so as to catch as much as possible
of the sunlight that falls upon it. Its business is
to swallow carbonic acid from the air, and digest
and assimilate it under the influence of sunlight.
And as different situations require different
treatment, various plants have leaves of very
different shapes, each adapted to the habits and
manners of the particular kind that produces
them. The difference has been brought about
by Natural Selection.

What does the leaf eat ? Carbonic acid.
There is a small quantity of this gas always
floating about dispersed in the air, and plants
fight with one another to get as much as possible
of it. Most people imagine plants grow out of
the soil. This is quite a mistake. The portion
of its solid material which a plant gets out of
the soil (though absolutely necessary to it) is
hardly worth taking into consideration, nume-
rically speaking ; by far the larger part of its
substance comes directly out of the air as
carbon, or out of the water as hydrogen and
oxygen. You can easily see that this is so if
you dry a small bush thoroughly, leaves and
all, and then burn it. What becomes of it
in such circumstances ? You will find that
the greater part of it disappears, or goes off

HOW PLANTS EAT. 37

into the atmosphere ; the carbon, uniting with
oxygen, goes off in the form of carbonic acid,
while the hydrogen, uniting with oxygen, goes off
in the form of steam or vapour of water. What
is there left ? A very small quantity of solid
matter, which we know as ash. Well, that ash,
which returns to the soil in the solid condition,
is practically almost the only part the plant got
from the soil ; the rest returns as gas and vapour
to the air and water, from which the plant took
them. You must never forget this most im-
portant fact, that plants grow mainly from air
and water, and hardly at all from the soil beneath
them. Unless you keep it firmly in mind,
you will not understand a great deal that
follows.

Why, then, do gardeners and farmers think so
much about the soil and so little about the air,
which is the chief source of all living material ?
We shall answer that question in the next
chapter, when we come to consider What Plants
Drink, and what food they take up dissolved in
their water.

Carbonic acid, though itself a gas, is the chief
source of the solid material of plants. How do
plants eat it ? By means of the green leaves,
which suck in floating particles of the gaseous
food. Their eating is thus more like breathing
than ours : nevertheless, it is true feeding : it is
their way of taking in fresh material for building
up their bodies. If you examine a thin slice
from a leaf under the microscope, you will find
that its upper surface consists of a layer of cells

38 THE STORY OF THE PLANTS.

with transparent walls, and no colouring matter
(Fig. 1). These cells are full of water ; they
form a sort of water-cushion on the top of the
leaf, which drinks in carbonic acid (or, to be
quite correct, its floating form, carbon dioxide)
from the air about it. Immediately below this
cushion of water-cells you come again upon a

"oocooqqqqaqq

FIG. 1. — A THIN SLICE FBOM A LEAF, SEEN UNDER

THE MICROSCOPE. On top are water-cells, which
suck in carbonic acid. Beneath these are
green cells, which assimilate it under the
influence of sunlight. The spongy lower
portion is used for evaporation.

firm layer of closely-packed green cells, filled with
living green- stuff, which take the carbonic acid
in turn from the water-cells, and manufacture
it forthwith into sugars, starches, and other
materials of living bodies. The lowest spongy
part evaporates unnecessary water, and so helps
to keep U£_cirgulation,

HOW PLANTS EAT. 39

The plant has often many hundred leaves, that
is to say, many hundred mouths and stomachs.
Why do plants need so many when we have but
one? Because they cannot move, and because
their food is a gas, diffused in minute quantities
through all the atmosphere. They have to suck
it in wherever they can find it. And what do
they do with the carbonic acid when once they
have got it? Well, to answer that question,
I must tell you a little more about what the
ordinary green leaf is made of, and especially
about the green-stuff in its central cells.

Now what is this green-stuff? It is the true*
life-material of the plant, the origin of all the
ImngTna/Eter in nature. You and I, as well as the
plants themselves, are entirely built up of living ?'
jelly which this green-stuff has manufactured
under the influence of sunlight. And the mate-
rial that does this is such an important thing in
the history of life that I will venture to trouble
you with its scientific name, CHLOROPHYLL.
When sunlight falls upon the Chlorophyll ^>r
green-stuff in a living leaf, in the presence of
carbonic acid and water, the chlorophyll at once
proceeds to set free the oxygen (which it turns
loose upon trie air again), and to build up the
carbon and hydrogen (with a little oxygen) into
a material called starch. This starch, as you
know, possesses jwergy — that is to say, latent
light and dormant' 1TB9F" and rribvement, because
we can eat it and burn it within our bodies. .
Other materials, hydro-carbons and carbo-hy-
drates, as they are called, are made in the same
way. The main use of leaves, then, is to eat

40 THE STORY OF THE PLANTS.

carbon and drink water, and, under the influ-
ence of sunlight, to take in energy and build
them up into living material.1*"

The starch and sugar and other things thus
made are afterwards dissolved in the sap, and
used by the plant to manufacture new cells and
leaves, or to combine with other important mate-
rials of which I shall speak hereafter, in order
to form fresh living chlorophyll.

Now we know what leaves are for ; and you
can easily see, therefore, that they are by far the
most essential and important part of the entire
plant. Most plants, in fact, consist of little else
than colonies of leaves, together with the flowers
which are their reproductive organs. We have
next to see Wliat Shapes various Leaves assume,
and what are their reasons for doing so.

The leaf has, as a rule, to be broad and flat,
in order to catch as much carbon as possible ; it
has also usually to be expanded horizontally to
the sunlight, so as to catch and fix it. For this
reason, most leaves that can raise themselves
freely to the sun and air are flat and horizontal.
But in very crowded and overgrown spots, like
thickets and hedgerows, the leaves have to fight
hard with one another for air and sunlight ; and
in such places particular kinds of plants have
been developed, with leaves of special forms
adapted to the situation. The fittest have
survived, and have assumed such shapes as
natural selection dictated.

Where the plants are large and grow freely
upward, with plenty of room, the leaves are

HOW PLANTS EAT. 41

usually broad and expanded, as in the tobacco-
plant and the sunflower. Where the plants
grow thick and close in meadows, the leaves
are mostly long and narrow, like grasses. In
overgrown clumps and hedgerows they are
generally much subdivided into numerous little
leaflets, as is the case with most ferns, and also
with herb-Eobert, chervil, milfoil, and vetches.
In these last cases, the plant wants to get as
much of the floating carbonic acid, and of the
sunlight, as it can ; and therefore it makes its
leaves into a sort of divided network, so as to
entrap the smallest passing atom of carbon, and
to intercept such stray rays of broken sunlight
as have not been caught by the taller plants
above it. In almost all cases, too, the leaves
on the same plant are so arranged round the
stem and on the branches as to interfere with
one another as little as possible ; they are placed
in an order which allows the sunshine to reach
every leaf, and which secures a free passage of
air between them.

An interesting example of the way some of
these principles work out in practice is afforded
us by a common little English pond-weed, the
water-crowfoot. This curious plant grows in
streams and lakes, and has two quite different
types of leaves, one floating, and one submerged.
The floating leaves have plenty of room to develop
themselves freely on the surface of the pond;
they loll on the top, well supported by the mass
of water beneath ; and, as there is little compe-
tition, they can get an almost unlimited supply
of carbonic acid and sunshine, Therefore, they

42 THE STORY OF THE PLANTS.

are large and roundish, like a very full ivy-leaf.
But the submerged leaves wave up and down in
the water below, and have to catch what little
dissolved carbonic acid they can find in the pond
around them. Therefore they are dissected into
endless hair-like ends, which move freely about
in the moving water in search of food- stuff. The
two types may be aptly compared to lungs and
gills, only in the one case it is carbonic acid and
in the other case oxygen, that the highly-dissected
organs are seeking in the water.

As a general rule, when a plant can spread its
leaves freely about through unoccupied air, with
plenty of sunlight, it makes them circular, or
nearly so, and supports them by means of a stem
in the middle. This is particularly the case with
floating river-plants, such as the water-lily and
the water-gentian. But even terrestrial plants,
when they can raise their foliage easily into
unoccupied space, free from competition, have
similar round leaves, supported by a central
leaf-stalk, as is the case with the familiar garden
annual popularly (though erroneously) known as
nasturtium. (Its real name is Tropaeplum.) On
the other hand, when a plant has^o struggle
hard for carbon and sunlight in overgrown
thickets, or under the water, it has usually very
much subdivided leaves, minutely cut, again and
again, into endless segments. Submerged leaves
invariably display this tendency.

But that does not conclude the whole set of
circumstances which govern the forms and size
of leaves, Not only do they want to eat, and to

HOW PLANTS EAT. 43

have access to sunshine ; they must also be sup-
ported or held in place so as to catch it. For
this purpose they have need of what we may
venture to describe as foliar architecture. This
architecture takes the form of ribs or beams of
harder material, which ramify through and raise
aloft the softer and actively living cell-stuff.
They are, as it were, the skeleton or framework
of the leaf ; and in what are commonly known
as " skeleton leaves " the living cell-stuff between
has been rotted away, so as to display this harder
underlying skeleton or framework. It is com-
posed of specially hardened, lengthened, and
strengthened cells, and is intended, not only to
do certain living work in the plant (as we shall
see hereafter), but also to form a supporting
scaffolding. The material of which ribs or
beams are composed is called " vascular tissue "
— a not very well chosen name, as this material
has only a slight analogy to what is called the
vascular system (or network of blood-vessels) in
an animal body. It is much more like the bony
skeleton. Similarly, the ribs themselves are
usually called veins — a very bad name again,
as they are much more like the bones of a wing
or hand ; they are mainly there for support, as
a bony or wooden framework, though they also
act for the conveyance of sap or water.

And now we are in a position to begin to
understand the various shapes of leaves as we
see them in nature. They depend most of all
upon certain inherited types of ribs or so-called
veins, and these types are usually pretty constant

44 THE STOEY OF THE PLANTS.

in great groups of plants closely related by
descent to one another. The immense difference
in their external shape (which often varies enor-
mously even on the same stem) is mainly due to
the relative extent to which the framework is
filled out or not with living cell-stuff, or, as it is
technically called, cellular tissue.

There are two chief ways of arranging the ribs
or veins in a leaf, which may be distinguished as
the finger-like and the feather-like methods (in

FIG. 2. — FINGER-VEINED LEAVES. The veins are the same
in the three leaves, but they differ in the amount to
which they are filled in.

technical language, palmate and pinnate}. In
the finger -like plan the ribs all diverge from a
common point, more or less radially. In the
feather -like plan the ribs are arranged in oppo-
site pairs along the sides of a common line or
midrib. Yet even these two distinct plans
merge into one another by imperceptible de-
grees, as you can see if you look at the accom-
panying diagram.

Now let us take first the finger-veined type
(Fig. 2). Here, if all the interstices of the ribs
are fully filled out with cellular tissue, we get a

HOW PLANTS EAf.

45

roundish leaf like that of the so-called nastur-
tium. But if the ribs project a little at the edge
— in other words, if the cellular tissue does not
quite fill out the whole space between them —
we get a slightly indented leaf, like that of the
scarlet geranium or the common mallow. If the
unfilled spaces between the ends of the ribs are
much greater, then the ribs project into marked
points or lobes, and we get a leaf like that of ivy.

FIG. 3. — FEATHER-VEINED LEAVES. The four leaves have
similar veins, but are differently filled in.

Carry the starving of the cellular tissue a little
further still, and we have a deeply-indented leaf
like that of the castor-oil plant. Finally, let the
spaces unfilled go right down to the common
centre from which the ribs radiate, and we get a
divided or compound leaf, like that of the horse-
chestnut, with three, five, or seven separate
leaflets. (See Fig. 5, No. 1.)

Similarly with the feather -veined type (Fig. 3) ;
the spaces between the ribs may be more or less
filled with cellular tissue in any degree you

46 THE STORY OF THE PLANTS.

choose to mention. When they are Very fully
filled out, you get a leaf like that of bladder

senna. A little more pointed, and less filled
out at the tips, it becomes like argel. When

Ro\v

EAT.

the edge is not quite filled out, but irregularly
indented, we get forms like the oak leaf.
Finally, when the indentations go to the very
bottom of each vein, so as to reach the midrib,
we get a compound leaf like that of the vetch,
with a number of opposite and distinct leaflets.

The reason why some leaves are thus more
filled out than others is simply this : it depends
upon the freedom of their access to air and
sunlight. I do not mean
the freedom of access of
the particular leaf or the
particular plant, but the
average ancestral free-
dom of access in the kind
they belong to. Each
kind has adapted itself,

as a rule, to certain situa- FIQ. 6.— i. Parallel veins, as
tions for which it has seen in one great group of
special advantages, and
it has learnt by the teach-
ing of natural selection
to produce such leaves
as best fit its chosen site
and habits. Where access to carbon and sunlight
is easy, plants usually produce very full round
leaves, with all the interstices between the ribs
filled amply in with cellular tissue ; but where
access is difficult, they usually produce rather
starved and unfilled leaves, which consist, as it
were, of scarcely covered skeletons (Figs. 4 and
5). This last condition is particularly observable
in submerged leaves, and in those which grow
in very crowded situations.

plants, the lilies. II.
Branching veins, as seen
in another great group,
the trees and herbs of the
usual type.

48 THE STOKY OF THE PLANTS.

The two types of rib-arrangement to which I
have already called attention exist for the most
part in one of the two great groups of flowering
plants about which I shall have more to say to
you hereafter. There is yet a third type, how-
ever, which occurs in the other great group (that
of the grasses and lilies), and it is known as the
parallel (Fig. 6). In this type, the ribs do not
form a radiating network at all, but run straight,
or nearly so, through the leaves. Examples of
it occur in almost all grasses, and in tulips,
daffodils, lily of the valley, and narcissus. Leaves
of this sort have seldom any leaf-stalk ; they
usually rise straight out of the ground, more or
less erect, and their architectural plan is gene-
rally quite simple. They are seldom toothed,
and hardly ever divided into deeply- cut segments
or separate leaflets.

A few more peculiarities in the shapes of
leaves must still be noted, and a few words
used in describing them must be explained very
briefly. When the leaf consists all of one piece,
no matter how much cut up and indented at the
edge, it is said to be "simple"; but if it is
divided into distinct leaflets (as in Fig. 5), it is
called "compound." If the edge is unindented
all round (as in Fig. 6), we say the leaf is " en-
tire " ; if the ribs form small projections at the
edge (as in Fig. 4), we call it " toothed " ; if the
divisions are deeper, we say it is "lobed" ; and
when the lobes are very deeply cut indeed, we
call it "dissected." Thus, in order to describe
accurately the shape of a leaf, we need only say
which way it is veined or ribbed — whether finger-

ttOW PLANTS EAtf. 49

wise, feather- wise, or with parallel veins — and
how much, if at all, it is cut or divided.

Endless varieties, however, occur, in accord-
ance with the peculiar place the plant and its
kind have been developed to inhabit. In
climbing plants, for example, the leaves are
usually opposite, so as to clutch more readily,
and they are almost always more or less heart-
shaped at the base, as in convolvulus and black
briony. The leaves of forest trees, on the other
hand, tend to be what is known as ovate in
shape, like the beech and the poplar ; while
those of the lime are a little one-sided, in order
that each leaf may not overshadow and rob its
neighbour. This one-sidedness is even more
markedly seen in the hot-house begonias. Some
leaves, again, are minutely subdivided into
leaflets twice or three times over ; such leaves
are said to be doubly or trebly compound. But
if you study plants as they grow (and this book
is written in the hope that it may induce you to
do so), you will generally be able to see that the
shapes and peculiarities of leaves have some
obvious reference to their place in the world,
and their habits and manners.

I have spoken so far mainly of quite central
and typical leaves, which are arranged with a
single view to the need for feeding. But plants
are exposed to many dangers in life besides the
danger of starvation, and they guard in various
ways against all these dangers. One very
obvious one is the danger of being devoured
by grazing animals, and, to protect themselves
4

50 THE STOKY OF THE PLANTS.

against it, many plants produce leaves which are
prickly, or stinging, or otherwise unpleasant.
The common holly is a familiar instance. In
this case the ribs are prolonged into stiff and
prickly points, which wound the tender noses
of donkeys or cattle. We can easily see how
such a protection could be acquired by the
holly-bush through the action of Variation and
Natural Selection. For holly grows chiefly in
rough and wild spots, where all the green leaves
are liable to be eaten by herbivorous animals.
If, therefore, any plant showed the slightest
tendency towards prickliness or thorniness, it
would be more likely to survive than its un-
protected neighbours. And indeed, as a matter
of fact, you will soon see that almost all the
bushes and shrubs which frequent commons,
such as gorse, butcher's broom, hawthorn,
blackthorn, and heather, are more or less spiny,
though in most of these cases it is the branches,
not the leaves, that form the defensive element.
Holly, however, wastes no unnecessary material
on defensive spikes ; for though the lower leaves,
within reach of the cattle and donkeys, are very
prickly indeed, you will find, if you look, that
jthe upper ones, above six or eight feet from the
/ground, are smooth-edged and harmless. These
upper leaves stand in no practical danger of
being eaten, and the holly therefore takes care
to throw away no valuable material in protecting
them from a wholly imaginary assailant.

Often, too, in these prickly plants we can
trace some memorial of their earlier history.
Gorse, for example, is a peaflower^*by family, a

HOW PLANTS EAT. 51

member of the great group of "papilionaceous,"
or butterfly-blossomed, plants, which includes
the pea, the bean, the laburnum, the clover, and
many other familiar trees, shrubs, and climbers.
It is descended more immediately from a special
set of trefoil-leaved peaflowers, like the clovers
and lucernes ; but, owing to its chosen home on
open uplands, almost all its upper leaves have
been transformed for purposes of defence into
sharp, spine-like prickles. Indeed, the leaves
and branches are both prickly together, so that
it is difficult at first sight to discriminate between
them. But if you take a seedling gorse plant
you will find that in its early stages it still pro-
duces trefoil leaves, like its clover-like ancestors;
and these leaves are almost exactly similar to
those of the common genista so much cultivated
in hot-houses. As the plant grows, however,
the trefoil leaves gradually give place to long
and narrow blades, and these in turn to prickly
spines, like the adult gorse-leaves. Hence we
'are justified in believing that the ancestors of
gorse were once genistas, bearing trefoil leaves ;
and that later, through the action of natural
selection, the prickliest among them survived,
till they acquired their existing spiny foliage.
In every case, indeed, young plants tend to re- j
semble their earlier ancestors, and only as they I
grow up acquire their later and more special
characteristics.

And now I must add one word about the
origin of leaves in general. Very simple plants,
we saw, consist of a single cell, which is not

52 THE STORY OF THE PLANTS.

merely a leaf, but also at the s;ime time a flower,
a seed, a root, a branch,- and everything. In
other words, in very simple plantslT single cell
does rather badly, everything which in more
advancecTand developed "plan is is better done by
distinct and highly-adapted organs. The whole
evolution of plants consists, in fact, injbhe tellmg
off of particular parts to do betterwhat $ie
primitive cell did for itself but badly. Above
the very simple plants which consist of a single
cell come other plants, which consist of many
cells glace^^n^^n^ri^togejher^ as in the case
of the HhaTr like" water- weeds ; and above these
again come other and rather higher plants, in
which the cellular tissue assumes the form of a
flat and leaf-like blade, as in many broad sea-
weeds. None of these, however, are called
leaves in the strict sense, because they consist
of cells alone, without any ribs or supporting
framework. The higher types, however, like
ferns and flowering plants, have such ribs or
frameworks, made of that stiffer and tougher
material called vascular tissue. This is the
most general distinction that exists between
plants ; the higher ones are knowrn as Vascular
Plants, including all those with true leaves, such
as the common trees, herbs, and shrubs, and the
ferns and grasses — in fact, almost all the things
ever thought of as plants by most ordinary
observers ; the lower ones are known as Cellular
Plants, and include the kinds without true
. leaves or vascular tissue, such as the seaweeds,
fungi, and microscopic plants only recognised
as a rule by botanical students.

HOW PLANTS EAT. 53

The higher plants, then, have for the most
part special organs, the leaves, told off to do
work for them as mouths and stomachs; while
other organs are told off to do other special work
of their own — as the roots to drink, the flowers
to reproduce, the fruit and seeds to carry on the
life of the species to other generations, and so
forth, down to the hairs that protect the surface,
or the glands that produce honey to attract the
fertilising insects. To the end, however, all
parts of the plant retain the power to eat car-
bonic acid, if necessary ; so that many higher
plants have no true leaves, but use portions of
\ the stem or branches for the purpose of feeding.
Any part of the plant which contains the active
living green- stuff? or chlorophyll, can perform
the f unctiomT'bi a leaf. In very dry or desert
places, leaves would be useless, because their
flat and exposed blades would allow the water
within to evaporate, too readily. Hence most
desert plants, like the cactuses, and many kinds
of acacias and euphorbias, have no true leaves
at all ; in their place they have thick and fleshy
stgms, often very leaf -like in shape, and curiously
jointed. These stems are covered with a thick,
transparent skin or epidermis, to resist evapora-
tion, and are protected by numerous stinging
hairs or spines, which serve to keep off the
attacks of animals. Stems of this type are used
as reservoirs of water, which the plant sucks up
during the infrequent rains ; and as they con-
tain chlorophyll, like leaves, they serve in just
the same way as swallpwers and digesters o^
carbonic acid.

54: THE STOEY OF THE PLANTS.

Many other plants which live in dry or sandy
places, like our common English stone-crops, do
not go quite as far as the cactuses, but have
thick and fleshy leaves on thick and fleshy stems,
to prevent evaporation. As a general rule, in-
deed, the drier the situation a plant habitually
frequents the fleshier are its leaves, and the
greater its tendency to make the stem share in
the work of feeding, or even to get rid of foliage
altogether. In Australia, however, most of the
forest trees, like the eucalyptuses, have got over
the same difficulty in a different way ; they arrange
their leaves on the stem so as to stand vertically
to the sun's rays, instead of horizontally, which
saves evaporation, and makes the woodland
almost entirely shadeless. Many of these Aus-
tralian trees, however, have no true leaves, but
use in their place flattened green branches.

Some plants are annuals, and some peren-
nials. When annuals have flowered and set
their seed they wither and die. But perennials
go on for several seasons. Most of them, how-
ever, in cold climates at least, shed their leaves
on the approach of winter. But they do not

• lose all the valuable material stored up in them.

f Trees and shrubs withdraw the starchy matter
into a special layer of the bark, where it remains

; safe from the winter frosts, and is used up again
in spring in forming the new foliage. This new
foliage is usually provided for in the preceding
season. If you look at a tree in late autumn,
after the leaves have fallen, you will see that it
is covered by little knobs which we know as

HOW PLANTS EAT. 55

buds. These buds are the foliage of the coming
season. The outer part consists of several
layers of dry brown scales, which serve as an
overcoat to protect the tender young leaves
within from the chilly weather. But the inner
layers consist of the delicate young leaves them-
selves, which are destined to sprout and grow
as soon as spring comes round again. Even
the scales, indeed, are very small leaves, with
no living material in them ; they are sacrificed
ByTKe" plant, as it were, in order to keep the
truer leaves within snug and warm for the
winter. Nor do the autumn leaves fall off by
pure accident ; some time before they drop the
tree arranges for their fall by making a special
row of empty cells where the leaf -stalk joins the
stem or branch ; and when frost comes on, the
leaf separates quietly and naturally at that point,
as soon as the valuable starchy and living
material has been withdrawn and stored in the
permanent layers of the bark for future service.

Smaller and more succulent plants do not
thus withdraw their living material into the
bark in autumn ; but they attain much the same
end in different manners. Thus lilies and
onions store the surplus material they lay by
during the summer at the base of their long
leaves, and the swollen bases thus formed pro-
duce what we call a bulb, which carries on the
life of the plant to the next season. Other
plants, like the common English orchids, store
material in underground tubers; while others,
again, and by far the greater number, so store
it in the root, which is sometimes thick and

56 THE STORY OP THE PLANTS.

swollen, or in an underground stem or root-
stock. In most cases, however, perennial
plants take care to keep over their live material
from one season to the other by some such
means of permanent storage. They are, so to
speak, capitalists. Natural selection has of
course preserved those plants which thus laid
by for the future, and has killed out the mere
spendthrifts which were' satisfied to live for the
fleeting moment only. The soil of our meadows
in winter is full of tubers, bulbs, and root-
stocks ; while our shrubs and trees carry over
their capital from season to season in their
living bark, secure from injury. In one way or
another all our perennial plants manage to tide
their living green-stuff, or at least its raw
material, by hook or by crook, over the dangers
of winter.

I have given so much space to the subject of
leaves because, as you must see, the leaf is
really the most important and essential part of
the entire plant — the part for whose sake all the
rest exists, and in which the main work of
making living material out of lifeless carbonic
acid and water is concentrated.

Let us sum up briefly the main facts we have
learned in this long chapter.

Plants eat carbonic acid under the influence
of sunlight. They store up the solar energy
thus derived in starches and green-stuff in their
own bodies. Very simple plants, which float
freely in water, eat and drink with all portions
of their surface, But higher plants eat with

HOW PLANTS DRINK. 57

special organs. These organs are known as
leaves, and are the parts where the chief busi-
ness of the plant is transacted.

A leaf is an expanded mass of cells, containing
living green-stuff, supported on a tougher frame-
work, or rib-like skeleton. Leaves take in car-
bonic acid by means of tiny absorbing mouths,
which exist on their upper surface ; and they
turn loose most of the oxygen, by the aid of
sunlight, building up the carbon into starch,
with hydrogen from the water supplied by the
roots to them. Leaves are of different shapes,
according to the work they have to do for the
plant in different situations. Where carbon and
sunlight abound they are round, or nearly so ;
where carbon and sunlight are scanty, or much
competed for, they are more or less divided into
minute sections.

CHAPTER V.

HOW PLANTS DRINK.

WE have now learnt that plants really eat for
the most part with their leaves. They grow, on
the whole, out of the air, not, as most people
seem to fancy, out of the soil. Yet you must
have noticed that farmers and gardeners think a
great deal about the ground in which they plant
things, and very little, apparently, about the air
around them. What is the reason for this
curious neglect of the real food of plants, and
this curious importance attached to the mould,
or soil they root in ?

58 THE STORY OF THE PLANTS.

That is the question we shall have to consider
in the present chapter ; and I shall answer it in
part at once by saying beforehand that, though
plants do grow for the most part out of the car-
bonic acid supplied by the air to the leaves, they
also require certain things from the soil, less
important in bulk, but extremely necessary for
their growth and development. What they eat
through their leaves is far the greatest in
amount ; but what they drink through their
roots is nevertheless indispensable for the pro-
duction of that living green-stuff, chlorophyll,
which, as we saw, is the original manufacturer
1 and prime maker of all the material of life, either
vegetable or animal.

Plants have roots. These roots perform for
them two or three separate functions. They
fix the plant firmly in the soil ; they suck up
the water which circulates in the sap ; and they
also gather in solution certain other materials
which are necessary parts of the plant's living
matter.

The first and most obvious function of the
root is to fix the plant firmly in the soil it grows
in. Very early floating plants, of course, have
no roots at all ; they take in water and the
dissolved materials it contains, with every part
of their surface equally, just as they take in
carbonic acid with every part of their surface
equally. They are all root, all leaf, all flower,
all fruit. But higher plants tend to produce
different organs, which have become specially

HOW PLANTS DEINK. 59

adapted by natural selection for special purposes.
If you sow a pea or bean you will find at once
that the young seedling begins from the very
first to distinguish carefully between two main
parts of its body. In one direction, it pushes
downward, forming a tiny root, which insinuates
itself with care among the stones and soil ; in
the other direction, it pushes upward, forming a
baby stem, which gradually clothes itself with
leaves and flowers.

The tip of the root is the part of the plant
which exercises the greatest discrimination and
ingenuity, so much so that Darwin likened it to
the brain of animals. For it goes feeling its
way underground, touching here, recoiling there,
insinuating little fingers among pebbles and
crannies, and trying its best by endless offshoots
to fix the plant with perfect security. Large
trees, in particular, need very firm roots, to moor
them in their places, and withstand the force of
the winds to which they are often subject. After
every great storm, as we know, big oaks and
pines may be seen uprooted by the power of
this invisible but very dangerous enemy.

The root, however, does not serve merely to
anchor the plant to one spot, and secure it a
place in which to grow and feed ; it also drinks
water. The hairs and tips of the root absorb
moisture from the soil ; and this water circulates
freely as sap through the entire plant, dissolving
and carrying with it the starches and other
materials which each part requires for its growth
find nourishment (Figs. 7, 8, and 9), Without

60

THE STORY OF THE PLANTS.

water, as we all know, plants will wither and
die ; and the roots push downward and outward
in every direction in search of this necessary of
life for the leaves and flowers.

In addition to
these two functions
of fixing the plant
and drinking water,
however, roots per-
form a third and
almost more impor-
tant one in absorbing
the other needful
materials of plant life
from the soil about
them. They drink,
not water alone, but
other things dis-
solved in it.

What are these
other things? Well,
the answer to that
question will fairly
round off our first
rough idea of the
raw materials that
life is made up from.

Fig. 7. ROOT OF THE CARROT. AT,

Fig. 8. ROOT OF THE FRooBiT, We saw already that
FLOATING IN WATER. Fig. 9. plants eat carbon and
ROOT OF THE RADISH. The hydrogen from the
small hair-like ends drink in air ancj water . out of
water and dissolved food-salts. tj>e^ they manufac-

ture a large number of compounds, such as

FIG. 7.

FIG. 8.

FIG. 9.

HOW PLANTS DBINK.

61

'starches, oils, sugars, and so forth, all of which
contain a littlc^oxygerjL, but far less than the
amount containcHTnthe carbonic acid and water
from which they are manufactured. These use-
:ul materials, however, though possessing energy,
ihat is to say the power^f-prddufijag light and\ /
jeat^ and motion, are not exactly livc^ stuffs ; fa
n orfleyKPPSRtairi^c^^

1 Jsrtuff of all tSBies, animal or vegetable?) proto-
plasm, we must have a four lit. dement, \rntr on en ;\
ind that element is supplied by tTiefTrlB r m*
;olution.

^o now you see the full importance of the\

" " K fc e °^s an<^ s*arcnes manu- /

lactured in 'the '"^g|ivea\that mysterious body, r
nitrogen, which isnecessary' Th"*^r3er to turn \
these'tmngsmtQ protoplasm and chlorophyll. T>

A i'ew offier" things besides nitrogen are also
needed by the plant from the soil ; the most
important of these are apljlnrr and pfcosjgfcprns.
The plant, however, does not take in these
substances in their free or simple form, as
nitrogen, sulphur, and phosphorus, but in com-
position, as soluble , nitrates, sulphates, and
phosphates.

Now, I am not going to trouble you with a.
long chemical account of how the plant combines,
these various materials — a thing about which
even chemists and botanists themselves know as
yet but very little. It will be enough to say
here that the \planti builds them up at last into f
.ex body, called protoplasm ; f

an extremely co?

62 THE STO&Y OF THE PLANTS.

livi

tnmg whihout

\

and this Qrotoplasnjjs thevultimate living matter,
the " physicaT basis of lii'e ; the

which there could be_ no plants
possible.

What is protoplasm — this mysterious stuff,
whferl builds up the bodies of plants and animals ?
^It is a curious transparent jelly-like substance,
full of tiny microscopic grains, and composed of

Sometimes it is almost watery, sometimes half-
horny, but as a rule it is waxy or soft in texture.
It is very plastic. Its peculiar characteristic is
that it is restlessly alive, so to speak ; seen under
a microscope, it moves about uneasily, with a
strange streaming motion, as if in search of
something it wanted. It is, in point of fact, the
building-material of life ; and out of it the living
parts of every creature that lives, whetner animal
or vegetable, are framed and compounded.

/ But it is plants alone that know how to make
protoplasm. Animals can only take it ready-

JL> made, -from planta. and burn it up again 6y
feumonwitri oxygen in their own bodies. The
jplant manufactures it. The animal destroys it.
Chlorophyll or the active green-stuff of leaves is
a special modification or ^ariety of protoplasm ;
and chlorophyll \alon o/ possesses the power to
manufacture

.

material, under the influence of sunlight, from
the .dead and inert bodies around it. The
materials which it thus produces are afterwards

worked up by the plant, together with the
nitrogen, sulphur, and phosphorus supplied by
the roots, into fresh protoplasm and fresh

HOW PLANTS DBINK. 63

chlorophyll. These the animal may afterwards
eat, either in the form of leaves like grass, or in
the form of seeds or fruits, like corn, rice, or
bananas.

The tiniest primitive one-celled plant con-
tains protoplasm and chlorophyll (though a
few degenerate plants, like fungi, have none
of the living green-stuff, and can make nonejL
living material for themselves, but depenHTTike
animals, upon the industry of others). Every
living cell of every plant contains protoplasm ; a
cell without anyls dead and lifeless. Protoplasm,
in short, is the only living material we know; and
its life constitutes fne
compounded of it.

Well, now you are in a position to see why
the farmer and the gardener attach so much
importance to the soil, and so little, apparently,
to the air and the sunlight. The reason is that
the air is everywhere ; you get it for nothing ;
but the soil costs money, and, when cultivated,
it requires to be supplied from time to time with
fresh stores of the particular materials the plants
take from it.

Let me give two simple parallel cases. A fire
is made by the combination of two sorts of fuel —
coal and oxygen. One is just as necessary for
fire-making as the other. But we buy coal dear,
and we neglect to take oxygen into consideration
accordingly. The reason is that oxygen exists
in abundance everywhere ; so we don't have to
buy it. If we paid a pound a ton for it, as we
do with coal, we should very soon remember

t>4 THIS STOliY OF THE fLANTtJ.

how necessary a part it is of every tire. Even
at present we are obliged to provide for its free
admission by the bars of the grate, and by
checking or regulating its ingress we can
slacken or quicken the burning of the fire.

Or, to take another analogy, oxygen is just as
necessary to human beings and other animals as
food and drink are. But, as a rule, we get
•oxygen everywhere in such great abundance
that we never think of taking it into practical
consideration. Still, in the Black Hole of Cal-
cutta, the unhappy prisoners thoroughly realised
the full value of oxygen, and would gladly have
paid its weight in gold for the life-giving
element.

Now, carbonic acid, on which plants mainly
live, is not so common or so abundant a gas
as oxygen ; but still, it exists in considerable
quantities in the air everywhere. So most plants
are able to get almost as much as they need of
it. Nevertheless, submerged plants, and plants
that grow in very crowded places, seem to com-
pete hard with one another for this aerial food ;
and in certain cases they appear to live, as it
were, in a very Black Hole of Calcutta, so far as
regards the supply of this necessary material.
In farms and gardens, however, the farmer takes
care that every plant shall have plenty of room
and space — in other words, free access to sun-
light and carbonic acid. He " gives the plants
air," as he says, not knowing that he is really
supplying them with their aerial food- stuff. He
does this by keeping down weeds — by ploughing,
by digging, by hoeing, or tilling. Indeed, what

HOW PLANTS DKINK. 65

do we really mean by cultivation ? Nothing
more than destroying the native vegetation of a
place, in order to make room for other plants
that we desire to multiply. We plough out the
grasses and herbs that occupy the soil ; we sow
or plant thinly seeds or cuttings of corn or vines
or potatoes that \ve desire to propagate. We
give these new plants plenty of space and air — -
in other words, free access to sunlight and car-
bonic acid. And that is the fumHameritar basis
of" cultivation — to keep down certain natural
plants of the place, in order to give free room
to others.

But as the crop-plants require to root them-
selves, the farmer naturally thinks most of the
soil they root in — which he has to buy or rent,
while the carbonic acid comes freely to him,
unperceived, with the breath of heaven. Where
water is scarce, as in irrigated desert lands, the
farmer recognises quite equally the importance
of water. But he never recognises the true
importance of carbonic acid. That is why most
people wrongly imagine that plants grow out of
the soil, not out of the air. Still, when we burn
them, the truth becomes clear. The portion of
the plants derived from air and water goes off
again into the air in the act of burning : so too
does the nitrogen : the remaining portion derived
direct from the soil is only the insignificant resi-
due returned to the soil as ash when we burn the
plant up.

Nevertheless, the farmer often needs to supply
certain raw materials to the soil for the plants
5

66 THE STORY OF THE PLANTS.

he cultivates. These raw materials are called
manures ; they are mostly rich^in. nitrate, pi ^ aa^-
phosghatesj and as they are usually the only
tEings^ directly supplied to plants by human
agency — the carbonic acid and water being
supplied by wind and rain in the ordinary
course of nature — they help to strengthen the
popular misapprehension that plants grow
directly out of the soil. Manures consist chiefly
of compounds of nitrogen, phosphorus, and pot-
ash. These are the things of which the plants
take most from the soil ; and when the crops
are cut down and carried away, it becomes
necessary to restore them. This is generally
done by means of farmyard manure, bones, or
guano. Most manures are really the remains
or droppings of animals ; so that when we lay
them on the soil, we are merely returning to it
in another form what the animal took from it
when he eat the plants up.

All plants, however, do not equally exhaust
the soil of all necessary materials. Some require
one sort of food, and others another. That is
why farmers have recourse to what is called
rotation of crops, so as to follow up one sort of
plant in a field by another, whose needs are
different. Thus corn is alternated with swedes
or turnips. Virgin soil will produce crops for
several seasons together without the need for
manuring ; but when many crops have been cut
from it in succession, the earth gets exhausted
of nitrates and phosphates, and then it becomes
necessary to manure and to rotate the crops in the
ordinary manner.

HOW PLANTS DRINK. 67

But in nature crops are not, as a rule, removed
from the soil ; they die and wither, and return
to it for the most part whatever they took from
it. The dead birds and insects, and the droppings
of animals, are sufficient manure for the native
woodland. Still, even in nature, certain plants
more or less exhaust the soil of certain valuable
materials; and therefore natural selection has
secured a sort of roundabout rotation of crops
in a way of which I shall have more to say here-
after. Many plants, for example, which greatly
exhaust the soil, have winged or feathery seeds ;
and these seeds are carried by the wind to fresh
spots, where they alight and root themselves, in
order to escape the exhausted soil in the neigh-
bourhood of their mothers. Other plants send
out runners, as they are called, on long trailing
branches, which root at a distance, and so start
fresh lives in unexhausted places. Yet others
have tubers, which shift their place from year
to year ; or they push forth underground suckers,
which become new plants at a distance from the
parent. All these are different natural ways for
obtaining what is practically rotation of crops ;
nature invented that plan millions and millions
of years before it was discovered by European
farmers.

Moreover, nature sometimes even goes in for
deliberate manuring. Plants like buttercups
and daisies, that live in ordinary meadow soils,
to be sure, get enough nitrogen and sulphur
and other such constituents from the mould
in which they are rooted. But in very moist

HOW PLANTS DRINK. 69

and boggy soils there is generally ajlack_qf these_
necessary earth-given elements of "protoplasm ;
and natural selection has therefore favoured
any device in the plants which grow in such
places for obtaining them elsewhere. This they
do as a rule by catching insects, killing them,
sucking their juices, and using them up as
manure for manufacturing their own protoplasm
and chlorophyll. Our pretty little English
sundew is one of these cruel and perfidious plants
(Fig. 10). Its leaves are round, and thickly
covered with small red hairs, which are rather
bulbous at the end, and very sticky. The
bulbous expansions, in point of fact, are small
red glands, which exude a viscid digestive
liquid. When a small fly alights on the leaf,
attracted by the smell of the sticky fluid, he is
caught and held by its gummy mass ; the hairs
then at once bend over and clutch him, pouring
out fresh slime at the same time, which very
shortly envelopes and digests him. In the
course of a few hours the leaf has sucked the
poor victim's juices, and used them up in the
manufacture of its own protoplasm.

Many other insect-eating plants exist in the
marshy soils of other countries. One of the
best-known is the Venus' 's fly -trap of tropical
or subtropical North America. In this curious
plant the leaf is divided into two portions, one
of which forms a jointed snare for catching
insects. It is hinged at the middle ; and when
a fly lights upon it, the two edges bend over
upon him, and the bristles on the margin
interlock firmly. As long as the insect struggles

70 THE STORY OF THE PLANTS.

they remain tightly closed ; when he ceases to
move, and is quite dead, they open once more,
and set their trap afresh for another insect. A
great many such carnivorous and insectivorous
plants are now known : and in almost every
case they inhabit places where the marshy
and waterlogged soil is markedly wanting, in
ni^ogencorirpound§. Insect- eating leaves are
trms^aT Uevice to supply the plant with nitrogen
by means of its foliage, in circumstances where
the roots prove powerless for that purpose.

Simpler forms of the same sort of habit may
be seen in many other familiar plants. Thus
our English catchflies and several other of our
common weeds have sticky glandular stems,
which exude a viscid secretion, by whose aid
they catch and digest flies. This is the begin-
ning of the insect-eating habit, more fully
evolved by natural selection in marsh-plants
like sundew, and especially in larger subtropical
types like the Venus's fly-trap. If you collect
English wild-flowers you will soon perceive that
a great many of them have sticky glands on the
summit of the stem, near the flowering heads ;
and this is useful to them, because the flowers
and seeds are particularly in want of nitrogenous
matter for the pollen and ovules and the de-
velopment of the seed. In short, though plants
get their nitrogen mainly by means of the roots,
they often lay in a supplementary store by their
stems and their foliage.

Our common English teasel shows us the
beginnings of another form of insect-eating,
which is highly developed in certain American

HOW PLANTS DBINK. 71

and Asiatic marsh-plants. The leaves of teasel
grow opposite one another, joining the stem at
the base, so as to form between them a sort of
cup or basin, which will hold water. If you
look close into this water you will find that it
is often full of dead midges and ants ; and the
plant puts forth long strings of living protoplasm
into the water, which suck up the decaying
juices of these insects, and use them for the
manufacture of more protoplasm and chlorophyll.
In this case, water is used both as a trap and as
a solvent ; the insects are first drowned in the
moat, and then allowed to decay and digest
themselves in it.

Teasel, however, is but a simple example of
this method of insect-catching. Several American
marsh-dwellers, collectively known as pitcher-
plants, carry the same device a great deal
further. They are far more advanced and
developed water-trap setters. The Canadian
side-saddle plant allures insects into its vase-
shaped leaves, which are filled with sugar and
water. This is just the same plan which we
ourselves employ to catch flies when we trap
them in a glass vessel by means of a sweetened
and sticky liquid. The pitchers are formed by
leaves which join at the edges; they are at-
tractively coloured, so as to allure the flies ; and
they secrete on their walls a honeyed liquid,
which entices the victim to venture further and
further down the fatal path. But the inner sides
of the vase are set with stiff down ward -pointing
hairs, which make it easy to go on, but im-
possible to crawl back again. So the flies creep

72

THE STOKY OP THE PLANTS.

down, eating away at the sticky sweet- stuff as
they go, till they reach the bottom and the
hungry water, when they fall in by hundreds,

FIG. 11. AN AUSTRALIAN PITCHER PLANT WHICH

EATS INSECTS.

and are drowned and digested. I have found
these plants often by the sides of Canadian bogs,
with a whole seething mass of festering and

FIG. 12.— INSECT-EATING PITCHERS OF THE MALAYAN NEPENTHES.

74 THE STOKY OF THK PLANTS.

decaying insects filling up every one of their
murderous vases. Other pitcher-plants are found
in Australia (Fig. 11).

The Nepenthes of the Malayan Archipelago is
a still more remarkable water-trap insect-eater,
in which the pitcher is formed by a curious jug-
like prolongation at the end of the leaf (Fig. 12).
It is provided with a lid, and its rim secretes a
sticky sweet liquid. Insects that enter the jug
are prevented from escaping by strong recurved
hooks ; and these hooks are so powerful that at
times they have been known even to capture
small birds which had incautiously entered.
This may seem curious, but it is not odder than
the fact that our own English bladderwort, a water
plant with pretty yellow flowers, which grows in
sluggish streams, has submerged bladders that
supply it with manure, not only from water-
beetles, larvae, and other insects, but also from
trout and other young fry of freshwater fishes.
I may add that while the sundew and other live-
insect catchers have to digest their prey,
the water-trap makers save themselves that
additional trouble and expense by macerating
and soaking it till it reaches the condition of a
liquid manure, ready dissolved for absorption,
and easy to assimilate.

Thus we see that while roots are the chief
organs for absorbing nitrogenous matter, they
are often supplemented irfspecial circumstances
by leaves and stems. Moreover, in many cases
leaves also supply the plant with water. On the
other hand, roots often fulfil yet another function,

HOW PLANTS DKINK. 75

by storing up food for the plant from one season
to another. It is true this is still more often
done by underground stems, but the distinction
between the two is very technical, and I do not
think I need trouble you here with it. Large
trees with solid trunks usually lay by their
starch and other valuable materials over winter
in a peculiar living layer of the bark ; and here
it is on the whole fairly free from danger. Still,
even in trees the lower part of the bark is often
nibbled by such animals as rabbits ; and to
prevent this mischance most smaller plants bury
their rich food- stuffs underground during the cold
season. For whatever will feed a young plant
or a growing shoot will also just equally feed an
animal. Hence the frequency with which plants
make hoards of their collected food- stuffs under-
ground, for use next season. The potato is a
well-known instance of such underground hoards ;
the plant lays by in what are technically sub-
terranean branches a supply of food- stuff for
next season's growth. These branches are
covered with undeveloped buds, which the
farmer calls " eyes " ; and from each of these
eyes (if the potato is left undisturbed, as nature
meant it to be) a branch or stem will start
afresh next season. It will use up the starch
and other foodstuffs in the potato, till it reaches
the light ; and there it will begin to develop
green chlorophyll, and to make fresh starch for
itself, and young leaves and branches.

An immense number of plants thus lay by
underground stores of food for next season's
use. Such are the carrot, the beet, and the

76 THE STORY OF THE PLANTS.

turnip. And in every case the young shoots
that spring from them use up the starches and
other food-stuffs at first exactly as an animal
would do. These stores are often protected
against animals by hard coats or poisonous
juices. Many well-known examples of sub-
terranean stores occur among our spring garden
flowers, which are for the most part either
bulbous or tuberous. The material laid by in
the bulb allows them to start flowering early,
while annuals and other unthrifty plants have
to wait till they have collected enough material
in the same year to flower upon. Hyacinths,
tulips, daffodils, snowdrops, crocuses, and the
various kinds of squills and jonquils are familiar
examples of plants which lay by in one year
material for the next year's flowering season.
But our wild flowers do the same thing quite as
much, though less obtrusively. Our earliest
spring buttercup is the bulbous buttercup, which
has a swollen root-stock, full of rich material ;
and this enables it to flower very soon indeed,
while the fibrous - rooted meadow - buttercup,
which closely resembles it in most other re-
spects, has to wait a month later, and then to
raise a much taller stem, in order to overtop the
summer grasses, which by that time have reached
a considerable height. Still earlier, however, is
another buttercup -like plant, the lesser celandine,
which has material laid by in little pill-like
tubers ; and these have given it its curious old
English name of pilewort. Other early spring
wild-flowers are the wood anemone and marsh-
marigold, with rich and thick almost tuberous

HOW PLANTS DEINK. 77

root stocks ; the bulbous wild hyacinth, the
tuberous meadow orchid, and the common arum,
or "lords and ladies," with its starchy root, very
rich in food-stuffs. Indeed, in every case where
a plant flowers very early in spring, you may be
sure the material for its flowering was laid up
by the plant in the previous year — that it is
really rather a case of delated than of very early
flowering.

This is especially true of trees, like the black-
thorn or the flowering almond, where the flower-
buds are usually formed over winter, and only
fully developed in the succeeding spring. The
same thing happens with gorse ; only here, a
few bushes always break into bloom in October
or November, while others burst spasmodically
into blossom whenever a warm and sunny spell
occurs in January or February. The remaining
bushes are covered through the winter with
hairy brown buds, and burst out in early spring
into golden masses of scented blossom. A like
arrangement also occurs in many catkins, which
are the flowers of certain trees ; the catkins of
the birch and the alder, for example, are always
formed in early autumn, though they only break
into bloom with recurring warmth in March or
April.

We have travelled away so far from our
original question of How plants drink, that a
summary of this chapter is even more necessary
than usual.

Plants drink by means of roots. But they
take up by them, not only water, which is their

78 THE STOKY OF THE PLANTS.

needful solvent, but also other materials urgently
required for their growth and development. The
most important of these materials is certainly
j nitrogen, which forms an indispensable com-
\ponent of protoplasm and chlorophyll. Where,
however, the roots do not supply nitrogenous
matter in sufficient quantities, plants procure it
for themselves by means of their leaves or stems,
and therefore become insect-eating or flesh-
eating. Soils get exhausted at times of nitrates,
phosphates, and other necessary materials of
plant-life. The farmer meets this difficulty by
manuring, and by rotation of crops. Nature
meets it by dispersion of seeds. Eoots, however,
have other functions besides drinking water and
sucking up with it certain dissolved materials ;
the chief of these other functions are fixing the
plant securely in the ground, and affording a
safe place of winter storage for starches and
other surplus food-stuffs. Many plants die down
almost entirely, above ground, in winter,
and keep their raw material in underground
reservoirs, most of which are stem-like rather
than root-like. Animals, however, find out these
subterranean reserves, and prey upon them ;
hence the plants often secure their hoard by
nauseous tastes or other protective devices.

CHAPTEE VI.

HOW PLANTS MAKRY.

WE next come to what is perhaps the most
fascinating chapter of all in the life-history of

HOW PLANTS MABKY. 79

plants — the chapter which tells us how they
marry and are given in marriage.

In order that you may fully understand this
curious and delightful subject, however, I shall
have to begin by telling you a few preliminary
points less interesting in themselves, and, I fear,
at times not a little troublesome.

Flowers are the husbands and wives of plants.
And in some
plants the sexes
are as fully sepa-
rated as in birds
or beasts; when
once you know
them, you can
distinguish at
sight a male
from a female

flower as readily ^

as you can dis- a ^PP ^ A

tinguish a bull FIG- 13. —A, MALE, & B, FEMALE FLOWER

from a nnw nr OF A SEDGE» M™H MAGNIFIED. The

om a cow, or gexes ftre here ite distinct and
a peacock irom unlike.
a peahen (Fig.

13). But in other cases the sexes are muddled
up in the same blossom or on the same plant in
a way that makes it rather difficult to understand
their true nature without a little pains and some
close attention.

So we must go back a bit for light to the
lower plants. Here we find no flowers at all,
and in the very lowest cases of any nothing in
the least resembling a blossom. Very simple
plants, in fact, have two ways of reproducing.

THE STORY OF THE PLANTS.

The earliest way is, when a single cell divides in
the middle, to form two others; a somewhat less
primitive way is when a single cell breaks sud-
denly up, and produces from itself a whole
swarm of young ones. In both these ways,
however, there is no trace of sex ; only one
single cell is concerned in the process ; the
plants have a mother, perhaps, but certainly not
a father.

The thread-like pond-weeds, however, which
are slightly higher plants in the
scale of being than the single-
celled floating types, show us the
first beginnings of something like
plant-marriage. These hair-like
little weeds consist each of a single
thread or string of cells, placed
end on end together, like beads
or pearls in a necklet, and con-
taining green chlorophyll. You
can find them in almost any stag-
nant pond in spring, where they
no. 14.— BEGIN- cling to the side in soft greenish
NINGS OF SEX moss-like or velvety masses. But
IN A POND WEED, ft vou €xamine one slimy string
MAGNIFIED™01* under a microscope, you will
see a curious thing often hap-
pening between the threads of two such hair-like
plants. As they grow side by side, two of the
strings will sometimes range themselves just
parallel to one another, with their cells facing
(Fig. 14). Then each opposite pair of cells
begins to bulge a little at the point where they
nearly touch (a and b in the figure), till at last

\

HOW PLANTS MABKY. 81

they join and coalesce with one another (c and d
in the figure). The contents of one cell pass
into another (at e), and the two form a sort of
egg (/), which lies quiet for a while, and then
buds out into a new thread or hair-like plant by
division. In this strange process we have the
beginning of sex — the first hint of plant and
animal marriages.

What is the meaning and good of it? Why do
the plants act thus ? That question we don't yet
quite understand, perhaps ; but this seems to be
in part at least its reason. Protoplasm requires
to be kept, as it were, perpetually young and ever
fresh ; it cannot afford to lose its elasticity and
its plasticity. If it does, it grows old in time
and dies. To prevent this misfortune, and the
death of all things, plants and animals have
invented all sorts of curious expedients; for
example, the protoplasm of a living cell some-
times breaks out of the cell- wall, and undergoes
a process which is called " rejuvenescence," or
growing young again. It lies quiet for awhile in
its free condition, and then begins to build up a
new wall afresh for itself. It seems by the
process of breaking out to have gained for itself
a new lease of life, as we ourselves often do by
a trip abroad or change of scene and air and
occupation. However this may be, it is certain
at least that the union of two cells often produces
a fresher, stronger, and more vigorous young
one than can be produced by mere division of a
single cell. In some way or other, when a
plant or animal reaches maturity, and arrives
at the limit of its own growth, it produces
ft

82 THE STOEY OF THE PLANTS

stronger and livelier young by so combining
with another of its own species.

In the thread-like pond-weeds the two uniting
cells are practically similar. They are not dis-
tinguished as male and female. Neither of them
is larger or smaller than the other; neither of
them is more active or more vigorous than its
consort. But in the higher plants a marked
difference invariably exists between the two cells
that join to form the new individual — a difference
of kind ; we have sex now appearing. One of
the cells is smaller, and more active ; it is called
a male cell or pollen cell. The other is larger,
richer, and more passive ; it is called a female
cell, or ovule — that is to say in plain English, a
little egg. Now the nature of the ovule is such
that it cannot grow out into a seed or young
plant till it has been united with and fertilised
by the smaller but more active and lively pollen-
cell.

Separate organs in the higher plants always
produce the pollen-grain and the ovule. These
organs are known as stamens and pistils (Fig.
15). They are really separate individuals, or
males and females. The stamen is the father
of the seed, so to speak, and the pistil its mother.

This is a hard saying, I know ; and, in order
that you may understand it, I must begin by
telling you another point about the plant which
I have hitherto to some extent studiously con-
cealed from you. It is this — each higher plant
is not so much a single individual as a commu-
nity or colony.

A hive of bees will help you to understand

HOW PLANTS MARKY. 83

this difficult paradox. I know it is difficult;
but, if only you will face it, it will throw floods
of light in due time on parts of our subject we
must consider hereafter. So let us look at it
close. A hive is a community. It consists for
the most part of workers, who are practically
neither male nor female. They are neuters, as
we say ; and their main work is to find food for
the whole hive,
including them-
selves and the
grubs or larvae
which are the
young of the
species. But, in
addition to these
workers, the hive
has a queen, who

i tne only per- FIG> ^ — A FLOWER, WITH ITS PETALS
feet female, or REMOVED. Outside are five stamens,
mother, and who which produce pollen : in the centre
lavs the eggs *s *ne P*8^* which contains the
from which the ovules or y°ung seeds'
larvae are produced ; and it has also several
drones, who are the males of the community, and
fathers of the larvae. Thus we have a colony or
city, as it were, consisting of a few males, a
single female, and a whole body of worker or
feeder neuters.

Now, a higher plant, like a cherry-tree (to
take a particular example), is just such a colony
or joint community. The leaves, each of which
is a distinct and almost self-supporting indi-
vidual, are its workers and feeders. Like the

84 THE STOEY OF THE PLANTS.

worker bees, too, the leaves are neuters —
neither true males nor true females. They feed
&nd lay by, and from them new leaves are
'continually produced in the buds and at the
lends of branches. This is called the sexless
/method of reproduction, and it is essentially
j similar to the way in which the single-celled
1 plant or the simple animal divides itself sexlessly
j^into two or more little plantlets or animals.
But, in addition to this sexless way, the plant
also at certain times produces other sorts of
leaves which are sexual individuals, and these
we call, in the lump, flowers. But flowers are
not all alike throughout. They consist of certain
male individuals, the stamens, which answer to
the drones, and of certain female individuals, the
pistils or carpels, which answer to the queen or
mother bee, and produce the ovules or little eggs
of the family. A cherry-tree is thus a plant-
hive or colony, consisting for the most part of
workers or leaves, but also at certain times of
year producing male and female members, whose
business it is to found fresh swarms, as it were
— to produce the seeds which are the basis and
foundation of new colonies.

There is of course one great difference between
a hive and a plant, and that is that in the hive
the individuals are separate and distinct, while
in the plant they are combined on a single stem,
which serves to join them. In this respect
plants are more like a branch of coral, which
consists of a number of distinct animals or
polypes, united by a core of stony material, and
a living mass of connecting matter. Yet the

HOW PLANTS MAEEY. 85

difference between the leaves and the bees is\
not so great as at first sight appears ; for though)
each leaf does not as a rule live separately, it is';
often capable of doing so if occasion arises. A
single leaf of stonecrop, separated from the'
parent plant, will root itself and grow into a
fresh colony ; and in some plants, like begonias,
a single fragment of a leaf, if placed on wet soil,
is capable of growing out into a new individual.
In other cases small leaves drop off from a plant
as bulbils, and root and grow ; while in others,
again, young plants sprout out from the edges
of old leaves to form new colonies. In short,
though the leaf is not usually a distinct plant,-*
it sometimes is, and it can often become one ; itfc
frequently gives rise in a sexless way to fresh v
plant colonies. A graver difficulty is this : the
plant differs from the hive in being more closely
connected and subordinated in its parts — the
stem and root (which bind and unite it), bringing
water and nitrogenous matter, while the leaves
elaborate the starch and protoplasm and other
chief food-stuffs. Even this difference, however,
is less grave than it seems, if we remember that
the queen bee and the larvae are similarly
dependent upon the workers for food and
protection. A plant, in short, is a colony of
various forms of leaves, very closely united
together for mutual service, and very much
specialised in various way's among themselves
for particular functions.

And now we are in a position to know what
work the flower has to do in the community.

86 THE STORY OF THE PLANTS.

It is a collection of special and peculiar leaves,
told' off to act as fathers and mothers to the
seeds, whence are to be born future plant
swarms or future colonies.

A flower, in its simplest form, consists of a
single stamen or a single carpel — that is to say,
of one leaf or leaf -like organ, told off for the
production of pollen ; or of one leaf or leaf -like
organ, told off for the production of young seeds
or ovules. Flowers as simple as that do actually
occur, but more often a flower is much more
complex, consisting of several stamens and
several carpels, as well as of other protective
or attractive leaves, often highly coloured and
conspicuous, which surround or envelop these
essential organs.

The most familiar flowers, as we actually
know them, are of this last more complex type ;
each comprises in itself several male and several
female individuals. The male individuals are
stamens, each of which generally consists of two
little pollen-bags, called the anthers, and a rather
slender stalk or support, known as the filament.
The female individuals are carpels, each of which
generally consists of a sort of sack or folded leaf,
enclosing one or more tiny seeds or ovules.

But that is not at all what you mean by a
flower ! No ; certainly not ; and half the flowers
you meet in a morning's walk you do not take
for flowers at all, and pass by unrecognised.
Such are the green or inconspicuous blossoms
of the grasses, nettles, oaks, and sedges, as well
as those of the pines, the dog's mercury, the
spurge, and the hazel. What you mean most

HOW PLANTS MABBY.

87

by a flower is a mass of red or yellow petals,
conspicuously arranged about the true floral
organs. The petals form, in point of fact, the
popular notion of a flower— though from the
point of view of science they are comparatively un-
important, and are
commonly spoken
of (with the calyx)
as "the floral en-
velopes." It is the
stamens and pistils
(or carpels) that are
the true flowers ;
they do the mass of
the real work ; and
an enormous num-
ber of flowers pos-
sess these organs
alone, without any
conspicuous petals
or other coloured
surfaces.

However, if you
take a pretty garden
flower (say a scarlet
geranium) as a typi-
cal example, and
begin to examine it
from the centre out- FIG. 16.— GRAINS OF POLLEN, VERY
ward (which is the MUCH MAGNIFIED, SENDING OUT
truest way), you ™LLE»-TUBEB.
will find it consists of the following parts, in the
following order : —

In the very centre of all comes the pistil,

88 THE STOEY OF THE PLANTS.

consisting of one or more carpels, and con-
taining the embryo seeds or ovules (see Fig. 15).
Outside this part, and next in order, come the
stamens, which are most often three or six in
one great group of flowering plants (the lilies),
and five, ten, or more in the other (the roses
and buttercups). The stamens produce grains
of pollen, which somehow or other, either by
means of the wind, or of insects, or of move-
ments on the part of the plant itself, are sooner
or later applied to the sensitive surface or stigma
of the pistil. As soon as a pollen-grain reaches
the surface of the stigma, it is held there by a
sticky secretion, and instantly begins to send
out what is called a pollen- tube (Fig. 16). This
pollen- tube makes its way down the long stem
or style which joins the stigma to the ovary, and
there comes in contact with the undeveloped
ovules. The ovules would not swell and grow
into seeds of themselves ; but the moment the
pollen-tube reaches them, they quicken into life,
and begin to develop into fertile seeds. Unfer-
tilised ovules wither away or come to nothing,
but fertilisation by pollen makes them develop
at once into new plant colonies.

Outside these essential organs, as botanists
call them, however, come, in handsome garden
flowers, two other sets of organs, more leaf-like
in appearance, but often brightly or conspicu-
ously coloured. The first of these sets of organs,
going still from within outward, is called the
petals, or, collectively, the corolla. Sometimes,
as in the dog-rose or the buttercup, the corolla
consists of five separate petals; sometimes, as

HOW PLANTS MABRY.

89

in the harebell and the gentian, it has five
points, or lobes, unit it at the base into a single
piece (Fig. 17). Last of all, outside the corolla
again comes another row or layer, called the
calyx, which sometimes consists of five separate
leaves or sepals, as in the dog-rose and the butter-
cup, but sometimes has five points, welded at
the base into one piece, as in red campion and

FIG. 17. — FLOWER OP A SHRUBBERY PLANT, WEIGELIA,
WITH THE PETALS UNITED INTO SINGLE COROLLA.

I. Entire flower. II. The same, with part of the
corolla cut away. III. and IV. A stamen, fe,
calyx ; b, corolla ; s, stamen ; a, anther of the
stamen ; g and ??, parts of the pistil.

convolvulus. It is these last comparatively
unessential but very conspicuous parts that
most people think of when they say " a flower.'1

What is their use ? Well, they are not essen-
tial, like the pistil and stamens, because many
flowers, perhaps, even most flowers, do without

90 THE STOKY OF THE PLANTS.

them altogether. But they are very useful for
all that, as we may easily guess, because they
are found in almost all the most advanced and
developed flowers. The use of the corolla, with
its brilliantly coloured petals, is to attract insects
to the flowers and induce them to carry pollen
from plant to plant. That is why they are
painted red and blue and yellow ; they are there
as advertisements to tell the bee or butterfly,
"Here 'you can get good honey." The use of
the calyx is usually to cover up the flower in the
bud, to keep it safe from cold, and to protect it
from the attacks of insect enemies, who often
try to break through and steal the half-developed
pollen in the bags of the stamens before it is
ripe and ready for fertilising. These are the
chief uses of the calyx or outer cup of the
flower ; but, as we shall see hereafter, it serves
many other useful purposes from time to time
in various kinds of flowers. In the fuschia, for
example, it is quite as brilliantly coloured as the
petals of the corolla, and supplements them in
the work of attracting insects. In the winter
cherry or Cape gooseberry it forms a brilliant
outer envelope or covering for the fruit, which
the French call "cerise en chemise" or "cherry
in its nightdress." Other uses of both calyx
and corolla will come out by and by, as we
proceed to examine individual instances.

" But why," you may ask, " do the plants
want to get pollen carried from plant to plant ?
Why can't each' flower fertilise itself by letting its
pollen fall upon its own pistil ? " Well, the ques-
tion is a natural one ; and, indeed, many flowers

HOW PLANTS MARKY. Ol

do actually so fertilise themselves with their
own pollen. But such flowers are almost always
poor and degenerate kinds, the unsuccessful in
the race, the outcasts and street arabs of plant
civilisation. All the higher, nobler, and more •
dominant plants — the plants that have carved
out for themselves great careers in the world,
and that occupy the best posts in nature — have
invented some mode or other of cross- fertilisa-
tion, as it is called, that is to say some plan by
which the pollen of one plant or flower fertilises
the pistil of another.

What does this mean? Well, regarding the
plant as a colony, you will see at once that the
stamens and pistil of the same blossom stand to
one another somewhat in the relation of brothers /
and sisters, while those of different flowers on the I
same plant may be regarded at least in the light j
of first cousins. Now the very same thing that
makes sex and marriage desirable, makes close
intermarriage of blood relations undesirable.
" Marrying in and in," as it is called, tends to
produce weak and feeble offspring, while "an
infusion of fresh blood" tends to make both
plants and animals stronger and more vigorous.
Hence, if any habit chanced to arise in plants
which favoured or rendered easier such cross-
fertilisation, it would result in stronger and more
vigorous young, and would therefore be fixed by
natural selection. The actual consequence is
that in the world of plants, as we see it to-day,
every great dominant or successful race has
invented some means of cross-fertilisation, either
by the agency of wind or of insects, while only

92 THE STOKY OF THE PLANTS.

ihe miserable riff-raff and outcasts of plant-life
still adhere to the old and bad method of fertili-
sation by means of the pollen of their own
flowers.

We are now in a position to understand the
main principles which govern the marriage cus-
toms of plants ; we will proceed in the next
chapter to consider in detail how these prin-
ciples work out in particular instances. But
first we must sum up what we have learnt in
this chapter,

Plants marry and are given in marriage. The
- very lowest plants, indeed, are sexless, but in
: the higher there are well-marked distinctions of
male and female. An intermediate stage exists
in certain thread-like pond- weeds, where mar-
Triage or intermixture takes place between two
/ adjacent cells, neither of which is male or female.
The higher plants, however, are really com-
munities or colonies, of which the leaves are
the workers, and the various parts of the flower
the males and females. The central part of the
flower, known as the pistil, is the female indi-
vidual ; it produces ovules, or young seeds,
which, however, cannot grow and swell without
the quickening aid of pollen. The next row in
the flower, known as the stamens, contains the
male individuals ; they produce pollen, which
lights on the sensitive surface of the pistil, sends
out tubes of very active living matter, and
quickens or impregnates the ovules in the pistil.
Besides these necessary organs flowers have
often two other sets of parts. The corolla,

VARIOUS MARRIAGE CUSTOMS. 93

which is made up of petals, united or distinct,
is usually brightly coloured, and acts as an
advertisement or allurement to the insects ; it
occurs chiefly in insect - fertilised flowers, and
generally implies the presence of honey. The
calyx or outer cup, which is made up of sepals,
distinct or united, acts mainly as a protective
covering. Plants can fertilise themselves if
nec.egs.ary, but in all the highest and most
successful plants some form or other of £ros§b.
fertilisation has become almost universal. Self-
f ertilisation goes down the hill ; cross-fertilisation
is the road to success and vigour.

CHAPTEB VII.

VARIOUS MARRIAGE CUSTOMS.

THE simplest and earliest flowering plants had
probably only three sets of organs — leaves, ^
stamens, and pistils — workers, males, and.
females. Their flowers consisted at best of the*'
necessary organs, enclosed, perhaps, in a few
protective sheathing leaves, rather smaller than
the rest, the forerunners of a calyx. How,
then, did modern flowers come to get at last
their brilliant corollas?

We must remember that anything which made
flying insects visit plants would be of use to the
flowers, as promoting cross-fertilisation. Now,
as far as we can see at present, before flying
insects were evolved in the animal world, there
could have been no such things as bright-hued

94: THE STORY OF THE PLANTS.

blossoms in the vegetable kingdom. But insects
must very early have gone about eating pollen
on plants, as they do to this day in many in-
stances ; and though in itself this would be a
loss to the plant, yet plants have often found it
well worth their while to pay blackmail to in-
sects in return for some benefit incidentally
conferred upon them. Again, as the insects flew
from plant to plant, they would be sure to carry
pollen on their heads and legs ; and they would
rub off this pollen on the sticky stigma of the
next flower they visited, which would make
them on the whole useful and profitable visitors.
So the plants, finding the good cross-fertilisation
did them, began in time to bribe the insects by
producing honey in the neighbourhood of their
pistils and stamens, and also to attract their
eyes from afar by means of those alluring and
brilliantly - coloured advertisements which we
call petals.

I don't mean, of course, that the plants knew
they were doing all this ; they were unconscious
agents. Whenever any variation in the right
direction occurred by chance, natural selection
immediately favoured it, so that in the end it
comes almost to the same thing as if the plant
deliberately intended to allure the insect; and for
brevity's sake I shall often so word things.

How did the plant first come to develop such
bright- hued petals ? I think in this way. Most
early types of flowers have a great many stamens
apiece, and these stamens are so extremely
numerous that one or two of them might readily
be spared for any other purpose the plant found

VARIOUS MARRIAGE CUSTOMS. 95

useful. Gradually, as botanists £ imagine, an
outer row of these stamens got flattened out
into a form like foliage leaves, only without any
ribs or veins to speak of, and developed bright
colours to attract the insects. Such a flattened
and gaily-decked stamen, with no pollen-bearing
bag, is what we call a petal. It is usually ex-
panded, thin, and spongy, and it is admirably
adapted for the display of bright colours.

We have still certain flowers among us which
show us pretty clearly how this change took place.
The common white water-lily is one of them.
In the centre of the blossom, in that beautiful
plant, we find a large pistil and numerous sta-
mens of the ordinary sort, with round stalks or
filaments, and yellow pollen-bags hanging out at
their ends. Then, as we move outward, we
find the filaments or stalks growing flatter and
broader, and the pollen-bags gradually less and
less perfect. Next we come to a few very flat and
broad stamens, looking just like petals, but with
two empty pollen-bags, or sometimes only one,
stuck awkwardly on their edges. Last of all we
arrive at true petals without a trace in any
way of pollen-bags. I believe the water-lily
preserves for us still some memory of the plan
by which petals were first invented. Such relics
of old conditions are common both in plants and
animals ; they help us greatly to reconstruct the
history of the path by which the various kinds
have reached their present perfection.

Even in our own day, in plants where stamens
are numerous, they often tend to develop into
petals, especially when growing in very rich

96 THE STOKY OF THE PLANTS.

soil, or under cultivation. This is what we call

" doubling " a flower. In the double rose, for

example, the extra petals are produced from the

stamens of the interior, and if you examine

1 them closely you will see that they often show

• every possible gradation and intermediate stage,

I from the perfect stamen to the perfect petal.

The same thing readily happens with buttercups,

poppies, and many other flowers. We may take

it for granted, then, that petals are, in essence,

a single outer row of stamens, flattened and

coloured, and set apart by the plant to advertise

its honey to insects, and so induce them to visit

and fertilise it.

In the largest and most familiar group of
flowering plants, to which almost all the best-
known kinds belong, the original number of
petals seems to have been five ; and we will take
this number as regular for the present, explain-
ing separately those cases where it is exceeded
or diminished. The common ancestor of all
these plants, we may conclude, had all its parts
f in rows of five. Thus it had five, ten, or fifteen
' carpels in its pistil — that is to say, one, two, or
'three rows of five carpels each; it had five, ten,
or fifteen stamens, it had five or ten petals, and
it had a calyx, outside all, of five sepals. We
will now proceed to examine in detail some of
the many curious marriage customs which have
arisen among the group of plants that started
with this ground -plan.

One great family of plants which early divided
itself from this great central stock is the family

VAEIOUS MAKBIAGE CUSTOMS. 97

of the buttercups. Our common English bulbous
buttercup is one of its best-known members. It
is yellow in colour, a point which is common to
most Dearly and simple flowers, because the
stamens are generally yellow, and when they
developed into petals they naturally retained at
first their original colouring. Only later and for
various special reasons did certain higher flowers
come by degrees to be white, pink, red, blue,
purple, or variegated. There is some reason to
believe, indeed, that the various other colours
were developed one after the other in the order '
here named, and to the present day all the
simplest families of flowers remain chiefly
yelSw, as do the simpler and earlier members
of more advanced families.

The common bulbous buttercup is thus pre-
vailingly yellow, because it is an early and
simple type of flowTer. It consists of four dis-
tinct and successive layers, or whorls of organs.
Outside all comes a calyx of five sepals, which
cover the flower in the bud, but are hardly
noticeable in the open blossom. They also
serve to keep off ants and other creeping in-
sects, for which purpose they are turned back
on the stem, and are covered with small hairs.
" But I thought the plant wanted to attract
insects," you will say. Yes, the right kind of
insects, the flying types, which go from one
flower to another of the same sort, and so pro-
mote due fertilisation. Flying insects, attracted
by colour and shape of petals, keep tojQAejDrajad-
of honey at a time ; they never mix their liquors.
But ants are drawn on by the smell of honey
7

98 THE STORY OF THE PLANTS.

only ; they crawl up one stem after another
indiscriminately, and steal the nectar which the
plant intends for its regular winged visitors.
Even if they do occasionally fertilise a flower,
it will probably be with pollen of another kind,
so that the result will be, not a perfect plant, but
a miserable hybrid, ill adapted for any condi-
tions. Hence plants usually possess advanced
devices for keeping off ants and other climbing
thieves from their precious honey. Hairs on
the stalk and calyx are enough to secure this
object in the meadow buttercup, which has a tall
stem, and therefore is not so easily climbed ;
for the hairs, small as they look to us, prove to
the ant a perfect forest of underwood. But in
the early bulbous buttercup, which has a shorter
stem, and the smell of whose honey is therefore
more alluring to the groundling ant, this device
is not alone sufficient ; so the calyx on opening
turns down its separate sepals close against the
stem in such a way as to form a sort of lobster-
pot, out of which the creeping insect can never
extricate himself.

Inside the calyx-layer of five sepals comes
next the corolla-layer of five petals. These
petals, as we saw, are the attractive business
advertisement of the flower ; they contain at the
base of each a tiny honey-gland or nectary,
which is covered by a scale or small inner petal,
so to speak, to protect it from the attacks of
thievish insects. But when the bee or other
proper fertilising agent arrives at the flower,
he lights on the set of carpels in the very centre
of the blossom, and proceeds to go straight for

VAEIOUS MAKEIAGE CUSTOMS. 99

the little store of honey. As he does so, he
turns gradually round all over the carpels, and
dusts himself with pollen from the ripe stamens.

And now we must notice another curious
device for ensuring cross-fertilisation in many
flowers. In the bulbous buttercup the stamens
and carpels do not come to maturity together ;
the stamens ripen first, and after them the
carpels. How does this ensure cross-fertilisa-
tion ? Why, if the bee comes to a flower in the
first or male stage, in which the stamens are at
their full, and discharging pollen, the sensitive
surfaces or stigmas of the carpels will yet be
immature, so that he cannot fertilise them with
pollen from their own blossom. He can only
collect there, without disbursing anything. But
as soon as he comes to a flower in its second or
female stage, with the carpels ripe, and their
sensitive surfaces sticky, he will rub off some
of the pollen he has thus collected, and so cross-
fertilise the flower he is visiting.

Each buttercup thus goes through two stages.
First, its stamens ripen from without inward,)
till all have shed their pollen and withered. »
Then the carpels ripen in the same order, till ^
all have been fertilised by the appropriate insect.
Each carpel here contains a single seed, which
begins to swell as soon as the ovary is impreg-
nated.

We may take it that some such flower as that
of the bulbous buttercup represents the qrig^njjl
ancestor of all the buttercup group, from which
other kinds have varied in many directions.
Omitting for the present all questions as to the

100 THE STORY OF THE PLANTS.

fruit and seed, which we must examine at length
in a later chapter, I will now proceed briefly to
describe a few of these variations in the butter-
cup family.

The true buttercups themselves are dis-
tinguished from all other members of the group
by having a tiny scale over the nectary or honey-
gland at the base of the petal, or at least by
having the nectary itself as a visible pit or small
depression. Almost all of them are yellow,
though in other respects they differ from one
another, as in the shape of the leaves, or in
the way in which the sepals are turned back
to form a protection against insects. One of the
yellow buttercups, too, commonly called the
lesser celandine, has varied from the rest of
the race in a peculiar fashion ; for it has only
three sepals, instead of five, according to the
usual pattern ; while, as if to make up for this
loss in one part, it has eight petals instead of
five in its corolla. I merely mention this fact
to show how many small changes occur in
different flowers, even within the limits of the
same family. And though most of the true
buttercups are yellow, a few are wiiite, such
as our own water-crowfoot, and the alpine
buttercup called bachelors' buttons ; while still
fewer are red, like the turban ranunculus of our
spring gardens.

But besides the true buttercups, we have also
a vast group of buttercup-like plants, descen-
dants of the same primitive five-petalled an-
cestor, and regarded as members of the butter-
cup order. In these we can trace some curious

VARIOUS MARRIAGE CUSTOMS. 101

gradations. The little winter aconite of our
gardens has this peculiarity : the petal and
nectary have grown into a sort of tubular honey-
cup, much more attractive to greedy insects than
the simple scale-bearing petal of the buttercups.
But as this involves loss of expanded colour-
surface, the winter aconite has made up for
the deficiency by colouring its calyx a brilliant
yellow, so as to resemble a coTolla. Several
other buttercup-like plants have even lost their
petals altogether, and make coloured sepals do
duty in their place. The marsh-marigold, for
instance, is one of these ; what look like petals
in it are really very brilliant yellow sepals.
Moreover, as the marsh-marigold is such a large
and handsome flower, it easily attracts insects
in early spring ; and this has enabled it to effect
an economy in the matter of its carpels or female
organs. In the buttercups, we saw, these were
very numerous, and each contained only one
seed ; in the marsh-marigold, on the other hand,
they are reduced to five or ten, but each contains
a large number of seeds. This arrangement
enables a few acts of fertilisation to suffice for
the whole flower. You will therefore find as
a rule that advanced types of flowers have very
few carpels — s^rnetimes only one — and that
wrien they are more numerous they are often
combined into a single ovary, with one sensitive
surface, so that one fertilisation is enough for
the whole of them.

Three familiar but highly-advanced members
of the buttercup group will serve to show the
immense changes effected in this respect by

102 THE STORY OP THE PLANTS.

special insect fertilisation. They are the colum-
bine, the larkspur, and the monkshood. In the
simple buttercups, the honey, we saw, was easily
accessible to many small insects ; but in the
winter aconite it was made more secure by
being kept, as it were, in a sort of deep jar; and
in these highest of the family it is still further
hidden away, in special nooks and recesses, like
vases or pitchers, so as to be only procurable by
bees and butterflies. These higher insects, on
' the other hand, are the safest fertilisers, because
. they have legs and a proboscis exactly adapted
» to the work they are meant for ; and they have
4 also as a rule a taste for red, blue, and purple
, flowers, rather than for simple white or yellow
\ ones. Hence the blossoms that specially lay
1 themselves out for the higher insects are almost
\ always blue or purple.

Columbine still retains the original five sepals
and five petals of its buttercup ancestor. But
the sepals here are blue or purple, and are
displayed between the petals in a most curious
manner, so as to help in the coloured advertise-
ment of the honey. The petals, on the other
hand, are turned into long spurred horns, each
with a big drop of honey in its furthest recess,
securely placed where only an insect with a very
long proboscis has any chance of reaching it.
Within these two rows come the numerous
stamens ; and within them again a set of five
carpels, each many-seeded. The columbine is
so secure of getting its seed set by bees or
butterflies that it is able to dispense with the
extra carpels.

VARIOUS MARRIAGE CUSTOMS. 103

Larkspur carries the same devices one step
further. Here, there are five sepals, coloured
blue, and prolonged into a spur at the base,
which covers the nectaries. Why this outer
covering ? Well, in columbine, thievish insects
like wasps often eat through the base of the
spurred sepals and steal the honey, without
benefiting the plant in any way, as they don't
come near the stamens and carpels. Larkspur
provides against that evil chance by covering its
honey with two protective coats ; for within the
spur of the sepals lies a spurred nectary made
up of the petals. The petals themselves are
reduced to two, because the sepals are coloured,
and do all the attractive duty ; and besides, even
these two petals are combined into one, as a
further economy. But the arrangement of the
flower is so admirable for ensuring fertilisation
that the plant is able still further to dispense
with unnecessary parts ; so many larkspurs have
, only a single many-seeded carpel. Such re-
tductions in the numbers of parts are always
^a sign of high development. Where the devices
for effecting the work are poor, many servants
/are necessary ; where labour-saving improve-
ments have been largely introduced, a very
(few will do the same work, and do it better.

Monkshood, again, is another example of the
same tendency. Here, the one-sidedness which
we saw in the larkspur reaches a still more
advanced development. The upper sepal is
formed into a brilliant blue hood, and it covers
two curiously shaped petals, which contain an
abundant store of honey. This arrangement is

104 THE STORY OF THE PLANTS.

so splendid for fertilisation that the plant is able
largely to reduce its number of stamens ; and
though it has three carpels, these are combined
at the base, thus showing the first step towards
a united ovary.

I have treated the single family of the butter-
cups at some length, because I wished to show
you what sort of variations on a single plan
were common in nature. We see here a family,
built all on one scheme, but altering its archi-
tecture and decoration in the most singular
degree in its different members. The simplest
4 kinds are circular, symmetrical, orderly, and
yellow ; the highest are irregular, somewhat
strangely shaped, and blue or purple. This is
the general line of evolution in flowers. They
. begin like the buttercup ; they end like the
monkshood.

Familiar instances of round or radial flowers,
consisting of separate petals, are the dog-rose,
the poppy, the mallow, and the herb-robert or
wild geranium. Most of these have five sepals
and five petals ; but in the poppy the petals are
usually reduced to four, and the sepals to two.
Again, a good instance of flowers with separate
petals which have become one-sided or irregular,
instead of circularly symmetrical, is afforded us
by the peaflowers, which include the pea, the
bean, the sweet-pea, the laburnum, the broom,
the gorse, the vetch, and the lupine. This
familiar family, known to botanists as the papi-
lionaceous or butterfly-like order (I trouble you
with as few long names as I can, so you must

VARIOUS MARRIAGE CUSTOMS. 105

forgive one or two occasionally), is one of the
largest in the world, and includes a vast number
of the most useful and also of the most orna-
mental species. Tho structure of the flower,
which is very similar in them all, can be easily
studied in the broom or the sweet-pea, plants
procurable by everybody. There are still five
petals, though two of them are united to form
a lower portion of the flower, known as the
keel; then two others at the side are called
the wings ; while a broad and often handsomely
coloured advertisement-petal at the top of all is
called the standard. The sepals are often com-
bined into a single calyx-piece, though as a rule
the calyx still retains five lobes or teeth, a
reminiscence of the time when it consisted of
five distinct and separate sepals. The stamens
are welded together into a sort of long tube ; and
the pistil is reduced to a single carpel or pod,
containing a few big seeds, very familiar to most
of us in the case of the pea, the bean, and the
scarlet-runner. This shape of flower has proved
so successful in the struggle for life that papi-
lionaceous plants are now common everywhere,
while hundreds of different kinds are known in
various countries.

Yet closely as the peaflowers resemble one
another in general aspect, they have still among
themselves a curious variety of marriage customs.
I will mention two only. In gorse, a flower r
which everybody can easily examine, the wings I
have two little knobs at the sides for the bee to |
alight upon. As he does so, the corolla springs j
open elastically, and dusts him all over with the i

106 THE STOKY OF THE PLANTS.

fertilising pollen. But once it has burst, it re-
mains permanently open, the keel hanging down
in a woe-begone way, so that no bee troubles
himself again to visit it. This saves time for the
bees, and enables them quicker to fertilise the
remaining flowers ; for when they see a gorse-
blossom " sprung " as we call it, they recognise
at once that it has already been fertilised, and
they know they can get no food by going there.
In the lupine, on the other hand, and in the
common little English birdsfoot-trefoil, the keel
is sharp at the point, and the pollen is shed into
it before the flower fully opens. When a bee
lights on the knobs at the side, he depresses the
1 keel, and the pollen is pumped out against his
breast in the most beautiful manner. I hope
my readers will try some of these experiments in
summer for themselves, and satisfy their own
minds whether these things are so.

So far, we have dealt mainly with flowers in
which the petals are all still distinct and
separate. But in a great many plants, the petals
have grown together, so as to form a single
piece, a "tubular corolla," as we call it. This
arrangement is very well seen in the harebell,
the Canterbury bell, the heath, and the con-
volvulus. How did such an arrangement arise ?
Well, in many flowers even with distinct petals
there is a slight tendency for adjacent parts to
adhere at the base ; and in certain blossoms
this tendency to adhesion must have benefited
the plant, because it would allow the proper
fertilising insect to get in with ease, and to find

VABIOUS MARRIAGE CUSTOMS.

107

his way at once to the stamens and stigma or
sensitive surface. The consequence is that the
majority of the higher plants have now corollas
in a single piece ; and most of these are also
coloured red, blue, or purple. Still, even now
many of them retain marks of the original five

FIG. 18. — PIN-EYED PRIMROSE,
CUT OPEN SO AS TO SHOW
THE ARRANGEMENT OF THE
STAMENS AND STIGMA.

FIG. 19. — THRUM-EYED
PRIMROSE, CUT OPEN
SO AS TO SHOW STA-
MENS AND STIGMA.

petals. For instance, the harebell has the edge
of the corolla vandyked into five marked lobes ;
while in the primrose, only the base of the
corolla forms a tube or united pipe, the outer
part being composed of five deeply-cut lobes,

108 THE STORY OP THE PLANTS.

reminiscences of the five original petals. Indeed,
some relations of the primrose, such as the pim-
pernel and the woodland loose-strife, have the
petals only slightly united at the base, and
would hardly be noticed by a casual observer
as possessing a tubular corolla.

There is one marriage custom of the primrose,
however, so very interesting that we must not pass
it by even in so brief a survey. Most children
are aware that we have in our woods two kinds
of primroses, which they know respectively as
pin-eyed and thrum-eyed. In the pin-eyed
form (Fig. 18), only the little round stigma is
visible at the top of the pipe, while the stamens,
here joined with the corolla-tube, hang out like
little bags half-way down the neck of it. In the
thrum-eyed form (Fig. 19), on the other hand,
only the stamens are visible at the top of the
tube, while the stigma, erected on a much
shorter style, occupies just the same place in
the tube that the stamens occupied in the sister
blossom. Now, each primrose plant bears only
one form of flower. Therefore, if a bee begins
visiting a thrum-eyed form, he will collect pollen
on his proboscis at the very base only ; and as
long as he goes on visiting thrum-eyed flowers,
he can only collect, without getting rid of any
grains on the deep-set stigmas. But when he
flies away to a pin-eyed blossom, the part of his
proboscis which collected pollen before will now
be opposite the stigma, and will fertilise it ;
while at the same time he will be gathering
fresh pollen below, to be rubbed off on the sensi-
tive surface of a short- sty led flower in due season.

VA1UOUS MAEKIAGE CUSTOMS. 109

Thus every pin-eyed blossom must always be
fertilised by a thrum-eyed, and every thrum-eyed
by a pin-eyed neighbour. This is one of the
most ingenious arrangements known for cross-
fertilisation.

Much as I should like to dwell further on
these interesting cases, I must hurry on to
complete our rapid survey of a great subject.
Flowers like the harebell and the primrose are
tubular but regular. Other flowers with a
tubular corolla go yet a step further and are
irregular also. This irregularity, like that of
the monkshood, secures for them in the end
greater certainty of fertilisation. Two well-
known groups of this sort are the sages, on the
one hand, and the fox-gloves, monkey-plants,
and snap-dragons on the other. I shall mention
only one instance of special devices for cross-
fertilisation in these groups, that of the various
sages, beautifully seen in the large blue salvias
of our gardens. In this plant there are only two
stamens, though most of the group to which it
belongs have four, because the excellent ar-
rangements for fertilisation make this single
pair a great deal more effective than the thirty
or forty required by the common buttercup.
For the stamens are delicately poised on a sort
of lever, so that the moment the bee enters the
flower, they descend and embrace him, as if by
magic. While the stamens alone are ripe, this
continues to happen with each flower he visits ;
but when he goes away to an older blossom, he
finds the stigma ripe, and bending over into the

110 THE STORY OF THE PLANTS.

spot previously occupied by the stamens. You
can try this experiment very easily for yourself
by putting a straw or bent of grass down the
tube of a garden salvia, when the stamens will
at once bend down and embrace it in the way I
have mentioned.

You must not suppose, however, that all
flowers are fertilised by bees and butterflies.
Many plants lay themselves out for quite dif-
ferent visitors. Take for example our common
English figwort. This is a curious, lurid-looking,
reddish-brown blossom, shaped somewhat like a
helmet, and it is fertilised almostexplusively by
wasps. Its shape and size exactlyaSapt it for
aTwasp's head ; and it blooms at the time of
year when wasps are numerous. Now wasps,
as you know, are carnivorous and omnivorous
creatures ; so the figwort, to attract them, looks
as meaty as it can, and has an odour not unlike
that of decaying mutton. Certain tropical flowers
again attract carrion-flies, and these have big
blossoms that look like decomposing meat, and
smell disgustingly. A South African flower of
this sort, the Stapelia, is sometimes cultivated
as a curiosity in greenhouses. I have already
remarked on the white flowers which open at
night, and attract tEe^moths of twilight ; while
others again lay themselves out to be fertilised
by midges, beetles, and other insect riff-raff.
Most of these have the honey displayed on wide
open discs, where it can be sipped by insects
with hardly any proboscis.

In our latitudes it is only insects that so act

VAEIOUS MARRIAGE CUSTOMS. Ill

as fertilisers ; but in the tropics the work of
fertilisation is often performed by birds, such as
humming-birds, sun-birds, and brush-tongued
lories. Many of the most brilliant and beautiful
among the bell-shaped tropical flowers have been
specially developed to suit the tastes and habits
of these comparatively large and powerful ferti-
lisers. The tongues of all, but especially of the
humming-birds, are admirably adapted for suck-
ing honey from flowers, as they are long and
tubular, sometimes forked at the tip, and often
hairy so as to lick up both honey and insects.
The length of the beak "and tongue varies to a
great extent in accordance with the depth of the
tube in the flowers they fertilise. Bird and
flower, in other words, have each been developed
to suit one another. The same sort of corre-
spondence may often be observed between in-
sects and flowers developed side by side for
mutual convenience.

One more point I should like to touch upon
before I pass away from this part of the subject ;
and that is the lines or spots so often found on
the petals of highly developed flowers. These
for the most part act as honey-guides, to lead
the bee or other fertilising insect direct to the
nectar. A very good case of this may be seen
in an Indian plant which is found in every
English cottage garden — that is to say the so-
called nasturtium. This beautiful blossom can »
only be fertilised by humming-bird hawk-moths,
no other insect in Europe at least having a L
proboscis long enough to reach to the bottom of J

112 THE STOEY OF THE PLANTS.

the very deep spur which holds the honey.
Now, humming-bird hawk-moths do not light
on a flower, but hover lightly poised on their
quivering wings in front of it. So all the ar-
rangements of the flower are strictly set forth in
accordance with the insect's habit. The calyx
consists of five sepals with a very long spur, the
end of which, as you can find out by biting it, is
full of honey. Then come five petals, not, how-
ever, all alike, but divided into two distinct sets,
an upper pair and a lower triplet. The upper
pair are broad and deeply-lined with dark veins,
which all converge about the mouth of the spur,
and so show the inquiring insect exactly where
to go in search of honey. The lower three, on
the other hand, have no lines or marks, but
possess a curious sort of fence running right
across their face, intended to prevent other
flying insects from alighting and rifling the
flower without fertilising the ovary. This
flower, too, has two successive stages ; it opens
male, with stamens only, which bend upward
towards the insect ; later, it becomes female,
the stigma opens and becomes forked, and bends
down so as to occupy the very same place pre-
viously occupied by the ripe stamens.

A great many well-known flowers have such
lines as honey-guides. If I have succeeded so
far in interesting you in the subject, you will
find it a pleasant task to hunt them out for
yourself in the violet, the scarlet geranium, the
spotted orchid, and the tiger lily.

So far I have dealt only with the marriage

MOKE MAURI AGE CUSTOMS. 113

arrangements of those plants which are fertilised
by insects or birds, and which belong to the
great group of flowering plants descended from
an early common ancestor with five petals. We j
must next deal briefly with the marriage customs
of the insect-fertilised class among the other
great group whose ancestor started with but
three petals ; and after that we must go on to
the other mode of fertilisation by means of the
wind or of self -impregnation.

This chapter has consisted so much of special
cases that I do not think it stands in the same
need of a summary as all its predecessors.

CHAPTEK VIII.

MORE MARRIAGE CUSTOMS,

ALMOST all the flowering plants with which most
people are familiar — all, indeed, save the pines
and other conifers — belong to one or other of
two great groups or alliances, each remotely
descended from a common ancestor. The
flowers we have hitherto been considering are
entirely those which belong to one out of these
two groups — the group which started with rows
of five, having five sepals, five petals, five or ten
stamens, and five or ten carpels. In several
cases, certain of these rows have been simplified
or reduced in number ; but almost always we
can see to the end some trace of the original
fivefold arrangement. This fivefold arrangement
is very conspicuous in all the stonecrops, and it
8

114 THE STORY OF THE PLANTS.

may also be well noticed in wild geraniums, and
less well in the strawberry, the dog-rose, and the
cinquefoil.

In the present chapter, however, I propose to
go on to sundry flowers of the other great group
which has its parts in rows of three, and to
show how they have been affected By insect
visits. This will give us a clearer view of the
whole subject, while it will also form a general
introduction to systematic botany for those of
my readers who may be induced by this book to
carry their studies in this direction further.

Before proceeding, however, there is one little
point I should like to note about the fivefold
flowers, which we shall find much more common
in the threefold, and among the wind-fertilised
species. This is the separation of the sexes in
different blossoms or even on separate plants.
All the flowers we have so far considered have
contained both male and female portions — have
been made up of stamens and carpels united
together in the self -same blossom. But many
of them, as you will recollect, have not been
actively both male and female at the same
moment. The stamens ripened first, the sensi-
tive surface of the carpels afterwards ; and this,
as we saw, tended to promote cross-fertilisation.
But if in any species all the stamens in certain
flowers were to be suppressed or undeveloped,
while in other flowers the same thing happened
to the carpels, self-fertilisation would become an
absolute impossibility, and every blossom would
| necessarily be impregnated from the pollen of a
\ neighbour. Natural selection has accordingly

MORE MARRIAGE CUSTOMS. 115

favoured such an arrangement in a considerable j
number of the higher plants. In such cases
some of the flowers consist of stamens only,
with no carpels ; while others consist of carpels
alone, with no stamens. But as all are de-
scended from ancestors which had both organs
combined in the same flower, remnants of the
stamens often exist in the female flowers as
naked filaments or barren threads, while
remnants of the carpels equally exist in the
male flowers as central knobs without seeds or
ovules.

The beautiful begonias, so much cultivated in
conservatories, give us an excellent example of
such single-sex flowers. In these plants the
males and females are extremely different. The
male flower has four coloured and petal-like
sepals, surrounding a number of central stamens.
The female flower has five coloured and petal-like
sepals, surrounding a group of daintily-twisted
central stigmas, while at the base of the blossom
is a large triangular ovary, containing the young
seeds or ovules. Usually the flowers grow in
little bunches of three, each bunch consisting of
two males and one female.

In the pumpkins, cucumbers, and melons,
separate male and female flowers also exist on
the same plant. The females here may be easily
recognised by having an ovary or small unde-
veloped fruit at the back of the blossom, which
you can cut across so as to show the young
seeds or ovules within it. As the proper insects
for fertilising cucumbers and melons do not live
in England, gardeners usually impregnate the

116 THE STORY OF THE PLANTS.

female flowers by bringing pollen from the males
1 to them with a camel's hair brush. This pro-
cess is commonly known as " setting " the
f melons. Many other garden flowers have
I separate male and female blossoms, which the
\ beginner can easily recognise for himself if he
takes the trouble to look for them.

In the instances we have hitherto considered,
the male and female blossoms live on the same
plant. But the best cross-fertilisation of all is
that which is secured where the fathers and
I mothers belong to totally distinct plants, a plan
J for facilitating which we have already seen in
^the common primrose. Well, now, if any
species took to producing all male flowers on
one plant, and all females on another, this great
end would become absolutely certain, for every
blossom would then always be fertilised by the
pollen brought from a distinct plant. Many such
instances have accordingly been produced in the
world around us by natural selection. Only, the
two kinds of plants must always grow in one
another's neighbourhood. Hemp, for example,
is a case of a plant where such an arrangement
already exists ; some plants are male only, while
some are female. Mistletoe and hops are other
well-known instances, which the reader should
carefully examine for himself at the proper
season.

All these are fivefold flowers, and I have
brought them in here merely because one of
the earliest and simplest threefold flowers we
are going to consider has also this peculiarity

MORE MARRIAGE CUSTOMS. 117

of separate sexes. This is the common arrow-
head, a plant that grows in watery ditches, and
a capital example of the threefold type in its
simpler development. Each flower, whether
male or female, has a green calyx of three small
sepals, and a white corolla of three much larger
and somewhat papery petals (Fig. 20). ^ But the
male flowers have in their centre an indefinite
number of clustering stamens ; while the female
flowers have an equally numerous set of tiny
carpels. The blossoms grow in whorls on the

II

FIG. 20. — I. MALE, AND II, FEMALE FLOWEKS
OF ARROWHEAD.

same stem, the males above, the females beneath
them* At first sight you would think this a bad
arrangement, because you might fancy pollen
from the males would certainly fall or blow out
upon the females beneath them. But the plant
prevents that catastrophe by a very simple
dodge, which we shall have occasion to notice
in many other parallel cases. The flowers open
from below upward ; thus the females mature
first, and are fertilised by insects which bring to
fliSm. pollen from other plants already rifled ;
later on the males follow suit, and their pollen

118 THE STORY OF THE PLANTS.

is carried off by the visiting insect to the female
flowers on the next plant it visits. Indeed, you
may gather by this time how great a variety
of devices natural selection has produced for
securing this great desideratum of fresh blood,
or cross-fertilisation, from a totally distinct plant
colony.

A much commoner English wild-flower than
the arrowhead shows us another form of early
threefold blossom. I
mean the water-plan-
tain (Fig. 21), a pretty
feathery weed, which
grows by the side of
most ponds and lake-
lets. In the water-
plantain you have a
flower of both sexes
combined ; it consists
of three green sepals,

FIG. 21.— FLOWER OF WATER- fnrrrijnfy o rirofppHvP

PLANTAIN. The male and to™mg a P10™
female parts are in the same calyx '> tnree delicate
blossom. pinky - white petals,

forming the corolla ;

six stamens — that is to say, two rows of three
each ; and a number of small one- seeded carpels,
exactly as in the buttercup, which occupies, in
fact, the corresponding place among the fivefold
flowers.

But it is not often in the threefold flowers that
we get the calyx green and the corolla coloured,
as in these simple and very early types. Most
often in this great group of plants the calyx and
corolla are both brightly coloured, and both alike

MOKE MAEBIAGE CUSTOMS. 119

employed as effective advertisements. A good
case of this sort is shown in the flowering-rush,
a close relation of the arrowhead and the water-
plantain, but a more advanced and deve-
loped plant than either of them. Here the
calyx and corolla, instead of forming two sepa-
rate rows, are telescoped into one, as it were,
and are both rose-coloured. In such cases we
speak of the combined calyx and corolla as the
perianth (another long word, with which I'm
sorry to trouble you). In such perianths, how-
ever, even when all the pieces are of the same
size and are similarly coloured, you can see if
you look close that three of them are outside
and alternate with the others ; and these three
are really the calyx in disguise, got up as a
corolla. (An excellent example of this arrange-
ment is afforded by the common garden tulip.)
Inside its six rose-coloured perianth-pieces, the
flowering-rush has nine stamens, arranged in
three rows of three stamens each. Finally, in
the centre, it has six carpels, equally arranged
in two rows of three. Here the threefold
architectural ground-plan of the flower is very
apparent. You may say, in short, that the
original scheme of the two great groups is some-
thing like this : five sepals, five petals, five
stamens, five carpels ; or else, three sepals,
three petals, three stamens, three carpels. But
in any instance there may be two or more such
rows of any organ, especially of the stamens ;
in any instance certain parts may be reduced
in number or entirely suppressed ; and in any
instance calyx and corolla may be coloured

120 THE STORY OF THE PLANTS.

alike so as almost to resemble a single row or
perianth.

There is one more point about the flowering-
rush to which I would like to allude before going
on to the other threefold flowers, and that is
this. In arrowhead and water-plantain the
carpels are very numerous, but each one-seeded.
In flowering-rush, on the other hand, which has
a larger and handsomer blossom, more attractive
to insects, they are reduced to six ; but these
six have many seeds in each, so that a single
act of fertilisation suffices for each of them.
You may remember that among the fivefold
flowers we found a precisely similar advance on
the part of the marsh-marigold above the
bulbous and meadow buttercups. This sort of
advance is common in nature. Where a flower
learns how to produce many seeds in a carpel,
it can soon dispense with several of its carpels,
because a few now do well what the many did
badly. Furthermore, in higher plants, there is
a tendency for these carpels to unite so as to
form what we call a compound ovary, with a
single style, when one act of fertilisation suffices
for all of them. Such combinations or labour-
saving arrangements obviously benefit both the
insect and the plant, and have therefore been
doubly favoured by natural selection.

We see this advance beautifully illustrated in
the largest and loveliest family of the threefold
flowers, the lily group, which contains a great
number of the handsomest insect - fertilised
blossoms, and is therefore deservedly an im-
mense favourite in flower-gardens. All the lilies

MOKE MAKKIAGE CUSTOMS. 121

have a perianth (or combined calyx and corolla)
of six almost similar HrTfTiantly-coloured pieces
(in which, however, you can still, as a rule,
detect the sepals by their habit of overlapping
the petals in the bud). Then they have a set of ;
six stamens. Inside that, again, they have a
single ovary, but if you cut it across with a
penknife you will see at once it contains three
chambers, each as a rule with several seeds j'lmd
these three chambers are a memorv^of the time
when the ovary consistecT of three t separai^
carpels. From their midst arises~^TsingfeTiong
style ; but you may observe all the same that it
is made up of ffixea o^jgjnfll a.nfl rh'nt.JTinti iiliT^Tj'
because it divides at the top into three stigmas
or sensitive surfaces. This is the general plan
of the lily group ; but in certain individual
lilies the stigma is undivided, and in others
again the parts are increased to four or even to
eight, so as to obscure the primitive threefold
arrangement.

Most of the large and handsome lilies culti-
vated in gardens have perianths of separate
pieces, such as one knows so well in the tiger-
lily, the Turk's-cap lily, and the beautiful Japa-
nese lilium auratum. They have also abundant
honey, stored in a deep groove of the spotted
petals, and they are variegated and lined in such
a way as to guide insects direct to their store of
nectar. But the family has been so successful
with the higher insects, and has produced such
an extraordinary variety of very beautiful and
brilliant flowers, that it is quite impossible to
speak of them in detail. A few among them,

122 THE STOKY OF THE PLANTS.

like our own wild hyacinth, show a slight ten-
dency on the part of the petals and sepals to
unite into a bell-shaped tube ; still, even here
the pieces are really distinct and separate. But
in the true garden hyacinth the pieces unite into
a tubular perianth, like the tubular corolla of
the common harebell, except that in the harebell
the tube is formed by the union of the five
petals, while in the hyacinth it is formed by the
similar union of three petals and three sepals.
A still higher form of the same union is shown
us by the lily-of-the-valley, in which the six
perianth-pieces join throughout to form a very
beautiful heather - like cup or goblet. Other
familiar members of this great lily group, which
you ought to examine at leisure for yourself, in
order to see how they are built up, are aspa-
ragus, Solomon's seal, fritillary, tulip, star-of-
Bethlehem, squill, garlic, onion, tuberose, and
asphodel. The cultivated lilies of one sort or
another to be found in our gardens may be
numbered by hundreds.

A family of threefold flowers almost as beauti-
ful as the lily group, and seldom distinguished
from them save by botanists, is that which
bears the pretty Greek name of amaryllids. The
amaryllids are lilies which differ from the rest
of their kind, in the fact that the perianth, still
composed of six pieces, has grown up and around
the ovary so as to seem to spring from above it,
not below it. Such flowers are said to have
"inferior ovaries." In other respects the
amaryllids closely resemble the lilies, having
six coloured perianth-pieces, six stamens, and

MORE MARRIAGE CUSTOMS. 123

an ovary of three chambers, with one style in
common. Several of the amaryllids are such
familiar flowers that I shall venture to describe
them as illustrative examples.

The snowdrop is an amaryllid which blossoms
in early spring, and which shows in a simple
form the chief features of the family. It has six
perianth-pieces, but these are still distinctly
recognisable as calyx and corolla. The three
sepals are large and pure white, and they
enclose the petals ; the three petals are dis-
tinctly smaller, and tipped with green in a very
pretty fashion. The summer snowflake, com-
monly cultivated in old-fashioned gardens, is
very like the snowdrop, only here the difference
between sepals and petals has disappeared ; all
six pieces form one apparent row, white, tipped
with green, in a single perianth.

In the daffodils and narcissuses we get a
second group of amaryllids more advanced and
developed. Here the six perianth-pieces are
almost alike, though they may still be distin-
guished as sepals and petals by a careful ob-
server. But the perianth, which is tubular
below, divides above into six lobes, beyond
which it is prolonged again into what is called
a crown, whose real nature can only be under-
stood by comparison with such other flowers as
the campions, where scales are inserted on the
tip of the petals. This crown is comparatively
little developed in the narcissus and the jonquil;
but in the daffodil it has become by far the
largest and most conspicuous part of the entire
flower, so as completely to hide the bee who

124 THE STOEY OF THE PLANTS.

visits it. Of course this large crown assists
fertilisation, and is a mark of advance in the
daffodil and the petticoat narcissus. I hope
these few remarks will induce you to examine
many kinds of narcissus in detail, in order to
see of what parts they are compounded.

This seems a convenient place to interpose
another remark I have long wanted to make,
namely, that the threefold flowers are also for
the most part distinguished by having those
narrow grass-like or sword-shaped leaves, with
parallel ribs or veins, about which I told you
when we were dealing with the question of
varieties of foliage. The fivefold flowers, on
the other hand, have usually net-veined leaves,
either feather-ribbed or finger-ribbed. And at
the risk of using two more horrid long words, I
shall venture to add that botanists usually speak
of the threefold group as monocotyledons, and of
the fivefold group as dicotyledons. I did not
invent those words, and I am sorry to have
to use them here ; but I will explain what
they mean when I come to deal with seeds and
seedlings. It is well at least to understand
their use in case you come across them in your
future reading.

Another family of threefold flowers, closely
allied to the amaryllids, is that of the irises,
many examples of which are familiar in our
flower-gardens. It only differs from the ama-
ryllids, in fact, in having the number of stamens
still further reduced to three, which is always
a sign of advance^ because it shows that the
plants are so sure of fertilisation as to be able

MORE MARRIAGE CUSTOMS. 125

to dispense with all unnecessary pollen. The
ovary is also inferior, which you will learn in
time to recognise as a constant sign of high
development, because it means that the base of
the corolla and calyx have coalesced with the
carpels, and so ensured greater certainty of
fertilisation. Some simple members of the
iris group, like the crocuses, have mere tubular
flowers, with a very long funnel-like base to
the corolla, and with the ovary buried in the
ground for greater safety. They are early
spring blossoms, which need much protection
against cold; therefore they thus bury their ova-
ries, and sheathe their flower-buds in a papery
covering, composed of a thin and leathery leaf.
Whenever a sunny day comes in winter the
bees venture out ; and on all such days, even
though it freeze in the shade, the crocuses are
open in the sunshine to welcome them.

But other irises are more complicated, like
the gladiolus, and still more the garden irises,
in which the difference between the calyx and
corolla is carried to its furthest point in this
family. The sepals in truefirises are large and
brilliantly coloured ; they hang over gracefully ;
the petals are smaller and erect ; the stigmas
are so expanded as to look like petals ; and
they arch over the stamens in a most peculiar
manner. If you watch a bee visiting a garden
iris, you will see for yourself the use of this
most peculiar arrangement ; the bee lights on
the bending sepal, and inserts his head between
the stigma and the stamen in a way which
renders fertilisation simply inevitable. But the

126 THE STORY OF THE PLANTS.

most curious part of it all is that the flower,
from the point of view of the bee, resembles
three distinct and separate blossoms ; he alights
one after another on each bending sepal, and
proceeds to search for honey as if in a new
flower.

Highest of all the threefold flowers, and most
wonderful in their marriage customs, are the

FIG. 22. — SINGLE FLOWER OF ORCHID, WITH THE

PERIANTH CUT AWAY. The honey is in the
spur, n; the pollen -masses are marked a;
their gummy base is at r ; the stigma at st.

great group of orchids, some of which grow wild
in our English meadows, while others fix them-
selves by short anchoring roots on the branches
of trees in the tropical forests. Many of these
last produce the handsomest and most extra-
ordinary flowers in the world, and they are

MORE MARRIAGE CUSTOMS. 127

much cultivated accordingly in hothouses and
conservatories. It would be quite impossible
for me to give you any account of the infinite
devices invented by these plants to secure
insect-fertilisation ; and even the structure of
the flower is so extremely complex that I can
hardly undertake to describe it to you intel-
ligibly; but I will give you such a brief state-
ment of its chief peculiarities as will enable you
to see how highly it has been specialised in
adaptation to insect visits.

The ovary in orchids is inferior, and curiously
twisted. It supports six perianth-pieces, three
of which are sepals, often long and very hand-
some ; while two are petals, often arching like a
hood over the centre of the flower. The third
petal, called the lip, is quite different in shape
and appearance from the other two, and usually
hangs down in a very conspicuous manner.
There are no visible stamens, to be recognised
as such ; but the pollen is contained in a pair
of tiny bags or sacks, close to the stigma. It
is united into two sticky club-shaped lumps,
usually called the pollen-masses (Fig. 22). In
other words, the orchids have got rid of all their
stamens except one, and even that one has united
with the stigma.

I will only describe the mode of fertilisation
of one of these plants, the common English
spotted orchis ; but it will suffice to show you
the extreme ingenuity with which members of
the family often arrange their matrimonial
alliances. The spotted orchis has a long tube
or spur at the base of its sepals (Fig. 22, ri), and

128

THE STORY OF THE PLANTS.

this spur contains abundant honey. The pollen-
masses are neatly lodged in two little sacks or
pockets near the stigma, and are so placed that
their lower ends come against the bee's head as
he sucks the honey. These lower ends (r) are
gummy or viscid, and if you press a straw or
the point of a pencil against them, the pollen-
masses gum themselves to it naturally, and
come readily out of their sacks as you withdraw
the pencil (Fig. 23), In the same way, when

I P

FIG. 23. — POLLEN-MASSES OF AN OBCHID, WITH-
DRAWN ON A PENCIL. In I, they have just
been removed. In II, they have dried and
moved forward.

the bee presses them with his head, the pollen-
masses stick to it, and he carries them away with
him as he leaves the flower, Just at first, the
pollen-masses stand erect on his forehead; but as
he flies through the air, they dry and contract,
so that they come to incline forward and out-
ward. By the time he reaches another plant
they have assumed such a position that they
are brought into contact with the stigma as he
sucks the honey. But the stigma is gummy too,
and makes the pollen adhere to it, and in this

MORE MARRIAGE CUSTOMS.

129

way cross-fertilisation is rendered almost a dead
certainty. The result of these various clever
dodges is that the orchids have become one of
the dominant plant-families of the world, and in
the tropics usurp many of the best and most
favoured positions (Fig. 24).

Darwin has written a most romantic book on
the numerous devices by which orchids alone
attract insects to fertilise them. I will say no
more of this family, therefore
— the highest and strangest
among the threefold flowers
— save merely to advise those
who wish to know more of
this curious subject to look
it up in his charming volume.
Instead of pursuing the
matter at issue further, I
will give one final example
in an opposite direction.

An opposite direction, I
say, because all the threefold
flowers we have hitherto been
considering are examples
of a strict upward move-
ment of evolution. Each group we have ex-
amined has been higher and more complex
than the group before it. But I will now show
you an instance, if not of degeneracy, at least of
extreme simplification, which yet produces in
the end the best possible results. This instance
is that of the common English arum, known to
children as cuckoo-pint or " lords and ladies "
(Fig. 25).

9

no. 24. — THE TWO

POLLEN-MASSES, VERY
MUCH ENLARGED.

130 THE STORY OF THE PLANTS.

The structure of the cuckoo-pint is very
peculiar. What looks like the flower is not
really any part of the flower at all, but a large

FIG. 25. — THE COMMON ARUM, OB CUCKOO-
PINT, SHOWING THE SPATHE WHICH SUR-
ROUNDS THE FLOWERS, AND THE SPIKE
STICKING UP IN THE MIDDLE.

outer leaf or spathe surrounding a group of very
tiny blossoms. You can understand this leaf
better if you look at a narcissus stalk, where

MOKE MAKKIAGE CUSTOMS.

131

a very similar leaf is seen to enclose a whole
bunch of buds and opening flowers. Only, in
the narcissus the spathe is thin, whitish, and
papery, while in the cuckoo-pint it is expanded,
green, and purple. Though not a corolla, it
serves the same purpose as a corolla generally
performs : it attracts insects
to the compound flower-head.
Inside the spathe we find
a curious club-shaped mass,
coloured bright purple, and
standing straight up in the
middle of the head. This is
the stem or axis on which the
separate little flowers are
arranged. Cut open the spathe,
and you will find these flowers
below in the centre (Fig. 26).
At first sight what you see
will look like a lot of confused
little knobs ; but when you
gaze closer you will see they
separate themselves into three
groups, which are the true
flowers. Lowest of all on the
stem come the female blossoms,
without calyx or corolla, each
consisting of a single ovary.
Above these in a group come the male flowers,
equally devoid of calyx or corolla, and each con-
sisting of a single stamen. Above these again
come abortive or misshapen flowers, each of
which has been reduced to a single downward-
pointing hair. I will explain first what is the

132 THE STOKY OF THE PLANTS.

use of these flowers in the cuckoo-pint as it
stands to-day, and then I will go back to con-
sider by what steps the plant came to develop
them.

The upper flowers, which look like hairs, and
point all downwards, occupy a place in the
compound flower-head just opposite the con-
spicuous narrowed part of the spathe which
surrounds and encloses them. At this narrow
point they form a sort of lobster-pot. It is easy
enough for an insect to creep down past them,
but very difficult or impossible tefTiim to creep
up in the opposite direction, as all the hairs
point sharply downward. Now, when the
spathe unfolds, large numbers of a very small
midge of a particular species are attracted into
it by the purple club which rises like a barber's
pole in the middle. If you cut a cuckoo-pint
open during its flowering period you will always
find a whole mob of these wee flies, crawling
about in it vaguely, and covered from head to
foot with pollen. They have come from another
cuckoo-pint which they previolisIy^vTslte^T^ari^
they have brought the pollen with them on their
wings and bodies. But when they first reach
the head, they find no pollen there ; the^ JgrngJ^
flowers at the bottom ripen first, and the midges,
creeping over the sensitive surface of these, fer-
tilise them with pollen from the last plant they
enterdd. Finding nothing to eat, if they could
they would crawl out again ; but they can't, for
the lobster-pot hairs prevent them. So they
stop on perforce, having unwittingly fertilised
the female flowers, but received themselves as

MORE MABBIAGE CUSTOMS. 133

yet no reward for their trouble. By and by,
however, rfjteE-Ali the female flowers have been
duly fertilise3, tne males' aBove begin to ripen.
When the stamens reach maturity, they shower
down a whole flood of golden pollen on the
expectant midges. Then the midges positively
roll and revel in the flood, eating all they can,
but at the same time covering themselves all
over with a dust of pollen-grains. As soon as
the pollen is all shed, the downward-pointing
hairs wither away; the lobster-pot ceases to act;
and tHexmi3gBsr1lre at liberty to fly away to
another plant, where they similarly begin to
fertilise the female flowers. Observe that, if
the stamens were the^jfirst to ripen here, the
pollen would fall on the stigmas of the same
plant, but that, by making the stigma£"iT6 TTTeT*
first to mature, the cuckoo-pint secures for itself
the desired end of cross-fertilisation.

In this case it is an interesting fact that all
the stages which led to the existing arrangement
of the flowers still remain visible in other plants
for us. These very reduced little blossoms of the
cuckoo-pint, consisting each of a single carpel or
a single stamen, arejet tl^^jscgnx^
feet blossoms^ whltfliTiad once a regular calyx
and corolla. Near relations of the cuckoo-pint
live in Europe and Africa to this day, which
recapitulate for us, as it were, the various stages
in its slow evolution. Some, the oldest in type,
have a calyx and corolla, green and inconspicu-
ous, with six stamens inside them, enclosing a
two or three-celled ovary. These are still essen-
tially lilies in structure. But they have the

134 THE STOEY OP THE PLANTS.

flowers clustered, as in cuckoo-pint, on a thick
club-stem, and they have an open spathe, which
more or less protects them. Our English sweet-
sedge is still at this stage of evolution. The
marsh-calla of Northern Europe and Canada, on
the other hand, has a handsome white spathe to
attract insects, while its separate flowers, still
both male and female together, have each six
stamens and a single ovary. But they have lost
their perianth. The common white arum or
"calla lily" of cottage gardens has a bright
yellow spike in its midst, and if you look at it
closely you will see that this spike consists
entirely of a great cluster of stamens, thickly
massed togetherT~Tne top of the s~pike~is entirely
composed of such golden stamens, but lower
down you will find ovaries embedded here and
there among them, each ovary as a rule sur-
rounded by five or six stamens. Lastly, in the
cuckoo-pint the lower flowers have lost their com-
plement of stamens altogether, while the upper
ones have similarly lost their ovaries ; moreover,
a few of the topmost have been converted into
the curious lobster-pot hairs which assist, as I
have shown you, in the work of fertilisation.
We have here a singular and instructive example
of what may be described as retrograde develop-
ment.

And now we must go on to those modes of
fertilisation which are effected by agencies other
than insects.

CHAPTEE IX.

THE WIND AS CAKHIER.

ALL flowers do not depend for fertilisation upon
insects. In many plants it is the wind that
serves the purpose of common carrier of pollen
from blossom to blossom.

Clearly, flowers which lay themselves out to
be fertilised by the wind will not be likely to
produce the same devices as those which lay
themselves out to be fertilised by insects.
Natural selection here will favour different quali-
ties. Bright- coloured petals and stores of honey
will not serve to allure the unconscious breeze ;
such delicate adjustments of part to part as we
saw in the case of bee and blossom will no longer
be serviceable. What will most be needed now
is quantities of pollen ; and that pollen must
hang out in such a way from the cup as to be
easily dislodged by passing breezes. Hence
wind-fertilised flowers differ from insect-ferti-
lised in the following particulars. They have
never brilliant corollas or calyxes. The stamens
are usually very numerous; they hang out
freely on long stalks or filaments ; and they
quiver in the wind with the slightest movement.
On the other hand, the stigmas are feathery and
protrude far from the flower, so as to catch every
passing grain of pollen. More frequently than
among the insect-fertilised section, the sexes are
separated on different plants or isolated in dis-
tinct masses on neighbouring branches. But

135

136 THE STOKY OF THE PLANTS.

numerous devices occur to prevent self-fertili-
sation.

You must not suppose, again, that the wind-
fertilised plants form a group by themselves,
distinct in origin from the insect-fertilised, as
Uhe three-petalled group is distinct from the
five-petalled. On the contrary, wind-fertilised
, kinds are found abundantly in both great
^groups ; it is a matter of habit ; so much so that
* sometimes a type has taken first to insect-fertili-
sation and then to wind-fertilisation, with com-
paratively slight differences in its external
appearance. Closely related plants often differ
immensely in their marriage customs ; each has
varied in the way that best suited itself, accord-
ing as insects or breezes happened to serve it
most readily. In my own opinion all wind-
fertilised plants are the descendants of insect-
fertilised ancestors ; but I do not know whether
in this belief my ideas would be accepted by
most modern botanists.

As a first example of wind-fertilised flowers,
I will take the common dog's mercury, a well-
known English wayside flower, frequent in
copses and hedgerows, and one of the very
earliest to blossom in spring. In this species
the males and females grow on senarate plants.
They have each a calyx of three sepals (two
more being suppressed, for they belong by
origin to the fivefold division). The males have
ten or twelve stamens apiece, which hang out
freely with long stalks to the breeze. The
females have a two-chambered ovary, with
rudiments or relics of some two or three

ttfiE WIND AS CARRIED.

137

stamens by its side, showing that they are
descended from earlier combined rnale-and-
female ancestors. The relics, however, consist
of mere empty stalks or filaments, without any
pollen-sacks. Of course there are no petals.
Male and female plants grow in little groups
not far from one another ; and the pollen, which
is dry and dusty, is carried by the wind from
the hanging stamens of the males to the large
and salient stigma of
the female flowers.
A still better ex-
ample of a wind-
fertilised blossom is
afforded us by the
common English
salad - burnet, a
pretty little weed,
very frequent on
close-cropped chalk
downs (Fig. 27).
Here the individual
flowers are ex-
tremely small, and
they are crowded
into a sort of mop-
like head at the top of the stem. They have lost
their petals, which are now of no use to thenf;
but they retain a calyx of four sepals, to represent
the original five still found among their relations.
For salad-burnet, in spite of its inconspicuous-
ness, belongs to the family of the roses, and we
can still trace in this order a regular gradation
from handsome flowers like the dog-rose, through

FIG. 27. — A, MALE, AND B, FEMALE
FLOWER OF SALAD-BURNET, VERY
MUCH MAGNIFIED. The floWGIS

grow together in little tassel-
like heads.

138 THE STORY OF THE PLANTS.

smaller and smaller blossoms like the strawberry
and the potentilla, to green petalless types like
lady's-mantle and parsley-piert, or, last of all, to
wind-fertilised blossoms like those of the salad-
burnet. In the male flowers the very numerous
stamens hang out on long thread-like stalks
from the wee green cup, so that the wind may
readily catch and carry the pollen : in the
female blossoms the stigma is divided into
plume-like brushes, which readily entrap any
passing pollen-grain. Moreover, though both
kinds of flower grow on the same head, the
females are mostly at the top of the bunch, and
the males below them. This makes it difficult
for the pollen from the same head to fertilise the
females, as it would easily do if the males were
at the top. Nor is that all ; the female flowers
open first on each head, and hang out their
pretty feathery stigmas to the breeze that bends
the stem ; as soon as they have been fertilised
from a neighbour plant, the males in turn begin
to open, and shed their pollen for the use of
other flowers. In salad-burnet, however, the
division of the sexes into separate flowers has
not become a quite fixed habit ; for, though
most of the blossoms are either maleor female
only, as shown in the figure, we often find a cup
here and there which contains both stamens and
pistil together.

I have already told you that in many plants
the calyx helps the corolla as an advertisement
for insects ; and sometimes, as in the marsh-
marigold and the various anemones, where there
are no petals at all, it becomes so brilliant as to

THE WIND AS CAKRIEK. 139

be mistaken for petals by all but botanists. One
way in which such a substitution often happens
is shown us by the
great burnet, which
is a close relation of
thesalad-burnet. This
plant, after having
acquired the habit of
wind-fertilisation, has
taken again at last
to insect marriage.
Having lost its petals,
however, it can't
easily redevelop them ;
30 it has had instead
to make its calyx
purple. The plant as
a whole closely re-
sembles the salad-
burnet ; but the
flowers are rather
different ; the stamens
no longer hang out
of the calyx ; the
calyx cup is more
tubular ; and the
stigma is shortened
to a little sticky knob,
instead of being
divided into feathery
fringes. These dif-
ferences are all very characteristic of the con-
trast between wind and insect-fertilisation.
The common nettle supplies us with an excel-

140 THE STOBY OF THE PLANTS.

lent example of another form of wind-fertilisa-
tion, carried to a still higher pitch of develop-
ment. Here the sexes grow on different plants,
and the flowers are tiny, green, and inconspicu-
ous. The males consist of a calyx of four sepals,
each sepal with a stamen curiously caught under
it during the immature stage. But as soon as
they ripen they burst out elastically, and shoot
their pollen into the air around them. In this
case, and in many like it, the plant itself helps
the wind, as it were, to disseminate its pollen.

The common English bur-reed is a waterside
plant of great beauty which shows us another
interesting instance of wind-fertilisation in an
advanced condition (Fig. 28). Here the sepa-
rate flowers are very much reduced — as simple,
in fact, as those of the cuckoo-pint. The males
consist of nothing but stamens, gathered in close
globular heads, with a few small scales inter-
spersed among them, which seem to represent
the last relics of a calyx. The females are made
up of single ovaries, each surrounded by three
or six scales, still forming a simple rudimentary
calyx. They, too, are clustered in round heads
or masses on antler-like branches. The plant
belongs to the threefold group, and represents
a very degenerate descendant of a primitive
ancestor something like the arrowhead already
described in the last chapter. But the arrange-
ment of the heads on the stem is very interest-
ing. The balls at the top are entirely composed
of male flowers ; those at the bottom are exclu-
sively female. The female flowers ripen first,
and receive pollen by aid of the wind from some

THE WIND AS CAKKIEK. 141

other plant that grows close by them. As soon
as they have begun to set their seeds the
stigmas wither, and then the male flowers open
in a bright yellow mass, the stalks of their
stamens lengthening out as they do so, and
allowing the wind to carry the pollen freely.
Here, although the males are above, the pecu-
liar arrangement by which the females ripen
first makes it practically impossible for the
flowers to be fertilised by pollen from their
immediate neighbours.

The devices for wind-fertilisation, however,
are on the whole less interesting than those for
insect-fertilisation, so I shall devote little more
space to describing them. I will only add that
two great classes of plants are habitually wind-
fertilised : one includes the majority of forest
trees ; the other includes the grasses, sedges,
and many other common meadow plants.

The wind-fertilised forest trees belong for the
most part to the fivefold group, and have their
flowers, as a rule, clustered together into hang-
ing and pendulous bunches, which we call cat-
kins. It is obvious why trees should have
adopted this mode of fertilisation, because they
grow high, and it is easy for the wind to move
freely through them. For this reason, most
catkin-bearing trees flower in early spring, when
winds are high, and when the trees are leafless ;
because then the foliage doesn't interfere with
the proper carnage of the pollen. In summer
the leaves would get in the way ; the pollen
would fall on them ; and the stigmas would be
hidden. Most catkins are long, and easily

142 THE STOKY OF THE PLANTS.

moved by the wind ; they have numerous
flowers in each, and they shake out enormous
quantities of pollen. This you can see for your-
self by shaking a hazel branch in the flowering
season, when you will find yourself covered by
a perfect shower of pollen.

In hazel (Fig. 29) the male and female
flowers grow on the same tree, but are most
different to look at. You would hardly take

1

FIG. 29. — FLOWERS OP THE HAZEL. I, a single
male flower, removed from a catkin. II,
a pair of female flowers. Ill, a female
catkin.

them for corresponding parts of the same
species. The male flowers are grouped in long
sausage-shaped catkins, each blossom covered
with a tiny brown scale, and all arranged like
tiles on a roof against the cold of winter. There
are about eight stamens to each blossom, with
little trace of a calyx or corolla. But the females
are grouped in funny little buds, like crimson
tufts, well protected by scales ; they consist of
the future hazel-nut, with a red style and
feathery stigma projecting above to catch the
pollen. Here the flowers are very little like

THE WIND AS CARRIER. 143

the regular types with which we are familiar;
yet intermediate cases help to bridge over the
gap for us.

For example, in the alder we get a type which
seems to stand half-way between the nettle and
the hazel (so far, I mean, as the arrangement of
the flower is concerned, for otherwise the nettle
belongs to a quite different family). The male
and female catkins of the alder grow on the
same tree ; the males consist of numerous
clustered flowers, three together under a scale,
which nevertheless, when we take the trouble to
pick them out and examine them with a pocket -
lens, are seen to resemble very closely the male
flowers of the nettle. Each consists of a four-
lobed calyx, with four stamens opposite the
sepals. The female flowers have degenerated
still further, and consist of little more than a
scale and an ovary.

Other well-known wind-fertilised, catkin-bear-
ing trees are the oak, the beech, the birch, and
the hornbeam. But the willows, though they
bear catkins, and were once no doubt wind-
fertilised, have now returned once more to
insect-fertilisation, as you can easily convince
yourself if you stand under a willow tree in
early spring, when you will hear all the branches
alive with the buzzing of bees, both wild and
domestic. Nevertheless, the willow, having
once lost its petals, has been unable to develop
them again. Still, its catkins are far hand-
somer and more conspicuous than those of its
wind-fertilised cousins, owing to the pretty
white scales of the female bunches, and the

144 THE STORY OF THE PLANTS.

numerous bright yellow stamens of the males.
It is this that causes them to be used for
" palm " in churches on Palm Sunday. The
male and female catkins grow on different trees,
so as to ensure cross-fertilisation, and the dif-
ference between the two forms is greater per-
haps than in almost any other plant, the males
consisting of two showy stamens behind a
winged scale, and the females of a peculiar
woolly-looking ovary.

Even more important is the great wind-ferti-
lised group of the grasses, to which belong by
far the most useful food-plants of man, such as
wheat, rice, barley, Indian corn, and millet.

Grasses are for the most part plants of the
open wind-swept plains, and they seem natu-
rally to take therefore to wind-fertilisation.
Their flowers are generally small, clustered into
light spikes or waving panicles, and hung out
freely to the breeze on slender and very movable
stems, so as to yield their pollen to every breath
of air that passes. Moreover, the plants as a
whole are slender and waving, so that they bend
before the breeze in the mass, as one often sees
in a meadow or cornfield. Thus the grasses are
almost the pure type of wind-fertilised plants;
certainly they have carried further than any
other race the devices which render wind-
fertilisation more certain.

On this account they are so complicated and
varied that I will not attempt to describe them
in detail. I will only say that grasses are
| descendants of the threefold flowers, and in all
probability degenerate lilies. Their individual

THE WIND AS CAKBIER,

145

blossoms usually consist of a very degraded
calyx (d and e) of two sepals (one of which
represents a pair that have coalesced, Fig. 30).
Inside these sepals come two very minute white
petals (c and c) ; the third has disappeared,
owing to pressure one-sidedly. The petals can

FIG. 30. — A FLOWER OF
WHEAT, WITH ITS PARTS

DIVIDED : a, the carpel
and stigmas ; b, the
stamens ; c, the petals,
very minute ; d and e,
the calyx.

FIG. 31. — FLOWER OF WHEAT,
WITH THE CALYX OF TWO
CHAFFY SCALES REMOVED.

This shows the arrange-
ment of petals, stamens,
and ovary.

scarcely be seen without the aid of a pocket-
lens. Next come three stamens (b), the only
part of the flower which still preserves the
original threefold arrangement. Last of all we
get the ovary (a), of one carpel, one seeded, but
with two feathery stigmas, which were once
10

146 THE STORY OP THE PLANTS,

three. In a very few large grasses, such as the
bamboos, the threefold arrangement is much
more conspicuous. As a rule the stamens of
grasses hang out freely to the wind, and the
stigmas are feathery and most graceful in out-
line (Fig. 31). The flowers are usually collected
in spikes like that of wheat, or in loose clusters
like oats ; they frequently hang over in pen-
dulous bunches. Their success may be gathered
from the fact that almost all the great plains in
the world, such as the American prairies, the
Pampas, and the Steppes, are covered with
grasses ; while even in hilly countries the valleys
and downs are also largely clad with smaller
and more delicate species. No plants assume
so great a variety of divergent forms ; the total
number of kinds of grasses can hardly be
estimated ; in Britain alone we have more than
a hundred native species.

I will give no further examples of wind-
fertilised flowers. If you look for yourself you
can find dozens on all sides in the fields around
you. They may almost always be recognised
by these two marked features of the hanging
stamens and the feathery stigma.

Before I pass on to another subject, however,
I ought to mention that by no means all flowers
are regularly cross- fertilised. There are some
degraded types in which self-fertilisation has
become habitual. In these plants, which are
usually poor and feeble weeds like groundsel
and shepherd's purse, the stamens bend round
so as to impregnate the pistil in the same
blossom. In other less degraded cases the

HOW FLOWEKS CLUB TOGETHER. 147

flower is occasionally cross-fertilised by insect
visits ; but if no insect turns up in time, the
stamens, even in handsome and attractive
blossoms, often bend round and impregnate the
pistil. A very good example of this is seen in *
our smaller English mallow, which has large
mauve flowers to attract insects ; but should
none come to visit it, the stamens and stigmas
at last intertwine, and self -fertilisation takes
place, for want of better. Still, as a general
rule, it holds good that self-fertilisation belongs
to scrubby and degraded plants ; it is only
adopted as a last resort when all other means
fail by the superior species.

CHAPTEE X.

HOW FLOWERS CLUB TOGETHER.

IN the preceding chapters I have dealt for the
most part with individual flowers ; I have
spoken of them separately, and of the work
they do in getting the seeds set. Incidentally,
however, it has been necessary at times to
touch slightly upon the way they often mass
themselves into heads or clusters for various
purposes ; and we must now begin to consider
more seriously the origin and nature of these
co-operative societies.

Very large flowers, like the water-lily, the
tulip, the magnolia, the daffodil, are usually
solitary ; they suffice by themselves to attract
in sufficient numbers the fertilising insects.

148 THE STOEY OF THE PLANTS.

. But smaller flowers often find it pays them
better to group themselves into big spikes or
masses, as one sees, for example, in the fox-
glove and the lilac. Such an arrangement
makes the mass more conspicuous, and it also
induces the insect, when he comes, to fertilise
at a single visit a large number of distinct
blossoms. It is a mutual convenience ; for the
bee or butterfly, it saves valuable time ; for the
splant, it ensures more prompt and certain
fertilisation. In many families, therefore, we
can trace a regular gradation between large and
almost solitary flowers, through smaller and
somewhat clustered flowers, to very small and
. comparatively crowded flowers. Thus the
largest lilies are usually solitary or grow at
best three or four together, like the lilium
auratum ; in the tuberose and asphodel, where
the individual blossoms are smaller, they are
gathered together in big upright spikes ; in the
hyacinth, the clustering is closer still; while
in wild garlic, grape-hyacinth, and star-of-
Bethlehem, the arrangement assumes the form
of a flat-topped bunch or a globular cluster. Of
course, small flowers are sometimes solitary,
and large ones sometimes clustered ; but as a
general rule the tendency is for the big blossoms
to trust to their own individual attractions, and
for the little ones to feel that union is strength,
and to organise accordingly.

Botanists have invented many technical
names for various groupings of flowers in par-
ticular fashions, with most of which I will not
trouble you. It will be sufficient to recall

HOW FLOWERS CLUB TOGETHER. 149

mentally the very different way in which the
flowers are arranged in the lily-of-the-valley, the
foxglove, the Solomon's seal, the heath, the
scabious, the cowslip, the sweet-william, the
forget-me-not, in order to see what variety
natural selection has produced in all these
matters. Two instances must serve to illustrate
their mode of action. The foxglove grows in
hedgerows and thickets, and turns its one-sided
spike towards the sun and the open ; its flowers
open regularly from below upward, and are
fertilised by bees, who enter the blossoms, and
whose body is beautifully adapted to come in
contact, first with the stamens, and later with
the stigma. (Examine this familiar flower for
yourself in the proper season.) In the forget-
me-not, on the other hand, the unopened flowers
are coiled up like a scorpion's tail ; but as each
one opens, the stem below it lengthens and
unrolls, so that at each moment the two or
three flowers just ready for fertilisation are
displayed conspicuously at the top of the
apparent cluster.

There are two forms of cluster, however, so
specially important that I cannot pass them
over here without some words of explanation.
These are the umbel and the head, both of
frequent occurrence. An umbel is a cluster in
which the flowers, standing on separate stalks,
reach at last the same level, so as to form a
flat-topped mass, like the surface of a table.
An immense family of plants has very small
flowers arranged in such an order ; they are
known as umbellates, and they include hemlock,

150 THE STOKY OF THE PLANTS.

fool's parsley, cow-parsnip, carrot, chervil,
celery, angelica, and samphire. In other

FIG. 32. — CLUSTEBS OF FLOWERS. I, Spike of

mercury, green, wind-fertilised. II, panicle
of a grass (brome), green, wind-fertilised.
Ill, head of Dutch clover, the upper flowers
unvisited as yet by insects; the lower fer-
tilised, and turning down to make room for
their neighbours.

families the same form of cluster is seen

HOW FLOWERS CLUB TOGETHEE. 151

ivy and garlic. A head, again, is a cluster in
which the individual flowers are set close on
very short stalks or none at all in a round ball
or a circle. Clover and scabious are excellent
examples of this sort of co-operation.

If you examine a head of common white Dutch
clover (Fig. 32, iii.), you will see for yourself
that it is not, as you might suppose, a single
flower, but a thick mass of small white pea-like
blossoms, each on a stalk of its own, and each
provided with calyx, corolla, stamens, and
pistil. They are fertilised by bees ; and as soon I
as the bee has impregnated each blossom, it)
turns down and closes over, so as to warn the
future visitor that he has nothing to expect)
there. The flowers open from below and with-
out, upward and inward ; and there is always a
broad line between the rifled and fertilised
flowers, which hang down as if retired from
business, and the fresh and upstanding virgin
blossoms, which court the bees with their bright,
corollas. Sometimes you will find a head of
clover in which all the flowers save one have ^
already been fertilised ; and this one, a solitary *
old maid as it were, stands up in the centre still
waiting for the bees to come and fertilise it.

By far the most interesting form of head,
however, is that which occurs in the daisy, the
sunflower, the dandelion, and their allies, where
the club or co-operative society of united blos-
soms so closely simulates a single flower as to
be universally mistaken for one by all but
botanical observers. To the world at large a
daisy or a dahlia is simply a flower ; in reality

152 THE STORY OF THE PLANTS.

it is nothing of the sort, but a city or com-
munity of distinct flowers, differing widely
from one another in structure and function, but
all banded together in due subordination for the
purpose of effecting a common object. There is
a vast and very varied family of such united
flowers, known as the composites ; it stands at
^ the head of the fivefold group of flowering
-? .plantisTas the orchids stand at the head of the

FIG. 33. — SINGLE FLORET FIG. 34. — SINGLE FLORET

FROM THE CENTRE OF FROM THE CENTRE OF A

A DAISY. DAISY, WITH THE COROLLA

OPENED, MUCH ENLARGED.

threefold ; and it is so widely spread, it includes
so large a proportion of the best-known plants,
and it fills so great a space in the vegetable
world generally, that I cannot possibly pass it
over even in so brief and hasty a history as this
of the development of plants on the surface of
our planet.

If you pick a daisy you will think at first
sight it is a single flower. But if you look

HOW FLOWEKS CLUB TOGETHER.

153

closer into it you will see it is really a great
group of flowers— a compound flower-head, com-
posed of many dozen distinct blossoms or florets,
as we call them (Fig. 33). These, however, are
not all alike. The florets in the centre, which
you took no doubt at first sight for the stamens
and pistils, are small yellow tubular blossoms,
each with a combined corolla of five lobes, little
or no visible calyx, five
stamens united in a ring
round the style, and a
pistil consisting of an in-
ferior ovary, with a style
divided above into a two-
fold stigma (Fig. 34) . Here
we have clear evidence
that the plant belongs by
origin to the five-petalled
group ; it rather resembles
the harebell, in the plan
of its flower, on a much
smaller scale ; but it has
almost lost all trace of a
separate calyx, it has its
five petals united into a FIG. 35.
tubular corolla, it has still
its original five stamens,
but its carpels are now
reduced to one, with a
single seed, though traces of an earlier inter-
mediate stage, when the carpels were two,
remains even yet in the divided stigma.

So much for the inner flowers or florets in the
daisy. The outer ones, which you took at first

-SINGLE FLORET
FROM THE RAY OF A DAISY,
PINK AND WHITE, WITH
AN OVARY, BUT NO STA-
MENS.

;

154 THE STOKY OF THE PLANTS.

no doubt for petals, are very different indeed
from these central blossoms. They have an
extremely curious long, strap-shaped corolla
(Fig. 35), open down the side, but tubular at its
base, as if it had been split through the greater
part of its length by a sharp penknife. Instead
of being yellow, too, these outer florets are
white, slightly tinged with pink, and they form
the largest and most attractive part of the whole
flower-head. Furthermore, they are female
only ; they have a style and ovary, but no
[stamens. Clearly, we have here a flower-head
with numerous unlike flowers, which at once
suggests the idea of a division of labour between
the component members. How this division
works we shall see in the sequel.

The best way to see it is to follow up in detail
the evolution of the daisy and the other com-
posifeT^tfom an earlier ancestor. We saw
already how the petals combined in the harebell
and many other flowers so as to form a tubular
corolla. A purple flower of some such type
seems to have been the starting-point for the
development of the great composite family. The
individual blossoms in the common ancestral
form seem to have been small and numerous ;
and, as often happens with small flowers, they
found that by grouping themselves together in
a flat head they succeeded much better in
attracting the attention of the fertilising insects.
Many other tubular flowers that are not com-
posites have independently hit upon the same
device ; such are the scabious, the devil' s-bit,
the sheep's-bit, and the rampion. But these

HOW FLOWEES CLUB TOGETHEK. 155

flowers differ from the true composites in two
or three particulars. In the first place, each
tiny flower has a distinct green calyx, of five
sepals ; while the composites have none, or at
least a degraded one. In the second place, the.
stamens are free, while in the composites they
have united in a ring or cylinder. In the third
place, the ovary is divided into from two to five
cells, a reminiscence of the original five distinct
carpels ; whereas in the composites t?ie ovary is
always single and one-seeded. In all these
respects, therefore, the composites are later and
more advanced types than, say, the sheep's-bit,
which is a flower-head composed of very tiny
harebells.

The composites, then, started with florets
which had little or no calyx, th£^sepal£jiaving
been converted into tiny feathery Tiairs, used to
float the fruit" (aS' in thistledow~ri~~ahd dandelion) ,
about which we shall have more to say in a
future chapter. They had a corolla of five
purple petals, combined into a single tube.
Inside this again came five united stamens, and
in the midst of all an inferior ovary with a
divided stigma. Hundreds of different kinds of
composites now existing on the earth retain to
this day, in the midst of the greatest external
diversity, these essential features, or the greater
part of them.

You may take the thistle as a good example of
the composite flowers in an early and relatively
simple stage of development (Fig. 36). Here
the whole flower-head resembles a single large
purple blossom, To increase the resemblance,

156

THE STOKY OF THE PLANTS.

it has below it what seems at first sight to be a
big green calyx of very numerous sepals. What
is this deceptive object ? Well, it is called an
involucre, and it really acts to the compound

flower-head very
much as the calyx
acts to the single
blossom. The
florets having got
rid of their sepa-
rate calyxes, the
flower-head pro-
vides itself with
a cup of leaves
(technically called
bracts), which pro-
tect the unopened
head in its early
stages, and serve
to keep off ants
or other creeping
insects exactly as
a calyx does for
the single flower.
Inside this invo-
lucre, again, all
the florets of the
thistle are equal
and similar. Each
has a tiny calyx,
hardly recognis-
able as such, made up of feathery hairs which
cap the inferior ovary. Within this fallacious
calyx, once more, the floret has a purple corolla

TIG. 36. — FLOWER - HEAD OP A
THISTLE, CONSISTING OF VERY
NUMEROUS PURPLE FLORETS,
ALL EQUAL AND SIMILAR.

HOW FLOWEBS CLUB TOGETHER. 157

of five petals, united into a tube. Then come
the five united stamens, and the pistil with its
divided stigma. This is the simplest and central -,
form of composite, from which the others are
descended with various modifications.

To this central type belong a large number of
well-known plants, both useful and ornamental,
though more particularly deleterious. Among
them may be mentioned the various thistles,
such as the common thistle, the milk thistle, the
Scotch thistle, and so forth, most of which have
their involucres, and often their leaves as well,
extremely prickly, so as to ward off the attacks
of goats and cattle. The burdock, the artichoke,
the saw-wort, and the globe-thistle also belong to
the same central division. Among these earlier
composites, however, there is one group, that of
the centauries, which leads us gradually on to
the next division. Our commonest centaury in
Britain (known to boys as hardheads) has all the
florets equal and similar, and looks in the flower
very much like a thistle. But one of its forms,
and most of the cultivated garden centauries,
have the outer florets much larger and more
broadly open than the central ones, so that they
form an external petal-like row, which adds
greatly to the attractiveness of the entire flower-
head. Of this type, the common blue cornflower
is a familiar example. Clearly the plant has
here developed the outer florets more than the
inner ones in order to make them act as extra
special attractions to the insect fertilisers.

The more familiar type of composites so much
cultivated in gardens carries these tactics a step

158 THE STOKY OF THE PLANTS,

further. We saw reason to believe in a previous
chapter that pgfel^ ^gre^ori^inally sepals, flat-
tened and brightly coloured, ~an3 told on Tor the
special attractive function. Just in the same
way the ray-florets of the daisy, the sunflower,
the single dahlia, and the aster are florets which
have been flattened and partially or wholly
sterilised in order to act as allurements to
insects. The ray-floret acts for the compound
flower-head as the petal acts for the individual
blossom.

In many other families of plants besides the
composites we get foreshadowings, so to speak,
of this mode of procedure. The outer flowers of
a cluster, be it head or umbel, are often rendered
larger so as to increase the effective attractive-
ness of the whole ; and sometimes they are
sacrificed to the inner ones by being made
neuter or sterile, that is to say, being deprived
of stamens and pistil. Thus in cow-parsnip,
which is a member of the same family as the
carrot and the hemlock, the outer flowers of each
umbel are much larger than the central ones,
while in the wild guelder-rose the central
flowers alone are fertile, the outer ones being
converted into mere expanded white corollas
with no essential floral organs. But it is the
composites that have carried this process of
division of labour furthest, by making the ray-
florets into mere petal-like straps, which do no
work themselves, but simply serve to attract the
fertilising insects to the compound flower-head.

An immense number of these composites with
flattened ray-florets grow in our fields or are

HOW FLOWERS CLUB tfOGEtfHEB. 159

cultivated in our gardens. In the simpler
among them, such as the sunflower, the corn-
marigold, the ragwort, and the golden-rod, both
ray-florets and central florets are simply yellow.
But in others, such as the daisy, the ox-eye
daisy, the aster, and the camomile, the ray-
florets differ in colour from those of the centre ;
the latter remain yellow, while the former
become white, or are tinged with pink, or even
flaunt forth in scarlet, crimson, blue, or purple.
Of this class one may mention as familiar
instances the dahlia, the zinnia, the Michaelmas
daisies, the cinerarias, and the pretty coreopsis
so common in our gardens. Gardeners, how-
ever, are not content to let us admire these
flowers as nature made them. They generally
"double" them — that is to say, by carefully
selecting certain natural varieties, they produce
a form in which all the florets have at last
become neutral and strap- shaped. This is well
seen in the garden chrysanthemum, where, how-
ever, if you open the very centre of the doubled
flower-head, you will generally find in its midst
a few remaining fertile tubular blossoms. The
same process is also well seen in the various
stages between the single and the double dahlia.
Such "double" composites can set little or no
seed, and are therefore from the point of view of
the plant mere abortions. Nor are they beautiful
to an eye accustomed to the ground plan of floral
architecture. Remember, of course, that what
we call " a double flower " in a rose, a butter-
cup, or any other simple blossom is one in
which the stamens have been converted into

160 THE STOEY OF THE PLANTS.

supernumerary and useless petals ; while in a
composite it is a flower-head in which the central
florets have been converted into barren ray-florets.
In either case, however, the result is the same —
the flowers are rendered abortive and sterile.

Nature's way is quite different. Here is how
she manages the fertilisation of one of these ray-
bearing composites — say for example the sun-
flower, where the individual florets are quite big
enough to enable one to follow the process with
the naked eye. The large yellow rays act as
advertisements ; the bee, attracted by them,
settles on the outer edgo. and fertilises the
flowers from without inward. To meet this
habit of his, the florets of tire sunflower pass
through four regular stages. They opeji^P^S
without inward. In the centre are unopened
buds. Next come open flowers, in which the
stamens are shedding their pollen, while the
stigmas are still hidden within the tube. Third
in order, we get florets in which the stamens
have withered, while the stigmas have now
ripened Imcf opened. Last of all, we get, next
to the rays, a set of overblown florets, engaged
in maturing their fertilised fruits. The bee thus
comes first to the florets in the female stage,
which he fertilises with pollen from the last
uplant he visited ; he then goes on to florets in
the male stage, where he collects more pollen
for tKeTnext plant to which he chooses to devote
his attention. The florets of the sunflower are
interesting also for the fact that, unlike most
composites, they still retain obvious traces of
a true

BLOWERS CLUB TOGETHER. 161

Hie composites which produce purple ^ or blue
ray-florets to attract insects are in some ways the
highest of their class. Still, there is another
group of composites which has proceeded a
little further in ojae direction ; and that is the
group which includes the dandelions. In these
heads all the florets alike have become strap-
shaped or ray-like ; but they differ from the
double composites of the gardeners in this, that
each floret sUU^retains its stamens and pistil.
The composites^aoT"'"ffie dandelion group are
chiefly weeds like the hawkbit and the sow-
thistle. A few are cultivated as vegetables,
such as lettuce, salsify, chicory, and endive ;
fewer still are prized for their flowers for
ornamental purposes, such as the orange hawk-
weed. The prevailing colour in this class is
yellow, and the devices for insect-fertilisation
are not nearly so high as in the ray-bearing
group. I regard them as to a great extent a
retrograde tribe of the composite family.

In this chapter I have dealt chiefly with the
co-operative clubbing together of insect-fertilised
flowers, for purposes of mutual convenience ; but
you must not forget that similar clubs exist also
among the wind-fertilised blossoms in quite equal
profusion. Such are the catkins of forest trees,
the panicles of grasses, the spikes of sedges, and
the heads of the black-cap rush and many other
water-plants. Some of these, such as the bur-
reed, we have already considered.

Lastly, I ought to add that where the flowers
themselves are inconspicuous, attention is often
called to them by a bright-coloured leaf or group
11

162 THE STORY OF THE PLANTS.

of leaves in their immediate neighbourhood. We
saw an instance of this in the great white spathe
or folding leaf which encloses the male and
female flowers of the " calla lily." In the
greenhouse poinsettia the individual flowers are
tiny and unnoticeable ; but they are rich in
honey, and round them has been developed a
great bunch of brilliant scarlet leaves which
renders them among the most decorative
objects in nature. A lavender that grows in
Southern Europe has dusky brown flowers ;
but the bunch is crowned by a number of
mauve or lilac leaves, hung out like flags to
attract the insects. A scarlet salvia much
grown in windows similarly supplements its
rather handsome flowers by much handsomer
calyxes and bracts which make it a perfect blaze
of splendid colour. It doesn't matter to the
plant how it produces its effect; all it cares
for is that by hook or by crook it should
attract its insects and get itself fertilised.

CHAPTEK XI.

WHAT PLANTS DO FOB THEIR YOUNG.

AFTER the flower is fertilised it has to set its
seed. And after the seed is set the plant has to
sow and disperse it.

Now, the fruit and seed form the most difficult
part of technical botany, and I will not apologise
for treating them here a little cavalierly. I will
tell you no more about them than it is actually

WHAt PLANTS DO FOE tfHElft YOUNG. 163

necessary you should know, leaving you to
pursue the subject if you will in more formal
treatises.

The pistil, after it has been fertilised and
arrived at maturity, is called the fruit. In
flowers like the buttercup, where there are
many carpels, the fruit consists of distinct
parts, each one-seeded little nuts in the meadow
buttercup, but many-seeded pods in the marsh-
marigold and the larkspur. Where the carpels
have combined into a single ovary, we get a
many-chambered fruit, as in the poppy, which
consists, when cut across, of ten seed-bearing
chambers. Most fruits are dry capsules or pods,
either single, as in the pea, the bean, the vetch,
and the laburnum ; or double, as in the wallflower
and shepherd* s-purse ; or many-chambered, as
in the lily, the wild hyacinth, the poppy, the
campion. As a rule the fruit consists of as
many carpels or as many chambers as the
unfertilised ovary.

Fruits are often dispersed entire, and this is
especially true when they contain only one or
two seeds. In such instances they sometimes
fall on the ground direct, as is the case with
most nuts ; or else they have wings or para-
chutes which enable the wind to seize them,
and carry them to a distance, where they can
alight on unexhausted soil, far away from the
roots of the mother plant. Such fruits are
common among forest trees. The maples, for
example, have a double fruit, often called a
key, which the wind whirls away as soon as the
seeds are ready for dispersion (Figs. 37, 38, 39,

164

THE STOBY OF THE PLANTS.

40, 41). In the lime, the common stalk of the
flowers is winged by a thin leaf ; and when the

little nuts are ripe the wind detaches them and
carries them away by means of this joint para-
chute. In the birch, elm, and ash the fruit is

WHAT PLANTS DO FOE THEIE YOUNG. 165

a one-seeded nut, with its edge produced into
a leathery or papery wing, which serves to
float it.

But more often the fruit at maturity opens
and scatters its seeds, as we see in the pea, the
wild hyacinth, and the iris. Sometimes the
seeds so released merely drop upon the ground,
but most often some device exists for scattering
them to a distance, so as to obtain the advantage
of unexhausted soil for the young seedling. Thus
most capsules open at the top, so that the seeds
can only drop out when the wind is high enough
to carry them to some distance. In the poppy-
head the capsule opens by pores at the side,
and, if you shake one as it grows, you will find
it takes a considerable shaking to dislodge the
seeds from the walls of their chamber. Thus
only in high winds are the poppy seeds dis-
persed. In the mouse-ear chickweed the cap-
sule is directed slightly upward at the end for
a similar purpose. Sometimes, again, the valves
of the fruit open elastically and shoot out the
seeds ; this device is familiarly known in the
garden balsam, and it occurs also in the little
English wallcress. The sandbox-tree of the
West Indies has a large round woody capsule,
which bursts with a report like a pistol, and
scatters its seeds with such violence as to inflict
a severe wound upon anybody who happens to
be struck by them.

Where seeds are numerous, they are oftenest
dispersed in some such manner, by the capsule
opening naturally and scattering its contents ;
but where they are few in number, it more,

166

THE STOEY OF THE PLANTS.

frequently happens that the fruit does not open,
as in the oak or the elm ; and when there is
only one seed, the fruit and seed become almost

indistinguishable, and are popularly regarded as
a seed only. For example, in the pea, we dis-
tinguish at once between the pod, which is a
fruit containing many seeds, and the pea which

WHAT PLANTS DO FOE THEIR YOUNG. 167

is one such seed among the many ; but in wheat
or oats the fruit is small and one-seeded, and its
covering is so closely united with the seed as to
be practically inseparable. Fruits like these do
not open, and are dispersed whole. The fruits
of most composites are crowned by the feather-
like hairs which represent the calyx, and float
on the breeze as thistledown or dandelion-clocks
(Figs. 42, 43, 44, 45). John-go-to-bed-at-noon,
an English composite of the dandelion type, has
a very remarkable and highly-developed para-
chute of this description. In the anemones and
clematis the fruit consists of several distinct
one-seeded carpels, each furnished with a long
feathery awn for the purpose of floating; our
common English clematis or traveller's joy,
when in the fruiting condition, is known on this
account as "old man's beard." Floating fruits
like these, or those of many sedges and grasses,
will often be carried by the wind for miles
together. A well-known example of this type
is the sedge commonly though wrongly described
as cotton-grass.

In other instances it is the seed, not the fruit,
that is winged or feathered. The pod of the
willow opens at maturity, and allows a large
number of cottony seeds to escape upon the
breeze. The same thing happens in the beau-
tiful rose-bay and the other willow-herbs.
Cotton is composed of the similar floating hairs
attached to the seeds of a sub-tropical mallow-
like tree.

You will have observed, however, that not one

168 THE STORY OF THE PLANTS.

of the fruits which I have hitherto mentioned
is a fruit at all in the common or popular accep-
tation of the word. They are only at best what
most people call pods or capsules. A true fruit,
as most people think of it, is coloured, juicy,
pulpy, sweet, and edible. How did such fruits
come into existence, and what is the use of
them?

Well, just as certain plants desire to attract
insects to fertilise their flowers, so do other
plants desire to attract birds and beasts to
disseminate their fruits for them. If any fruit
happened to possess a coloured and juicy outer
coat, or to show any tendency towards the
production of such a coat, it would sooner or
later be eaten by animals. If the animal
digested the actual seed, however, so much
the worse for the plant, and we shall see by
and by that most plants take great care to
prevent their true seeds being eaten and assimi-
latecl by animals. But if the seed was very
small and tough, or had a stony covering, it
would either be passed through the animal's body
undigested, or else thrown away by him when
he had finished eating the pulpy exterior. So,
many plants have acquired fruits of this de-
scription— edible fruits, intended for the attrac-
tion of birds and animals. As a rule the animals
disperse the seeds in the well-manured soil near
their own nests or lairs, so that the young plants
produced from such fruits start in life under
exceptional advantages.

Fruits that seek to attract animals use much
the sarne baits to allure them in the way of

WHAT PLANTS DO FOR THEIR YOUNG. 1G9

colour and sweet taste as do the flowers that
seek to attract insects. But just as almost any
part of the flower may be brightly coloured, so
almost any part of the fruit may be sweet and
pulpy. Thus we get an astonishing and rather
embarrassing variety of special devices in this
matter.

A few instances must suffice us. In the
raspberry and blackberry the fruit consists of
separate carpels, in each of which the outer
coat becomes soft and sweet, while the actual
seed is hard and nut-like. In the one case the
fruit is red, in the other black, but very con-
spicuous among the green leaves in autumn.
These berries are eaten by birds, and their seeds
are dispersed in copse or hedgerow. But in the
strawberry, which is a near relation of both,
with a very similar flower, the actual carpels
remain to the end quite small and seed -like ;
they are the tiny black objects scattered about
in pits like miniature nuts over the surface of
the ripe berry. Here it is the common recep-
tacle of the fruit that swells'outf andT reddens,
the part answering to the central piece which
comes out whole in the middle of the raspberry ;
so that what we eat in the one fruit is the very \
same part as what we throw away in the other. \
In the plum, the cherry, and the peach, on the
other hand, there is but one carpel, and its outer
covering grows soft, sweet, and brightly coloured;
while the actual seed, though soft, is contained
in a hard and stony jacket, an inner layer of the
fruit coat. Here the true seed is what we call
the kernel, but it is amply protected by its bone-

170 THE STORY OF THE PLANTS.

like coverlet. In the apple and pear the ovary
is inferior ; the fruit is thus crowned by the
remains of the calyx ; if you cut it across you
will find it consists of a fleshy part, which is the
swollen stem, enclosing the true fruit or core,
with a number of seeds which we call the pips.
All these fruits belong to the family of the roses ;
they serve to show the immense variety ol plan
and structure which occurs even in closely re-
lated species. Other succulent fruits of the
same family are the rose-hip, the haw, the
medlar, and the nectarine.

Among familiar woodland fruits dispersed by
birds I may mention the elderberry, the dog-
wood, the honeysuckle, the whortleberry, the
holly, the cuckoo-pint, the barberry, and the
spindle-tree. The white berries of the mistletoe,
which is a parasitic plant, are eaten by the
missel-thrush, a bird who has a special affection
for this particular food. But they are very
sticky, and the seeds therefore adhere to the
bird's beak and feet. To get rid of them, he
rubs them off on the fork of a poplar branch, or
in the bark of an apple-tree, which are the exact
places where the mistletoe most desires to place

I itself. Many such close correspondences between

1 bird and fruit exist in nature.

Our northern berries are chiefly designed to
be eaten by small birds like robins and haw-
finches. But in southern climates larger fruits
exist, adapted to the tastes of larger animals
such as parrots, toucans, hornbills, fruit-bats,
and monkeys. Our own small kinds can gene-
rally be eaten whole? like the currant and the

WHAT PLANTS DO FOB THEIR YOUNG. 171

strawberry ; but these large southern fruits have
often a bitter or unpleasant or very thick rind,
which the birds or monkeys, for whose use they
are intended, know how to strip off them.
Cases in point are the orange, the lemon, the
shaddock, the banana, the pine-apple, the
mango, the custard-apple, and the breadfruit.
The melon, cucumber, pumpkin, gourd, vegetable
marrow, and water-melon are other southern

FIG. 4t>.

FIG. 47.

FIG. 48.

ADHESIVE FRUITS. Fig. 46, of houndstoDgue. Fig. 47, of
cleavers. Fig. 48, of herb-bennet.

forms cultivated in the north for the sake of
their fruits. In the pomegranate the fruit itself
is a dry capsule, but the seeds are each enclosed
in a separate juicy coat. The grape is a fruit too
well known to require detailed description.

As flowers sometimes club together, so also do
fruits. In the mulberry the apparent berry is
really made up of the distinct carpels of several
separate flowers, which grow together as they

172 THE STORY OP THE PLANTS.

ripen ; while the fig is a hollow stalk, in which
numerous tiny fruits, commonly called seeds, are
closely embedded.

In all these cases animals act as willing agents
in the dispersal of fruits or seeds. But some-
times the plant compels them to carry its seeds
against their will. Thus the fruits of the hounds-
tongue (Fig. 46) consist of four small nuts, covered
with hook-like prickles, which cling to the coats
of sheep or cattle. The beasts rub these annoying
burdens off against bushes or hedges, and so
disseminate the seeds in suitable places for ger-
mination. The double fruit of cleavers (Fig. 47)
is also supplied with similar prickles, while that
of herb-bennet (Fig. 48) has a long curved awn
whicji makes it catch at once on any passing
animal.

There are a large number of fruits, however,
with richly stored seeds, which desire rather to
escape the notice of animals, some of whom, like
squirrels and dormice, try to make their living
out of them. These we call nuts. Their tactics
are the exact opposite of those pursued by the
edible fruits. For the edible fruits strive to
attract animals to disperse them ; the nuts, on
the contrary, having the actual seed richly stored
with oils and starches, desire to protect it from
being eaten and destroyed. Hence they are
generally green when on the tree, so as to
escape notice, and brown when lying on the
ground beneath it. Cases of these protectively-
arranged fruits, with hard shells and often with
nauseous external coverings (some of which are

WHA1? PLANTS 1>O FOB THEIR tOUNG. 173

not regarded as nuts in the strict botanical
sense), are the walnut, the hazel-nut, the coco-
nut, the chestnut, the acorn, the lime-nut, the
almond, and the hickory-nut. In the Brazil nut
the seeds (which are what we commonly call the
nuts) are enclosed in a solid shell like that of a
coco-nut, and are themselves also hard and nut-
like. In the chestnut the fruit is a prickly
capsule, inside which lie the seeds, which we
know as chestnuts.

But why have some plants so many seeds and
some so few? Well, the simpler and earlier
types produce a very large number of ill-pro-
vided seeds, which they turn loose upon the
world to shift for themselves almost from the
outset. Many of them perish, but a few survive.
On the other hand, the more advanced plants,
as a rule, produce only a small number of seeds,
but each of these is well provided with starches
and oils for the growth of the young plant ; and
as most such survive, any tendency in the direc-
tion of laying by food- stuffs would of course be
favoured by natural selection. Just so among
animals, a codfish produces nearly a million
eggs, of which only two or three on an average
survive to maturity ; while a bird produces half
a dozen large and well- stored eggs, and a cow or
a horse rarely brings forth more than one calf or
foal at a birth. Decrease in the number of seeds/
is a fair jrou^h test, of relative progress.

In nuts, you can see at once, the seeds are
very richly stored, and the young plant starts
in life, able to draw for a time on these ready-

174 THE sfomr OF

made food-stuffs, until its green leaves are in a
position to lay by starches "and protoplasm in
plenty for it. It draws by degrees upon the
/accumulated materials. Such plants are like
' capitalists who can start their sons well in life
with a good beginning. On the other hand, the
poppy has to set out on its career with a very
poor equipment ; it must begin picking up car-
bonic acid for itself almost from the outset.
Such plants are like street arabs, compelled
to shift as best they can from their earliest
days. A coco-nut starts so well that the young
palm can grow to a considerable size without
working for itself ; so to a less degree do wal-
nuts, hazels, and oak-trees. Among other sets
of plants there are two great groups which have
especially learned to lay by food for their seed-
lings— the peaflower family and the grasses.
In both these cases the young plants start in life
with exceptional advantages. But what will
feed a young plant will also feed an animal.
Hence men live largely in different countries
off such richly-stored seeds — among nuts, the
coco-nut, the chestnut, and the walnut ; among
peaflower seeds, the pea, the bean, the vetch,
the lentil; among grasses, wheat, rice, barley,
Indian corn, rye, millet.

Eecollect, however, that in all these cases the
plant does not desire the seed to be eaten. It
stored the tissues richly for its own sake and its
offspring's alone, and we come and rob it. So,
too, with the edible roots or tubers, such as
potatoes, yams, turnips, beet-root, and so forth ;
the plant meant to use them for its own future

WHAT PLANTS DO FOR THEIR YOUNG. 175

growth ; man appropriates them and disappoints
its natural expectations. It is quite different
with the succulent fruits, like the date and the
plantain, which form in many countries the
staple food of great populations ; nature meant
those to be eaten by animals, and offered the
pulp in return for the benefit of dispersion.

Finally, when the seed is put into the ground
and exposed to warmth and moisture, it begins
to germinate. This it does by sending up a
small growing shoot towards the light, which
soon develops green leaves ; as well as by
sending down a root towards the earth, which
soon begins to suck up water, together with the
dissolved nitrogenous matter. That is the be-
ginning of a fresh plant-colony, which thus owes
its existence to two separate individuals, a father
and a mother. The seed consists of two_ first
seed-leaves in the fivefold plants, as you can see
very well in a sprouHng bean, and of one such
seed-leaf in the threefold division, as you can
see very well in a sprouting grain of wheat, or,
still better, a lily seed. These earliest leaves
are technically known as seed-leaves or cotyle-
dons, and that is why the fivefold plants are
known to botanists by the awkward name of
dicotyledons, while the threefold are called
monocotyledons. These names mean merely
plants with two or with one seed-leaf.

CHAPTER XII.

THE STEM AND BRANCHES.

You may have observed that so far I have told
you a good deal about leaves and roots, flowers
and seeds, but little or nothing about the nature
of the stems and branches that bear them. I
have done this on purpose; for my object has
been to give you as much information at a time
as you could then and there understand, build-
ing up by degrees your conception of plant
economy. Now, leaves and flowers are, so to
speak, the units of the plant-colony, while stem
and branches are the community as a whole and
the mode of its organisation. You must know
something about the component parts before
you can get to understand the whole built up
of them ; you must have seen the individual
citizens themselves before you can comprehend
the city or nation composed by their union.

The stem, then, is the part of the plant-colony
which does not consist of individual leaves,
either digestive or floral, but which binds them
all together, raises them visibly to the air, and
supplies them with water, nitrogenous matter,
and the results of previous assimilation else-
where. The stem and branches are common
property, as it were ; they belong to the com-
munity : they represent the scaffolding, the
framework, the canals, the roads, the streets,
the sewers, of the compound plant-colony.

How did stems begin to exist at all ? The

176

SFEM AND

17?

taost probable answer to that question we ;owe,
not to any professional botanist, but to our
great philosopher, Mr-. Herbert Spencer.

The simplest and earliest plants, we saw-,
were mere small floating cells, endowed with
active chlorophyll. Next in the upward order
of^evolution came rows of such cells, arranged
in long lines, like hairs or threads, or like
pearls in a necklace,
as in the green ooze
of ponds and lake-
lets. Above these
simple plants, again ,
come flat expanded
collections of cells,
as in the fronds of
seaweeds. Now, all
these kinds of plant
are stemless. But
suppose in such a

plant as the last, FIG. 49. — FIRST STEPS IN THE
one frond or leaf EVOLUTION OF THE STEM.
took to growing out

of the middle of another, as it actually does
in many instances, we should get the beginning
of a compound plant, many-leaved, and with a
sort of early or nascent stem, formed by the
part that was common to many of the leaves,
like a midrib. The accompanying diagram
(Fig. 49) will make this clearer than any amount
of description could possibly make it. Starting
from such a point, certain plants would soon
find they were thus enabled to overtop others,
and to obtain freer access to lighr"ancf carbonic
12

178 THE STORY OF THE PLANTS.

acid. Gradually, natural selection would ensure
that the common central part of the growing
plant, the developing stem, should become
harder and more resisting than the rest, so as
to stand up against the wind and other opposing
forces. At last there would thus arise a clearly-
marked trunk, simple at first, but later on
branching, which would lift the leaves and
flowers to a considerable height, and hang them
out in such a way as to caTjcrTTihe sunlight and
air to the best advantage, or to attract the
fertilising insects or court the wind under the
fairest conditions. I leave you to think out for
yourself the various stages of the process by
which natural selection must in the end secure
these desirable objects.

In order to understand the nature of the stem,
in its fully developed form, however, we must
remember that it has three main functions.
The first is, to rajise the foliage, with the flowers
and fruits as well, visibly above the surface of
the ground on which they grow, so that the
leaves may gain the freest possible access to
rays of sunlight and to carbonic acid, while the
flowers and fruit may receive the attentions of
insects and birds, or other fertilising and dis-
tributing agents. The second is, to conduct
from the root to the foliage and other growing
parts wrhat is commonly called the raw sap —
that is to say, the body of water absorbed by
the rootlets, together with the nitrogenous
matter and food-salts dissolved in it, all of
which are needed for the ultimate manufacture

THE STEM AND BRANCHES. 179

of protoplasm and chlorophyll. The third is, to
carry away and distribute the various matured
products of plant life, such as starches, sugars,
oils, and protoplasm, from the places in which
they are produced (such as the leaves) to tho
places where they are needed for building up
the various parts of the compound organism
(such as the flowers and fruit or the growing
shoots), as well as to the places where such
materials are to be stored up for safety or for
future use (as, for example, the tubers and roots,
or the buds, bulbs, and other dormant organs).
Each of these three essential functions we must
now proceed to consider separately.

In order to raise the leaves and branches
visibly above the ground into the air above it,
the stem is made much stronger and stouter
than the ordinary leaf -tissue. If the plant does
not rise very high above the ground, indeed, as
in the case of small herbs, and especially of
annuals, its stem need not be very hard or stiff,
and is often in point of fact quite green and
succulent. But just in proportion as plants
grow tall and spreading, carry masses of foliage,
and are exposed to heavy winds, do they need
to form a stout and woody stem, which shall
support the constant weight of the leaves, or
even bear up under the load of snow which may
cover the boughs in wintry weather. Thus, a
tapering tree like the Scotch fir requires a com-
paratively smaller stem than an oak, because its
branches do not spread far and wide, while its
single leaves are thin and needle-like ; whereas

180 THE 'STORY OF THE PLANTS.

the oak, with its massive boughs extending fax*
and wide on every side, and covered with a
weight of large and expanded absorbent leaves,
requires a peculiarly thick and buttressed stem
to support its burden. Both in girth and in
texture it must differ widely from the loose and
swaying pine-tree. Every stem is thus a piece
of ingenious engineering architecture, adapted
on the average to the exact weight it will have
to bear, and the exact strains of wind and
weather to which on the average it may count
upon being exposed in the course of its life-
history. We see the result of occasional failure
of adaptation in this respect after every great
storm, when the corn in the fields is beaten
down by hail, or the fir-trees in the forest are-
snapped off short like straw by the force of the
tempest. But the survivors in the long run are
those which have succeeded best in resisting
even such unusual stresses ; and it is they that
become the parents of after generations, which
of course inherit their powers of resistance.

Most stems, at least of perennial plants, and
all those of bushes, shrubs, and forest trees, are
strengthened for the purpose of resisting such
strains by means of a material which we call
wood. And what is wood ? Well, it is an
extremely hard and close-grained tissue, manu-
factured by the plant out of its ordinary cells
by a deposit on their walls of thickening matter.
This process of thickening goes on in each cell
until the hollow of the centre is almost entirely
filled up by the thickening material, leaving only
a small vacant space in the very middle. The

THE STEM AND BKANCHES. 181

thickening matter, which consists for the most
part of carbon and hydrogen, is built up there
by the protoplasm of the cell itself : but as soon
as the process is quite complete, the protoplasm
emigrates from the cell entirely, and goes to
some other place where it is more urgently
needed. Thus wood is made up of dead cells,
whose walls are immensely thickened, but whose
living contents have migrated elsewhere.

In large perennial stems, like those of oaks
and elms, a fresh ring of wood is added each
year outside the ring of the last growing season.
This new ring of wood is interposed between the
bark (of which I shall speak presently) and the
older wood of the core or heart, which was
similarly laid down when the tree was younger.
In this way, the number of rings, one inside
another, enables us roughly to estimate the age
of a tree when we cut it down ; though, strictly
speaking, we can only tell how many times
growth in its trunk was renewed or retarded.
Still, as a fair general test, the number of rings
in a trunk give us an approximate idea of the
age of the individual tree that produced it.

The principle is only true, however, of the
great group of dicotyledonous trees, such as
beeches or ashes, as well as of the pines and
other conifers. In monocotyledonous trees, like
the palms and bamboos, the stem does not
increase in quite the same wray from within
outward, and there are therefore no rings of
annual growth to judge by. Palms rise from
the ground as big or nearly as big at the begin-
ning as they will ever be in the end ; and though

182 THE STOKY OF THE PLANTS.

each year they rise higher and higher into the
air, and produce a fresh bunch of leaves at their
summit, they seldom branch, and they never
produce large buttressed sterns like the oak or
the chestnut.

The second main function of the stem is to
convey the raw sap absorbed by the roots to the
leaves and branches, and especially to the
growing points. This is such a very important
element in plant life that we must now consider
it in some little detail.

If you look for a moment at a great spreading
oak-tree, with its top rising forty or fifty feet
above the level of the ground, and its roots
spreading as far and as deep beneath the earth,
you will see at once how serious and difficult a
mechanical problem it is for the plant to raise
up water from so great a depth to so great a
height without the aid of pump or siphon. For
the plant can no more work^miragles than you
or I can. Yet every leaf must be constantly
supplied with water, that prime necessary of
life, or it will wither and die ; and every growing
part must obtain it in abundance, in order to
give that plasticity and freedom which are
needful for the earlier constructive processes.
^Protoplasm itself can effect nothing without the
assistance of water as a solvent for all materials
<jit employs in its operations.

How does the plant get over these difficulties ?
Well, the stem is well provided with a whole
system of upward distributing vessels in which
water may be conveyed to the various parts,

THE STEM AND BBANCHES. 183

just as it is conveyed in towns through the pipes
and taps wherever it is needed. But what is
the motive power for this mechanical work ?
How does the plant raise so much liquid to such
a ^considerable height, without the intervention
of any visible and tangible machinery?

Two main agents are employed for this pur-
pose. The one is known as root-pressure; the
other as evaporation.

I begin with the former. The cells of which
roots are made up are most ingeniously con-
structed so as to exert this peculiar form of
pressure. Each one of them has at its outer
or free end, where it comes into contact with
the moist earth, a wall of such a nature that it
very readily absorbs water, and allows the water
so absorbed to flow freely through it inward.
But once in, the water seems almost as if
imprisoned in a pump ; it cannot pass outward
again, only inward and upward. You may
compare the cell in this respect with those
mechanical \^&*o$ which yield readily to the
pressure of fluids from outside, but instantly 4
close when a fluid from inside attempts to pass;
through them. In this way the outer cells of*
the hairs on the roots, which come in contact
with the moistened soil, get distended with
water, and swell and swell, till at last their
walls will give no longer, and their own elas-
ticity forces the water out of them. But the
water cannot flow back ; so it has to flow for-
ward. Again, each cell or vessel which the
stream afterwards enters is constructed on just
the same general principle as the absorbent

184 THE STORY OF THE PLANTS..

root-cells ; it allows water to pass into it freely
/from below upward, but does not allow it to
vpass; back again from above downward. Thus
we get a constant state of whiat is called
tiirgidiiy in the lower cells ; they are as full as
they can hold, and they keep on contracting
elastically, so as to expel the water they contain
into other cells next in order above them. By
means of such root-pressure, as it is called, raw
sap is being for ever forced up from the soil
beneath into the stem and branches, to supply
the leaves with water and food-salts, especially
in early spring, when the processes of growth
are most active and vigorous.

It is owing to this peculiar property of root-
pressure that cut stems " bleed" or exude sap,
especially in spring-time. The root-pressure
continues of itself in spite of the fact that the
stem has been divided ; and the sap absorbed
by the roots is thus forced out at the other end
by the continuous elasticity of the cells and
vessels. The fact that severed stems will thus
" bleed " or exude raw sap shows in itself the
reality of root-pressure.

But root-pressure alone would not fully suffice
to r-aise so large ft bo4y of water as the plant
requires \o> SQ great a hpigh^ above the earth's
surface^ Jt fs therefore largely supplemented
an4 assisted by the second or subsidiary power
pf evaporation. This evaporation, QJC " transpi-
ration " as it is generally called, is just as
necessary and essential to plants as breathing
is to men and animals.

We must therefore enter a little more fully

THE STEM AND BRANCHES. 185

here into the nature of so important and uni-
versal a plant function. You will remember
that when we were discussing the nature of
leaves, I gave you a woodcut of a thin slice
through a leaf (Fig. 1) which showed the blade
as naturally divided into an upper and under
portion. The upper portion consisted of very
close-set green cells, containing living, chloro-
phyll, and covered by a single transparent
water-layer, which absorbed carbonic acid from
the air about, and passed it on to be digested
by the living chlorophyll-layer just beneath it.
But the under portion was sparse-looking and
spongy ; it was composed of cells loosely
arranged among themselves, and interspersed
with great empty spaces. I told you but little
at the time of the function or use of this lower
portion ; we must return to it now in the
present connection, as a component element in
the task of water-supply.

The low£r portion of most leaves is the part
employeoin the great and necessary work of
evaporation.

For this purpose the tissue at the under side
of the leaf is composed of loose and spongy cells
which have much of their surface exposed to the
empty spaces between them : and these empty
spaces are really air-cavities. The object of the
cavities, indeed, is to facilitate evaporation.
Liquid transpires into them from the various
cells through the wall that bounds them. How
fast water evaporates in the leaves of plants we
all know by experience in a thousand ways.
We know, for instance, that if we pick bunches

186 THE STOKY OF THE PLANTS.

•of flowers and leave them in the sun without
water, they fade and dry up in a very short
time. We also know that if we forget to water
plants in pots, the plants similarly dry up
and die after a few hours' exposure. Leaves,
in fact, are purposely arranged in most cases
so as to encourage a very rapid evaporation ;
and evaporation is one of their chief means of
\aising water from the roots to the growing and
living portions.

If you examine the under side of a leaf under
the microscope, you will find it is covered by
hundreds of little pores which look exactly like
mouths, and which are guarded by two cells
whose resemblance to lips is absurdly obvious.
These pores are commonly known to botanists
by the awkward name of stomata, which is the
Greek for mouths ; and mouths they really are
to all external appearance. You must not
suppose, however, that they are truly mouths
in the sense of being the organs with which the
plant eats ; the upper surface of the leaf, as we
saw, with its layer of water-cells and its assimila-
ting chlorophyll-bodies, really answers in the
plant to our mouths and stomachs. The stomata
or pores are much more like the openings in
the skin by which we perspire ; only perspira-
tion or evaporation is an even more important
part of life to the plant than.it is to the animal.
Each of the stomata opens into an air-cavity ;
and through it the liquid evaporated from the
cells passes out as vapour into the open air.
Many leaves have thousands of such pores on
their lower surface ; they may easily be recog-

THE STEM AND BBANCHES. 187

nised under the microscope by means of the
curious guard-cells which look like lips, and
which give the pores, in fact, their strange
mouth-like aspect.

What is the use of these lips ? Well, they
are employed for opening and closing the evapo-
rating pores, or stomata. In dry weather it is not
desirable that the pores should be open, for then
evaporation should be limited as far as possible.
So, under these conditions, the lips contract, and
the pore closes. Excessive evaporation at such
times would, of course, damage or destroy the
Toliage ; the plant desires rather to store up and
retain its stock of moisture. But after rain, and
in damp weather, the roots suck up abundant
water ; and then it becomes desirable that
evaporation should go on, and the leaves and
growing shoots should be supplied with liquid
food, as well as with the nitrogenous matter and
salts dissolved in it. Hence at such times the
pores open wide, and allow the water in the
form of vapour to exude from them freely.

The object of this evaporation, again, is two-
fold. In the first place, it supplements root-
pressure as a means of raising water to the
leaves and growing shoots ; and in the second
place, by getting rid of superfluous liquid, it
leaves the nitrogenous material and the food-
salts in a more concentrated form, at the very
points where they are just then needed for the
formation of fresh living protoplasm and other /
useful constructive factors of plant-life. But how
does evaporation raise water from the ground ?
In this way. The living contents of each cell

188 THE STORY OF THE PLANTS.

on the upward path have a natural chemical
affinity for water, and will suck it up greedily
wherever they can get it. Thus each part, as
fast as it loses water by evaporation, takes up
more water in turn from its next neighbour
below ; and that once more withdraws it from
the cell beneath it ; and so on step by step until
we reach the actual absorbent root-hairs. Eoot-
pressure by itself could not raise water as high
as we often see it raised in great forest trees and
tropical climbers ; it has not enough mechanical
motor power. But here evaporation comes in,
to aid it in its task ; and the real motor power
in this last case is the very potent force of
chemical attraction.

What I have said here about evaporation, and
the way it is conducted by means of pores on the
surface of the leaves, is true of the vast majority
of green plants ; but considerable varieties and
modifications occur, of course, in accordance
with the necessities of various situations. For
example, the brooms and many other shrubs of
the same twiggy type have few green leaves, but
in their stead produce lithe green stems, filled
with active chlorophyll. These stems and
branches do all the work usually performed
by ordinary foliage. Stems and twigs of this
type are covered with mouth-like pores, or
stomata, in exactly the same way as the under
side of leaves in most other species. Similarly,
the very flattened leaf-like branches of the
butcher's broom, and of the Australian aca-
cias and other Australasian trees, are well
supplied with like pores for purposes of evapora-

STEM AND BHANCHEg. 189

tion. Again, while the pores are usually found
on the under surface of the leaf, they are situated
on the upper surface of leaves which float on
water, like the water-lily and the water-crow-
foot ; because in such plants they would be
obviously useless for purposes of evaporation on
the lower side, which is in contact with the
water. Some leaves have the stomata on both
sides alike, especially when no one side is much
more exposed to sunlight than another. But
wherever they are found, they always lie above
masses of loose and spongy cell-tissue, in whose
meshes and air-spaces evaporation can go on
readily.

On the other hand, as I noted before, leaves
which grow in very dry or desert situations
require as much as possible to curtail evapo-
ration. Such leaves are therefore usually thick
and fleshy, and possess a very small allowance
of pores. The forms of several leaves, again,
are largely dependent upon the necessity for
keeping the pores free from wetting, and pro-
moting evaporation whenever it is needful for
the plant's health and growth ; and this is
particularly the case with what are called
"rolled leaves," such as one sees in the
heaths and the common rock-roses. Many such
additional principles have always to be taken
into consideration in attempting to account for
the various shapes of foliage : indeed, we can
•only rightly understand the form of any given leaf
when we know all about its habits and its native
situation.

The stem, then, besides raising the leaves and

190 THE StOKY OF THE t>LANT3.

flowers, for which purpose it is often streng-
thened by means of mechanical woody tissue,
also acts as a conductor of raw sap from the tips
of the roots to the leaves and growing points,
for which purpose it is further provided with an
elaborate system of canals and vessels, running
direct from the absorbent root to all parts of the
compound plant community.

The third function of the stem and branches
is to convey and distribute the elaborated pro-
ducts of plant-chemistry and plant-manufacture
from the places where they are made to the
places where they are needed for practical
purposes.

I We saw long since that starches, sugars, pro-
toplasms, and chlorophyll are manufactured in
the leaves under the influence of sunlight ; and
from the materials so manufactured every part
of the plant must ultimately be constructed.
But we never said a word at the time about the
means by which the materials in question were
carried about and distributed to the various
organs in need of them. Nevertheless, a mo-
ment's consideration will show you that new
leaves and shoots must necessarily be built up
at the expense of materials supplied by the
older ones ; that flowers, fruits, and seeds must*
be constructed from protoplasm handed over
for their use by the neighbouring foliage. Nay
more ; the root itself grows and spreads ; and
the very tips of the roots, which themselves^f
course can manufacture nothing, must be sup-
plied from, above. with most active and discrimi-

THE STEM AND BRANCHES.- I9l

hating protoplasm, to guide their ffioVements.
Whence do they get it ? From the factory in
the foliage. Thus, from the summit of the tallest
tree down to the lowest root that fastens it in
the soil, there runs a complex system of pipes
and tubes for the special conveyance of elaborated
material ; and this system supplies every grow-
ing part with the food- stuff necessary for its
particular growth, and every living part with the
food-stuff necessary for maintaining its life and
activity, An interchange of protoplasmic matter,
starches, and sugars, goes on continually through
the entire organism.

This downwar^^d fmf.wa.rrl stream of living \ /
matter, carrying along with it live protoplasm
and other foods or manufactured materials, must
be carefully distinguished from the upward
stream of crude sap which rises from the roots '
to the leaves and branches. The one contains
only such raw materials of life as are supplied
by the soil — namely, nitrogenous matter, water,
and food-saltst; the other contains the things
eaten from the air by the plant in its leaves, I
and afterwards worked up by it into sugars,/ £•
starches, protoplasm, and chlorophyll.

Stems are usually covered outside for purposes
of protection by a more or less thick integument,
which in trees and shrubs assumes the corky
form we know as bark. Bark consists of d,eacl
and empty cells, thickened with a lighter
thickening matter than wood, and presenting
as a rule a rather spongy appearance. But
beneath the bark comes a ^i^nci^_layer_Qf living

192 THE STOftY OF Tftfc PLANTS.

material, interposed between the corky dead I
cells of the integument and the woody dead •
cells of the interior. This living layer extends
over stem, twigs, and branches : it forms the
binding and connecting portion of the entire
plant community ; it links together in one united
/whole the living material of the leaves, and shoots
v \with the living material of the roots arid rootlets.
It is thus^the stem, above all, that gives to the
complex plant colony of foliage and flowers
whatever organic unity and individuality it ever
possesses.

All situations, however, are not alike. Just
as here this sort of leaf succeeds, and there that,
so in stems and branches, here this form does
best, and there again the other. The shape of
the stem and branches, in fact, is the shape of
the entire plant colony ; and it is arranged to
suit, on the average of instances, the convenience
of all its component members. Much depends
on the shape of the leaves ; much on the condi-
tions of wind or calm, shade or sunshine.

Some plants are annuals. These require no
large and permanent stem ; they spring from
the seed each year, like peas, or wheat, or
poppies ; they make a stem and leaves ; they
produce their flowers ; they set, and ripen, and
scatter their seed ; and then they wither away
and are done with for ever. Hundreds of such
plants occur in our fields and gardens. Even
these annuals, however, differ greatly in the
amount of their stem and branches. Some
are quite low, humble, and succulent, like

THE STEM AND BRANCHES. 193

chickweed and sandwort ; others have tall and
comparatively stout stems, like wheat, oats, and
barley, or still more, like the sunflower. As a
rule, annuals are not very large ; but a few rich
seeds produce strong young plants which even
within a single year attain an astounding size ;
this is the case with the garden poppy, the
tobacco plant, and the Indian corn, and even
more so with certain climbing annuals, such as
the gourd, the cucumber, the melon, and the
pumpkin.

Many plants, however, find it pays them better
to produce a hard and woody stem, which lasts
from year to year, and enables them to put forth
fresh leaves and shoots in each succeeding
season. Among these, again, great varieties
exist. Some have merely a rather short and
stout stem with many bundles of water-vessels,
as in the pink and the wallflower. Their growth
is herbaceous. Others, however, produce that
more solid form of tissue which we know as
wood, and which is made up of cells whose walls
have become much thickened and hardened.
Among the woody group, again, we may dis-
tinguish many intermediate varieties, from the
mere shrub or bush, like the heath and the
broom, through small trees like the rhodo-
dendron, the lilac, the hawthorn, and the holly,
to such great spreading monsters of the forest as
the oak, the ash, the pine, the chestnut, and the
maple.

Once more, some plants produce an under-
ground stem, and send up from this fresh annual
branches. That is the case with hops, with
13

194 THE STORY OF THE PLANTS.

meadow-sweet, and with buttercup, as well as
with many of our garden flowers. When a
plant becomes perennial, it is a mere question of
its own convenience whether it chooses to produce
a thick and woody stem, like trees and bushes,
or to lay up material in underground roots,
stocks, and branches, like the potato, the dahlia,
the lilies, the bulbous buttercup, the crocus, the
iris, the Jerusalem artichoke, and the meadow
orchis.

Ordinary people divide most plants into three
groups — herbs, shrubs, and trees. But I think
you will have seen from what I have just said,
that in every great family of plants different kinds
have found it worth while to adopt any one of
these forms at will, according to circumstances.
Trees, in other words, do not form a natural
group by themselves ; any family of plant may
happen to develop a tree-like species. Thus
the herb-like clover and the tall tree-like labur-
num are closely related peaflowers. Most of
the composites are mere herbs or shrubs, but a
very few of them in the South Sea Islands have
grown into large and much-branched trees. The
grasses are mainly herbs ; but some of them,
like the bamboos, have developed tall and tree-
like stems, much branched and feathery.

Take the single family of the roses, for example,
so familiar to most of us ; some of them are mere
annual weeds, like the tiny parsley-piert that
occurs as a pest in every garden. Others, again,
are perennials with low tufted stems, like the
strawberry ; or creeping, like the cinquefoil ; or
rising into a spike, like the burnet and the agri-

THE STEM AND BKANCHES. 195

mony. Yet others become scrambling bushes,
like the blackberry and the raspberry. In the
blackthorn and the hawthorn the bush has
become more erect and tree-like. Both types of
growth occur in the dog-rose and many other
roses. The cherry attains the size and etature
of a small tree. The mountain-ash is bigger ;
the apple-tree bigger still ; while the pear often
grows to a considerable height and much spread-
ing dignity. These are all members of the rose
family. Here, therefore, every variety of shape
and size is well represented within the limits of
a single order.

One word must be given to the varieties of the
stem. Sometimes, as in the oak, the trunk is
much branched and intricate ; sometimes, as in
the date-palm, simple and unbranched, bearing
only a single tuft of circularly arranged leaves.
But the most interesting in this respect are the
climbing and twisting stems, which do not take
the trouble to support themselves, but lean for
aid upon the trunk of some stronger and more
upright neighbour. Stems of this sort are
familiar to us all in the hop and the bindweed.
In other climbers the stems do not twine to any
great extent, but the plants support themselves
by root-like processes, as in ivy, or by tendrils,
as in the vine, or by twisted leaf-stalks, as in
the canary creeper. Others cling by means of
suckers, as the Ampelopsis Veitchii, or hang by
opposite leaves, like clematis, or cling by hooked
hairs, as is the case with cleavers. In certain
instances, such creeping or climbing plants tend
to become parasitic — that is to say, they fasten

196 THE STOKY OF THE PLANTS.

themselves by sucker-like mouths to the bark of
the harder plant up which they climb, and feed
upon its already elaborated juices. Our English
dodder is an example of such a plant. It has no
leaves of its own, but consists entirely of a mass
of red stems, bearing clusters of pretty pale pink
flowers.

Other plants show another form of parasitism.
Misletoe is one of these. It fastens itself to a
poplar or an apple-tree (very seldom an oak) and
sucks its juices. But it has also green leaves of
its own, which do real work of eating and
assimilating as well. It is therefore not quite
such a parasite as the dodder. Several plants
are similarly half-parasitic on the roots of wheat
and grasses. Among them I may mention, as
English instances, the cow-wheat, the yellow
rattle, and the pretty little eyebright.

Broomrape is a parasite of a different sort. It
grows on the roots of clover, and has no true
leaves ; in their place it produces short scales,
which contain no chlorophyll. Several other
plants are also devoid of chlorophyll, and there-
fore cannot eat carbonic acid, for themselves.
They live like animals on materials laid by for
them by other plants. Such are toothwort, a
pale rose-coloured leafless plant, with pretty
spiked flowers, which grows by suckers on the
roots of hazel-trees. The bird's nest orchid, a
delicate brown plant with curious ghost-like
blossoms, feeds rather on the organised matter
in decaying leaves among thick beechwoods. In
this book I have purposely confined your atten-
tion for the most part to the true green plants,

THE STEM AND BKANCHES. 197

which are the central and most truly plant-like
type ; but I ought to tell you now that a great
many plants, especially among the lower kinds,
behave in this respect much more like animals :
instead of manufacturing fresh starches and
protoplasms for themselves from carbonic acid,
under the influence of sunlight, they eat up
what has already been made by other and more
industrious species. Such plants are retrograde.
They are products of degeneracy. Amoiign&hem
I may specially mention all the fungi, like mush-
rooms, toadstools, mould, and mildew, as well as
the bacilli and bacteria, microscopic and de-
generate plants which cause decomposition.
Their life is more like that of animals than of
true vegetables.

In tropical forests, where the soil is almost
monopolised by huge spreading trees, the smaller
plants have been forced to secure their fair share
of light and air by somewhat different means
from those which are common in cooler climates.
Many of them, without being parasitic, have
learnt to attach themselves by their roots to the
outer bark of the trees, and so to get at the
light, no ray of which ever struggles through the
living canopy of green in the dense jungle.
These plants have green leaves, and eat for
themselves ; but they use the boughs of their
host instead of soil to root themselves in. Such
plants are technically known as epiphytes. This
is the mode of life of most of the handsome
orchids cultivated in our conservatories.

Now let us recapitulate. The stem unites the

198 THE STORY OF THE PLANTS.

various parts of the plant — the root, the leaves,
the flowers, the fruit. It conducts water and
nitrogenous matter from the soil to the foliage.
It also carries the manufactured materials from
the points where they are made to the points
where they are wanted for the growth of fresh
organs. It supports and raises the whole plant
colony. Finally, it stores up material in
drought or winter, which it uses for new
branches, leaves, or flowers, when rain or
spring or favourable conditions in due time
come round again.

CHAPTEE XIII.

SOME PLANT BIOGRAPHIES.

WE have considered so far the various elements
which go to make up the life of plants — how
they eat and drink, how they digest and assimi-
late, how they marry and get fertilised, how they
produce their fruit and set their seeds, finally
how they are linked together in all their parts
by stem and vessels into a single community.
But up to the present moment we have con-
sidered these elements in isolation only, as so
many processes the union of which makes up
what we call the life of an oak, or a lily, or
a strawberry plant. In order really to under-
stand how all these principles work together in
practical action, we ought to take a few specimen
lives of real concrete plants, and trace them
through direct, from the cradle to the grave,

SOME PLANT BIOGRAPHIES. 199

with all their vicissitudes. I propose, therefore,
in this chapter to give you brief sketches of one
or two such life-histories ; and I hope these few
hints may encourage you to find out many more
for yourself, by personal study of plants in their
native surroundings.

" In their native surroundings," I say, since
all life is really, in Mr. Herbert Spencer's famous

* phrase, " adaptation to the environment ; " and

* therefore we can only understand and discover
the use and meaning of each part or organ by
watching the plant in its own home, and among
the general conditions by which it and its
ancestors have always been limited. It would
be impossible, for example, to see the use of
the thick outer covering of the coconut (from
which coconut matting is manufactured) if we
did not know that the coconut palm grows
naturally by the sea shore in tropical islands,
and frequently drops its fruits into the water
beneath it. The nuts are thus carried by the
waves and currents from islet to islet ; and
the coconut palm, which is a denizen of sea-
sand, owes to this curious method of water-
carriage its wide dispersion among the coral-reefs
of the Pacific. But a plant that is so dispersed
must needs make provision against wetting,
bruising, and sinking in the sea ; and since only
those coconuts would get dispersed over wide
spaces of water which happened to possess a
good coating of fibre, the existing plant has come
to produce the existing nut as we know it — richly
stored with food for the young palm while it
makes its first steps among the barren rocks and

200 THE STOBY OF THE PLANTS.

sand-banks, and well provided by its shaggy
outer coat against the dangers of the sea, the
reefs, and the breakers. Similarly, we could
never understand the cactus except as a native
of the dry plains of Mexico. Or again, there is
an orchid in Madagascar with a spur containing
honey at a depth of eighteen inches. Now, no
European insect could possibly reach so deep a
deposit ; but a Madagascar moth has a gigantic
proboscis, exactly fitted for sucking the nectary
and fertilising the flowers. Thus no plant can
properly be understood apart from its native
place ; and I have therefore confined myself for
the most part in these few brief life-histories to
native British plants, whose circumstances and
surroundings are known to everybody.

As an example of a very simple and easy life-
history, I will take first a little wayside weed,
commonly known as whitlow-grass, but called
by botanists, in their scientific Latin, Draba
rcrna. This curious little herb is not a grass at
all (as its name might make you think), but a
member of the great family of the crucifers,
succulent plants with four petals and six stamens
in each flower, to which the cabbage, the turnip,
the sea-kale, and many other well-known garden
species belong. But whitlow-grass is not a large
and conspicuous plant like any of these ; it is one
of the smallest and shortest-lived of our British
weeds. It has managed to carve itself out a
place in nature on the dry banks and in clefts of
rock during the few weeks in spring while such
spots are as yet unoccupied by more permanent
denizens. The herb starts from a very minute

SOME PLANT BIOGRAPHIES. 201

seed, dropped on the soil by the parent plant
many months before, and patiently waiting its
time to develop till winter frosts are over, and
warmer weather and moisture begin to quicken
its tiny seed-leaves. As soon as these have
opened and used up their very small stock of
internal nutriment, the young plant begins to
produce on its own account a rosette of little
oblong green leaves, pressed close to the ground
for warmth and shelter. They eat as they go,
and make fresh leaves again out of the absorbed
and assimilated material. Direct sunshine falls
upon them full front ; and as no other foliage
overshadows them or competes in their neigh-
bourhood for carbonic acid, they grow apace into
a little tuft of spreading leaves, about half an
inch long or less, and forming in the mass a
rough circle. For about a week or ten days the
little mouths go on drinking in carbonic acid as
fast as they can, and manufacturing it under the
influence of sunlight into starches and proto-
plasm. At the did of that time they have
collected enough material to send up a slender
blossoming stem, about an inch high or more,
bearing no leaves, but developing at the top a
few tiny flower-buds. These shortly open and
display their flowers, very small and incon-
spicuous, with four wee white petals, each so
deeply cleft that they resemble eight to a casual
observer. Inside the petals are six little active
stamens ; and inside the stamens again a two-
celled ovary. The blossoms are visited and
fertilised on warm March mornings by small
spring midges, attracted by the petals. They

202 THE STOBY OF THE PLANTS.

immediately set their seeds in the flat green
capsule, ripen them rapidly in the eye of the
sun, and shed them at once, the whole life of the
plant thus seldom exceeding three or four weeks
in a favourable season. At the same time, the
leaves and roots wither, as the material they
contained is rapidly withdrawn from them, and
used up in the process of maturing the seeds ; so
tlfat as soon as the fruiting is quite complete,
the plant dies down, having exhausted itself
utterly in the two short acts of flowering and
seed-bearing. During the remaining ten months
of the year or thereabouts, there are no more
whitlow-grasses at all in existence ; the species
remains dormant, as it were, for a whole long
period in the form of seeds lying buried in the
soil, and only springs to life again when the
return of March gives it warning that its day
has once more come round to it.

Contrast with this brief and very spasmodic
life of some thirty days the comparatively long
though otherwise extremely similar biography
of the Mexican agave, commonly cultivated in
hothouses in England, and largely grown in
the open air in the South of Europe under
the (incorrect) name of " American aloes."
The agave is a large and strikingly handsome
lily of the amaryllis family, about which I have
already told you something in a previous chapter.
It begins life as a small plant, like a London
pride, springing from a comparatively large and
richly-stored seed on its own dry prairies. Its
leaves, which spread in a rosette, are not unlike
those of the house-leek in shape ; they are very

SOME PLANT BIOGRAPHIES. 203

large, thick, and fleshy. But as they grow in
the hot and dry climate of Mexico, an almost
desert country, with a very small rainfall, they
have a particularly hard outer skin, so as to
prevent undue evaporation ; and they are pro-
tected against the attacks of herbivorous animals
by being spiny at the edges, and ending in
a stout and dagger-like point of the most for-
midable description. The centre of the plant
is occupied by a sort of sheath of leaves, con-
cealing the growing point. For several years
the round bunch of outer leaves grows bigger
and bigger, till it attains a diameter of ten or
fifteen feet at the base, seeming still like a huge
rosette, with hardly any visible stem to speak of.
Meanwhile these huge leaves are busy all the
time, eating and assimilating, and storing up
manufactured food- stuffs as hard as they can in
their thick and swollen bases. After six or
seven years in their native climate, the plant feels
itself in a position to send up a flowering stalk,
which is formed from the materials already laid
by in these immensely thick and richly-stored leaf
bases. The stalk springs from the middle of the
central leaf-sheath. In a very few weeks the
agave has sent up from this point a huge flower-
ing scape, twenty or thirty feet high, and a foot
or fifteen inches thick at the bottom. On this
scape it produces with extraordinary rapidity a
vast number of large and showy yellow flowers,
which look not unlike an enormous candelabrum,
with many divided branches. The plant is
enabled to produce this immense flowering stem
and these numerous flowers in so short a period,

204 THE STORY OF THE PLANTS.

because it draws upon its large store of elabo-
rated material for the purpose. But as the
flowering stem rises, and the flowers unfold, and
the big fruits and seeds develop and ripen, the
leaves below grow gradually flaccid and empty ;
and their bases shrink, being depleted of their
store of valuable food-stuffs ; so that by the time

[ the seeds are ripe, the whole plant is used up,
having exhausted itself, like the tiny whitlow-

) grass, in the act of fruiting. It then dies down
altogether, and never recovers, though new
plants or offsets usually develop at its base from
side buds, after the original agave has begun to
wither. In English hothouses it takes thirty
or forty years before the agave has collected
enough material to send up a stem and flower ;
hence the common exaggeration that it needs a
hundred years for " the blossoming of an aloe."

As a familiar example of a very different kind
of perennial plant, we may take our English
beech- tree. The beech sets out in life as a
tender young seedling, which grows from a good-
sized triangular nut, whose cotyledons are well-
stored with food- stuffs for its early development.
As the nut germinates, the cotyledons open out,
become flat and green, like thick fleshy leaves,
and begin to absorb carbonic acid from the air,
which they work up at once with the material
supplied by the tiny root into protoplasm and
chlorophyll. In the angle between them a young
shoot develops, which soon puts forth delicate
blades of true foliage leaves ; and these in turn
grow and assimilate material under the influence
of sunlight. In the first year the little beech-tree

SOME PLANT BIOGRAPHIES. 205

is but a tiny sapling, with a short stem, already
woody ; but year after year, this stem grows
higher, branches out and divides, and slowly
clothes itself in the smooth grey bark charac-
teristic of the species. The particular way in
which it branches is this : each autumn there is
formed at the base of every leaf a winter bud,
long and brown, and covered with close scales,
which enable it to survive the cold of winter.
When spring comes round again, each one of
these buds develops in turn into a leafy branch,
so that (accidents excepted) there are as many
new branches or twigs every year as there were
leaves on the tree in the preceding season. The
young leaves and branches emerge slowly and
cautiously from the buds in spring, for fear of
frost ; they are protected at first by certain scaly
brown coverings known as stipules. Gradually,
however, as the weather grows warmer, the
stipules fall off, and display the tender green
leaves, exposed to the air, but still folded to-
gether. As soon as they car*, trust the season,
however, the leaves unfold, though they are still
thickly covered at the edges by protective hairs,
which afterwards fall off, but which guard the
fresh green chlorophyll in the cells just at first
both from chilly winds and from the injurious
effect of excessive sunlight. Year after year
the beech-tree grows by so subdividing and
adding branch to branch ; while its stem in-
creases by yearly rings of growth, till it attains
at length considerable dimensions.

During many such seasons of growth the
beech-tree does not flower ; all the material it

206 THE STORY OF THE PLANTS.

manufactures through the summer in its large
flat leaves it lays by in its stem to supply the
young shoots and branches at the beginning of
the subsequent season. But at last, when it has
reached the height and girth of a small tree, it

/ begins to store up protoplasm and starches for
blossom also. Some of its buds are now leaf-

"buds, but some are flower-buds, produced in
autumn, and held over till April. In the spring
these flower-buds lengthen and produce bunches
of blossoms, which we call catkins, some of
them males, and some females, but both sexes
growing on the same tree together. They
bloom, like most otEer catkins, in the early
spring, while the leaves are still very little
developed, so as to prevent the foliage from
interfering with the carriage of the pollen. The
males are produced in hanging clusters an inch

. or so long ; while the females stand u^ in small
globular bunches, on erect flower^sTems. They
are wind-fertilised ; and shortly after flowering,
the male catkins d.rop off entire, having done
their life-work, while the females swell out into
the familiar husks or four-valved cups, con-
taining each some two or three triangular
nuts, richly stored with food-stuffs.

The agave only flowers once, and then dies
down, exhausted. But the beech goes on
flowerin^or "many years together, and grows
meanwhile larger and larger in bulk, its trunk
increasing in girth, and becoming buttressed at
the base, so as to support the large head of
branches and the dense mass of foliage. For
the boughs are so arranged that a great crown

SOME PLANT BIOGKAPHIES. 207

of leaves is exposed in summer to the sun and
air at the outer circumference of the dome-
shaped mass ; and in this way every leaf gets
its fair share of light and carbon, and interferes
as little as possible with the work of its neigh-
bours. Old beeches will grow to more than
100 feet in height, and live for probably three or
four centuries. At last, however, their proto-
plasm grows old and seems to get enfeebled ;
the trunk decays, and the entire tree falls first
into dotage, then dies by slow degrees of pure
senility.

The common vetch is another familiar plant
whose life -history introduces to us some totally
different yet interesting features. It belongs to
the wide-spread family of the peaflowers, to
which I have already more than once alluded,
and it takes its origin from a comparatively large
and rich round seed, not unlike a pea, whose
cotyledons are well stored with supplies of starch
and other food- stuffs. It sends up at first a
short spreading stem, which twines or trails
over surrounding plants, developing as it goes
very curious leaves of a compound character.
Each leaf consists of five or six pairs of leaflets,
placed opposite one another on the common
stalk in the feather- veined fashion. But the
four or five leaflets at the end of each leaf-
stalk do not develop any flat blade at all, and
are quite unleaflike in appearance : they are
transformed, indeed, into long thin tendrils,
which catch hold of neighbouring branches or
stems of grasses, twine spirally round them, and
so enable the vetch to climb up bodily in spite

208 THE STORY OP THE PLANTS.

of its weak stem, and raise its leaves and flowers
to the air and the sunlight.

At the base of every leaf, again, you will find,
if you look, two arrow-shaped appendages, which
block the way up the stem towards the deve-
loping flowers for useless creeping insects such
as steal the honey without assisting fertilisation.
On each appendage is a curious black spot, the
use or function of which is not apparent while
the blossoms are in the bud. But after a few
weeks' growth, the vetch begins to produce
solitary flowers in the angle of each upper
leaf ; flowers of the usual pea-blossom type,
but pink or reddish purple, and handsome or
attractive. These flowers contain abundant
honey to allure the proper fertilising insects.
Just as they open, however, the black spot on
the arrow-headed appendages of the lower
leaves, in whose angles there are no flowers,
begins also to secrete a little drop of honey.

What is the use of this device ? Well, if
you watch the vetch carefully, you will soon
see that ants, enticed by the smell of honey in
the opening flowers, crawl up the stem in hopes
of stealing it. But ants, as we know, are
thieves, not fertilisers. As soon as they reach
the first black spot, they stop and lick up the
honey secreted by the gland, and then try to
pass on to the next appendage above it. But
the arrow-shaped barbs, turned back against the
stem, block their further progress ; and even if
they manage to squeeze themselves through with
an effort, they are met just above by another
honey-gland and another barrier in the shape of

SOME PLANT BIOGRAPHIES 209

a second arrow-shaped appendage. No ant ever
gets beyond the third or fourth barricade ; the
device is efficient : the vetch thus offers black-
mail to creeping thieves in the shape of stem-
honey, in order to guard from their depredations
the far more valuable and useful honey in the
flowers, which is intended to attract the fertilising
insects.

When the purple flowers have in due time
been fertilised, they produce long narrow pods,
each containing about a dozen round pea-like
seeds. As the pods ripen, the plant shrivels up,
and usually dies away, leaving only the ripe
seeds to represent its kind through the winter.
But sometimes, in damp and luxuriant autumns,
the stem struggles through the winter to a second
season, and flowers again in the succeeding
summer. We express this fact as a rule by
saying that the vetch is usually an annual, but
occasionally a biennial.

With most annuals, such as wheat or sun-
flower, thg^yvhqle strength d: the plant.j^used^
up in tSepfod ilc Lion of seed T ana as Tsoonas
the seed is set, the plant dies immediately.
Where annuals have the sexes on separate
plants, however, thejm£j£_4jlan^
as they have sheT^TheirpolIen^
being thus complete ; while the^females live^og
till their seed has ripened.

Common coltsfoot is another well-known plant
whose life-history shows some points of great
interest. It grows in the first instance from
a feathery fruit, one- seeded and seed- like, which
is carried by the wind, often from a greafe
14

SlO T?ltE StfOKY OF tfHE PLANTS*

distance. These flying fruits alight at last
upon some patch of bare or newly-turned soil,
such as the bank of a stream where there has
been lately a landslip, or the side of a railway
cutting. These bare situations alone suit the
habits of the baby coltsfoot ; if the fruit happens
to settle on a light soil, already thickly covered
with luxuriant vegetation, it cannot compete
against the established possessors. But the
winged fruits, being dispersed on every side,
enable many young plants to start well in life
on the poor stiff clays which best suit the con-
stitution of this riverside weed. The seedling
grows fast in such circumstances, and soon pro-
duces large angular leaves, very broad and thick,
which in the adult plant have often a diameter
of five or six inches. They are green above,
where they catch the sunlight and devour
carbonic acid ; but underneath they are covered
with a thick white wool, which is there for a
curious and interesting purpose. The damp
clay valleys and river glens where coltsfoot
lives by choice are filled till noon every day
with mist and vapour ; and heavy dew is
deposited there every night through the summer
season. Now, if this dew were allowed to clog
the evaporation pores or stomata on the leaves of
•coltsfoot, the plant would not be able to raise:
water or proceed with its work except for per-
haps a few hours daily. To prevent this mis-
• fortune, the under side of the leaves is thickly
covered with a white coat of wool, on which no-
dew forms, and off which water rolls in little-
-round drops, as you have seen it roll off a serge5

PLAN* BIOGRAPHIES. 211

table-cloth. By this ingenious device the colts-
foot manages to keep its evaporation pores dry
and open, in spite of its damp and moisture-
laden situation. One may say, indeed, that
every point in the structure of every plant has
thus some special purpose; indeed, one large
object of the study of plants is to enable us to
understand and explain such hidden purposes in
the economy of nature.

During its early life, once more, the young
plant of coltsfoot is constantly engaged, like the
whitlow-grass and the agave, in laying hy
material fqr. its future flowering "season, jiu't
it does not lay by, as they do, in its expanded
le aves or other portions of its body visible above
g round ; instead of that, it puts forth a creeping
underground stem or root-stock, which pushes
its way sideways through the tough clay soil,
often for several feet, and sends up at intervals
groups of large roundish leaves, such as I have
already described, to work above ground for it.
You might easily take each such group for a
separate plant, unless you dug up the root- stock
and saw that they were really the scattered
foliage of one subterranean stem, which grows
horizontally instead of upward. During the
summer the coltsfoot lays by in this buried
root-stock quantities of rich material for next
year's leaves and for its future flowers. In
winter the leaves die down, and you see not
a trace of the plant above ground. But in very
early spring, as soon as the soil thaws, certain
special buds begin to sprout on the underground
stem, and send up tall naked scapes or flower-

^12 THfc STORY OF THE PLANTS;

stems, usually growing in tufts together, and
each crowned by a single large fluffy yellow
flower-head. These stems are covered below
by short purplish scales ; and their purple
colouring matter enables them to catch and
utilise to the utmost the scanty sunshine that
falls upon the plant in chilly March weather.
For this particular colouring matter has the
special property of converting the ehergy in.
rays of light into heat for warming the plant.
The scape is also wrapped up in a sort of
cottony Wool, which helps to keep it warm ; and
the unopened flower-head turns downward at
first for still further safety against chill or
injury. These various devices enable the colts-
foot to blossom earlier in the season than almost
any other insect-fertilised flower, and so to
monopolise the time and attention of the first
flower-haunting March insects.

Coltsfoot is a composite by family ; so its
flowers are collected together into a head, after
the ancestral fashion, and enclosed by an in-
volucre which closely resembles a calyx. But
the type of flower-head differs somewhat from
that in any of the composite plants I have
hitherto described for you, because its outer
florets are not flat and ray-shaped, but strap-like
or needle-shaped. The inner florets, however,
are bell-shaped, and much like those of the
common daisy. The naked scapes, each re-
sembling to the eye a shoot of asparagus, and
each crowned by a single fluffy yellow flower-head,
are familiar objects on banks or railway cuttings
in the first days of spring ; I have known them

SOME PLANT BIOGKAPHIES. 213

open as early as the 12th of January, in sunny
weather. But they grow entirely without
leaves, and are produced at the expense "of ~tKe
material laid up in the underground stem by
last season's foliage. They blossom, are/
fertilised, set their seeds, turn into heads of
white feathery down, and produce ripe fruits
which blow away and get dispersed, all before
the leaves begin to appear at all above the^soiT
Thus you never can see the foliage and flowers
together ; it is only by close observation that
you can discover for yourself the connection
between the heads of yellow flowers which come
up in early spring, and the groups of large
angular woolly leaves which follow them in the
same spots much later in the season.

The life-history of the coltsfoot introduces us
also to another conception which we must clearly
understand if we wish to know anything about
many plant biographies. I have said already
that parts of one and the same coltsfoot plant
might easily be mistaken for separate indi-
viduals ; and, indeed, if the stem gets severed,
particular groups of leaves may live on as such,
in two or more distinct portions. This leads us
on to the consideration of a great group of
plants like the common wild strawberry, in
which a regular system of subdivision exists,
and in which new plants are habitually pro-
duced by offsets or runners, as well as by seed-
lings. Such a method of increase is to some
extent a survival into higher types of the primi-
tive, mode of reproduction by subdivision.

A strawberry plant grows' in the first instance

214 THE STORY OF THE PLANTS.

from a seed, which was embedded in a carpel or
seed-like fruitlet on the ripe red swollen recep-
tacle which we commonly call *§T?frawBerry.
This seed germinates, and produces a seedling,
which puts forth small green leaves, divided
into three leaflets each at the end of a long and
slender leaf -stalk. As it grows older, however,
besides its own tufted perennial stem or stock,
it sends out on every side long branches or
runners, which are in fact horizontal or creeping
stems in search of new rooting places. These
stems run along the ground for some inches,
and then root afresh. At each such rooting-
point, the plant sends up a fresh bunch of leaves,
which gradually grows into a distinct colony, by
the decay of the intermediate portion or runner.
Again, this new plant itself in turn sends forth
runners in every direction all round it ; so that
often the ground is covered for yards by a net-
work of strawberry plants, all ultimately derived
from a single seedling. Theoretically, we must
regard them all as severed parts of one and the
same plant, accidentally divided from the main
stem, since only the union of two different
parents can give us a totally distinct individual.
But practically they are separate and indepen-
dent plants, competing with one another thence-
forth for food, soil, and sunshine.

A great many plants are habitually propagated
in such indirect ways, as well as by the normal
method of flowering and seeding. Indeed, it is
difficult to separate the two processes of mere
growth, as shown in budding or branching, and
reproduction by subdivision, as shown in the

SOME PLANT BIOGKAPHIES. 215

springing of saplings from the roots or stem,
the production of runners, the division of bulbs,
and the rooting of suckers. I will therefore give
here a few select instances of these frequent
incidents in the life-history of various species.

The tiger-lilies of our gardens produce little
dark buds, often called bulbils, in the angles of
their foliage leaves. These buds at last fall off
and root themselves in the soil, forming to all
appearance independent plants. Much the
same thing happens with many English wild-
flowers. For example, in the plant known 'as
coral-root (allied to the cuckoo-flower) little bud-
bulbs are formed in the angles of the leaves,
which drop on the damp soil of the woods
where the plant grows, and there develop into
new individuals. In this last-named case the
plant seldom sets its fruit at all, the reproduction
being almost entirely carried on by means of the
bulbils. Such instances suggest to us the
pregnant idea that a seed is nothing more than
a bud or young shoot, to whose making two
separate parents have contributed. There is, in
short, no essential difference between the two
processes of growth and reproduction.

Again, in the common lesser celandine the
root-stock emits a large number of tiny pill-like
tubers, which grow and lay by rich material
underground (derived from the leaves) during
the summer season. In the succeeding spring,
however, each of these tubers develops again
into a separate plant, in a way with which
the familiar instance of the potato has made us
familiar, In the crocus, once more, and many

216 THE STORY OF THE PLANTS.

other bulbous plants, several small bulbs are pro-
duced each year by the side of the large one, and
these smaller bulbs are of course, strictly speak-
ing, mere branches of the original crocus-stem.
But they grow separate at last, by the decay or
death of the central bulb, and themselves in
turn produce at their side yet other bulbs, which
become the centres of still newer families. We
may parallel these cases with those of trees whose
boughs bend down and root in the ground so as
to become in time independent individuals ; or
with runners like those of the strawberry and
the creeping buttercup, which root and grow
afresh into separate plantlets.

Sometimes still more curious things happen
to plants in the way of reproduction by sub-
division. There is an English pondweed, for
example, which grows in shallow pools liable to
be frozen over in severe winters. As cold
weather approaches, the top of the growing
shoots in this particular pondweed break off
of themselves, much as leaves do at falling time.
But they break off with all their living material
still preserved within them undisturbed ; and
they then sink and retire to the unfrozen
depths of the pond, where they remain unhurt
till spring comes round again. This is just
what the frogs and newts and other animal
inhabitants of the pond do at the same time, to
prevent getting frozen. Next year the severed
tops send out roots in the soft mud of the bottom,
and grow up afresh into new green pondweeds.

It is therefore impossible to make any broad
line of distinction in this way between what may

SOME PLANT BIOGRAPHIES. 217

be considered as modes of individual persistence in
the self-same plants, and what may be regarded
as modes of reproduction by subdivision. Some
plants, like couch-grass and elm, are almost
always surrounded by young shoots which may
ultimately become to all intents and purposes
independent individuals ; while others, like
corn-poppy or Scotch fir, never produce any off-
sets or suckers. In the meadow orchids each
plant produces every summer a second tuber by
the side of the old one ; and from the top of
this tuber the next year's stem arises in due
time with its spike of flowers. Here we may
fairly regard the tuber as a simple means of
persistence in the plant itself ; there is nothing
we could possibly call reproduction. But in
many lilies the older bulbs produce numerous
small branch bulbs at their sides ; and these
younger bulbs may become practically indepen-
dent, each of them sending up in the course of
time its own stem and its own spike of
flowers.

Even when the main trunk of a tree is dead,
through sheer old age, it often happens, as in
the elm and birch, that the roots send up fresh
young shoots, which may grow again, and
prolong the life of the plant indefinitely. In
stone-crops and other succulent herbs, which
grow in very dry and desert situations, the
merest fragment of a stem, dropped on moist
soil, will send out roots and grow afresh
into a new individual. Cactuses and other
desert plants have often to resist immense
drought, and therefore possess extraordinary

218 THE STORY OF THE PLANTS.

vitality in this way. They will grow again from
the merest cut end under favourable conditions.
These few short hints as to the life-history of
various plants in different circumstances will
serve to show you how vast is their variety.
Every plant, indeed, has endless ways and
tricks of its own ; and every point in its
structure, however unobtrusive, has some
purpose to serve in its domestic economy. Thus
the ivy-leaved toad-flax, which grows on dry
walls, has straight flower-stalks, which become
bent or curved when the flowering is over.
Why is this ? Well, the plant has acquired the
habit of bending round its flower-stalk after the
blossoming season, because it cannot sow its
seeds on the bare stone, so it hunts about
diligently for a crevice among the mortar into
which it proceeds to insert its capsule, so that
the seedlings may start fair in a fit and proper
place for their due germination. So, too, the
subterranean clover, growing on close-cropped
hillocks much nibbled over by sheep, where its
pods of rich seeds would be certainly devoured
if exposed on a long stalk like that of other
clovers, has developed a few abortive corkscrew-
like blossoms in the centre of its flower-head,
by whose aid the whole group of pods burrows
its wayj spirally into the soil beneath ; so that
the plant thus at once escapes its herbivorous
enemies, and sows its own seed for itself auto-
matically. It would be impossible in our space
to do more than thus briefly indicate by two or
three examples the immense number and variety
of these special adaptations. Every plant has

SOME PLANT BIOGRAPHIES. 219

hundreds of them. There is not a tiny hair on
the surface of a flower, not a spot or a streak in
the blade of a leaf, not a pit or depression on the
skin of a seed, that has not its function. And
close study of nature rewards us most of all
for our trouble in this, that it reveals to us
every day some delightful surprise, forces on
our attention some hitherto unsuspected but
romantic relation of structure and purpose.

I will mention but one more case as a typical
example. There exists as a rule a definite
relation between the shape and arrangement of
the leaves in plants, and the shape and arrange-
ment of the roots and rootlets, with regard to
water-supply. Each plant, in point of fact, is
like the roof of a house as respects the amount
of rain which it catches arid drains away ; and
it is important for each that it should utilise to
the utmost its own particular supply of drainage
or rain water. Hence you will find that some
plants, like the dock, have large channeled
leaves, with a leaf -stalk traversed by a depres-
sion like a drainage runnel : plants of this type
carry off all the water that falls upon them
towards the centre, inwards. But such plants
have always also a descending tap-root, which
instantly catches and drinks up the water poured
by the drainage system of the leaves towards
the middle of the plant. In other plants, again,
however, with round leaf-stalks and outward
pointed leaves, the water that falls upon the
foliage drains outward towards the circum-
ference ; and in all such plants the roots, in-
stead of descending straight down, are spread-

220 THE STORY OF THE PLANTS.

ing and diffused, so as to go outward towards
the point where the water drips on them.
Moreover, in this latter case it is found, on
digging up the plant carefully, that the ab-
sorbent tips of the rootlets are clustered
thickest about the exact spots where the leaves
habitually drop the water down upon them.
Every plant is thus to some extent a catchment-
basin which utilises its own rainfall : it collects
rain for itself, and conducts it by a definite
system of pipes and channels to the precise
spots in the soil where it can best be sucked up
for the plant's own purposes.

On the other hand, while every part of every
plant is thus minutely arranged for the common
advantage, every species of plant and animal
fights only for its own hand against all comers.
Nature is therefore one vast theatre of plot and
counterplot. The parasites prey on the vegeta-
tive kinds ; the vegetative kinds respond in turn
by developing checks to counteract the parasites.
The squirrels produce sharper and ever sharper
teeth to gnaw through the nutshells ; the nut-
trees retaliate by producing for their part thicker
and ever thicker shells to baffle the squirrels.
And this play and by-play goes on unceasingly
from generation to generation ; because only the
cleverest squirrels can ever get enough nuts to
live upon ; and only the hardest-shelled and
bitterest-rinded nuts can escape the continual
assaults of the squirrels. In order, therefore,
really to understand the structure and life of
any one species, we should have to know in the
minutest detail all about its native conditions,

THE PAST HISTORY OF PLANTS 221

its soil, its surroundings, its allies, its hired
friends, its blackmailing foes, its exterminating
enemies. Such exhaustive knowledge of the
tiniest weed is clearly impossible ; but, even the
little episodes we can pick out piecemeal are full
of romance, of charm, and of novelty.

CHAPTEE XIV.

THE PAST HISTORY OF PLANTS.

I PROMISED some time since to return in due
season to the question why plants, as a rule,
exhibit distinct kinds or species, instead of
merging gradually one into another by imper-
ceptible degrees. This problem is generally
known as the problem of the origin of species.
You might perhaps expect (since plants have
grown and developed, as we have seen, one out
of the other) that they would consist at present of
an unbroken series, each melting into each, from
the highest to the lowest. This, however, is
not really the case ; they form on the contrary
groups of distinct kinds : and the reason is, that
natural selection acts on the whole in the oppo-
site direction. It tends to make plants group
themselves into definite bodies or species, all
alike within the body, and well marked off from
all others outside it.

Here is the way this arrangement comeb
about. As situations and circumstances vary,
a form is at last arrived at in each situation
which approximately fits the particular circum-

^" '" ^

222 THE STOKY OP THE PLANTS.

stances. This form may perhaps vary again in
other situations, and give rise to individuals
better adapted to the second set of circum-
stances. But just in proportion as such in-
dividuals surpass in adaptation one another will
they live down the less adapted. Hence, the
intermediate forms will tend to perish, and the
world to be filled in the end with groups of
plants, each distinct from others, and each
relatively fixed and similar within its own
limits.

At all times, and in all places, this process of
variation and adaptation is continually going
on ; new kinds are being formed, and inter-
mediates are dying out between them. For the
intermediates are necessarily less adapted than
the older form to the old conditions, and than
the newer form to the new ones.

Moreover, when any great point of advantage
is once gained by a kind, it tends to go on and
be preserved, while variations in other parts
continue uninterrupted. Thus, the first com-
posite plant (to take a concrete example) gained
by the massing of its flowers into a compact
head : and it then became a starting-point for
fresh developments, each of which maintained
the massed flower-head, with its ring of united
stamens, while adding to the type some fresh
point of its own, which specially adapted it to a
particular situation. So, too, the first peaflower
gained by the peculiar form of its oddly-shaped
corolla, and therefore became the ancestor of
many separate kinds, each of which retains the
general pea-like type of blossom, while differing

THE PAST HlSTOIiY OF PLANTS. 223

in other respects as widely from its neighbours
as gorse and clover, peas and laburnum, broom
and vetches, scarlet-runners and lupines. A
group of kinds, so derived from a common pro*
genitor, but preserving throughout one or more
of that progenitor's peculiarities while differing
much in other respects among themselves, is
called a family. Thus we speak of the family
of the peaflowers, the family of the roses, the
family of the lilies, the family of the orchids.
Each family may include several minor groups,
Jmown as genera (in the singular, a genus) ; and •
each such genus may further include several
distinct kinds or species.

For example, all the peaflower family are dis-
tinguished by their possession of a peculiar
blossom whose corolla consists of a standard, a
keel, and two wings, like sweet-pea or broom.
This family contains several genera, one of
which is that of the clovers, including certain
peaflowers which have learned to mass their
blossoms into a roundish head, and have trefoil
leaves, and very few seeds in the short seed-pod.
The clovers, again, are subdivided into species or
kinds, such as purple clover, Dutch clover, hop
•clover, and hare's foot clover ; in Britain alone,
we have twenty-one such distinct species or
kinds of clover. You will see at once that this
method of grouping by ancestral forms enables
us largely to reconstruct the history of each
particular plant or animal.

Why don't these kinds cross freely with one \
•another, and so produce an endless set of
puzzling hybrids ? Well, they do occasionally ; J

224 THE STORY OP THE PLANTS.

and such mongrel forms often show us every
possible variation between the two parents.
But this can only happen when the parent stocks
are very close to one another; and even then,
the hybrids tend to die out rapidly. Why?
Because each of the parents is better adapted to
a particular situation ; the hybrid usually falls
between two stools, and gets killed down accord-
ingly. It cannot stand the competition of the
true species. New kinds, however, may some-
times take their rise from chance hybrids,,
which happen to possess some combination of
advantages.

Thus plants in the mass, as we see them
around us at the present day, are divisible into
several well-marked groups, some of which are
now dominant or leading orders, while others
are hardly more than mere belated stragglers or
loitering representatives of types once common,
but now outstripped in the race by younger
competitors. I cannot close without briefly
describing to you the main divisions of such
orders or groups, as now accepted by modern
botanists.

The widest distinction of all between plants is
that which marks off the simpler and earlier
forms, which are wholly composed of cells, from
the higher and stem-forming types, which are
also provided with systems of vessels and woody
tissue. The first class is known as CELLULAB
I PLANTS ; the second class as VASCULAR PLANTS.
These are the greatest and most general
divisions.

THE PAST HISTORY OP PLANTS. 225

The CELLULAR PLANTS comprise many sorts,
from the simple one-celled types which float
freely in water, up to the relatively high and
complex seaweeds, which produce large fleshy
fronds, and often display a considerable division
of labour between their various parts and organs.
Still, as most of them live in water, either fresh
or salt, and wave freely about in the liquid that
surrounds them, they have no need of an elabo-
rate system of conducting vessels, because every
part can drink in water and dissolved food- salts
from the neighbouring pond, sea, or river. Still
less have they any necessity for a woody stem,
which would only be a disadvantage to them in
stormy weather. Hence most of the cellular
plants (with certain exceptions to be noted here-
after) are water- weeds ; while most of the
vascular plants (with other exceptions to be
similarly treated) are land plants. In particular
trees and shrubs, the highest forms of plant life,
are invariably terrestrial.

Various successive stages of these cellular
plants may be briefly described in rough out-
line. First of all we get the simple one-celled
plant, the lowest type of all, consisting of a
single mass of protoplasm, generally with
chlorophyll, surrounded by a cell- wall. Next
above these come the hair-like water-weeds,
which consist of rows of such simple cells,
placed end to end in single file, one in front of
another, like pearls in a necklace. These kinds
are many-celled, but each cell is here in contact
with two others only, one below, and one above
it. Thirdly, we get the flat leaf-like water-

226 THE STOKY OF THE PLANTS.

weeds, which have thin green fronds, composed
of a single broad sheet of cells, not a hair-like
row ; each cell has here many cells around it,
but all lie in one plane ; the sheet is only one
cell thick ; it does not spread abroad in more
than two directions. Lastly, we get the ordi-
nary thick-fronded seaweed, in which sheets of
cells, many layers deep, grow in divided masses
on rope-like bases, and closely resemble to the
eye true vascular plants with stems, leaves, and
branches.

Most of these cellular plants, when they
possess green chlorophyll, are known as algce.

There are several low forms of plants, how-
ever, which do not possess chlorophyll, but live
at the expense of other plants, exactly as
animals do. These are generally known in the
lump as fungi. Many of them are terrestrial.
The distinction, however, is not a genealogical
one. Cellular plants of various grades have
often taken, time after time, to this lower
parasitic or carrion-eating habit ; and though
they therefore resemble one another externally
in their absence of green colour, in their usual
whiteness and fleshiness, and in their mush-
room-like substance, they do not really form a
natural class ; their resemblance is due to their
habits only. In short, we call any cellular plant
a fungus, if instead of supporting itself by green
cells, it has adopted the trick of living on
organised material already laid up by other
plants or animals.

Among these fungus-like plants, again, some
of the simplest and lowest are the celebrated

THE PAST HISTOBY OF PLANTS. 227

bacteria, which are one-celled organisms, living
in stagnant or putrid fluids, and also in the
bodies and blood of diseased animals. They
answer among fungi to the one-celled alga.
Many of them cause infectious diseases ; such
are the bacilli of diphtheria, typhus, cholera,
consumption, small-pox, and influenza. Sur-
rounded by a suitable nutritious fluid, these tiny
parasitic plants increase with extraordinary and
fatal rapidity. Though they are really one-
celled, and reproduce by cell-division, they often
hang together in rude lumps or clusters which
simulate to some extent the many-celled bodies.
In this book, however, where we have concen-
trated our attention mainly on the true or green
plants, I have not thought it well to dwell at
any length on the habits or structure of these
animal-like organisms.

Another well-known group of small fungus-
like plants is that which contains the yeast-
fungus, a one-celled plant, which reproduces by
budding.

The higher fungi are many-celled, and often
possess well-marked organs for different pur-
poses. They answer rather to the seaweeds
and higher alga. Familiar examples are the
common moulds, which form on jam, dead
fruit, and other decaying material. Some of
them, like the smut of wheat and oats, are
parasitic on growing plants, and most dangerous
enemies to green vegetation. The highest fungi
are the groups which include the mushroom,
the puff-ball, and all those other large and
curiously-shaped forms commonly lumped to-

228 THE STORY OF THE PLANTS.

gether in popular language under the name of
toadstools. Their anatomy and physiology is
extremely complex.

To recapitulate ; CELLULAR PLANTS belong to
two main types ; those which contain chlorophyll,
and live like plants by eating and assimilating
carbon under the influence of sunshine ; these
are generally grouped together in a rough class as
ALG.E : and those which contain no chlorophyll,
but live, like animals, by using up or destroying
the carbon-compounds already stored up by
green plants ; these are generally grouped to-
gether in a rough class as FUNGI.

The lichens form a curious mixed group,
whose strange habits cannot here be described
at any adequate length ; they are not so much
separate plants as united colonies of algae and
fungi, in which the green alga does the main
work of collecting food, while the parasitic
fungus, increasing with it at the same rate, eats
it up in part, while contributing in turn in various
ways to the general good of the compound
community. This is therefore hardly a case of
pure destructive parasitism, but rather one of
a co-operative society banded together on pur-
pose for mutual advantage.

The mosses and liverworts, once more, show
us an intermediate stage between the true
cellular and the true vascular plants. They
have a rudimentary stem, and beginnings of
vessels, r They have also leaves, or'~ organs
equivalent to them ; and they display the first
approach to something like flowers.

THE PAST HISTORY OF PLANTS. 229

r

The VASCULAR PLANTS, again, which are
characterised by the possession of special vessels
for the conveyance of sap and organised material,
and by the presence of more or less woody fibres,
are divisible into two main groups — iheflowerless,
and the flowering.

The flcnverless group of Vascular Plants are
mainly represented by the ferns and horsetails.
These were at one time the leading vegetation
of the entire world, far outnumbering in kinds
all the rest put together. But they have now
been lived down by the flowering plants, which
at present compose the main mass of the plant
aristocracy.

The flowering plants, once more, fall into two
main groups ; the small but widespread group of
naked-seeded plants , including the cycads, pines,
firs, cypresses, and yews; and the very large
group of fruit-bearing plants, including almost
all the kinds of herb, shrub, bush, or tree
familiarly known to you, as well as almost all
those various plants with which we have busied
ourselves in this little volume. You will thus
see that the vast majority of species in the
vegetable kingdom belong to small and relatively
inconspicuous orders. Indeed, for the most
part, we habitually disregard the cellular plants,
thinking only of the vascular ; while among the
vascular themselves, again, we disregard the
flowerless, thinking only of the flowering; and
among the flowering kinds, we concentrate our
attention as a rule on the fruit-producing group
(in the botanical sense of the word') and neglect
the naked-seeded. In short, we usually confine

230 THE STORY OF THE PLANTS.

our attention to the highest division of the
highest group of the highest half of the vegetable
kingdom. The rest are for us mere inconspicu-
ous mosses, moulds, or seaweeds.

The fruit-producing group of flowering plants
are finally divided into the dicotyledons and the
monocotyledons, whose chief differences I have
already pointed out to you. And to complete
our picture of this infinite hierarchy, the dicoty-
ledons, once more, are divided into various
families, such as the buttercups, the roses, the
crucifers, the composites, the labiates, the
umbellates, the saxifrages, and the catkin-
bearers. The buttercup family, in particular (to
select a single group), is further divisible into
genera, such as buttercup, marsh marigold,
larkspur, anemone, clematis, and aconite ; while
the buttercup genus (to take one only among
these) comprises in turn a vast number of
species, such as the water-crowfoot, the ivy-
leaved crowfoot, the meadow buttercup, the
bulbous buttercup, the lesser celandine, the
goldilocks, and so on for pages. Similarly, the
monocotyledons are divided into various families,
such as the orchids, lilies, grasses, and sedges :
the families are divided into many genera ; and
each genus into several species. The infinite
variety of circumstances is such that each type
goes on varying and varying for ever in order to
nt itself for the endless situations it is called
upon to fill, and the endless diversity in the
accidents of climate or soil or position that it
may chance to come across. Thus we have in
England* more than a hundred different kinds of

THE PAST HISTOEY OF PLANTS. 231

grasses, each specially adapted for some one
particular situation.

Only the closest individual study can give any
adequate idea of this immense diversity of
plants in nature.

The geological history of the world shows us
that the development of plants has been slow
and progressive. In the earliest rocks (of which
an account is given in another volume of this
series), we get few traces of any plants but the
lowest : so that at that time it is probable none
but seaweeds and their like existed — cellular
plants which contain hardly any parts solid
enough for preservation. By the age when the
coal was laid down, however, ferns, horsetails,
ami many gigantic extinct plants with solid
stems had begun to exist ; but few or no flower-
ing plants, except conifers, had yet been de-
veloped. Lajer still came the true flowering
plants, witrTcovered seeds , at first in simple and
antiquated forms, but becoming more complex
as birds, mammals, and flying insects of the
flower-haunting types were developed side by
side with them to visit and fertilise them or to
disperse their seeds. Succulent fruits, of course,
could only arise when tribes of fruit-eaters had
been evolved to assist them ; while such special
bee-fertilised types as the sage group, and such
complex forms as the orchids and composites,
requiring the aid of highly-developed insects,
are of extremely recent evolution. Plant and J
animal 'life have continually reacted upon one j
another.

232 THE STOKY OF THE PLANTS.

Whoever has been interested in the study of
plants by this little book may be glad to know
what is the best way of continuing his acquaint-
ance with the subject in future. Nothing
gives one such a grasp of the facts of botany
and of life in general as careful study of the
plants which grow in one's own country.
Students in the British Isles should therefore
buy a copy of Bentham and Hooker's British
Flora, and seek by the aid of the key at its
beginning to identify for themselves every
flowering plant they come across in our woods
and meadows. American students should get
in like manner Asa Gray's Manual of Botany. In
the course of identifying all the plants you find,
you will begin to understand the nature of plant
life and the course of plant evolution in a way
that is quite impossible through any mere
book-reading. Buy also a simple platyscopic
lens, and a sharp penknife to assist you in
dissection. Armed with these simple but useful
tools, you will soon make rapid and solid progress
in the knowledge of nature.

For further and more detailed information on
the laws of plant life, you cannot do better than
consult Kerner and Oliver's Natural History of
Plants, which sets forth in full an immense
number of interesting and curious facts, in
language comprehensible to any attentive and
careful student.

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