They are in many respects similar to bulbs, and if we cut one in half

and compare it with a divided hyacinth we shall see that they both

consist of over-lapping scales. In the onion these scales are fleshy

and succulent, but in most tree buds they are dry, hard membranes.

The pear and magnolia buds are secured against wintry cold by woolly

linings to the scales, and in the horse-chestnut they are covered with

a kind of resin which renders them impervious to moisture.

[Illustration: HORSE-CHESTNUT.]

It requires a careful use of the microscope to trace all that a bud

contains; I will therefore quote the words of a German naturalist who

dissected a horse-chestnut bud gathered in winter, and found that it

contained sixty flowers. It would be interesting to select a terminal

flower-bud of this tree; by taking it carefully to pieces one might,

with patience and using a powerful lens (or a microscope if one is

available), see for ourselves a good deal of what the writer describes:—

“Having removed the outer scales, seventeen in number, cemented

together by a gummy substance to render the bud waterproof, I

discovered four leaves surrounding a spike of flowers, so clearly

visible when magnified that I not only counted the number of flowers,

but could discern the pollen on the stamens.”

The winter covering of a bud, both the inner and outer scales, are

only a temporary protection in order to keep out moisture and keep in

warmth, so that as the sun begins to gain power, the gummy covering of

the bud melts and yields to the expanding pressure from within, when

one after another the sticky scales fall off, showing the young leaves

with their soft woolly surfaces; these leaves rapidly unfold and hang

droopingly until the midribs gain strength enough to hold them upright.

Evelyn remarked that, “As soon as the leading shoot of the

horse-chestnut has come out of the bud, it continues to grow so fast as

to be able to form its whole summer’s shoot, sometimes eighteen inches

long, in about three weeks. After this it grows but little more in

length, only thickens, becomes strong and woody, and forms the buds for

next year’s shoot.”

Buds have always been to me a most interesting subject of study; there

is much variety of character in them, and to those who observe them

closely they reveal in the autumn and winter what the tree is purposing

to do in the following season.

A beech-tree on my lawn bears its nuts only every second or third

summer, and in the previous autumn I can always tell whether the

squirrels are likely to be well off for food in the coming year, by

observing the size and shape of the buds. Those which contain the

flowers are round and bulky, whilst the leaf-buds are long and slender.

[Illustration: YOUNG BEECH.]

Embryo flowers are disposed in the buds in different ways. The

woodsorrel is rolled into a spiral, rose-petals are placed one within

the other, the pink is folded in five divisions, and others are pleated

and fluted into the smallest possible space. Perhaps of all others

the bud of the great Oriental poppy is the best example of exquisite

packing. Early on a summer’s morning you may see its huge green hairy

bud at the end of a stem several feet in length, and whilst you are

looking the sepals or calyx leaves suddenly divide and fall off, the

mass of vivid scarlet petals crumpled into a thousand folds begins to

open out, and before long the glorious flower, which is often as much

as seven inches across, holds itself erect in majestic beauty.

Those who possess a tulip-tree will find its opening buds reward

examination. The leaves are folded in half and bent double, a pair

of leaf-scales enclosing each of the true leaves. One may unpack the

entire bud until we come to leaves almost too minute to be discerned.

Young sycamore-trees often have buds of large size and brilliant

crimson colour; the foldings of their leaves are very intricate, and

form an interesting contrast to those of the tulip-tree. Hart’s-tongue

fern, arum, and pear leaves afford three very remarkable modes of

folding in the bud.

[Illustration: UNFOLDING ARUM LEAF.]

[Illustration: PEAR LEAF.]

[Illustration: UNFOLDING LEAVES OF HART’S-TONGUE FERN.]

Another point of character in buds is of considerable importance to the

horticulturist, namely, the fact that in some cases the value of the

flowers produced varies with the position of the buds. For instance,

the blossoms produced from the crownbud[13] of certain chrysanthemums

are poor and pale in colour compared with those grown on the side

shoots; the latter are therefore retained and fostered, so that from

them flowers of the finest description may be obtained.

[13] The uppermost bud of the central shoot.

In cultivating fruit-trees it is found needful not only to prune away

redundant branches which bear leaves only, but also where strong

woody roots are promoting the growth of leaf-buds, they also have to

be pruned, so that the check thus given to the growth of the tree

may result in the formation of fibrous roots, which will tend to the

production of flower-buds and a resulting crop of fruit.

I have often observed that the transplantation of trees leads to their

throwing out flowers in the succeeding year. This was notably the

case with an avenue of deodars which had overgrown my carriage drive;

they received a considerable check in being transplanted, but in the

following year their branches were covered with male catkins and some

few cones succeeded.

For this reason the removal of fruit-trees is not unfrequently resorted

to, as a means of inducing fruit-bearing.

So much vigour is stored up in the bud, that it will bear being

removed from one tree and inserted in the stem of another, within which

it will grow and become a part of the living tree. This is one of the

means by which we have obtained such an infinite variety of roses; the

buds from choice species being readily made to grow upon strong briar

stocks, and thus one may also see roses of several different colours

blossoming on the same stem. Choice varieties of fruit-trees are

cultivated in the same way by means of buds inserted in the bark.

Having observed how flowers are arranged in the bud, we may go on to

dissect incipient leaves and learn how they are placed.[14] We shall

find that the frond of the hart’s-tongue fern is rolled up from the

tip, the arum gracefully curved lengthwise. Pear leaves are rolled

from side to side towards the middle, and so is the primrose, but the

reverse way. Beautiful examples of curled leaves may also be seen in

the water-lily and banana.

[14] Venation.

In grasses the first leaves are equivalent to budscales, and protect

those which continue to grow from the centre, each one sheathing out of

the previous leaf after the manner of monocotyledons.[15]

[15] One seed leaf plants.

The colouring of buds is one of the lovely features of spring. Seen

against the blue of the sky, the coral red of the lime, sycamore,

and Japanese maple buds, cannot be passed by without notice. The

whitebeam has a beauty of its own for its buds are large and white

with downy coverings, giving promise of the future leaves which are so

light-coloured underneath, that the effect when they are blown aside by

the wind is curious and beautiful. The Germans call it _mehl-baum_ or

meal-tree, from its whitish downy leaves.

The variegated vine, sometimes seen in greenhouses, has exquisite buds

of pinkish crimson, with bright yellow stipules. By way of contrast,

I once placed some sprays of it in a glass with twigs of purple hazel

which are of a deep claret brown; they were not only opposite in

colour, but curiously different in habit, the vine holding its bud

erect, and the hazel as persistently drooping. These variations lead me

again to remark that, to a close observer, buds will be found to differ

much in character and to be well worthy of close attention.

I will mention some trees whose buds are specially remarkable for

beauty of form whilst unfolding. The mountain ash has very graceful

leaves when just emerging from the bud; they show on their upper and

under surfaces two distinct shades of green.

The unfolding weigelia buds are extremely pretty in shape, the leaves

being pointed and delicately curled.

I need hardly mention the beech; nothing can be more exquisite than a

spray of its opening buds with their silky fringed young leaves and

crimson leaf-scales. I look forward every spring to the joy of watching

the unfolding of these caskets.

A warm shower or two and some sunny days cause them to expand with a

rapidity which seems magical, and one almost regrets to find the beauty

of the buds in their early stages so quickly passing away. The ash

attracts notice by its jet-black buds, and the wayfaring tree by the

delicate venation of its young leaves.

I cannot refrain from mentioning another beautiful effect arising from

young buds in the case of a _Picea nobilis glauca_, which long name

simply means a sea-green silver-fir, standing on our lawn. In the

summer its terminal buds are a very pale sea-green, and as they grow

and are seen against the dark green of the rest of the foliage the

effect is very curious, as though each branch had become tipped with

frosted silver.

[Illustration: BUDS OF WAYFARING TREE.]

The soft silky buds of the willow, and especially those of the low

growing sallow which are gathered as “palm” for church decoration, are

amongst the welcome signs of early spring. The sallow has its male

blossoms on one tree, but not far away we shall find the female tree

bearing the flowers which will eventually produce the seeds. We may

therefore seek for three kinds of buds, those which produce the flowers

on each tree, and the others which will clothe the tree with leaves

when the blossoms are over.

This chapter shows us how much there is to instruct the student of

nature during the winter as well as the summer months.

I have but indicated a very few out of the many lines of study which

may be taken up; one could write essay after essay upon the growth of

a single hedgerow, but all I can hope to do in simple chapters of this

kind is to throw out hints and indications, and trust that my young

readers may find their interest sufficiently excited by what they have

read, to lead them on to fuller, deeper study of each point touched

upon.

Nature is an inexhaustible storehouse of wonders, and the further we

explore, the more our eyes are opened to see the vistas that lie before

us, branching out in various directions.

This special path of botanical study is one that, more or less, can be

pursued at intervals, as opportunity may offer through life, and as it

adds much pleasure to leisure hours, I specially commend it to my young

readers.

Specimens to be obtained and compared with the descriptions in this

chapter:—Search for buds in summer; plane-tree buds; Japanese maples;

terminal and axillary buds; observe shape and outline of trees; buds

of coniferous trees; fir cone; fir-tree that has lost its leading

shoot; pollard willow, and other trees, buds on marsh tway-blade, and

viviparous fern; buds on underground stems; suckers from wall-fruit

trees; dormant buds or knobs on tree-stems; bulbils on lily, dentaria

and allium; horse-chestnut terminal bud; observe leading shoot of

horse-chestnut in early summer; flower and leaf buds on beech; various

flower-buds; Oriental poppy; tulip-tree buds; various leaf-buds

unfolding; colouring of Japanese maple, lime, and sycamore buds;

whitebeam; variegated vine; purple hazel; mountain ash; spray of beech

buds; ash buds; _Picea nobilis glauca_; willow and sallow, male and

female flower buds and leaf buds; bamboo.

CHAPTER VI

_FLOWERS_

“Your voiceless lips, O flowers, are living preachers;

Each cup a pulpit, every leaf a book

Supplying to the fancy numerous teachers

From loneliest nook.”

+Horace Smith.+

CHAPTER VI

FLOWERS

Instead of looking at flowers as bright and beautiful objects made to

be a source of continual delight in our daily lives, though such they

truly are, we will rather now, for purposes of study, consider them as

the means by which the plant carries out the purpose of its creation,

namely, to perfect its seed and thus perpetuate its species.

In the life-history of shrubs, trees, and plants we find this is their

one aim, and that everything else is subservient to it.

The stamens and pistil being of essential importance in forming the

seed, we find them placed for safety in the centre of the flower;

folded round them are the petals or coloured parts of the flower, and

outside these again are the green sepals, or leaves of the calyx.

These two sets of enfolding leaves are called “floral envelopes,”

because they fold over and protect the central organs, the stamens and

the pistil.

We will select a buttercup as a type, and taking it to pieces we will

try to learn the names and uses of its various parts.

The outside is a greenish-yellow cup which is called the calyx.

The divisions of this little green cup are called sepals, and their

office is to protect the five bright yellow leaves within, which are

called petals when we speak of them singly, but, taken all together,

form the corolla.

In the buttercups the petals are all separate, but if we look at a

primrose we shall see that the corolla is in one piece, united in a

tube; so also is the calyx.

The botanical term for a corolla thus formed is _gamopetalous_, a long

word but easily understood when we know that _gamos_ means united; a

flower with petals in one instead of many divisions is more easily

referred to by this word than if we had each time to express it by a

sentence.

[Illustration: PRIMROSE.]

Gathering a newly-opened flower, we can see at a glance that the sepals

are placed quite below the central green organs of the flower, and

that they are in no way influenced by the petals; we also see that

the petals are entirely separate from the other parts of the flower,

and we learn, as the result of our examination, that the parts of the

buttercup are _free_. To express this botanically we prefix the word

“poly” to the words sepals and petals, and so we get _polysepalous_,

meaning that the sepals are quite free and distinct, and _polypetalous_

referring to the same condition of the petals.

Now, having removed the petals and sepals, we can proceed to study the

other parts of the flower.

First we find a great number of little yellowish stalks tipped with

tiny pouches; these are the stamens, and in the little pouches

(anthers) the yellow powder termed pollen is developed. We will

carefully take away these stamens, and note in so doing that they are

all distinct and all sprung below the green central part. Like the

sepals and petals, we find the stamens are free and uninfluenced by the

other parts. If we again compare this with a primrose-flower we shall

find a difference; the stamens of the primrose spring from the petals

and are therefore called _epipetalous_ (_epi_ upon, a petal). Again in

the sweet-pea or scarlet runner we find the stalks of the stamens are

all joined together. We now have left upon the flower-stalk the little

central green parts previously mentioned; there are quite a number

of them; each one is distinct from its neighbour and is free. These

bodies are known as carpels, they are large at one end and taper to a

curved point at the other, the broad end being attached to the stem.

Collectively these carpels constitute the _pistil_, and because the

carpels are apart and free it is said to be _apocarpous_.

The flower of the little woodsorrel (_Oxalis acetosella_) will help us

to understand better the arrangement of the carpels. If we take away

the sepals, petals and stamens, we shall have only the carpels left,

and these are five in number. They are in the same position as those

of the buttercup, but they are not separate, they are joined by their

inner surfaces. We can plainly see that this is the case, since each

carpel is distinctly outlined and there are five little tapering ends

(stigmas). The pistil in this case is said to be _syncarpous_.

Names are given to express some quality, and they often draw our

attention to interesting facts about the plant’s mode of growth or the

place where it is found; for instance, the pretty blue nemophila is so

called from _nemos_, a grove, and _philo_, I love, because it delights

in shady places.

Geranium is derived from _geranos_, a crane, because the fruit of some

of the species resemble the beak of that bird.

Some plants are named after famous botanists, as _Linnæa_ after Linnæus.

Others derive their names from their mode of growth, as stone-crop,

which is called sedum, from _sedo_, I sit, the plant having scarcely

any stalk, and sitting, as it were, on walls and rocks.

These instances will show that it is well worth while to study names

and learn their meanings, as they often throw so much light upon the

history of a plant.

In the flowers of bulbous plants we find that the calyx and petal

leaves are frequently alike in colour and texture; in that case the

three sepals and three petals, of which they usually consist, are

spoken of as a perianth.

In looking at the brilliant colouring of a flower we should hardly

imagine that the petals have to some extent the nature of leaves, and

under certain conditions may be changed to the green colour and form of

ordinary leaves.

In very wet seasons we may sometimes find rose-buds with the sepals of

the calyx developed into perfect green leaves. The floral envelopes

therefore possess the nature of true leaves.

[Illustration: POINSETTIA.]

The brilliant scarlet so-called flowers of the poinsettia are really

coloured bracts, the true flower being the small inconspicuous

blossom in the centre.

In the chapter on leaves we saw that bracts are those small

imperfectly-shaped leaves in the axils of which flowers are placed.

They are usually green, but may be also brilliantly tinted as in the

mauve-coloured Bougainvillia, the bright violet spikes of the _Salvia

Hormineum_, and also pure white as in the spathe of the arum.

By special cultivation flowers can be made double, for excess of

nourishment will cause the plant to multiply its petals. Instead of

the five pink petals of the wild rose we find one of our garden roses

bearing as many as eighty or a hundred petals.

Double flowers but rarely produce seeds, because the stamens and pistil

have been turned into petals, and as there is no need to attract

insects for fertilising purposes, there is no secretion of honey, and

therefore we scarcely ever see honey-bees in double flowers; they are

wise enough to know that their visits to them would be in vain.

In composite flowers such as asters and sunflowers the change, when

they are double, occurs in several ways.

The centre may become filled with florets similar to those in the

outside ring, or the florets in the middle may become larger or of a

different colour.

These various changes may be readily observed in the cultivated

chrysanthemums, in which every form and variety of flowering can be

traced.

When the pollen has reached the pistil the flower begins to fade,

because its end has been attained; nature, however, has such variety

in even the smallest of her operations that the passing away of a

flower is accomplished in different ways. In the primrose the corolla

withers and drops to the ground. The flower of the spiderwort, one

of our common garden plants, becomes pulpy as it fades, in this way

resembling the pineapple plant, the flower of which eventually becomes

the luscious succulent fruit.

The poppy is proverbial for its fleeting petals, which scarcely last

more than a few hours, a passing wind soon scattering them far and wide.

“Pleasures are like poppies spread,

You seize the flower, its bloom is shed!

Or like the snow-fall in the river,

A moment white—then melts for ever.” (+Burns.+)

Some flowers, as the hydrangea, have persistent petals, which simply

lose their brilliant tints and become tough and brown.

[Illustration: WINTER CHERRY.]

The calyx of the physalis or winter cherry continues to grow after the

flowers are fertilised until the round balloon-like bag is formed in

which the fruit is enclosed.

We will now examine the parts of a flower separately, beginning with

the calyx.

In the buttercup the calyx consists of one whorl or ring of five sepals.

In the strawberry there are two whorls of sepals, and in the cotton

plant there are three whorls forming its green calyx.

There are also variations in the mode of flower expansion.

As a poppy-bud opens it detaches its calyx from the stem, and the

sepals fall off (the calyx is therefore called caducous, a term which

means ready to drop off).

Many flowers retain the calyx until the petals wither and it falls off

with them. It is then called a deciduous calyx.

Others again have a permanent calyx, so that when, as in the primrose,

the corolla withers and drops off, the sepals close over the

seed-vessel and protect it until the seeds are matured; this would be

called botanically a persistent calyx.

The best way to learn the names of the different parts of a flower is

to pull it carefully to pieces and arrange the separate organs on a

thin card. They can be tacked on to the card with a stitch or two of

fine thread, and when the lesson is over, if the card is placed between

sheets of blotting-paper under a weight, the flower dissections will

dry and be useful for reference later on.

Each separate part of the flower should have its name neatly written

beneath it, so that when a good many different flowers have been thus

dissected they may be compared and the variations in form and position

duly noted.

[Illustration: WALLFLOWER.]

A wallflower will be a good subject for our dissection.

At the back of the petals we first take off the calyx, which consists

of four divisions called sepals. We then pull off the four yellow

petals, and as they are placed in the form of a cross it shows

that this plant is a crucifer, or cross-bearer, one of a very large

natural order, _Cruciferæ_,[16] none of which are poisonous and very

many are useful food-plants, such as cabbage, turnip, watercress, and

cauliflower. Now there remain six stamens—four long and two shorter

ones; these last rise outside of and alternate with two nectaries or

honey-glands.

[16] All cross-shaped flowers do not, however, belong to this order.

The stems of the stamens are called filaments, from _filum_, a thread;

and the upper part, containing yellow powder, is called the anther, the

proper name for the powder itself being pollen.

In the centre of the flower is the pistil, the lower part of which is

the ovary, the part of a flower which contains the ovules, and is so

named from _ovum_, an egg.

The stem part of the pistil is called the style and the top of it is

the stigma.

Such simple words as I have given must be learned, else we cannot

understand botanical descriptions, and if this page is studied whilst

we have the flowers in our hands it will not be difficult to identify

each separate organ; when these are once arranged on a card with the

name of each part written beneath it, we shall have attained some very

useful information ready for future study.

In the buttercup flower all the five petals are the same size and

shape; therefore, like hundreds of other evenly-formed blossoms, it

would be described as “regular”; but if we take a sweet-pea, balsam, or

monkshood-flower and examine its separate petals, we shall find they

vary very much in form, and they are known as “irregular” flowers.

The sweet-pea is a type of a large order of plants producing what

are called butterfly-shaped flowers, and _papilio_ being Latin for

a butterfly, they are therefore called papilionaceous flowers. If

we learn clearly about the various parts of such a flower we shall

henceforth be able to recognise it at a glance.

In the sweet-pea we find a broad petal at the back of the flower which

is called the standard, beneath it are the two side petals called

wings, and within them is the keel, so named because it is shaped like

the bottom of a ship. Within the keel lie the stamens and pistil—the

most important parts of the flower, and to protect them from injury the

standard is so formed as to catch the wind like a sail and turn the

blossom round so that this broad petal shelters the keel from rain.

[Illustration: SWEET-PEA.]

In our next ramble out of doors it will be well to try and gather all

the specimens we can find of this order of plants. If it be in summer

or autumn we shall soon collect a handful of these butterfly-shaped

flowers.

On a common we shall find broom, furze, restharrow, vetches, tares,

trefoil, clover, saintfoin, and other plants. In the garden and

greenhouse we shall see many more species belonging to this class.

Having shown the difference between a regular and irregular flower, we

will now proceed to notice how irregularity is caused.

If we pull off one of the buttercup petals and look at the base of it,

we shall see a small pouch which contains honey; it is called a nectary

or honey gland, and the position of this gland has much to do with the

shape of the flower.

As each petal of the buttercup has a nectary at its base it follows

that, all the petals being the same size and shape, the flower is

perfectly regular—like a small golden cup. Now in other flowers we

shall find the nectary very large and confined to one petal or sepal

only, and this results in the flower having an irregular shape. Gather

a violet, examine and compare the petals; four of them will be found

to be nearly alike, but the lower petal is much larger because it has

grown into a tube (called a spur) to secrete honey, and I need hardly

say that the honey is intended to attract the bees so that the flower

may be enabled to produce fertile seed. The enlargement of the lower

petal gives the flower an irregular shape, and the same thing happens

in the monkshood and many other flowers, where both the petals and

sepals are thrown out of shape to form nectaries. In the orchid family

this influence may be traced to a wonderful degree. The contrivances

for insuring the fertilisation of their flowers are so many and various

that books of the greatest interest have been written on that subject

alone.

In the flowers we have hitherto noticed, both stamens and pistils are

found, the petals are coloured, honey-glands exist, and some specimens

also possess a powerful scent.

Such flowers are obviously very attractive to insects, and on that

account they are called by modern botanists, entomophilous, which long

word means that they are beloved by insects.

In sharp contrast to these gay and conspicuous flowers we may observe

the very simple catkins of the birch, _Betula alba_. If we examine a

twig of this tree in spring, we shall find two very distinct kinds of

flowers (or catkins, as tree-blossoms ought properly to be called),

one a stiff green spike standing upright, and the other longer and of

yellowish colour, always to be found hanging down.

The former consists of a number of scales arranged on a central stem,

and in the axil of each scale is the little pistil, with its pointed

and divided stigmas. This catkin, later on, becomes the fruit of the

tree, and sheds out with every passing breeze its little winged fruits,

which are carried far and wide and often sow themselves in rocky

crevices, and appear able to grow and flourish with only a modicum of

soil.

[Illustration:

_Natural Size._ _Magnified._

BIRCH FRUIT.]

The pendulous catkin is very soft and loose, and on the inner surface

of its scales we find the stamens, which in due time will shed from

their anthers the fertilising pollen. Here then we see flowers which

are not so attractive to insects, flowers in which the stamens and

pistils are separated and developed in different catkins, and such

flowers are termed monœcious, from _monos_, single, and _oikos_, a

house.

The most interesting feature of these tree-blossoms is their

fertilisation by the wind; the slightest puff of air liberates little

clouds of pollen from the loose swinging anthers; these pollen grains

become entangled in the upright catkins bearing the pistils, and the

future seed thus becomes fruitful. There are many trees and plants

which are thus fertilised by the agency of the wind, and they are

termed by botanists _anemophilous_, from the Greek words _anemos_,

wind, and _philos_, beloved by.

In the common bryony of the hedges, we get another example of a green

inconspicuous flower. Gather a few sprays of this in early summer,

taking care to keep the specimens of each plant separate. Take up one

specimen and you will find each flower has a small green calyx, a

minute corolla, and five little stamens; not one pistil can we find on

the spray.

The flowers on the next spray look very similar, but in them there are

no stamens, the centre of each flower being occupied by a small pistil,

and thus we learn that there are two distinct sexes in the bryony

plant, the one bearing only staminate flowers, and the other producing

those bearing only pistils. Such plants are termed diœcious, from _di_,

two, and _oikos_, a house.

[Illustration: WILD ARUM.]

One of the earliest spring flowers is the arum of the hedges, known

to village children as “lords and ladies.” Accustomed as we are to

bright-hued flowers if in our gardens and fields, it is somewhat

difficult to recognise that the pale-green sheath of the arum is a

flower at all. It consists of a beautifully-folded spathe or bract,

curving over at the top, and if we remove that we find a central stalk

bearing a number of little naked flowers, arranged in the order shown

in the plate.

First, below the club-like apex, a few hairs tending downwards,

then the anthers containing pollen, and below these the pistils with

protruding stigmas. The whole stalk is termed a spadix.

The outer green spathe forms a kind of prison, into which flies are

enticed by the somewhat fetid odour which is exhaled by the flower. The

flies easily creep in past the circle of hairs, which, as they point

downwards, do not prevent their entrance, but, once in, these hairs are

like a _chevaux-de-frise_, and hinder the escape of the insects. The

flies in all probability carry upon their wings pollen from some other

arum flower, and in their efforts to escape they brush off this pollen

upon the stigmas, which thus become fertilised. When this has taken

place the stigmas throw out a sweet juice upon which the insects feed;

the anthers now shed out their pollen, with which the flies become

covered; the hairs meanwhile have withered, and thus the flies, having

done their appointed work in fertilising the flower, are free to crawl

out and perform the same office for some neighbouring plant.

We have not space to do more than allude to certain plants, whose

flowers never open and are self-fertilised. The common violet, for

instance produces, in addition to its well-known fragrant flowers,

certain inconspicuous blossoms, hidden under the leaves and close to

the root, very seldom noticed by any but botanists, and known to them

as cleistogamic flowers; these are fertile, and always produce seed.

Other such plants are the woodsorrel and sundews.

It is interesting to observe the various ways in which flowers are

protected from browsing animals, snails, and caterpillars by thorns,

spines, prickles, and spiny bracts. The teasel secretes water in the

bracts around its stem, which prevents ants from ascending to the

flowers, and in many plants we may see quantities of small insects

caught by a sticky gum exuded from the leaves and twigs.

Many delicate plants entirely alter the position of their flowers in

order to protect them from rain. On a sunny day the wood-anemone holds

its little snowy cup so as to receive the full sunlight, but on a damp

day every blossom is closed and held downwards. We may observe this in

the poppy, the blue-anemone, and nearly all composite flowers.

These are merely hints scattered over a wide field of study, which

some readers may like to follow out.

Objects to collect and examine:—Buttercup flowers, seed-vessel of

wild-geranium, stonecrop growing on walls, flowers of bulbous plants,

flowers of poinsettia, bougainvillia, salvia hormineum, arum. Examine

various chrysanthemum flowers, sunflowers, asters and woodsorrel.

Difference between hydrangea and poppy flowers, winter cherry

(physalis); prepare flower dissections. Examine various cruciferous

flowers and pea-shaped flowers, regular and irregular flowers, birch

catkins, wild arum flowers, cleistogamous flowers, protection of

flowers, position of flowers.

CHAPTER VII

_POLLINATION_

“When summer shines,

The bee transports the fertilising meal

From flower to flower, and even the breathing air

Wafts the rich prize to its appointed use.”

+Cowper.+

CHAPTER VII

POLLINATION

We now come to the consideration of the real function of the flower

of a plant. In whatever form it is developed, whether as a gay and

fragrant blossom, in a dull foul-smelling structure like the arum, or

as a green inconspicuous little floret like the grass, its main office

is to reproduce itself by the formation of seed. We will first glance

at some of the wonderful agencies that actively help in this work.

There are at least three distinct processes necessary for the complete

formation of a perfect seed, and we must, I fear, persuade ourselves

to learn some of the long words by which botanists speak of these

processes. They are known as pollination, fertilisation, and the

growth of the ovule. There is so much to be said about the first

subject, that I must leave the two latter for a succeeding chapter.

Before seed can be formed it is necessary that the powder contained

in the anthers, which is called pollen, should be transferred from

those anthers to the stigma or upper part of the pistil, and this

transference is called pollination. If we examine a tulip or, better

still, a buttercup, we find the anthers and stigmas so near together

that the transfer of the dust-like pollen to the sticky-looking

stigmas can easily take place. This would be called an instance of

self-pollination, but although cases of this kind do occur in nature,

they are not at all common. As a rule, in order to ensure what is

called cross-pollination, the transfer of the pollen of one flower to

the stigma of another, many wonderful and interesting arrangements

exist even in some of our commonest flowers.

Cross-pollination must be the case in such plants as dog’s mercury,

because we find in a colony of these plants—so frequently seen by the

roadside—that some plants have flowers with stamens only, and others

containing only pistils. Again, in the hazel we may see how impossible

it is for self-pollination to take place, as, if we examine the

pistils, we find that they consist of scales bearing stamens and pollen

only, whilst somewhere close by, on the same stem, hangs the pretty

little red flower which possesses the pistil and forked stigma. If seed

is to be formed in either of these flowers and in many others similarly

arranged, then the pollen of one flower must be transferred to the

stigma of the other.

[Illustration: PRIMROSE.]

There are interesting facts to be learned about the common primrose.

When we examine a little bunch of these flowers we find quite half of

them are what children call pin-eyed, meaning that the stigma, which

is at the end of a long pistil, is like the head of a pin in the throat

of the primrose.

Looking at the sketch, we see at once that self-pollination is hindered

by the fact that the anthers in this flower being at the bottom of the

tube, the pollen they contain must be transferred by some direct agency

before it can come in contact with any stigma. Now let us examine the

other flowers in our primrose nosegay; we find the stamens in these are

placed in the mouth of the tube, and the pistil is quite short and low

down in position. At first sight it appears as if the pollen would fall

directly upon the pistil, since the stamens are above that organ, but

this is not exactly what happens; the pollen of this particular form of

flower is shed before the stigma is mature, so that when it has reached

maturity the pollen is all gone.

The arrangement of nature is as follows. An insect attracted by the

sweet-smelling bank of primroses will visit the flowers, thrusting

its proboscis down a pin-eyed flower until in so doing its head has

been dusted with the pollen of the stamens; then withdrawing from that

flower the insect visits another near by, possibly one with a short

pistil; the pollen on its head is now rubbed off and falls upon the

stigma below and pollinates it, for that is the term used when this act

takes place.

[Illustration: MAIDEN PINK.]

The pretty maiden-pink will help us still more clearly to understand

how cross-pollination is promoted in flowers containing both stamens

and pistils. Select a flower that has just opened, the petals of which

are spreading and fringed, whilst from the centre of the flower a

cluster of stamens projects with the pollen mature and easily shaken

out of the anther lobes; the pistil is concealed in the long tube, and

in this stage there is no sign of stigma. In a short time, however, if

we examine the flower again, we shall find the stamens have shrivelled

up, and in their place a forked stigma appears, as shown in the sketch.

Here again it is obvious that the fact of the stamens ripening first

and expending their energy before the pistil is ripe must mean, that

in order to secure seed the pollen from some younger flower must

be transferred, probably also by insect agency. It will give fresh

interest to our garden rambles if we remember that the bees and flies

we see hovering over the flowers are not only collecting honey or

feasting upon it, but are also performing a very important office for

the benefit of the plants they are visiting.

We may now proceed to notice the various agencies for the conveyance of

pollen between flowers.

These agencies are water, wind, insects and birds.

In an earlier chapter I gave an account of the _Vallisneria spiralis_,

which will serve as a type of a water-pollinated flower.

Those pollinated by wind are, as I have said in a previous chapter,

called anemophilous (_anemos_, wind, and _philos_, loving). They are

usually of small size and inconspicuous character, with very little or

no scent, and devoid of colour; these are characteristics that are not

always associated in the same species; thus in the hazel, which is a

wind-pollinated flower, we find a bright yellow catkin (so well known

to children as lambs’ tails) and a small but bright red pistil.

Let us notice, however, how wonderfully these plants are adapted

for this method of pollination; the stamens are usually hanging,

and the pollen, produced in great quantities, is easily set free by

the slightest breath of wind. The stigma of the hazel, of different

grasses and of sedges are both forked and plumed, so that pollen grains

floating in the air are readily intercepted.

The firs and pines are excellent examples of wind-pollinated trees. I

remember once possessing a ripe male cone of the _Araucaria imbricata_,

and ascertaining that it contained as much as a wine-glassful of

pollen. Speaking about this fact to the gardener at the Pinetum

at Dropmore, I was shown how this fertilising dust from the great

Araucaria (which was planted there in 1830) was carried by the wind

for an amazing distance to a female tree on the other side of the

garden, pollinating its cones so that they produced fertile seeds.

In some of the Canadian pine forests, the trees shed forth such

quantities of pollen in the flowering season that the ground becomes

perfectly yellow. The early settlers, being unable to account for the

strange phenomenon in any other way, ascribed it to showers of sulphur

descending from the clouds. Even in our own country the foliage and

undergrowth in the neighbourhood of fir woods is often thickly coated

with the yellow dust falling from the male catkins of the trees; the

structure of the pollen grains is such that they float very buoyantly,

each grain being provided with two air bladders. I may mention in

passing that this apparently wasted pollen affords a rich feast to

endless species of bees and flies, and is in many cases stored up by

them as food for their young grubs. The various adaptations for wind

pollination will perhaps be better understood if we glance at the

attractions which flowers offer to birds and insects.

Colour serves to render flowers attractive to insects, and to make them

conspicuous; the bracts, petals, and sepals of flowers are usually of

some light or dark colour quite distinct from the green tone of the

foliage.

It has been ascertained also that plants which are pollinated by

night-flying moths generally have white or light-yellow flowers so as

to be easily seen in twilight.

One of the most interesting of these night-pollinated flowers is

_Silene nutans_, the Nottingham catchfly. In the daytime the five

narrow petals are curled up and look dead and withered, but as night

comes on they change their position, and the flower has the expanded

shape of an alpine pink. In this open condition it is visited by the

moths which, flying from one flower to another, transfer the pollen,

and thus accomplish at night what more frequently occurs in the

sunlight; at daybreak the petals roll up once more, and one would again

suppose the flower to be dead; but no, it will continue to open at

nightfall until some moth finally succeeds in pollinating its blossom.

A small species of moth[17] visits this catchfly in order to deposit

its eggs; these, by means of a very long ovipositor, it places in the

ovary, and in that somewhat inflated cavity they produce microscopic

caterpillars which find shelter and nutriment in the strange nest.

When the caterpillars arrive at maturity they escape by biting a hole

in the wall of the capsule, and creeping out, they seek for a suitable

place in which to turn to chrysalides.

[Illustration: ARISTOLOCHIA.]

[17] _Dianthræcia albimacula._

Scentless flowers usually have some equivalent form of attraction, such

as honey, brilliant colour pollen in abundance, or the grouping of a

number of small florets, in order to secure a conspicuous effect as in

the ox-eye daisy, or hedge parsley.

Strong and varied odours are great helps to ensure pollination by

insects. The bee-tribe and moths and butterflies are specially

attracted by the sweet scents of roses, violets, carnations, and

sweet-peas, and the powerful odour emitted by such flowers as the

evening primrose, tobacco, and night-flowering rocket as evening comes

on tends to guide the nocturnal moths to these and similar flowers. An

odour may, of course, be pleasant to an insect which to us would be

simply intolerable. The arum of the hedges, and those curious plants,

the aristolochias and stapelias, all emit scents of the most fœtid

description, as we think, but flies, on the contrary, are attracted by

thousands, and hold apparently joyous revels in the blossoms which

they are pollinating by their frequent visits.

[Illustration: STAPELIA.]

A little care and patience in watching the visits of insects to

different flowers will soon be rewarded by a perception of the tastes

and likings of insect life, and we shall gradually learn to expect to

see certain insects on the flowers they specially frequent.

[Illustration: HYPERICUM.]

I would call attention to the interesting fact that if one agency

fails to effect pollination, another is adopted in order to attain the

desired end. Thus, when the flowers of the common bartsia first open,

they are visited by insects; but, in the later stages of flowering,

the pollen is blown out by the wind, and the neighbouring stigmas thus

become pollinated. We see in the arrangement of the flower of the St.

John’s wort (_Hypericum_) a perfect type of this provision against any

possible failure of pollination. The stigma is surrounded by groups of

stamens of unequal length; those in the centre nearest to the stigma

are as long as the style itself, whilst those on the outside are short,

and these shed their pollen first, whilst those in close contact with

the stigma shed their contents last. Thus we find that if insects fail

to effect cross-pollination by means of the short and early opened

stamens, it is secured by means of the longer stamens whose anthers are

in close contact with the stigma. Again, when we stand under a sycamore

tree, we may see that the green tassel-like flowers are having their

pollen dispersed both by wind and bees.

We cannot draw hard-and-fast lines in nature, for although a special

end may be kept in view, the various means and adaptations by which

it is attained are a continual source of admiration and wonder to the

reverent student of nature.

We have already seen that there are all kinds of devices by which the

pollen of one flower may be made sure to reach the stigma of another;

but, if by any means this crossing fails, if the weather is such that

insects are scarce, or other conditions cause failure, then, in the

case of many flowers, most curious contrivances are provided to secure

seed by self-pollination. Truly this is one of the most beautiful of

God’s wonders in floral construction. One of the gems of my own flower

garden is a lovely little Japanese toad-lily (_Tricyrtis hirta_). In

this flower there are three styles which stand well above the stamens;

the points of the styles are bent over as in the plate, and the

stigmatic surface grows mature before the anthers shed their pollen;

if, however, no insect visits the flowers, pollination is effected in

the following way. The styles bend down and place their forked points

in direct contact with the open anther-lobes (as shown in drawing),

the style assuming almost the form of a semicircle. This is done very

deliberately, for it is often fully a week before the act is complete.

[Illustration: TOAD-LILY.

_Stigma and Stamen._]

Pollination is effected in tropical countries not only by insects of

many kinds, but by the lovely tribes of humming-birds which abound in

those regions. Their slender, curved beaks are specially adapted to

penetrate the honey-laden flowers with long-tubed blossoms, which could

only be pollinated by some such agency.

Those who are within reach of the Natural History Museum at South

Kensington may there see a gallery filled with exquisite specimens of

humming-birds, arranged in cases, and some of the birds are shown as

they appear in life, hovering over tropical flowers, drawing honey

from their hanging blossoms, and performing the useful office of

transferring the pollen from one flower to another, thus ensuring the

fertilisation of the seed.

I might go on multiplying examples of the various methods by which seed

is rendered fertile, but perhaps enough has been said to show what

hidden force exists in flowers to enable them to attain the end for

which they mainly exist, namely, the perpetuation of their species by

means of seed.

Specimens to be obtained and compared with the descriptions in this

chapter:—Buttercup flower, dog’s mercury, hazel catkins, primrose

flowers, male blossoms of pine trees in June, Nottingham catchfly,

ox-eye daisy, bartsia, St. John’s wort flowers, and Japanese toad-lily.

CHAPTER VIII

_FERTILISATION_

“The men

Whom Nature’s works can charm, with God Himself

Hold converse.”

+Akenside.+

CHAPTER VIII

FERTILISATION

Having now considered some of the many wonderful arrangements by which

the pollen of plants is dispersed, we will endeavour by tracing the

course of the pollen-grains after they reach the stigma, to learn what

is meant by the term “fertilisation of the ovules.” These are the

minute specks contained in the ovary which are to become seeds, and by

means of which the plant will eventually reproduce itself.

To the naked eye the yellow pollen we see on the anthers of flowers

appears as small grains; but, when magnified, these grains are seen to

be singularly beautiful, each little sphere having on its surface a

chequered network and delicately sculptured patterns.

The forms, too, are as varied as the ornamentation.

Some plants have triangular grains, some oval-shaped and others

many-sided.

[Illustration: POLLEN-GRAINS.

1 _Morina._

2 _Cobea._

3 _Convolvulus._

4 _Dianthus._

5 _Pinus._

6 _Albucca._

7 _Buphthalmum._

]

I have given a few examples, and would specially call attention to the

pollen-grains of the Pinus tribe (fir-trees), to which I alluded in the

last chapter. These are remarkably buoyant, owing to the two little

bladders with which they are furnished.

[Illustration: WHITE-LILY PISTIL.]

[Illustration: SECTION OF PISTIL.]

Now we are going to watch this yellow dust performing its appointed

office in the central organ of a flower. In order to do so we will take

a white garden lily, and remove the petals, sepals, and stamens,

leaving only the pistil, which, as shown in the drawing, consists of

three parts, the club-like stigma, a very long style, and its base the

ovary, which contains three cavities. In these last we see a number

of small, colourless spore-like bodies termed ovules (from _ovum_, an

egg), each consisting of an outer coat, and a mass of cells in the

centre called the _nucellus_.

[Illustration: POLLEN TUBE.]

An opening exists at one end of each ovule called the micropyle

(meaning a little gate or entrance), and this opening leads down

into the middle of the nucellus, where lies what we may call the

life-principle, but what is known in botany as the embryo-sac.

We need the aid of a microscope to enable us to see how the pollen

exerts its influence upon the ovules.

If we place a drop of very weak sugar and water upon a slip of grass,

and sprinkle over it some pollen grains of the common white lily, then

allowing the slide to remain for a few hours in a dark place, it will

be fit for our purpose.

When placed in the microscope we shall observe that many of the

grains will have thrown out long thread-like tubes, and this is just

what happens when pollen falls upon the viscid stigma of the lily.

Referring to the section of a lily pistil we see that a pollen grain

has rested on the stigma, and, excited into growth by the sweetish

fluid which holds it there, it sends down a slender tube through the

centre of the pistil, which is lined with a very delicate loose tissue

of cells filled with starch, oils and food-materials. The pollen-tube

is stimulated and fed by this nourishment stored up in the conducting

tissue, and on it goes until, passing through the micropyle, it enters

the embryo-sac of one of the ovules, adheres to it, and renders it

fertile.

Only one grain is shown in the drawing for the sake of clearness, but

of course each ovule is sought out and fertilised by a pollen-tube.

With infinite variation this process takes place in every flower,

so that even the commonest weed affords evidence of the marvellous

provisions made by an All-Wise Creator for the preservation of species.

The time occupied by the passage of the pollen-tube varies

considerably. In the fir tribe it takes nearly twelve months, in the

hazel-nut and orchis it requires several weeks, whilst in many other

plants the whole process is completed in a few hours.

One of the first results of fertilisation is a rapid withering of

the style and flower; the great end of the flowering period has been

attained, and so without further expense of energy the bright petals

die away.

At the same time other external changes take place, which are obvious

to every observer of nature. The lower end of the pistil, known as the

ovary, begins its second growth, and in a short time swells into a

large structure, the shape of which varies much in different species

of plants. Finally, the ovary changes colour and develops other

characteristics quite different from its former conditions. These

characters have reference to the distribution of its seeds, and in

our chapter on fruits we shall learn something about the interesting

botanical significance of the various hard and soft fruits, and see how

they all arise from fertilisation.

Take, for example, the flower of an apple immediately after

fertilisation is effected. The petals fall off, the styles shrivel up

and the ovary rapidly enlarges; the tube of the calyx becomes fleshy,

and finally the well-formed apple is produced. The change, however,

does not end here; in this stage of development the little apple

is bitter and is charged with a vegetable acid. As the fruit grows

on, however, this acid changes into sweet juice varying in flavour

according to the species of apple.

Now let us examine the interior of the ovary and see what changes have

arisen as a consequence of fertilisation.

The egg cell which has received the pollen grain becomes filled with an

embryo, whilst the thin delicate coat of the ovule develops into strong

seed-coats.

The embryo is the first germ of the young plant that is to be. It is

a tiny speck indeed in its beginning, but deeply interesting to us

when we realise that, because it possesses life, it will grow on and

on, and result, according to its species, either in a plant but a few

inches in height, or in a grand forest-tree which may give shelter to

man and animals for hundreds of years.

The naked eye can scarcely trace any indications of form in the embryo,

but when dissected and examined with a lens it is seen to consist of a

tiny plant, root, stem and leaves (cotyledons).

The size of the embryo in comparison with the other part of the seed is

a point which should be observed.

As the embryo develops it absorbs the special nutrient or reserve

tissue that exists in all ovules; a bean embryo, for example, rapidly

absorbs all the nucellus of the ovule, so that at length the seed-coat

contains nothing but the embryo, the two cotyledons of which are thick

and filled with stores of food for the first growth of the seed.

I would advise students to plant a few broad beans in a little damp

cocoa fibre, and carefully watch their growth. It is advisable to

dissect these beans successively at different stages, so as to watch

the development of the radicle (root) and plumule (young leaf-bud).

Place the seed in what position we may, the radicle will always find

its way down into the earth, while the plumule obeys its vegetable

instinct, and rises into the air. The embryo of the castor-oil bean

and that of the cocoa-nut do not, however, use up all the nutritive

matter in the ovule as the broad bean does, so that when the seed is

ripe we find inside it, not only the embryo, but also a quantity of

cheesy matter known as _albumen_, and seeds of this kind are hence

called _albuminous_, whilst peas, beans and hazel-nuts are classed as

_ex-albuminous_ (without albumen).

[Illustration: SECTION OF COCOA-NUT.]

An interesting development consequent upon fertilisation is a growth

which occurs in some plants from the base of the ovule. The pretty red

coverings of the seeds of the spindle-tree, and the bright berry-like

structure on the seeds of the yew-tree are examples of this growth,

which is known botanically as an aril (from _arillus_, a wrapper). In

the willows this aril is a very lovely covering of silky hairs, these

serve to float the seeds on the atmosphere at every puff of wind.

[Illustration: SPINDLE-TREE.]

The pretty lace-like covering on the nutmeg is another example of an

aril, better known to us in the form of the fragrant spice called mace.

The style, which in most plants dies as soon as the ovules are

fertilised, is in other cases persistent, as in the hedge-climber

called travellers’ joy. The white, feathery-looking seeds owe their

special character to the persisting styles, which, after fertilisation,

grow into the bunches of fluffy seeds, which hang in profusion on

hedges in the country.

[Illustration: NUTMEG AND MACE.]

[Illustration: CLEMATIS OR TRAVELLERS’ JOY.]

I will conclude this chapter with a reference to a change of quite a

different character. Not unfrequently, fertilisation results in the

suppression of certain chambers in the ovary, and in the consequent

failure of the development of the ovules.

A cross-section of a young oak ovary shows a three-chambered structure,

each cavity containing two ovules, so that the ovary in this stage

contains six ovules in three chambers. Soon after the act of

fertilisation, one of the fertilised ovules takes the lead in growth,

starves the other five ovules, and, as it grows, pushes the partitions

of the other chambers aside, and gradually fills up the whole interior,

converting it into a one-celled structure. This change happens also in

the birch; its two-chambered ovary becomes one; and in the lime, though

at first it has a many-chambered ovary, yet in the ripened fruit there

is rarely more than one to be found.

In a few plants, changes of quite an opposite character take place.

In the ovary of the datura,[18] for instance, we find two cells;

after fertilisation, two false or spurious partitions are developed,

dividing the original two-celled structure into four parts, and as a

consequence we get a four-chambered fruit. The same change takes place

in some of the pea family.

[18] Thorn-apple.

Specimens to be observed:—Examine pollen grains, with lens or

microscope, dissect white lily, flower-pollen on glass slide. Observe

changes in growing apple, plant broad beans, castor-oil seeds, and

maize; examine spindle-tree berries (_euonymus_), yew-tree berries,

willow seeds, nutmeg, and mace; travellers’ joy (clematis), section of

oak ovary in the pistillate flower. Examine birch catkins and lime-tree

flowers. Datura seed-vessel.

CHAPTER IX

_FRUIT_

“Here, as I steal along the sunny wall,

Where Autumn basks, with fruit empurpled deep,

My pleasing theme continual prompts my thought;

Presents the downy peach; the shining plum;

The ruddy, fragrant nectarine; and dark,

Beneath his ample leaf, the luscious fig.

The vine, too, here her curling tendrils shoots,

Hangs out her clusters, glowing to the south,

And scarcely wishes for a warmer sky.”

+James Thomson.+

CHAPTER IX

FRUIT

If we are shown a collection of delicious apples, pears, grapes,

peaches and cherries, we form a very appreciative opinion of the use

and function of fruit, but that opinion is somewhat modified when we

are shown a basket of poppy-heads, acorns, the light downy seeds of the

thistle, the small dry carpels of the buttercup or the winged fruits

of the maple. We usually connect the term fruit with some luscious

product of the vinery or kitchen-garden, and we may include as such

the brightly-coloured berries of the hawthorn and wild rose, which are

so conspicuous on trees and hedges in autumn; but if we examine the

subject botanically we shall have to widen our ordinary conception of

the term.

There is probably no part of a plant so difficult to understand as

its fruit, and this difficulty is due to those many changes which I

described in my last chapter. A very general definition of fruit is

that it consists of the ripened ovary, and this will be found to be

correct in a great number of cases, but this term is not exactly wide

enough to express the general formation of all fruit. In some cases

it is composed of the ripened ovary with the parts of the stalk or

the original flower, enlarged or incorporated in the structure of the

fruit, but in other specimens we find the ovary, although present, very

little enlarged, and playing but a minor part in the ultimate character

of the mature fruit.

No fact seems so emphatic to the observant botanist as that which

upsets his artificial rules and classifications of plants and the parts

of plants. We say, for instance, that fruit is the ripened ovary, and

yet directly we leave our books and go out to study botany in the

fields and woods, we find a large group of fruits perfectly innocent of

any such structure. The firs and pines have no organ of this kind, and

yet their fruits are most important and extremely interesting. Scarcely

any part of a plant varies so much in different species as the fruit

does. Although leaves may be found of every size and shape, they still

have some general similarity of form, but we hasten to observe what

an immense contrast there is between the huge _Musa_ fruit (banana)

and that of the oak (acorn), although the former is, compared to the

latter, but a poor weakly plant.

Again, let us note the difference between the cocoa-nut palm fruit, a

nut, which with its outer husk is almost as large as a peck measure,

and that of the St. John’s wort or any other of our native wild flowers.

These differences in size have their counterparts in other directions.

We generally think of fruits as being soft, luscious, and pleasant to

the taste. Many fruits of delightful colour and texture are, however,

bitter as gall, and possess highly noxious qualities. I well remember

gathering a plateful of rich purple berries from a plant I discovered

in one of my childish rambles and carrying them home as a great prize;

I was not a little disappointed when I learned that they were the

poisonous fruits of the deadly nightshade; their deceitful resemblance

to plums, as well as the berries of the woody nightshade to red

currants, make these two of our most dangerous native plants.

As offering very distinct contrasts to the above, we may note the dry

membranous fruits of many of our forest-trees, the hard nuts of the

hazel and walnut and the leathery husk of the chestnut. Again, the

shape of fruits is wonderfully diversified. We have round and oval

apples, plums, and gooseberries; the linear seed-pods of the cabbage,

cauliflower, wallflower, peas and beans, and other plants in endless

varieties of forms.

There are contrasts again in the smooth surface of some fruits and the

hairy coats of others where the roughness is due to hooks, prickles

and other contrivances. How different, too, is the airy pappus of the

dandelion to those heavy fruits which drop like stones and are to be

found lying exactly beneath the branches where they have ripened.

These differences in external form are multiplied when we examine fruit

more minutely. We shall then find a useful dividing line in the manner

in which fruits allow their seeds to escape. In one large division the

fruit when perfectly ripe splits open and allows the seed to fall out;

such fruits are termed dehiscent (from _dehisco_, I gape). In the other

division the fruit remains closed, and the substance of it must decay

before the seeds can escape and grow; these are classed as indehiscent

(I gape not). Before referring to a few examples of each division we

will endeavour to distinguish clearly the various parts of a fruit and

learn their proper botanical names.

We must be careful not to confound the seed and the coats of the ovary;

the latter is termed the pericarp (_peri_, around, _karpos_, a fruit).

In some fruits this pericarp is developed into distinct coats, or

layers. In a peach, for instance, the outer coat is rough and hairy,

this is called the epicarp (1) (_epi_, upon, _karpos_, a fruit); the

middle coat is the succulent delicious fruit, and is known as the

mesocarp (2) (_mesos_, middle, _karpos_, fruit), whilst the inner coat

is the hard stone, or endocarp (3) (_endon_, within, _karpos_, fruit),

and inside it lies the kernel, or true seed. As a type of a dehiscent

fruit we may select a pea-pod; here we get no division of the coats

into distinct parts, the pericarp is dry and tough, and when perfectly

ripe it bursts open, and allows the seeds to escape.

[Illustration: SECTION OF PEACH.]

It would be very interesting to make a collection of various

seed-vessels, and note the immense variety of ways in which the seeds

find their way out of the dry capsules. A poppy-head, campanula and

antirrhinum sprays, henbane, columbine, stramonium, and many other

plants afford good examples.

[Illustration: POPPY CAPSULE.]

The woody pear is the hard fruit of a New Holland plant which splits

open to release the seeds. The horse-chestnut is a conspicuous instance

of a dehiscing fruit, the rough prickly part is the pericarp, and

when the fruit is mature this splits open and allows the two large

chestnuts (seeds) to escape. In the sweet-chestnut we get an altogether

different structure. If we pick up one of its spiny burrs, we hold in

our hand what is called in botany an involucre (from _involucrum_,

a cover), that is, a number of bracts which have grown together and

formed an outer case to the fruit. The acorn-cup is an involucre, and

we may find other good examples in composite flowers and those of the

umbelliferæ. The small green whorl in which a daisy-flower is set is,

therefore, not a calyx, but an involucre consisting of minute bracts

grown together. The true fruit of the sweet-chestnut is enclosed in a

mass of spiny bracts, and thus differs entirely from the pericarp of

the horse-chestnut; if we wish to speak of it correctly we must call

it either a cupule or involucre. We will now select a few examples of

fruits that are indehiscent.

[Illustration: WOODY PEAR.]

On the outside of an orange we find the yellow coat of the pericarp,

next to it is the white mesocarp, and inside is the juicy endocarp,[19]

in which the seeds are embedded. When an orange falls to the ground

these different coats simply decay, and the seeds are aided in their

efforts to grow by the succulent flesh of the fruit, which affords them

moisture and nutriment. The hazel-nut is a fruit of another texture

altogether. The hard shell is the pericarp, and the one or two seeds

within it must remain enclosed there until the shell decays and the

kernels can germinate and become new plants.

[19] Strictly speaking, the endocarp of the orange is a thin membrane,

and the pulp grows from it and fills up the ovary cavities.

In the currant, gooseberry, and date we find examples of indehiscent

fruits with a sweet fleshy pericarp. In the date there is only one seed

in each fruit, and a curious thin endocarp can be observed enveloping

the solitary seed. Many allied species, as well as the date, possess

this sweet pericarp, which must decay in order to liberate the seeds,

and in the case of succulent fruits the process is frequently assisted

by the fruit-eating birds.

It may be well to draw attention to the very simple kind of fruit

possessed by the buttercup and other similar plants. It is a dry

membranous pericarp, and inside one seed exists free from the pericarp;

this remains closed, like other forms of the indehiscent types, and

technically this fruit is known as an achene (from _achanes_, not

gaping), and it is well named, as it remains closed until decay enables

the growing radicle to break through the pericarp and enter the ground.

The curious after-development of the strawberry fruit is worth a little

careful study.

This flower is known as apocarpous (_apo_, apart, _karpos_, fruit),

consisting of a number of distinct ovaries each with one ovule; these

ovaries when ripe are exactly like the achenes of the buttercup, but

they are developed upon a receptacle which, when fertilisation has

taken place, begins to dilate and swell, with the result that the

little achenes are gradually scattered over the surface of a large

fleshy receptacle which, as it nears its time of perfection, becomes

of a most tempting crimson colour. The little seed-like dots we notice

on the strawberry are distinct and perfect fruits embedded in a sweet

succulent floral receptacle. Thus we find that the strawberry, speaking

botanically, is not a berry, but a collection of achenes, the term

“berry” being usually restricted to such fruits as the currant and

gooseberry. For this reason the strawberry and the common fig are

sometimes termed spurious fruits, for in these the soft pulpy flesh is

really the receptacle and the little round so-called seeds are the true

fruit.

There is a very different formation in the pineapple, since this fruit

is the development of an entire spike of flowers; these in their early

stage are crowded together on the flower stalk, but as time goes on

they coalesce and fuse, with their ovaries, bracts, and receptacles,

into a succulent mass, the various parts of which can be well defined

if we cut a section through a pineapple before it is quite ripe.

This chapter may fittingly conclude with a brief reference to the

ultimate purpose of these varied forms and textures of fruit, for

that they each have their special work, and that there is a meaning

for every form, is a truism we may accept without doubt. The fruit is

in reality the storehouse for the seeds, the latter being the vital

part of the plant. If we review the life-history of a plant, first

its producing flowers, then the special and intricate processes of

pollination and fertilisation, and subsequently the growth of that

wonderful little part, the ovule, into a seed, and further if we

reflect that the whole strength of the plant has been concentrated on

producing that seed, we shall then comprehend the true significance of

fruit.

The seed is first stored up in the recesses of the ovary; clearly

then the ovary, which subsequently becomes the fruit (pericarp), is

intended to protect the seeds, and it is interesting to note some of

the various ways in which this protection is afforded. Take first the

soft and sweet fruits so plentiful in the autumn; this edible sweet

flesh is not developed until the seeds are quite ripe. All through the

period of growth and ripening the pericarp is hard or stringy or it

may be also sour or acid. This is especially true of hedgerow fruit,

such as crab-apples, sloes, and wild pears, texture and juice alike

affording complete protection.

Again, such fruit as the walnut and chestnut are protected by their

rough covering and hard shells, and many others have their outer coats

covered with prickles and spines for the same reason. The most extreme

case is perhaps that of _Mucuna pruriens_, a leguminous climber found

in the tropics; this has downy pods not unlike those of a sweet-pea,

and these pods are covered with brownish hairs which, if incautiously

touched, enter the pores of the skin and cause a most intolerable

irritation; a truly formidable protection this to the seed.

Let me now point out how the seed is protected in some of the pine

family (firs), where there is no pericarp. During the growth and

development of the pine seeds, the woody cone is rich in resin, and

should an enterprising nuthatch try to peck out the seeds, he finds his

beak covered with the resin and his effort baffled.

[Illustration: PINE-CONES.]

Protection is also afforded to the seed by the movements of fruit

after fertilisation, and of this the cyclamen flower affords a good

illustration. As soon as fertilisation has taken place the flower stalk

coils up like a watch-spring, and the seed-pod is thus placed safely

beneath the leaves to ripen.

In crevices of old walls we may often find that charming little

wilding, the ivy-leaved toad-flax; it has a highly intelligent method

of protecting its seeds. When the flower is fertilised its stalk bends

its point round to the wall, and places the tiny ovary in a cranny

of the brickwork to mature and ripen its seeds. These are but two

instances, out of hundreds, of plants whose fruits are protected by

what we call instinctive movements.

It is of essential importance to young seedlings that they should have

sufficient soil, light, and air, to ensure their healthy growth. To

begin life directly under the leaves of the parent plant is to court

failure and starvation, and so we find in the fruit that wonderful

provisions are made to ensure the dispersion of the seed when it

leaves the parent plant, and so endless are the contrivances for the

dispersion of fruits and seeds, that it will be needful to devote the

next chapter entirely to that subject.

Objects to collect and examine:—Compare various fruits, fir-cone,

banana, acorn, seeds, and berries, &c. Examine a peach and pea-pod.

Collect seed-vessels, horse-chestnut, sweet-chestnut, daisy-flower,

orange, hazel-nut, date-fruit, strawberry, pineapple.

Observe seed coverings, pine-cones, cyclamen stems after flowering,

seed capsules of ivy-leaved toad-flax in wall crevices.

CHAPTER X

_DISPERSION OF FRUITS AND SEEDS_

“Who gave the thistle’s feather’d seed its plumes,

That wing-like waft it on each gentle breeze

To sterile yet to it congenial soils,

Investing them with purple beauty, rife

With fragrant treasures for the wild bees’ store?”

+T. L. Meritt.+

CHAPTER X

DISPERSION OF FRUITS AND SEEDS

I purpose in this chapter to explain some of the many remarkable ways

in which plants are enabled to scatter their fruits and seeds. The

chief agencies which assist in carrying out this purpose are wind,

animals, birds, running water, and moisture in the atmosphere. We

shall find that many seeds are furnished with certain outgrowths and

peculiarities which are specially adapted to the action of these

agencies, with the result that such seeds are distributed far and wide.

We will first examine some of those fruits which are scattered by

animals; this end is generally attained by means of hooks and curved

spines on the outside of the fruit.

Perhaps one of the most remarkable instances of this class is the

seed-pod (or capsule) of the Martynias. During the visit of the Prince

of Wales to India, a panther killed in one of the shooting excursions

was found to have quantities of long-hooked seeds attached to his skin:

these must have been brushed from a plant of _Martynia proboscidea_,

which has sharp curved horns three or four inches long.

[Illustration: SEED-POD OF MARTYNIA.]

Another species called by the Italians _Testa di Quaglia_, or quail’s

head, sows itself in a similar manner by clinging to moving objects.

Many common hedgerow plants have their fruits armed with quite

formidable hooks, so that creeping or flying creatures may be made

unwittingly the means of distributing the fruits. The burdock is a

most persistent plant in this respect, each of its numerous fruits

being covered with long hooks which successfully retain their hold

of our clothing if we happen to brush past the plant when covered

with its troublesome burrs. Other examples are the rough seeds of

the forget-me-not, agrimony, enchanter’s nightshade—a great pest in

gardens—and all the bedstraw tribe.

These plants, we may observe, are low-growing and herbaceous, quite

distinct in the matter of position from the tall trees and shrubs which

depend upon the wind to scatter their seeds.

We are all familiar with the winged fruits of the sycamore; they are to

be seen in early autumn. The clusters are first of a pale green, and

then the seeds[20] often attain a flush of pale crimson which adds

much to the picturesque beauty of the tree. The equinoctial gales

separate the seeds from their stalks, and away they go far and wide,

borne up by the delicate membrane attached to the seed which catches

the wind, and is carried by it to a great distance from the parent

tree. In the same way the winged keys of the ash, being very light,

are borne by the autumn gales to strange habitats, so that the tree

may often be found growing on church towers, in ruins, and on crags

inaccessible to man.

[20] In botany the fruit of the sycamore, maple, ash, &c., is called a

_samara_, and is properly speaking a winged _achene_.

[Illustration:

_Natural Size._ _Magnified._

BIRCH SEED.]

The pinus tribe of trees have seeds with wings slightly twisted so

that, if we hold up a dry fir-cone, the seeds descend from it with a

whirling motion like small shuttlecocks.

The winds which blow strongly in mountainous places carry these seeds

before them, and are thus ever renewing the pine-forests by sowing

the products of their cones on bare tracts of land. The lightest of

all tree seeds is that of the birch; it is gifted with two wings or

membranes, so that it floats in the air before the lightest breeze,

and this may account for the wide distribution of the tree which has

been found growing from Mount Etna to Iceland and Greenland. I may give

an instance of a common which, twenty years ago, was covered only by

furze, broom, and brake-fern; about fourteen years since, a shower of

birch seed must have been strewn over the ground, and now it has become

a wood, shutting out the distant views and quite altering the character

of the landscape.

The wind again is the agency for the dispersion of the seeds of such

plants as the common groundsel; here it may not be uninteresting to

note the beautiful provision made in regard to the buoyancy of the

seeds. These winged structures which the wind so lightly blows into the

air must attain a certain altitude from which they can be successfully

launched, and therefore we find that a large class of low-growing

plants have their seeds furnished with accessories in the form of light

silky down or hairs.

[Illustration: PARACHUTE.]

[Illustration: DANDELION SEED.]

Most of the plants known as _compositæ_ have their seeds thus

feathered, and amongst them are those plagues of the farmer, the

thistle, dandelion, goat’s-beard and others. The dandelion may serve

as our example, and I would advise my readers to watch carefully the

variations of position in the flowering stems. Whilst the flower is

still fully expanded the stalk remains in an upright position so that

it is conspicuous and likely to attract the notice of insect visitors.

After the florets are fertilised it gradually lowers itself until it

lies on the ground under the leaves for a period of ten or twelve

days. During this time the seed-vessel matures and ripens, then the

stalk rises to the erect position once more, and the beautiful downy

globe expands into a soft fluffy ball of seeds hanging so loosely

that the first breeze carries them away, and their descent into the

ground is curiously provided for. Persons have sometimes alighted on

the earth from a balloon by means of a parachute, a machine which

closely resembles an open umbrella with a car at the lower end. Now

the dandelion seed descends in a similar manner, touching the ground

first with its lower end, the weight of the seed enabling it to drop

into some hole in the soil, and the spiny projections at the upper

end preventing the feathery part of the seed from dragging it out

again. The common goat’s-beard is perhaps the most beautiful English

example of fruit with a downy pappus. A single flower will produce a

sphere as large as a cricketball, and each seed is furnished with a

starlike crown of branched feathers which the wind can bear away to a

considerable distance.

[Illustration: GOAT’S BEARD.]

The handsome willow-herb, which adds so much colour and beauty to our

river banks, bears its seed in long, narrow pods, and these, when ripe,

split up into five segments which, curling back as they open, leave the

downy seeds free to be carried off by the passing breeze.

Bird agency in seed dispersion is a most interesting subject, and

one can but admire the wonderful way in which the services of winged

creatures are made available.

Succulent berries and sticky fruits are highly attractive to many kinds

of birds, and whilst they revel upon the sweet, soft flesh of the

berry, the seeds which they swallow with it are enabled to resist the

action of digestion by a hard covering which protects the kernel until

the shell shall decay and allow the seed to germinate. In this way I

find my garden in early spring quite thickly strewn with the seeds of

the Irish ivy, always a favourite food of the common wood-pigeon which

is so frequently to be heard cooing in my woods.

The seeds of aquatic plants often cling to the feathers of birds that

visit pieces of inland water, and are widely distributed by them in

their flight from one lake to another.

[Illustration: COCOS-DE-MER.]

Darwin has shown by careful experiment that the mud clinging to the

feet of various birds almost always contains seeds. A wounded partridge

had a ball of earth weighing six and a half ounces adhering to its

legs. From this earth Darwin reared no less than eighty-two separate

plants of five distinct species. Seas and rivers also do their part in

dispersing seeds. The huge nuts of the _Cocos-de-mer_ palm, which grows

only upon the Seychelles Islands, are often thrown upon very distant

shores. This nut is said to take ten years to come to perfection; it

is exceedingly hard, and sometimes weighs as much as forty pounds.

The common cocoa-nut is often found growing on the shores of coral

and other islands in the Pacific Ocean, and owes its position there

to the buoyant nature of the nut, which floats uninjured in the sea

until it finds a resting-place and a home on some atoll or island. In

this way the cocoa-palm has spread to such an extent that it is now

perhaps the only palm common to the western and eastern hemispheres.

West Indian seeds and fruits have even been thrown upon the Norwegian

coasts, and, but for the unsuitability of the climate, there is little

doubt that tropical trees and plants might sometimes be found growing

even so far north. It is obvious that the seeds of all vegetation on

the banks of rivers, small running streams and lakes, must be liable

to very wide distribution. Darwin made many interesting experiments as

to the length of time seeds could retain their vitality when floating

in fresh or salt water. Ripe hazel nuts germinated after being ninety

days in water. An asparagus plant with mature berries, when dried,

floated for eighty-five days, and the seeds afterwards grew vigorously.

Out of ninety-four plants experimented upon, eighteen floated for

more than a month and some for three months, their germinating power

not being destroyed. In quite a large number of species the plants

themselves possess the means necessary to distribute the seed. It is

true the distance traversed by each seed may not be great, but it is

sufficient to give the seed a new field of growth. This power varies in

different species. It is perhaps best defined as elastic force, and in

the majority of cases the seed is actually thrown away from the parent

plant by the expenditure of this force. The seed-pod is generally in

a state of tension, due to the gradual drying up of the tissues. Then

a puff of wind, a slight blow, or even a change in the atmospheric

condition of the air, gives the final impetus, causing the pod to

burst with such force that seeds are thrown out in all directions. The

fibro-vascular cords are often found crossing the pod in an oblique

direction, or even in a spiral manner, so that finally, as they

shorten through dryness, they act upon the walls of the legume and we

see the result in such dried pods as those of the sweet pea, broom, and

laburnum.

[Illustration: BROOM AND SWEET-PEA PODS.]

The pansy has a three-valved seed-pod, and as it dries the edges of

the valves press upon the polished, hard-shelled seeds and they are

squirted out with a jerk to a distance of several feet. I was once

greatly puzzled by a strange, crackling sound in my room, and after

a few minutes’ search I discovered it was caused by a fusillade of

pansy seeds striking against the sides of a small box in which I had

placed the capsules to ripen. It is worthy of notice that the capsule

hangs down to protect the seed-valves from rain; but when the seeds

are matured the capsule rises to an upright position so that they

may be projected far and wide. A conspicuous example of the elastic

force of which I have spoken is seen in the British balsam, _Impatiens

Noli-me-tangere_ (touch-me-not). When its seeds are mature, the valves

of the capsule curl up in a spiral form with such force as to project

both themselves and the seeds through the air many feet from the plant

dropping the seeds by the way. On a hot summer’s day one may hear the

dispersion of seeds! The furze and broom pods, the sweet peas, and

especially fir tree cones, make quite a loud report as they split and

scatter their contents. The tension causing these explosions is in some

cases brought about by the fluids inside the fruit. This is the case

with the squirting cucumber, which, when fully ripe, is so distended

with fluids that the slightest touch or movement is sufficient to

cause it to break away from its stalk, and then the whole contents are

ejected with great force, so that the seed is thrown some distance. The

extent of dispersion is very limited in those plants that are dependent

upon the varying moisture of the air. Such plants are usually furnished

with special awn-like[21] appendages; these are hygroscopic[22] in

their nature, and the difference in the amount of moisture in the air

lengthens and contracts these apparently moving organs. When the seeds

fall from an ear of barley they lie thickly strewn around the bottom

of the stem, and, were they to take root there, they must inevitably

choke each other; but each awn is thickly set with bristles, and as the

morning sun shortens and the evening dew lengthens the hair-like awn,

the prickles only allow the awn to move in one direction, and the seed

which is attached to it is slowly but surely drawn many inches away.

What is popularly called the dancing oat is another curious example

of this hygrometric property. If a dry seed (or oat) is placed for a

moment in water, and then laid on a smooth table, it will be seen to

wave its long horns as if they were the antennæ of an insect, and to

turn over and over until it has progressed some inches from the point

where it was first placed. In _Avena elator_ (the tall oat grass) and

_Stipa pinnata_ the awns are bent sharply just as they emerge from the

flowers, the part below the bend being like a corkscrew and highly

sensitive to moisture, relaxing and contracting according to the amount

of moisture in the air, with the result that the seed travels along the

ground. By the help of the long awn it can pass over small obstacles,

such as stones or clods, the movement resembling that of a lever.

[Illustration: STIPA PINNATA (FEATHER GRASS).]

[21] The beard of corn.

[22] Sensitive to moisture.

I must here guard my readers against those movements that are caused

by some insect larva. The so-called jumping bean imported from Mexico

is now so well known that it may be taken as a type of these curious

movements due, not to the seed itself, but to the efforts of an

imprisoned insect, the grub of a small moth which passes its larval

stage inside the hard-shelled seed of a kind of euphorbia.

In conclusion, we may glance at a small group of plants that develop

sticky glands for the purposes of dispersion.

That charming Alpine plant _Linnæa borealis_ has a pair of bracts

closely adherent to the fruit and these bracts are covered with

stalked glands of a sticky nature, so that when an animal, bird, or

even a passing moth brushes against the little fruits they stick to

the intruder and are thus borne away. Now it may perhaps occur to the

thoughtful reader that the Linnæa seed-vessel, being part of a growing

plant, would not readily break off with a slight touch, but it is

another instance of that consummate skill and arrangement that is so

apparent to the close observer. In the stalk of the little fruit there

is a special separating layer[23] (analogous to that of the falling

leaf which we noted in a previous chapter), and at this point the

fruit readily separates if the slightest pressure is brought to bear

upon it. This example is typical of what takes place in such plants as

_Salvia glutinosa_ and _Plumbago capensis_ and _Rosea_. As a contrast

to these various modes of dispersion I may mention those seed-vessels

which are actually buried by the plants themselves, such as the

ground-nut, ivy-leaved toad-flax, and others. We must bear in mind that

these plants usually have aerial flowers in addition to those matured

underground, and that these aerial flowers produce fruits which are

subject to dispersion. We may therefore conclude that the underground

seeds are to ensure the continuance of the plant when the ordinary

methods have perhaps partially failed. My readers may each autumn find

an endless source of wonder and interest in the thousands of differing

fruits and seed-vessels which may be obtained in any hedgerow and

field; and by careful observation they may yet learn many new facts and

be ever adding to their store of knowledge by gathering and comparing

the fruits and their dispersion, as shown in the types sketched in this

chapter.

[23] Called botanically an “absciss layer.”

Objects to collect and examine:—Fruits and seed-vessels of martynia,

burdock, forget-me-not, agrimony, enchanter’s nightshade, bedstraw,

samara of sycamore, ash-keys, pinus seeds, birch seeds, dandelion and

goat’s-beard seeds, pods of sweet-pea, broom, laburnum, and pansy.

Seed-vessels of balsam, wild oat, feather-grass, _Linnæa borealis_,

salvia, plumbago, ground-nut, and ivy-leaved toad-flax.

CHAPTER XI

_GERMINATION_

“O Source unseen of life and light,

Thy secrecy of silent might

If we in bondage know,

Our hearts, like seeds beneath the ground,

By silent force of life unbound,

Move upward from below.”

+T. T. Lynch+

CHAPTER XI

GERMINATION

Having considered the processes which lead up to the formation of seed,

we may now investigate the life-history of a seed and its various forms.

Like fruits, seeds differ much in their outward shape. In size alone

we find a great contrast between the dust-like seeds of the orchids

and the huge seeds of the cocoa-nut-palm, while between those two

extremes we may note every gradation of size. In other respects, also,

the seed offers no less variety of form and covering than the fruit,

such variations having relation to the particular mode of dispersion

and germination. The outer skin or coat of a seed, called the _testa_,

offers a very interesting field of study, and such seeds as the poppy

and _silene_ with beautiful network, the _bignonia_ and _pinus_ with

membraneous wings, the cotton-plant seed with long hairs, and the

_collomia_ with hairs that are resolved into mucilage when wetted, are

all worth special study. When a small portion of _collomia_ seed is

moistened and placed in a microscope one may see the rapid change being

effected; that which had been a hard dry atom suddenly throws out coils

of gum, like watch springs, and a novice is led to ask, “Is the thing

alive?” so full of motion does the object appear.

[Illustration: BIGNONIA SEED.]

We may regard a seed under various aspects. As a special means of

continuing the life of a plant, one of its modes of reproduction, as

a special means of tiding a plant over a season that would be fatal

to its life in its ordinary condition of leafage, in the seed we have

the germ of the future plant, a reproduction of its parent. This germ

or embryo is lethargic or hibernating like many animals which exist

throughout the winter in a dormant condition, yet still continue to be

living vital bodies waiting for some special influence to come into

play, and ready to resume all the activity of a growing organism.

The construction of a seed is simple; inside the coat or _testa_ we

find the embryo with or without a special supply of albumen; if the

seed is ex-albuminous, then we may expect to meet with thick, fleshy

seed-leaves especially stored with this substance. The embryo contains

all the essential parts of the plant, the root, stem, and leaves; the

root in the seed state is called the radicle, and is that part of the

embryo which usually points towards the micropyle; this radicle forms

one end of the first shoot which comes out of a seed, the other end

terminating in the stem or plumule. This first shoot is known by three

names—axis, _tigellum_, or hypocotyle. The _tigellum_ in many plants

gives rise to a special structure; thus in the cyclamen it forms the

tuber, and the greater part of the “roots” of radishes and turnips is

due to it. In other instances it is a mere collar forming a slightly

thickened surface between the base of the cotyledon and the radicle.

The _tigellum_ is in reality a centre of growth, as may easily be shown

by cutting off an inch of the upper part of a well-grown carrot and

placing the slice in a saucer of water; before long a crown of young

leaves will spring up and will continue to grow and flourish as long

as the plant food contained in the slice is sufficient to maintain the

leafage. In botanical language we have thus been growing carrot leaves

from this _tigellum_.

The embryo varies very much in the relative position of its parts.

Thus the embryo of the reed-mace is straight in the _tigellum_ of the

embedding albumen. In contrast to this is the curved embryo of the

deadly nightshade and the spiral embryo of the hop.

[Illustration: DOUBLE EMBRYO OF ORANGE.]

The seeds of the orange often contain two embryos, which is rather

a rare occurrence in the vegetable world. Before we can trace the

future of these parts we must attain a clear idea of the change the

seed undergoes when it germinates. In the whole of our studies our

attention has been drawn to no process so deeply interesting and yet

so mysterious as that of the breaking into life of the seed. There

are three conditions that promote the process of germination: warmth,

moisture, and air. When these three conditions are present and the

seed is healthy, growth begins, and its first stage is the absorption

by the seed of moisture; this, combined with warmth and the oxygen of

the air, sets up a change in the contents of the seed. We have already

seen that seeds are of a dry and starchy nature, and in this condition

they are insoluble and unfit to be active plant food. The change that

ensues results in this starchy matter being converted into sugar which

is soluble; then the parts of the embryo begin to unfold, first the

radicle and finally the plumule are developed. In this early stage

these parts live entirely upon the contents of the seed, just as a

young chick is developed and nourished upon the albumen of the egg.

The temperature requisite for germination varies according to the

species; those of us who possess gardens know to our cost at what a

low temperature such plants as chickweed, bittercress, groundsel,

and some of the speedwells grow; as long as the thermometer is above

freezing-point these troublesome weeds will make their appearance in

our flower borders. Sach’s experiments on germination tend to show that

wheat and barley begin to grow below five degrees centigrade, whilst

French beans and maize germinate at nine degrees centigrade.

Some plants start into growth very quickly. Garden cress, vegetable

marrows, and some grasses appear above ground a few days after they

are sown, whilst other seeds, enclosed in a hard, woody seed-case,

will require twelve months to germinate. This was the case with a

seed taken out of a cedar cone brought from Mount Lebanon; I vainly

watched for the young plant, and when a year had passed by the pot

was thrown aside on a rubbish heap. Shortly after I was passing by and

observed a fir-cotyledon growing on the heap, and this proved to be the

long-desired young cedar-plant.

Seeds have the power to retain their vitality for years, especially

those of the _Leguminosæ_, but I believe the stories of Egyptian mummy

wheat germinating are scarcely to be believed. A good object-lesson

upon this subject is furnished by a newly-made railway cutting; here

we may always find growing upon the freshly-turned soil quite a crop

of plants which have sprung from seeds that in the course of years

have become embedded in the earth, it may be at so great a depth as

to preclude the admission of air or prevent one of the necessary

conditions of germination. When, however, the underlayer of soil is

brought to the surface and exposed to light, air, and moisture, the

seeds are able to grow.

[Illustration: BROAD BEANS.]

To this we owe the richness of our railway-bank flora, and many a

rare plant may be discovered there which cannot be found elsewhere in

the neighbourhood. We will now in imagination conduct a few simple

experiments that we may learn something of the behaviour of seeds

during their early stages of growth. Each seed that we thus study may

be regarded by us as a type of many others. First, then, we will sow,

in a few pots, about a dozen broad beans; before doing so we may notice

on the seed the black stripe or ridge known as the _hilum_; this is the

scar showing where the seed was attached to the pod, and at one end of

it is the micropyle (_small gate_). If we remove the skin of the seed

we shall observe the two fleshy cotyledons or seed leaves, a tiny point

which is the rudimentary root, and, lying close to the inner face of

the cotyledon, the slightly curved plumule. After the beans had been

sown a few days and carefully watered, we may take up two or three for

examination. At first we may only see the radicle just emerging from

the little hole at the end of the _hilum_, but if we wait, say, eight

or nine days, we shall get a further development.

Before digging up our seed we will see if any others are peeping

through the soil. Yes, here is one, just an arched kind of shoot, no

leaves, only the bow of the arch pushing up the particles of the soil,

so that the point of the shoot is clearly still below the ground.

Now, taking up a seed we notice that the radicle has penetrated some

way down into the soil, and with a pocket lens we are able to see a

little higher than the tip of the root quite a crop of delicate little

root-hairs. The cotyledons are still enclosed in the tough skin, but

the upward growth of the _tigellum_ is acting on them like a lever,

and we can now plainly see that it is this _tigellum_ that, by its

upward growth, is penetrating the soil, and in so doing is drawing

the cotyledons from the seed coat. All this time the delicate plumule

is kept out of danger by the arched shape of the _tigellum_ and the

folding of the cotyledons. Leaving our seeds for a day or two longer

we find a further change. The plumule has been carried up beyond the

soil-level and has begun to expand into leafage. It is interesting

to note how the curved _tigellum_, pushing through the soil first,

effectually guards the plumule from injury arising from contact

with rough particles of earth; the cotyledons remain just below the

soil-level and we see that the _tigellum_ is thickening and forming

a distinct connecting branch between the new shoots and the fleshy

seed leaves; these latter are full of plant food, and the plumule is

supplied from this storehouse of nutriment until the first leaves are

formed and are able to decompose carbon-dioxide for the nourishment

of the plantlet. The seed-leaves in this case do not perform this

function, but act simply as storehouses.

Our next seed example will be the familiar mustard plant. These we may

sow in two lots, the first we only need to sprinkle upon some fine soil

and the second may be sown in a shallow drill and covered with fine

earth.

[Illustration: GROWING MUSTARD SEEDS.]

The first sowing will quickly germinate, and the movement of the

radicle which pushes out of the micropyle may be understood by

reference to the appended diagram. In it we see the white thread-like

radicle emerging from the seed coat; it turns very quickly towards

the ground and pushes directly into the soil. Here I must direct my

readers’ attention to one of those minute arrangements which, though

apparently insignificant enough if we fail to study the context, is

really an evidence of the infinite perfection, care, and wisdom of the

Creator in even such a tiny detail as the springing up of a mustard

seed. As the seed lies upon the ground, the lengthening radicle, while

it penetrates the ground, has a tendency to force the seed into the

air (as shown in the illustration), and were it allowed to do so the

seedling would soon shrivel up and die. This catastrophe is, however,

averted by the development upon the radicle of quite a crop of fine

white root-hairs; these adhere closely to the minute particles of the

soil, and are thus enabled to counteract the force exerted by the tip

of the radicle; the latter pushes through the ground without uplifting

the seed. This action can be watched and the growth of the root-hairs

observed by means of a pocket lens and by the exercise of that virtue,

most necessary for all young naturalists—patience.