[Illustration: Fig. 129. A Prothallium (~p~), with a young Fern (~f~)

growing out from it. (Magnified).]

Some ferns take a short cut, and bear little ones directly on their

leaves without any prothallium. You see this in the “Hundreds and

Thousands” fern, where the old plant is sometimes covered over with

little ones, which will grow if they are taken off and planted

carefully.

Sometimes people are deceived by what is called the “flowering fern,”

and expect that it will have flowers. In this fern we find that all the

spore-cases grow together on a special leaf, which is so covered by

them that it looks quite different from a usual one, and is called the

flower, though it is not one. In all other ways the story of the spore

building and growth is like that of usual ferns.

In our study of ferns, you see that they have many characters which are

exceedingly different from either the flowering plants or pine-trees.

In fact, they are so different that we require to add some new points

to our list of characters for family divisions, which are:--

7. ~Instead of flowers there are little spore-cases, which contain

a number of simple one-celled spores.~ These are generally found on

leaves which are otherwise like the rest of the leaves of the plant.

8. ~Each spore grows out to form a small green structure, which differs

from the parent, and which we call the prothallium.~

9. ~The new fern-plant grows at first attached to the prothallium~, but

soon grows out beyond it, and is quite independent.

What we call “ferns” are not the only plants which belong to this big

family, for the club-mosses and also the horsetails have almost the

same arrangement for their building of new plants. Our character-points

(7) (8) and (9) apply to them, even though the rest of their structures

appear to be so different from the ferns. They are, therefore, put in

the same big family with the ferns, though they have smaller classes

for themselves apart from the true ferns.

Neither the ferns nor their near relatives are very important in the

vegetation of to-day, but very long ago they were among the chief

plants in the world, and grew to be as big as forest trees. Even then,

however, they had almost the same way of forming spores that they have

to-day, a fact which still marks them out as a family different from

all the other families of plants.

CHAPTER XXVI.

MOSSES AND THEIR RELATIVES

=Mosses form another big family=, the members of which are generally

=easy to recognise=, even when you know little about them, because

they all have a very strong family likeness. If you look for mosses in

a shady wood, or on stones and tree stumps near a waterfall, you will

often find large numbers of them growing together, sometimes forming

sheets of soft green, covering the stones and earth and tree stumps.

These luxuriant mosses grow, as a rule, in moist and shady places, but

there are others which grow on dry walls or between the cobbles of

little-used paths, and generally form brilliant green patches of tiny

plants, like masses of velvet. If you pick out a separate plant from

among these and look at it through a magnifying-glass, you will see

that it is very like the bigger ones of the wood.

[Illustration: Fig. 130. A clump of Mosses, showing the flower-like

appearance of the tips of their branches.]

For our study it is perhaps better to choose one of the bigger ones,

because all its parts show so clearly.

1. If you take a single plant, you will find that it appears to be

marked out into root, stem, and leaves, though all these parts are

small and simple.

2. The stem is delicate, and you will not be able to see any

“water-pipe” cells when you examine it with your magnifying-glass.

3. The leaves are always very simple and small, generally narrow,

pointed, and clustered thickly round the stem with no special leaf

stalks.

4. At the ends of the stems, you will often find little structures,

sometimes rather pink in colour, which look something like flowers

(~see~ fig. 130), but they are really ~quite different in their nature

from true flowers~.

[Illustration: Fig. 131. (~a~) The part of the Moss corresponding to

the prothallium; (~b~) with the spore-capsule attached; (~c~) enlarged

capsule, showing the covering; (~d~) naked capsule, showing the lid

which falls off at (~l~).]

5 and 6. ~There are no seeds~ and no seedlings.

7. At the top of some of those plants which seem to have flowers you

will find later that a long slender stalk grows out with a little

capsule or box at the end of it (~see~ fig. 131 (~b~)). This single box

or capsule really corresponds to the numbers of small spore-cases on

the backs of fern-leaves, for it ~is in this capsule that we find the

spores~, which are simple and ~single-celled~ like those of the fern.

8. When ~these spores~ grow, however, they do not form a prothallium as

they do in the ferns, but they ~grow out into the leafy moss-plant~.

It is very difficult really to see how this can be the case, unless you

study mosses very carefully with a microscope, but all the same it is

true that ~the leafy moss-plant corresponds to the prothallium of the

fern~.

9. On the leafy moss-plant you find the simple stalk and capsule which

gives rise to the spores; this ~spore forming part of the plant always

remains attached to the leafy plant~, so that we find the two portions

of the plant in contact all their lives, and not separated as they are

in the fern.

[Illustration: Fig. 132. A piece of Liverwort, showing the flat,

creeping body, not divided into root, stem, and leaves.]

The only other plants which are built on anything like this plan are

the liverworts, though you might hardly believe it, because most of

them are not marked out into leaf and stem at all, but are only flat,

creeping, green structures, which do not look in the least like the

mosses. It is true that they are not very near relatives, but because

they have spore-cases rather like those of the mosses in some very

important ways, the scientists have put them together in the big moss

family. The true mosses have a special smaller family to themselves

within this, a family which is quite easy for you to recognise when you

go out on your rambles into the woods.

CHAPTER XXVII.

ALGÆ AND FUNGI

=The last big family of plants is that containing the simplest plants

of all.= They are often very small and apparently unimportant,

sometimes so small that we cannot study them at all without magnifying

them very much with the microscope. In other cases they are quite large

and easy to see; for example, the big red and brown seaweeds, and the

many toadstools in the autumn woods. Sometimes they may even be very

huge indeed, as are some of the seaweeds which grow in tropical seas.

All the same, though we examine one which is as big as can be, it is

really more simple in its detail than the mosses.

In very ~many of the algæ and fungi, the whole plant body consists only

of one single cell~. When this is the case, the plant lives floating or

swimming about in water, or in very damp places. In rain-water which

has stood for a long time you may find numbers of these tiny algæ. If

you put some of the water in a glass tube and hold it against the light

you may just see them, with a magnifying-glass, as specks of green,

often swimming actively about.

The fine green “scum” which floats on many ponds and slow-moving

streams consists of masses of these simple plants, in this case

generally of forms in which the single cells keep attached together

in long rows or chains, forming hair-like plants. Colourless plants

of this kind are the fungi, which are often built on the same plan

as the hair-like green algæ, only they do no food-building work for

themselves, but live as parasites on other things. This is the case in

many moulds and the plants which form potato-disease, and, in fact, the

greatest number of plant-diseases are caused by such simple parasites.

All these plants are very small and simple, and as you can see at once,

are not at all to be compared even with the mosses, but there are

others which seem to be more complicated, as are the big seaweeds and

the toadstools. Let us see how it is they are put in the same family as

the simplest plants of all.

You can see, even with your magnifying-glass, that they have no special

“water-pipes” in what you may call their “stem,” (for want of a better

name), but that their whole body is built up of numbers of soft cells

all very much alike, which twine in and out, and build a kind of

soft weft; they have no really marked out stem and leaves. Look at a

toadstool, for example, there is just a stalk and a cap spreading out

above ground, while under the ground there are many twining thread-like

strands (~see~ fig. 133).

[Illustration: Fig. 133. A Toadstool, showing the “cap” and “stalk.”

Under the cap are the radiating gills, on which the spores are formed.

Thread-like strands under the soil.]

Even in the seaweeds, which may seem to have stems, you will find that

such is not really the case. They have generally a flat body, which is

thin at the edges, with a stronger mid-rib, and the flat edges get worn

away in the older parts of the plant, and so leave the mid-rib looking

like a stem, though it is not so really (~see~ fig. 134).

[Illustration: Fig. 134. A Seaweed, showing the branched body, which is

not divided into stem and leaves.]

When we come to look for flowers or even spore capsules, we see still

more clearly how simple these plants are; they have not nearly such a

complicated history as the moss. For example, in the toadstools we find

that there are many spores formed directly on its lower surface, on the

“gills,” and these grow out to form new toadstool plants. You can see

the spores if you cut off a toadstool or mushroom head which looks full

grown and is quite expanded, and then lay it on a sheet of gummed paper

over-night, with the gills downwards, and another beside it with the

gills up. Next day you will find that the paper under the one where the

gills were downwards is covered with radiating lines of spores, just as

they fell from the gills, and repeating their pattern.

[Illustration: Fig. 135. Part of a Bladder-wrack, showing the floats

(~f~) and special swollen tips (~s~).]

The seaweeds have the most complicated way of forming spores of any

of this family. There are special little swellings at the ends of the

plant, as in the ordinary bladder-wrack, for example (fig. 135 (~s~)),

and in these are formed the cells which will give rise to new plants.

The other simple bladders (fig. 135 (~f~)) are only full of air, and

act as floats to keep the plant up in the water.

In this the simplest family of all, we find more variety in the

appearance of its members than in any of the others, so that it may

seem to be rather difficult to recognise the plants which belong to

it. Perhaps the easiest way of settling this, is to see if the plant

fits into any of the other families, and if it never has flowers nor

cones, neither fern spore-capsules nor the big spore-capsules of the

moss family, then you are fairly safe in classing it with the simplest

plants.

Very many of the plants of this family are found living in water, which

is perhaps one of the reasons that they can afford to be so simple,

because the water protects them from many of the dangers land-plants

have to prepare against, such as wind, drought, or too much sunshine.

This is the simplest family of real, undoubted plants; but there is

one class still simpler, and that is the family of ~bacteria~, about

which you must have heard much, as many of them cause our diseases,

though others do much valuable work for us. All the same, we will leave

these little creatures alone, and content ourselves with the five great

families of plants which we can see with our own eyes.

[Illustration: PLATE IV.

A LOW EDGE OVERGROWN WITH FOXGLOVES AND MANY OTHER WILD PLANTS]

PART V.

PLANTS IN THEIR HOMES

CHAPTER XXVIII.

HEDGES AND DITCHES

We do not see plants growing under quite natural conditions in the

hedges and ditches, because they are put there by man in the first

instance, and are continually kept in order by him. All the same, the

hedgerows, which are so common in England, deserve a little study. They

are within the reach of every one, and there we may often find many

wild plants growing sheltered by the actual hedge.

The principal plant is, naturally, the one which forms the hedge,

and this is very commonly the hawthorn; but, growing under it, and

over it, and on the banks on either side, there are many others which

are generally quite self-planted and truly wild. Of the bigger ones,

the white clematis or Travellers’ Joy is very common in the south of

England, and grows climbing all over the hedge, and often covering it

with its white flowers. We noticed this plant among those which are

special climbers (p. 105), and we can often see very well on the hedges

how it climbs over tree and shrub, and supports itself on them.

A smaller plant, of somewhat similar habit, is the goosefoot. This

has long, weak stems, which grow up amidst the other vegetation and

so support themselves, while its leaves are arranged in whorls round

the stem, and are narrow and rough, and help to keep the plant from

slipping down. Notice also its fruits, how rough they are, and how they

cling to everything. They are beautifully adapted to catch on to every

passer-by, whether man or animal, and so to get carried to a distance

where the seeds may grow.

~A character of the ordinary plants growing in the hedges~ is the

tendency they often have to form ~very long, straggly stems~, which are

too fine and weak to support themselves, but which are quite strong

enough to grow up through the hedge and bear leaves, as they are partly

held up by the other vegetation. You may frequently find plants which

are usually only a foot or so high, and able to support themselves very

well, growing up through the hedge to a height of two or three feet,

and having thin, limp stems with long spaces between the leaves (~see~

fig. 136). These plants have some of the characters both of those grown

in the dark and of climbing plants, because the thick-set hedge keeps

off the light from the low-growing parts, so making them straggly, and

at the same time gives them the support they need if they grow rapidly

out into the light, and do not build strong stems. Very often you may

find plants of the same species as those that grow so tall in the hedge,

growing in the shorter turf away from it, and there only reaching their

usual height.

[Illustration: Fig. 136. Two Toadflax plants growing near together: A,

on the bank by a hedge; B, among the plants of the actual hedge.]

This shows us not only that different species are specialised to grow

under different conditions, but that even two individual plants of

the same species may be growing within a few feet of each other, and

yet have quite a different appearance owing to the influence of their

immediate surroundings. There are many such cases to be seen in the

hedgerows.

If the hedge runs from east to west, it will cast a shadow over

the side lying to the north. Notice ~how different is the general

appearance of the plants on the bleak side from that of those on the

south~. You may also find that some species which grow on the south

side do not grow on the north at all, or only in far smaller numbers.

It is quite worth while making out lists of all the plants you can find

on one side and the other of the hedge if it is a big, well-established

one, and comparing the numbers and condition of the two sets of plants.

[Illustration: Fig. 137. A, Dead Nettle which has grown up through

the hedge. B, the same after being cut back with all the others. Side

branches have begun to sprout now that it is well lighted and the top

has been cut off.]

As we noticed before, hedges are not entirely natural, and as ~man

therefore forms a part of the plants’ environment~, it is quite

interesting to ~see how they respond to his influence~. For example,

we may study the effect of his trimming the hedge. In a hedge which

had been left for some time to itself, the plants would have long,

thin stems, bare at the base, where no leaves would develop, as they

would be cut off from the light by all the other plants. Then comes

the “hedger and ditcher,” and cuts them all back, leaving often only

a few inches of nearly leafless stem. What is the result? Soon on

these bare stumps leaves begin to sprout now that the light can get at

them and the top is cut off, and many short side-branches come out,

also bearing leaves, so that where before were only long, bare stems

carrying the top tufts of leaves out to the light, we now have short,

thickly clustered plants of bushy appearance (~see~ fig. 137). Soon,

however, the race for light begins again, and the plants grow taller in

their attempt to overtop each other. Notice also how the hawthorn (or

whatever woody plant it may be which makes the hedge) responds when its

leafy shoots are cut away. Many hidden and sleeping buds in the brown

woody stem now get their chance and wake to active life. It is this

continual cutting back which makes the hedge so thick with many short

branches.

[Illustration: Fig. 138. Bulrushes growing in a wet ditch.]

~In the ditches~, which often run alongside of hedges, ~we find quite a

different set of plants~. The ditches are generally cut out to a lower

level than the surrounding bank, and so they often contain water while

the rest is dry. In such watery ditches the plants which you will find

depend a good deal on the quantity of water in the ditch, and whether

it is always there or not. If it is really a wet ditch, you may get

many of the inhabitants of the lakes, or if it is a dry ditch where but

little moisture collects, you will get only rushes and rank grass. An

interesting kind of ditch to watch is one which is well supplied with

water nearly all the year round, but may dry up during the height of

summer. In such a position as this you are nearly sure to find many

pond-dwellers, such as water-cress, duckweed, water parsnip, water

buttercups, bulrushes, reeds, and many others, which will vary with

the locality. These plants generally choose a spot where there is a

permanent supply of water, but plants cannot foresee the unexpected

draining of the ditch, or a summer drought, and they are sometimes

left through these causes to grow on bare mud. When this happens,

notice how they behave; those which were already rooted in the mud may

continue to flourish for some time, while those which were floating may

be able to root themselves and tide over a short danger. If the water

is permanently drained off, however, they gradually have to give in;

they seem to draw themselves together and the long, luxuriant branches

die off, only the short shoots remaining, which are not so extravagant

with water. The duckweeds, which you know very well as little floating

green leaves, have long, thread-like roots hanging from them unattached

to the soil. When the water goes, they first root themselves in the

soil with these water-roots, but if the drought lasts long the roots

die away and the plant hides in the mud, where it can remain for a long

time waiting for the return of the water.

[Illustration: Fig. 139. Duckweed, with simple leaves and long roots

hanging in the water.]

In the ditches you will probably find a number of green, thread-like

algæ; these may also remain on the mud for some time when they are

dried up, and in their case some of the cells at such times get a

specially thick coat, and remain living for long. Then, if the water

returns, it is again the home of these algæ, which rapidly grow out

from their protected cells.

So that you see, even if you had no plants but those in the hedges

and ditches to study in their homes, yet you could manage to find

many examples of living plants which are trying to fit themselves to

their ever-changing surroundings. Those that cannot succeed must die

away in that spot, and confine themselves to some other place where

the struggle is not too hard for them. All the plants which we find

anywhere living together are, therefore, those which are suited to the

conditions in that place, and all such plants growing together in this

way form what is called a “plant association.”

CHAPTER XXIX.

MOORLAND

[Illustration: Fig. 140. A moorland stream. Notice the low growth of

all the plants.]

The word “moorland” brings at once to the mind’s eye great stretches of

land which the farmer has left practically untouched. It is not like

a woodland, for the plants are all so short that they do not shut out

the view; hence on the moors there is a sense of space, and one can see

all around the hillsides and plateaux clothed, though their form is not

hidden, by their covering of plants. Let us see what are the characters

of the plants which grow so lowly, and yet so thickly on these expanses

of uncultivated ground. Almost the first which rises to one’s mind

is the heather, with its short, bent stem and many wiry branches. If

you try to pull it up you will find that the roots are long and fine,

but strong, and that they grow for great distances into the soil, so

that it is very difficult to get the plant out. The leaves are small

and tough, and the lower ones on the stems generally have their edges

half rolled in, while the leaves on the ends of the branches which

stand further out in the air are often so much rolled as to be almost

entirely closed. Some of the heather-plants seem to be covered over

with short hairs like soft down, while others have shiny strong leaves.

In fact, the heather has many of the characters of plants which have to

protect themselves from drought.

Look at the others growing with the heather; there is the heath, which

is so like it that almost the same description applies to it. Then

there is the cranberry, which lies close to the ground, and is somewhat

protected by the other plants, and has more delicate stems, and larger,

flatter leaves, which are also rolled in at the edges. The bilberry

has certainly larger leaves than these others, but notice in the early

autumn how soon and readily they drop off, and leave the thick, green,

ridged stem to do their work. The moorland grasses also have protected

leaves; generally they are narrow and pointed, and the whole leaf rolls

over, so protecting the side on which are the transpiring pores (~see~

p. 102). ~All these plants have the appearance of protecting themselves

from loss of water~; how is it? It may seem strange when you remember

that it is from our moorlands that so much of our water supply comes,

and also that the moors are common in the north, where there is a large

rainfall. All the same, the plants on a moor do actually require to

preserve their water, as they suffer from “drought conditions.”

Stand on a high moor on a windy day, and you will soon feel how the

force of the wind sweeps across it. Such a day is what laundresses

call “fine drying weather,” and so do the plants. Then if you go on

a bright sunny day in summer, you will soon feel how very hot the

moorland can be, for there is no shade to be had anywhere, and the cool

green glades of a wood offer a tempting change. The moorland plants

suffer from this heat, and require to protect their transpiring pores

from the glare, so that you will find all those that can do so, have

rolled their leaves up tightly. Then notice the soil of the moors, how

springy it is, and how black and “rich”; very often there are traces

in it of the partly decomposed plants which form it. This is what is

called a peaty soil, and may even be true peat. The decomposing plants

in this soil give rise to an acid which is rather preservative, and

at the same time it acts on the living plants and makes it difficult

for them to draw in water by their root hairs. This kind of soil adds

very greatly to the “drought conditions” of the moorland plants, for

it makes it hard for them to use the water which surrounds them. All

these things cause the moorland plants to be as sparing as possible of

their water, and so they have the appearance of plants grown under dry

conditions.

But why are there no trees on the moors, you may ask! It cannot be that

they are on too high a level for trees to grow, for some even higher

hills are clothed with them. The truth is that probably long ago there

were trees on the moors, but men cut them down foolishly without having

planted young ones between the old ones, which would have replaced

them. When once all the trees are cut down on a hillside, it is very

difficult for young ones to get a start again, because everything which

makes it hard for ordinary small plants to grow hinders the young

trees, and the worst of all these things is the strong wind, which can

rush unchecked over the bare moor. A strong wind is more powerful than

a young tree, and kills it.

The plantations of young trees which are to be found on the moorland

have to be started on the sheltered side, and require much care and

attention. You will notice that the trees which do grow there are those

which are specially fitted for a hard life, such as the pine, larch,

and birch.

Another feature of the moorland, and one which cannot long escape our

notice if we walk about moors at all, is the number of patches of wet

moss which shake and tremble beneath our feet, and may form great

stretches of bog-land. Sometimes this is so soft that it gives way

altogether, and one may be knee-deep in moss and water, where it looked

firm enough to the eye. You will find this bog moss grows in a peculiar

way, the fresh green branches growing up and up, while below lie the

half dead older stems, which are partly preserved by the peaty acids.

These layers of moss collect for many years, till very thick masses of

peat-bog may be formed.

Among the bog-moss you will often find the sundew and butterwort (~see~

pp. 114-15), which are two of our chief insect-eating plants. They love

the boggy moorland, or a damp spot beside a little moorland stream.

There is a curious thing you may have the chance of seeing in a wet

moor. If you find a stream dripping over a ledge some little distance

on to the rocks below, you may see how thick and beautifully green are

the patches of moss growing beneath its spray. If the stream has passed

over much limestone (and is therefore carrying some in solution), you

may see below the living moss much dead moss just covered with a thin

coating of lime. Below this is more moss, which has been made quite

hard with the lime, and is brittle and snaps if you try to bend it,

while below this again is a hard, compact mass of stone which is made

from the stony stems of the moss crushed together by the weight above

them and filled in with more deposited lime. In some places great

masses of rock are formed in this way. You have here, acted before

your eyes, a piece of the history not only of the living and dying

plants of to-day, but of the building of rocks, which may some day help

in the building of mountains.

[Illustration: PLATE V.

WATER PLANTS GROWING PARTLY BELOW AND PARTLY ABOVE THE SURFACE OF THE

WATER]

CHAPTER XXX.

PONDS

The water of a natural pond is crowded with plant-life. Do not go to

one in a London park, which is cleaned out by the County Council at

intervals, but to one which is left to itself, and you will find it

full of interest.

[Illustration: Fig. 141. Water Buttercup, showing the much-divided

water-leaves, and the simpler leaves rising into the air.]

Some of the plants float freely in the water, as do the duckweeds, and

others, such as the water-lilies, are rooted in the mud with their

leaves floating on the surface, while yet others are rooted in the mud

at the bottom and live almost entirely under water, like some of the

potamogetons, or curly pond-weeds. The plants which are more or less

attached to the muddy bottom, and have floating as well as submerged

leaves, are perhaps among the most interesting, for they show two kinds

of leaves. Look at a water buttercup, for example (fig. 141); on the

surface of the water, or just above it, are the flowers and leaves,

which are rather like the leaves of an ordinary buttercup. Follow the

stem a little way down under the water, and you will see that the

leaves are no longer simple, but are split up into many hair-like

divisions, which sway about easily with the water’s movements. These

two kinds of leaves are each suited to their position, as you will see

if you think about them. The broad, undivided leaves on the top of the

water expose their surface to the sunlight and do as much manufacturing

of starch as possible, while the soft much-divided leaves below the

surface are in keeping with their position, for they allow the current

to pass between their fine divisions instead of pushing them up or

tearing them, as it must do if they had broad, flat surfaces, which

would be overpowered by the strength of the current.

Compare these leaves with those of the water-lily. In the lily you find

no divided leaves, but they all rise to the surface and float there,

spreading their expanded blades on the water. Notice what very long

leaf-stalks they have, sometimes eight or ten feet in length. Think

how absurd the plant would look on dry land, with its short stem and

its huge leaf-stalks, though they are so well suited for floating in

the deep water. In the air the long, soft stalks would flop about on

the ground, as they need some support, but this they get in the water,

which buoys them up and saves them from expending too much material in

the formation of strengthening tissue.

Even those plants which, like the water marestail, can stand up by

themselves some way out of the water, yet have softer stems than most

land-plants, and far fewer well-developed “water-pipe” cells, because

they are so surrounded by water that they can get it easily. Both these

plants and the water-lilies, as well as many others, store air rather

than water in their stems, and often the spaces in the meshes of the

stem-tissue are filled with air, which acts both as an air reservoir

and a buoy to float the leaves. We find all through the plant-world

that the structure of a plant depends very much on the kind of

conditions under which it is living, and in the case of those growing

in the water, it is quite clear how the soft, air-filled stems are one

result of their mode of life, and are well adapted to it.

[Illustration: Fig. 142. Duckweed, with simple leaves, and long roots

hanging in the water.]

In the ponds you will often find that the duckweed grows in large

masses on the surface. Each plant seems to consist of but one leaf

and a slender root about an inch long, hanging freely in the water.

Sometimes two or more of the leaves are attached and form a little

cluster, but it is exceedingly rare to find the duckweed in flower.

Simple as it is, almost suggesting the algæ rather than the flowering

plants by its general appearance, yet the duckweed is really a

flowering plant. It is, in fact, one of the very tiniest of flowering

plants which are known.

Floating with the duckweed are frequently many fine, thread-like algæ,

sometimes quite free, and sometimes attached to stems or rocks. They

are very delicate, unprotected plants, their whole body consisting of

simple rows of cells. Notice how their feathery tufts cling together in

a close mass when they are taken out of the water; they require its

support and protection to enable them to live.

[Illustration: Fig. 143. Creeping rhizome of the Bulrush, which pushes

out towards the middle of the pond.]

There are many plants growing round the borders of the pond, half in

and half out of the water, such as the reeds and sedges, irises and the

tall marsh buttercups. Watch how these plants gradually grow further

and further in towards the middle of the pond. They advance with their

creeping underground stems (~see~ fig. 143), and collect mud, dead

leaves, and stalks around them, gradually building up a little firm

soil round their roots. Slowly these accumulations from different

plants meet, and the whole gets more compact, till the plants from the

shore which require soil are able to grow with them.

[Illustration: Fig. 144. A water channel grown over by floating plants

and the advancing reeds and rushes.]

In this way the shore slowly advances, the floating plants first

building up some mud, and the reeds following and bringing shore

plants in their train, till in the end the edges of the pond all meet

in the middle, and the pond, as such, no longer exists. Only a marsh

remains, till this may be gradually grown over by the ever-increasing

land-plants, and an oak-tree may grow where once the water-lilies

bloomed. If the advancing reeds at the edge had been kept cut back, as

they often are, then the land-plants could not have taken such hold,

and the pond would have remained a pond with all its “water-weeds.”

[Illustration: PLATE VI.

LOOKING DOWN ON A SANDY SHORE AND RIVER MOUTH

The long spit of sand-dune A protects the marshy land B from the

strength of the waves, and here many salt-marsh plants grow. C is

the open sea, which at full tide beats on the sandy shore so that no

seaweeds or marsh-plants can grow on this side of the dune.]

CHAPTER XXXI.

ALONG THE SHORE

Sandy shores with dunes are so common round Britain that you will

probably have opportunities of studying them. Did you ever notice with

any care what kind of plants grow on the sand next the sea? As you walk

inland from the sea, you will find first little hummocks of sand with a

few low, bent grasses, scattered and often far apart. Then as you go a

little further inland, the sand mounds are higher, and a stronger grass

grows first in tufts and then thickly over them; this grass is the

useful sand-binder, or marram grass, and grows on the shifting sand,

quite near the sea (~see~ fig. 145). Try to pull up a plant of this

grass, and you will probably find out some of the things which help it

to hold its position in the moving sand. It is not at all easy to pull

up, and you will have to dig rather carefully if you are to get it out

at all complete.

You will find that what you thought was a simple tuft of grass is

really connected, by an underground stem, with other tufts. If you

follow this along, you will find that the underground stem runs for a

long distance, burrowing in the sand and sending up tufts of leaves at

intervals. The tip of the stem always remains under the sand, prepared

to grow in whatever direction is best, and unless it is buried to a

very great depth it will always continue growing. Coming off from the

stem there are very many long roots, and at the places where the leaf

tufts arise there are generally one or two much longer and stronger

than the others, which run a very great distance into the sand, and if

you wish to get them out without breaking them, you may have to dig

for several hours. It is by means of these branching underground stems

and long roots that the marram grass gets its hold on the sand. When

once this grass holds the sand it is soon helped by a number of other

plants, which come on behind it and cover the surface, and so prevent

the wind from scattering the sand-grains, and blowing them about in

clouds.

[Illustration: Fig. 145. A Sand-dune by the sea with the Marram grass

in tufts, and the Carex tufts coming up in straight lines from their

underground stems.]

One of the first plants to follow the marram is the sea-star grass,

or carex. You have probably seen its little tufts following in lines

across bare banks of sand (~see~ fig. 145). This appearance is due

to the underground stem, which runs very great distances in nearly

straight lines, sending up groups of leaves at short intervals as well

as side-stems, which form lines crossing the main line. Often a bank

may be covered with lines of this plant. A little piece of the plant is

shown in fig. 146, where you can see that the structures are on very

much the same plan as those described for the marram grass. There are

many other plants with this kind of habit, which enables them to live

on the sandy shores and dunes. Look at all the plants you can find on

the sand-hills, and you will see that in some way they have their parts

adapted to suit the conditions. Very long roots and a running stem are

the commonest characters, and these you will find on almost every plant

you try to dig up.

[Illustration: Fig. 146. A small piece of the underground stem of

Carex, with tufts of leaves coming above the level of the sand; (~s~)

stem, (~r~) roots (cut off) with small side roots, (~sc.~) scale leaves

underground.]

Sometimes the stem can grow up and up, even though it is continually

buried by the shifting sand, as you can see very well in the case of

the sea holly. You may dig for more than a dozen feet before you come

to the end of the vertical stem of what seemed to be quite a small

plant (~see~ fig. 147).

[Illustration: Fig. 147. Sea Holly, showing the plant at the surface,

and the long stem below the level of the sand (~s~).]

Along the shore are other plants of quite a different kind, which have

also special characters to help them to conquer a region which seems

to be very inaccessible to land plants. Many curious plants live in

the mud-flats that are frequently covered by the tides, and which can

therefore only get salt water. You remember that salt kills ordinary

land-plants, so that these must be specially built to be able to stand

it. Most of them have very thick, fleshy leaves, and rather bushy

stems, while others have leathery leaves covered with a kind of wax, or

with hairs, which make them look grey. Look at the sea-daisy, and you

will see that the leaves are very thick and juicy; so are those of the

sea-blite and salt spurry. The boldest of all these plants, the marsh

samphire, which goes furthest out to sea, and may grow on bare mud

covered by every tide, has not leaves at all, but very thick, fleshy

stems, which are green and do the work of leaves (~see~ fig. 148).

[Illustration: Fig. 148. Marsh Samphire or Glasswort, a plant with

swollen green stems which do the work of leaves.]

All these forms must remind you of the plants which were characteristic

of dry regions; how is it that these plants, often actually growing in

the water, should yet be specialised in the same way? It is because all

the water they get is salt, and it is very difficult for them to live

in it. They can only use a relatively small quantity, otherwise they

would be forced to take in too much salt, so they must prevent their

leaves from transpiring much and using the water up. In this way they

are really in the same kind of position and so require to have the same

kind of leaves as a plant growing where very little water of any kind

is to be had. They are in the same difficulty as the Ancient Mariner,

with “Water, water everywhere, nor any drop to drink.”

Pull up a marsh samphire, and you will see that it has a very much

branched, spreading root, which gives the plant a firm grip on the sand

or mud, but it has not long roots like the sand-dune plants, for all

the water which it can use is to be had quite easily and is near at

hand.

You may notice, too, on these mud flats the mingling of plants from

land and sea. When the marsh samphire and sea-daisy invade the flats

which are covered every day by the tide, they are entering the region

of the sea-plants, and you may find them growing side by side with the

true seaweeds, and even in some cases we may notice the bladderwrack

seaweed further in toward the shore than the samphire, which has

ventured far out to sea.

As you will find in everything in nature, it is always difficult to

draw a fixed line and say that on one side lies one type of thing, and

on the other side something different; so, in dealing with different

“plant associations,” we find that they have their special regions,

but that they tend to cross over any limiting lines set between them.

In deep water and on high, dry land, we find quite different kinds of

plants which never mix with each other, but on the border land between

such regions the boundary is not strictly kept, and we sometimes find

plants growing where we might expect the conditions to be unsuited to

them.

[Illustration: PLATE VII.

BLADDERWRACK GROWING ON THE ROCKS EXPOSED AT LOW TIDE.]

CHAPTER XXXII.

IN THE SEA

All the plants which grow in the sea are hastily grouped together by

most people under the name “seaweeds.” We know that there are many

kinds of seaweeds, and yet even to one who has not studied them, they

do not seem to differ so much from each other as to deserve special

classes. And this general view is quite a correct one, for with very

few exceptions, all the plants which actually live in the sea are algæ,

and so belong to the simplest family of plants (~see~ Chapter XXVII.).

Yet they are not without interest and individuality. In the sea these

simple plants have everything to themselves; and it is there that we

get them developed in a very special way.

You must have noticed that you never find seaweeds actually rooted in

the sand (except in protected marshes, where the sea samphire and some

flowering plants may grow), because sand is always shifting and being

churned up by the waves, so that they cannot get a firm hold. This is

almost the same on the pebbly shores where the stones are rolled over

by the waves, and so would batter any unfortunate plant growing on

them. If you go along a rocky coast at low water, however, you will

find countless true seaweeds, growing so thickly that the rocks are

covered by their slimy masses, while in the rock pools are beautiful

tufts of more delicate seaweeds of all colours (~see~ Plate VII.).

Examine a single plant of bladderwrack or fucus, and pull it up if

you can. You will find that it is very slimy and slips out of your

fingers, and then, that when you have got a firm hold on it, it sticks

so fast to the rocks that it is difficult to get it off without

breaking it. Does this mean that it has roots which go right into the

rock as the roots of land-plants go into the soil? Find a plant growing

on a small stone, if possible, and look closely at it; the “root” does

not go into the stone at all, but is much divided and clasps round it,

bending into every little crevice and sticking tight. Note, too, that

there are no root hairs as there are in land-plants, which is natural

enough when the whole plant is growing in water, and can therefore

absorb it through all its surface. All that is required from the “root”

is that it shall hold firmly on to the rocks and keep the plant from

being dashed on to the shore by the waves. The “root” is not a true

root, but is really only a part of the simple body, which is specially

adapted for attachment.

The many large bladders on the plant are filled with air, as you will

see if you split them open, and they help to buoy it up in the water.

Notice, too, how flat the whole plant is; it is really a single sheet

of tissue or “thallus,” which is much divided, but does not branch in

many directions as a land-plant does. All these characters are those of

the simple family of algæ, to which all the seaweeds belong. Though in

some cases they may form what look like very complicated structures,

yet they are always built upon these simple lines.

Often you may find little plants growing on the bigger ones; sometimes

a well-established weed may be almost covered by small seaweeds of

many kinds, brown, green, or red. These attach themselves to the big

plant in much the same way as they would to a rock, but only use it as

a place of anchorage, and do not tap its food supply, as the parasitic

mistletoe does to the land-plants. In the same way you may find numbers

of seaweeds planted on shells or growing on the backs of crabs.

As the tide goes out it gradually exposes the rocks and pools with

their innumerable inhabitants. Now in the case of those which are first

uncovered, a long time must pass before the water returns, while those

quite near the low water level are only uncovered for a little while.

Follow the falling tide some day, and look for the effect which this

difference (in the time for which they are exposed) has on the plants

growing at different depths.

[Illustration: Fig. 149. The Laminarias, which are only exposed at

quite low water.]

As you go out towards the low water mark you will find first and

commonest the bladderwracks, which get more luxuriant where they are

a little removed from the region of the pounding waves at the actual

shore. Then further out you will find that the bladderwrack gives up

its place to another plant very like it, but with more jagged margins.

Beyond this you will come to the big strap-shaped laminarias, which

never grow where they are very long exposed without water (~see~ fig.

149).

These different regions of seaweeds (some of which are only laid bare

by the tides which go very far out) really depend on the fact that the

different levels of the shore are left exposed for varying lengths of

time according to their depth. If the shore is flat or gently sloping,

then the tide has a very great distance to recede before the same

~depth~ is reached as would be attained much nearer in where the shore

slopes steeply (~see~ fig. 150). This explains how it is that in one

place you may have to walk out a quarter of a mile till you come to the

region of laminarias, while in another you need walk no distance, but

merely clamber down the rather steep rocks to get to it. But as the

actual time taken by the falling tide is the same in both cases, the

plants at any level are left exposed for almost the same time whatever

the kind of shore may be.

[Illustration: Fig. 150. A diagram to show how the slope of the

shore influences the distance the tide goes out, and, therefore, the

distance from high-water mark at which the different seaweeds grow.

A, a gently-sloping shore; B, a steep shore. The line H indicates the

high-tide level, and L the low-tide level.]

One thing that may perhaps puzzle you about the seaweeds is their

colour; some few of them are green, but most are blackish, brown, or

even red. How then do they build their food? It is found that true

chlorophyll is present as well as the other colours, and that though

they hide the green tone from our eyes, they do not hinder its activity

in the plant. You can see that the brown bladderwrack is really a green

plant if you soak some of its tissues in hot water; the brown colour

will be washed out and will leave the plant bright green. In almost

all cases these simple algæ living in the sea are self-supporting

plants, which have adapted themselves to the special conditions in the

depths of the sea where no flowering plants can live, and there they

reign supreme.

CHAPTER XXXIII.

PLANTS OF LONG AGO

When we were on the moors we noticed that we may sometimes find plants

being actually turned to stone under our eyes (~see~ p. 156). These are

plants which are living at the present time, but this same thing has

also happened to plants which lived long ago, and which otherwise we

could not see and study, because they are all dead. In those cases in

which they did not decompose in the ordinary way after death, but were

turned to stone, we are sometimes able to find out almost as much about

them as we can about the plants living to-day.

[Illustration: Fig. 151. Plant which was living at the time coal was

made, pressed in a stone and so preserved.]

You must have seen in museums, or even found for yourself in stones,

the remains of leaves and stems of plants which, too, are turned to

stone, but which yet show the shape and form of the plant with great

beauty. If you go to the north of England, where there are many

coal-mines, you will have a good chance of finding pieces of stone

which have been thrown out from the mines as refuse, and which have in

them or on them most beautiful leaves of ferns and other plants. We

know from geologists that these rocks are very old indeed, older than

the valleys and downs of the south of England, yet we can see to-day

what the plants which lived then looked like, because they have been

turned into stone and kept for us in the rocks till the miners dig them

out when digging the coal.

[Illustration: Fig. 152. Fern which was living at the time of the coal,

pressed between sheets of stone.]

But what is coal itself? You know that it is not at all like an

ordinary rock, for it burns as well as wood, and has been found to be

largely made of carbon. Even directly on top of the coal, and sometimes

actually in the coal seams, we find plants preserved, and geologists

and botanists have combined to prove that coal is really entirely

composed of the crushed remains of ancient plants.

You will remember that we found that many of the plants in the peat

bogs did not get decomposed entirely because of the preservative

peaty acids present in the water and soil. Something of the same kind

happened to the plants of the old forests which now form our coal. As

they died they did not entirely decompose, but got pressed tightly

together, all their living juices being squeezed away till little but

the carbon in them remained. These masses of plants gradually sank

beneath the sea, were covered by sandstones and limestones, and were

preserved between the beds of rock, forming masses nearly as firm as

the rocks themselves. These old plants, which to-day act as our fuel,

are really “as old as the hills,” for they were growing in the country

before the hills were made.

[Illustration: Fig. 153. The trunk, A, of a fossil tree turned

into stone, still standing in the position in which it grew. It is

surrounded and covered by the pressed masses of plants (coal) C, fine

mud (shales), O, and sandstones, S. Its roots, R, are still in the

clays, U, in which they grew, which are now hardened to rock.]

As well as the many plants which were preserved in this way, and in

which we can now see little but masses of carbon, there were others

which were preserved in stone, sometimes pressed between the layers of

stone as you press a flower between sheets of blotting-paper, in other

cases turned directly into stone without crushing, so that they show

their complete form, cell by cell. It is from these stone plants that

we learn what the plants of the coal were like. Sometimes we find great

trunks of trees standing petrified together in the positions in which

they were growing, with their roots twining round one another, and

entering the muddy soil on which they lived. Sometimes such tree-stumps

stand up through the coal-beds and rocks which must have been deposited

all round them (~see~ fig. 153). We find also leaves and stems, cones

and seeds, in the stones, till we can build up completely the form

and life history of several of the plants which were then living. But

in all the wealth of material which has been found, no flowers have

ever been discovered. The seeds seem to have belonged to plants of the

pine-tree family, so that these old forests were without any of the

plants which are to-day the most important family of all, that is, the

flowering plants. They lived so long ago that flowers had not come into

existence by that time.

Another strange thing about these forests is, that although there were

great trees in them, they were not like those of our present forests.

To-day our trees are chiefly flowering plants, such as oaks, limes,

and beeches; but the giants of these ancient forests were club-mosses

and horsetails, plants belonging to the fern tribe. Their descendants,

the club-mosses and horsetails growing now, have degenerated, and are

humble plants not more than a few feet high at the most, and always of

little real importance in the landscape.

The true ferns then living seem to have been more like those of the

present, though perhaps a little larger and more important. In the

family of ferns then living were some with strange histories, and

among the ferns which you may find in the stones some leaves may have

belonged to a plant which was truly a “missing link” in the history of

plants, and helps us to see the relationship between ferns and pines.

Many and strange are the tales the fossil plants can tell us of the

life in the forests when the coal was made, and just as, in the moors,

only those moss-plants which were turned to stone will still be there

after centuries have gone by, so it was in the old coal-forests that

only the plants which were turned to stone remain to tell us their

story to-day. For this reason our knowledge of the forests of long ago

is not complete; but even now it is enough to tell us something of

the life of the plants which were then doing the food-building work

of the world. Though the individual plants were so different, the

“associations” were in a general way the same as those now living.

Great trees reared their heads into the air, and below them, or

climbing round and over them, the smaller plants found place long ago

as they do to-day.

CHAPTER XXXIV.

PHYSICAL GEOGRAPHY AND PLANTS

If we examine the plants of any district, we find that a number of

outside influences affect them very greatly. The most important of

these are the physical geography and geology of the place. The form

and nature of the rocks and soil, as well as the climate, have a great

effect on the plants growing in any spot.

You can see this in an extreme case if you imagine yourself up in a

balloon looking down on England as on a map. In certain places you see

lakes, that is to say, the rocks and soil are so arranged that they

form a basin and hold the water permanently there. Now in a lake, as

you know, only water-plants will be growing, so that the presence of

a fairly deep and constant lake makes it quite certain what kind of

plants must grow in that spot. Imagine an earthquake or some slower

earth-movement which is strong enough to change the rocks so that

the water all runs away, and the result is that there will be dry

land in the same spot where before was the lake. This will cause the

water-plants to die sooner or later, and land-plants will replace them.

There is continual change in the arrangement of lakes and rivers, hills

and shores, which takes place all around us, but so slowly that we do

not notice it. It is slow, and therefore there is not a sudden killing

off of any one kind of plant, and a rapid incoming of a different

set of plants, but it causes a gradual shifting and moving of the

groups among themselves. Sometimes there may be some swift and sudden

change, as the result of a landslip or volcano, or in a stream or

lake which has been artificially drained, which shows us a very good

object-lesson in plant geography.

The importance of the physical form of any place, however, does not

only lie in the position of its lakes and streams and the size of its

hills. The kind of rock, and nature of the soil covering the rocks, are

very important, as well as the many other details of the land.

In England there are no very high mountains, so that you cannot study

the effect of great heights on plants, but all the same England affords

quite sufficient opportunity for the study of physical geography in its

relation to plant-distribution.

Even in the cultivated fields, where man tries to help the plants to

overcome their surroundings, you will find the influence of the soil

is very largely felt. Ask any farmer about his land, and he may tell

you that a certain one of his fields is specially good for potatoes,

another for barley, or that in a village a few miles away they can grow

splendid crops of strawberries, while his are not worth the planting.

Then think of the different kinds of plants for which the different

counties of England are noted. No one could get the produce of the

cherry orchards and hop-gardens of Kent to grow on the Yorkshire

moors. Nor do we find acres of heather moor on the downs in the

south of England, but instead there is a short turf with many little

flowers which love the chalk and limestone, such as the blue and white

polygala, rock roses, and several small orchids.

Now what is the difference between the north and the south of England?

It is chiefly one of rock and soil. On the Downs in the south you find

a thin coating of brown earth over thick masses of white chalk through

the surface of which the water supply quickly runs, so that we get few

streams or bogs. In the north the hills are built of coarse sandstones,

hard grey limestones, and fine black shales which hold much water, so

that there are many swampy places and innumerable streams and little

waterfalls. Then, again, the land in the north of Kent, which is so

famous for its cherries and hops, is a rich, fine clay, with a muddy

and sandy soil, which centuries ago was the bed of a great river, and

now is the most important factor in making Kent one of the most fertile

parts of England.

If we find that the influence of the physical nature of the land is so

strong even in the case of cultivated plants, which are helped by man’s

knowledge, we shall expect to find that it is still more felt by the

wild plants.

Let us go, for example, to the moors east of Settle, in Yorkshire,

where you find the three kinds of rock, the hard limestone, coarse

sandstone, and soft, black shales. If you walk across the moors, you

will see that the principal plants are heather, bilberry, and several

coarse grasses, which grow in more or less irregular patches. If you

notice the grasses carefully, you will find that they are of several

different kinds, showing varieties in their size, form of leaf, colour,

and so on, and that very frequently the different kinds grow on the

different types of rock beneath them. After a little experience, you

will almost be able to tell what is the nature of the rock on which you

are standing by the appearance of the plants at your feet.

If you live anywhere in the south of England, walk over some part of

the downs till you see below you in the valley a clay-pit or pottery

factory, which shows you that the chalk is no longer under the surface

soil, but that it has been replaced by clay. Walk straight towards this

place, collecting the plants you meet on the way. On the actual downs

you will find many which do not grow near the clay-pit, since they are

special chalk lovers. In the clayey valley it is very likely that you

may find a pond; if so, walk towards it, noting all you pass on the

way. As you get to the edge, reeds and bulrushes, water forget-me-not,

tall spikes of water loosestrife, and many others appear which you

would have been astonished to meet with on the downs.

[Illustration: Fig. 154. A recently formed pond in Delamere with a dead

forest tree standing up in the middle.]

A very important factor also is the amount of rain which the district

gets. This tells particularly among the ferns and mosses. Along the

hedgerows of Kent, for example, where it is rather dry, true ferns will

seldom grow, while in Devonshire every hedge and bank has many hundreds

of the common polypody fern and the hartstongue. When we come, however,

to consider on what it is that the rainfall depends we find that it is

the structure, size, and relations of the land masses to the sea and

the winds. In fact, it depends on the physical geography of England as

a whole. So that in the end the plants and the physical nature of any

place are so much in touch that it is almost impossible to do anything

in the study of plant distribution without considering physical

geography.

[Illustration: Fig. 155. A recently formed pond which has covered a

large area of the forest and killed many of the trees. Notice the dead

trunks standing and lying about, and the rushes growing near the edge,

which would not have been there but for the coming of the water.]

Although the changes in physical geography which made and unmake

continents are slowly acting around us all the time, it is not often

that we can clearly see them taking effect. Photos 154 and 155 are

therefore particularly interesting, for they show one of the processes

at work. Part of a forest is in the actual course of being killed

by the pond which is forming on sinking land. This pond and several

smaller ones of the same kind can be studied in the neighbourhood of

Delamere forest, in Cheshire. Here the under soil gets washed out in

certain places, and the surface earth sinks and forms a hollow in which

water collects. In fig. 154 you see one tree standing in the middle of

the pond. It is dead, and has been killed by the water (you remember

that ordinary plants are drowned by too much water) and in fig. 155

you see a large area entirely covered with water, and the dead trees

standing up through it. This pond is spreading rapidly, and is a good

illustration of the reverse condition from that seen in fig. 144, where

the plants by their growth are filling up a pond. The washing out of

the soil and the collecting of the water in this case was quite beyond

the control of the plants themselves, but they are supremely affected

by it.

CHAPTER XXXV.

PLANT-MAPS

In the last chapter we noticed a few of the many facts which show us

that a close relation exists between the plants and the nature of the

land on which they grow. We may now try to express these facts in a

simple way by making maps of the land according to the plants growing

on it.

There are maps of the whole of England, made by the Government, which

show all the roads and houses, the chief rocks, hills, ponds, and so

on. The geologists have taken these maps and added to them details of

the kinds of rock and soil of which the land is built. If now we take

fresh copies of the “ordnance” maps, as they are called, and put on

them all the plants growing in different associations, we can compare

the resulting “plant-maps” with the land-maps of the geologists, and

I think you will be surprised to find how much the plant-maps and

land-maps correspond.

To do this on a large scale, however, is far too big a piece of work

for one person, or a few people, to attempt. We can only do some small

piece of work on one area which will show how the rest is done, and

yield some interesting details.

Let us suppose, for example, that the moor east of Settle is to be

mapped. First get an ordnance survey map on a large scale--25 inches to

the mile is the best, but the 6 inches to the mile will do. On the map

are marked all the walls, streams, and even some of the bigger trees,

so that it is easy to find on it the exact spot where you are standing.

For working you should cut the sheet up into at least eight pieces, of

regular size and shape, and use one of these at a time in the field.

First get to know the part you are to work on later in a general way,

noting the chief plants and in what way they are associated.

Be careful in working to keep your sheets in regular order, and begin

with the one at the bottom left-hand corner of the whole map. Find

the exact spot on the ground which is represented by the point of the

bottom left-hand corner of your first sheet, and put a white stake

into it at least two feet high; it is better if you add a little red

and white flag, so that you can see it from a distance. Then find each

of the other four corners of your small sheet, measuring the distance

from a wall or tree if need be, and put in each a white stake similar

to that marking the first corner. If your map is on the 25-inch scale,

and you have cut it into sixteen equal pieces, you will find that the

area staked out on the ground represented in one piece is not so large

but that you can see over it, and by walking about within it, get all

the features of the plants growing there mapped out on to your sheet.

In studying the different patches of plants, you will find that, as

a rule, in each there is one important plant which grows in great

numbers, while there are many more scattered and less important species

growing with it. Such patches of plants growing together may be called

~Associations~, and in mapping we only pay attention to the chief of

these. In a patch where cotton-grass is the most conspicuous thing,

there may be also half a dozen small grasses and plants growing with

it, in which case everything but the cotton grass would be ignored in

the mapping, and the association called the “cotton grass” association.

Similarly, a patch where heather is the most important plant would be

called the heather association. Sometimes you may find two or more

plants growing together which seem to share the area between them,

so that it is impossible to tell which is the chief one; in such a

case where, for example, heather and bilberry are apparently equally

important, the association would be described as “heather-bilberry.”

For the sake of reference, lists should be kept of all the plants of

less importance growing in the associations, though they are ignored in

the mapping.

At the beginning it is wise to go over the area and find out roughly

how many chief associations there are in it, and to make out a list of

them. Then choose either a colour or a sign to represent each of them

in the mapping,--a colour will generally be found to be clearer and

more effective in the finished map, though a sign is very useful for

the field-work.

When all these preliminaries are finished, begin the actual mapping

by going very carefully over the different patches in the staked-out

area of one piece of the sheet. From the details already printed in

the ordnance survey map, you will generally be able to find the exact

position of the patches of plant associations (unless they are very

small, when they must be ignored), and you should soon be able from the

help of the given details to fill in the shape of the patches by the

eye. If in any case this is difficult, a 5-foot rule and a string of

20 feet or 30 feet marked out into 5 feet and 1 foot lengths will be

found very useful. From the actual measurements you will then get, it

is easy to find how much will represent them on the map by the simple

sum:--1,760 actual yards are represented by 25 inches on the map, so

that 16, 10, or whatever number of feet you require will be represented

by (25 in. x 10 in.)/(1,760 x 3) or (25 in. x 16 in.)/(1,760 x 3) and

so on.

Do all your field-work in pencil, and take notes in a “field-book” as

you go, so that you will be able to copy out a neat, correct map at

home in which to colour in the associations and outline the patches

with waterproof ink. When one of the sheets is done in this way, stake

out the area for the next, and so on, till you have all the sheets

finished. Then paste them together again on a piece of muslin in their

proper order, and you will have a complete “plant-map” of one definite,

though small, area. This can be easily compared with a geological map

of the same area, though the geological one will be on a rather smaller

scale (best 6 inches to the mile), and you will see how the patches of

plants frequently follow the arrangement of the rocks. This does not

show so clearly on too small an area; the larger the district you can

cover the better.

To work from an ordnance survey map is the easiest way of proceeding,

but if you like to combine the plant study with a little simple survey

work, it is quite possible to make the map from the very beginning.

This is not generally worth the trouble, except in cases where you find

a rich and interesting area which would repay very careful mapping on

a larger scale than the survey have published. For example, it would

be a very good plan to choose some small area, and in it stake out

exactly 100 feet square. Along the sides plant smaller stakes every 20

feet, and map all the details very carefully on to mathematical paper

on the scale of either 5 inches or better, 10 inches to 100 feet. Such

an area would well repay the trouble of repeated mapping at different

times of the year. If you have a series of maps of the exact area every

two months, for example, you will be able to see from them very well

the succession of plants throughout the year, and how the associations

change according to the seasons.

Another thing that should go with the mapping is the plotting out of

“sections” through the irregular land, which will show clearly how

frequently the plants growing on any spot are determined by the level

of the spot and its consequent relation to the water supply. The most

striking case of this kind is that of a section through a pond or

stream and its banks. Unless you have a boat at your service, you will

have to choose a stream where two people can meet across it from the

banks, or else content yourself with going out only as far as you can

wade.

To begin the “section” you should choose a good place where there seems

to be plenty of variety in the plants; then fix a strong stake into the

water as far out as you intend to go, tying on to it a string measured

out into 1-foot divisions. This string should be 20, 30, or more feet

long, according to the kind of edge the pond has, and its other end

should be fastened to a stake also.

[Illustration: Fig. 156. A “section” of the edge of a pond plotted

out on mathematical paper. ~a-b~, the level of the water. A-B, a line

parallel to it, marked by a measured string fastened to stakes, from

which the measurements are taken.]

Take the dry land where ordinary land-plants are growing as your

starting-point, and fasten your string to it, as in (B) fig. 156,

making it level on your stake in the water (A) if possible, so that the

same string can be used to take measurements and levels from.

As you work measure the actual distance ~along~ the string, and the

~depth from~ the string of each variety of plants, and where there

are few, of each individual plant crossed by the string. When you

come to plotting this out on mathematical paper you will require to

reduce the scale by letting two small squares of the paper represent

an actual foot, or whatever seems to be convenient. Then from your

actual measurements you can soon plot out a “section” of the pond,

e.g., in actual measurements the bulrushes were growing 1 foot below

the water surface, that is, 4-1/2 feet below the fixed level, and the

first was 6-2/3 feet distant from the stake in the water. In plotting

you should represent the actual plants by symbols or simple signs, as

is done in the figure, so as to be able to see at a single glance just

how everything was arranged. Note also the level of the surface of the

water, which you may choose as your working level if you prefer it to

the line given by A-B.

From this you will see very clearly how extremely important is the

amount of water in determining what kind of plant is growing in any

given spot.

After having done these small pieces of mapping, other problems will

suggest themselves to you, and you will find that the work of making

maps and plans of the plants is more than repaid by the facts you find

out from the plants themselves, and the insight you get into some of

the rules which guide the plants in their choice of their homes.

CHAPTER XXXVI.

EXCURSIONS AND COLLECTING

When you plan an excursion do not take your collecting tin and a

“Flora” in which to look up the names of all you find, and then imagine

that you are fully prepared for a day’s botanising. It is, of course, a

very useful thing to learn the names of the flowers you find, because

you cannot even speak of a plant if you do not know its name, but the

~mere~ naming is in reality the least interesting and important thing

about them, as you will know if you have followed the study of plants

in the way suggested in this book.

~In arranging an excursion~, or what is far better, a series of

excursions into the country, ~the most important thing to have is

a plan of action~. Do not wander aimlessly in the woods, attracted

from side to side by all that comes in your way; choose rather some

special set of things to collect and study. If there are several of you

together, then each one should have a particular subject about which

to make notes and collections; then afterwards all the members of the

excursion party should meet together and compare their results, and

show each other any interesting specimens obtained.

Each person should be provided with:--A tin collecting-box, a strong

knife or digger, a note-book, pencil, and magnifying-glass, some

string, and a fine knife.

In case you find it difficult to decide on special things to do, here

is a list of a few of the many suitable subjects which may be chosen.

The list is not at all complete, but it may give you a few ideas at the

beginning of your field-work.

1. In the early spring, study particularly all the plants which are

flowering. Dig up complete specimens of all the smaller plants, and

notice how many of them have some special means of storing food

underground through the winter, such as ~bulbs~, ~tubers~, and so on.

This stored food makes it possible for the flowers to bloom before the

leaves have done any work, a thing which would be impossible in the

case of ordinary young plants. Our “early” spring flowers are really

~late~ flowerers, as they bloom on the result of the food made in the

previous year. Make drawings, or press a series of these.

2. Collect buds and opening buds, getting series of scales from the

outer hard ones to the inner developed leaves, and press them.

3. Notice, and make sketches of, the different ways in which leaves are

folded in buds: the fan-like beech, the coiled fern, and so on.

4. Collect seedlings; notice specially those of trees. Study the form

of their earlier leaves, which are generally simpler than the mature

ones.

5. In summer, collect as many forms as possible of full-grown leaves.

Compare and classify them according to their nature and shape: those

which are simple or compound, and then in more detail. Dry and mount a

series of representative ones.

6. Study very particularly flowers in relation to their insect

visitors. For this it is better to remain a long time in one place,

so that it is not so good for a general excursion, but is splendid if

you can get off for an early excursion by yourself, or with one or two

companions.

7. Make collections and lists of all climbing plants, noting by what

means they climb.

8. Keep a list for the whole year of the colours of the flowers as they

come out, noting in general which are the most characteristic for the

different seasons.

9. Collect fruits, and arrange them according to the way they scatter

the seeds.

10. When the leaves are falling, notice where they break away, and

what form of scars they leave. In the case of compound leaves, whether

they fall off whole or in parts.

11. Collect series of plants which are growing together in different

places, e.g., those in a woodland glade, those at the edge of a pond,

those on a sandy hill, and so on. Dry them by pressure between sheets

of paper, and mount them, noting how their forms correspond to their

surroundings.

12. Go to the same spot in a wood in spring, summer, autumn, and

winter; make notes and drawings of what you see each time. In the

spring there will be a carpet of flowers under the bare trees, note

what happens in the summer, and later on.

* * * * *

These suggestions are only a beginning, and special problems will arise

of their own accord in connection with the work you are doing, till you

find that the real excursion becomes the most interesting and important

part of your work. If we go to the plants themselves and ask them

to teach us, they will never fail to give us the chance of learning

lessons of ever-increasing interest.

INDEX

~The roman numbers refer to the pages, and italicised numbers to the

figures~

A

Absorption by roots, 33, ~21~, ~22~

Adventitious roots, 56, ~40~, 57, ~41~

Alcohol, 24

Algæ, 141

Algæ in ditches, 151

Algæ in the sea, 143, ~134~, 173

Ampelopsis, 108, ~105~

Animals eaten by plants, 114

Animals, life of, 3, 7

Anther, 80, 81

Assimilation (~see~ Food building)

Associations of plants, 152, 189

Axil of leaf, 75, ~66~

B

Bacteria, 144

Bean seeds, 8, ~3~, 9, ~4~

Bean seedlings, 10, ~6~, 11, ~7~

Bean seedlings grown in dark, 38, ~27~

Bean seedlings, growth of, 41, ~28~

Beech leaf, 65

Bees and flowers, 119

Bidens, fruits of, 90, ~87~

Bilberry, 154

Bladderwort, 116, ~113~, ~114~

Bladderwrack, 144, ~135~, 173, ~Pl. VII.~

Bog-land, 156

Bracken fern, 133, ~Pl. I.~

Bramble, 63, ~49~

Bread, starch in, 11

Breathing of animals, 6, ~2~

Breathing of plants, 5, ~1~, 96

Breathing pores, 96, ~96~

Broom, 62

Broomrape, 113, ~109~

Buds, 72

Buds of fern, 134, ~127~

Buds of horse chestnut, 72, ~62~, ~63~

Buds, overlapping scales of, 73, ~63~, ~64~

Bud scales, 74, ~65~

Bud scars, 75, ~66~

Buds of sycamore, 75, ~66~

Buds, unfolding of, 72, ~62~

Bulbs, 77, ~68~

Bulrushes, 151, ~138~

Bulrushes, rhizome of, 161, ~143~

Bur, fruit of, 90, ~86~

Buttercup, flower of, 82, ~76~

Buttercup, water-, 159, ~141~

Butterwort, 115, ~112~

C

Cactus, 2, 62, ~48~, 99

Calcium phosphate, 15

Calcium sulphate, 15

Calyx, 79, ~70~

Canadian water-plant, 21, ~13~

Capsule of moss, 139, ~131~

Capsule of poppy, 89, ~85~

Carbon, 19, 23

Carbonic acid gas, 6, 19, 24, 27

Carex, 166, ~146~

Carpel, 82, ~76~, ~77~, ~78~

Carrot, 55, ~38~

Caustic potash, 20, ~12~

Cells, 92, ~91~

Cherry flower, 82, ~78~

Cherry fruit, 88, ~82~

Cherry leaf, 64, ~50~

Cherry leaf arrangement, 69, ~58~

Cherry stipules, 64, ~50~

Chlorophyll, 17, 24, 27

Circulation of water, 28

Climbing plants, 104

Climbing assisted by roots, 106, ~101~

Climbing by tendrils, 107, ~104~, 108, ~105~

Climbing by twining stem, 106, ~102~, 107, ~103~

Clover attacked by dodder, 110, ~106~, ~107~

Club-moss, 137

Coal, 153, 178

Collecting, 194

Colour of petals, 80

Cones of pine, 127, 128, ~123~

“Control plant,” 16

Convolvulus, twining of, 106, ~102~

Cork, 95

Cornflower, 121, ~122~

Cotyledons of bean, 9, ~4~

Cotyledons of pine, 129, 130, ~126~

Cotyledons of rose, 66, ~54~

Cow-wheat, 113

D

Dahlia, roots of, 56, ~39~

Daisy, flower of, 121, ~121~

Dandelion, fruit of, 88, ~83~

Darkness, effect on growth of, 38, ~27~

Dead nettle, 68, ~56~, 149, ~137~

Deserts, 100

Dicotyledons, 126

Distilled water, 15

Ditches, 150

Dodder, 110, ~106~, ~107~

Downs, 183

Duckweed, 151, ~139~, 161

Drowning, of trees, 185, ~154~, ~155~

E

Elder tree, twig of, 96, ~96~

Elodea, 21, ~13~

Embryo, 9

Excursions, 194

Eyebright, 113

F

Ferns, bud of, 134, ~127~

Ferns, family of, 133

Ferns, fossil, 179, ~152~, 181

Ferns, prothallium of, 135, ~129~

Ferns, spore-cases of, 135, ~128~

Ferns, “sporeling” of, 136

Flowers, 78

Flowers in relation to insects, 118

Flowering family, 125

Food-building in leaves, 23

Food materials, 14, 18

Food solutions, 15

Fossils, 179, ~151~

Fossils, tree, 180, ~153~

Foxglove flower, 119, ~117~

Foxglove in hedges, 146, ~Pl. IV.~

Fruits, 86

Fucus, (~see also~ Bladderwrack), 173, ~Pl. VII.~

Fungi, 109

Fungi, spores of, 143

Fungi, structure of, 142, ~133~

G

Goose-grass, leaves of, 69, ~60~

Goose-grass, fruit of, 90, ~87~

Gorse, 102, ~99~

Gorse, flowers of, 119, ~119~

Grass, leaves of 66

Grass, roots of, 54, ~37~

Gravitation, 44

Growth, 40

Growth, direction of, 41, ~29~, 43, ~30~

Growth, region of, 40, ~28~

H

Hairs, 96

Harebell, 78, ~69~

Heather, 154

Hedges, 147, ~Pl. IV.~

Holly, 54, ~36~

Honeysuckle, leaves of, 68, ~57~

Hop, 106

Horse chestnut, buds of, 72, ~62~

Horsetail, leaves of, 69, ~59~

Horsetail, family of, 137

I

Indiarubber tree, leaves of, 31, ~20~

Insects and flowers, 83

Iodine, 11

Iron chloride, 16

Iron, importance of, 17

Ivy, adventitious roots of, 56, ~40~

Ivy, climbing of, 106, ~101~

Ivy as host plant, 112, ~109~

Ivy, leaves of, 65

Ivy, position of leaves of, 37, ~26~

L

Lake or pond-maps, 193

Lamina of leaf, 64, ~50~

Laminarias, 175, ~149~

Larch, branching of, 59, ~44~

Larch, family of, 127

Larch, seed-scales of, 128, ~124~

Larch, tufts of leaves of, 76, ~67~

Leaves, 64

Leaves, arrangement as regards light, 36, ~25~, 37, ~26~

Leaves, arrangement on stem, 68

Leaves, compound, 65, ~51~

Leaves, form of, 64, ~50~

Leaves, “Mosaic,” 37

Leaves, no growth without CO_{2}, 20

Leaves, simple, 64, ~50~

Leaves, veins of, 67, ~55~

Lenticels of, 96, ~96~

Life, signs of, 4

Light, 35

Light from one side, 35, ~23~, 36, ~24~

Light, influence on position of leaves, 36, ~24~, ~25~

Light, influence on size of leaves, 38, ~27~

Light, influence of, in formation of starch in leaves, 24

Lime-tree, stem of, 94, ~95~

Lime-water, 6, ~2~, 20, ~12~

Linear leaves, 66

Liverworts, 140, ~132~

Louse-wort, 113

M

Magnesium sulphate, 15

Maize, seeds of, 10, ~5~

Maize, seedlings of, 10, ~5~, 13, ~8~

Maps of plants, 188

Marram grass (~see~ Sandgrass), 166, ~145~

Mistletoe, 112, ~108~

Monkshood, 119, ~118~

Monocotyledons, 126

Moorland, 153, ~140~, 184

Moss, 138, ~130~

Moss in bogs, 156

Moss, capsule of, 139, ~131~

Moss, spores of, 140

Movement caused by light, 36, ~24~

Movement of minute plants, 48

Movement of sensitive plants, 46, ~33~, ~34~, ~35~

Movement of plants in sleep, 46, ~32~

Movement of tendrils, 45, ~31~

N

Nasturtium, movement of leaves, 36, ~24~

Nasturtium, shape of leaves, 65, ~52~

Nasturtium, twining of petioles, 106, ~103~

Needle leaves, 66, ~53~

Nepenthes, 117, ~115~

Nitrogen, 19

Nucleus of cells, 92, ~91~

Nurse leaves (~see~ Cotyledons)

O

Oak, branching of, 59, ~43~

Orchid, roots of, 57, ~41~

Ovate leaves, 65

Oxygen, 19, 21, ~13~, 22

P

Palm, 57, ~42~

Palmate leaves, 66

Parasites, 109

Pea-flowers, 86, ~80~

Pea-fruits, 87, ~81~

Pea-pod (~see~ Pod)

Pea-tendrils on leaf, 107, ~104~

Pea-tendrils, movement of, 45, ~31~

Peat, 155, 179

Peltate leaves, 65, ~52~

Petals, 80, 121, ~121~, ~122~

Petiole, 64, ~50~

Petiole, twining of, 107, ~103~

Physical geography, 182

Pine-cones, 128, ~123~

Pine-family, 127

Pine-leaf, 66, ~53~

Pine-seeds, 129, ~125~

Pine-seedlings, 129, ~126~

Pitcher plants, 117, ~115~

Plantation of trees, 155

Pod of pea, 87, ~81~

Pollen, 81, 120, 127

Pollination, 83, 118

Pollination, arrangements to ensure cross-, 120, ~120~

Pond-maps, ~see~ Lake

Ponds, 159, ~Pl. V.~ 185, ~154~, ~155~

Poppy, ~Pl. II.~

Poppy capsule, 89, ~85~

Pores giving off water vapour, 31

Pores in stems, 96

Potassium iodide, 11

Potassium nitrate, 15

Potato, starch in, 11

Potato, underground stem of, 61, ~47~

Primrose flower, 80, ~72~, 84, ~79~, 120, ~120~

Prothallium, 135, ~129~, 139

R

Receptacle of flower, 82, ~76~, ~78~

Reeds, 162, ~144~

Rhizome, 61, ~46~, 161, ~143~

Rice, starch in, 11

Roots, adventitious, 56, ~40~, 57, ~41~

Roots, entrance of water into, 33, ~21~, ~22~

Roots, forms of, 54

Root-hairs, 13, ~8~, 15, ~9~

Root pressure, 34

Roots of seedlings, 9

Roots, stilt-, 57, ~42~

Roots, storage in, 55, ~38~, 56, ~39~

Roots, uses of, 53

Rose, flowers of, 79, ~70~, ~71~, 118, ~116~

Rose-leaf, 65, ~51~

Rose-seedling, 66, ~54~

Runners of strawberries, 63

Rushes, 162, ~144~

S

Salts, 14, 17, 27

Sandgrass (~see~ Marram), 102, ~100~, 165, ~145~

Sea, 174

Sea holly, 168, ~147~

Seaweeds, 143, ~134~, ~135~, 173

Seaweeds, colour in, 176

Section of pond, 192, ~154~

Section of stems, 93, ~92~

Seedlings, bean, 10, ~6~, 40, ~28~, ~29~

Seedlings, grass, 35, ~23~

Seedlings, maize, 10, ~5~, 13, ~8~

Seedlings, pine, 129, ~126~

Seedlings, rose, 66, ~54~

Seeds, 86, 125

Seeds, bean, 8, ~3~, 9, ~4~, 10, ~6~, 91, ~89~

Seeds, dodder, 111

Seeds, larch, 128, ~124~

Seeds, maize, 9, ~5~, 91, ~90~

Seeds, mistletoe, 112

Seeds, pine, 129, ~125~

Sensitive Plant, 47, ~33~, ~34~, ~35~

Sepals, 78, ~69~

Shore, 165, ~Pl. VI.~, 176, ~150~

Skin of leaf, 95

Skin of seed, 9, ~3~

Sleep of plants, 46, ~32~

Sodium chloride, 15

Solomon’s Seal, 61, ~46~

Speedwell, 80, ~73~

Spines of cactus, 62, 99, ~97~

Spines of gorse, 102, ~99~

Spores, 135, 139, 140, 142

Stamens, 80, ~72~, ~73~, 81, ~74~

Starch, 11, 12, 21, 23

Starch formed in leaves by sunlight, 24

Starch stained by iodine, 11

Starch stored underground, 26

Stellaria, 59, ~45~

Stems, 58

Stems bending again to earth, 63, ~49~

Stems, branching of, 59

Stems, breathing pores in, 94, 96, ~96~

Stems, fleshy, 62, ~48~

Stems, sections of, 93, ~92~

Stems, twining, 106, ~102~, 110, ~106~

Stems, underground, 61, ~46~, ~47~

Stigma, 83

Stipules, 64, ~50~, ~51~

Stone-crop, 102, ~98~

Strawberry fruit, 90, ~88~

Strawberry runners, 63

Sundew, 114, ~110~, 115, ~111~

Sunflower, 1, 2

Sunflower stem, 94, ~93~, ~94~

Sunlight, oxygen given off in, 21, ~13~

Sunlight helps to form starch in leaves, 25

Sweet pea flower, 86, ~80~

Sweet pea fruit, 87, ~81~

Sweet pea leaf and tendrils, 45, ~31~, 70, ~61~

Sweet pea seed, 87, ~81~

Sycamore, buds of, 75, ~66~

T

Tendrils, movement of, 45, ~31~

Tendrils part of leaf, 70, 71

Tendrils assist climbing, 107, ~104~, 108, ~105~

Tissues, 93

Toadflax, 148, ~136~

Toadstool, 142, ~133~

Transpiration, 31

Traveller’s Joy, 147

Tree ferns, 133, ~Pl. III.~

Tubers, 61, ~47~

Tulip bulb, 77, ~68~

Tulip carpels, 82, ~77~

Tulip flower, 81, ~75~

Tulip stamens, 81, ~74~

V

Variegated leaves, 26, ~16~

Veins of leaf, 67, ~55~, 95

Vine, 33

Violet, 84, ~79~, 119, ~118~

W

Water, 12, 13

Water, circulation of, in plant, 28, 34

Water, entry into plant by roots, 33, ~21~, ~22~

Water given off by leaves, 28, ~17~, 30, ~18~, ~19~, ~20~

Water, protection against loss of, 99

Water stream in plants, 28, 34

Water vapour, 28, ~17~, 31

Water buttercup, 159, ~141~

Water-lily leaves, 160

Water-lily, section of stem of, 93, ~92~

“Water-pipe” cells, 94, 97

Whorls of leaves, 69, ~59~

Whortleberry, 62

Willow herb, 89, ~84~

Wind, 154

Wood-sorrel, sleep of, 46, ~32~

THE NATURAL HISTORY OF PLANTS

THEIR FORMS, GROWTH, REPRODUCTION, AND DISTRIBUTION

FROM THE GERMAN OF THE LATE ANTON KERNER VON MARILAUN

Professor of Botany in the University of Vienna

TRANSLATED BY F. W. OLIVER, M.A., D.Sc.

Quain Professor of Botany in University College, London

WITH THE ASSISTANCE OF

LADY BUSK, B.Sc., AND MRS. M. F. MACDONALD, B.Sc.

~With about Two Thousand Original Woodcut Illustrations~ In Two

Volumes, cloth, 30s. net

“The best account of the vegetable kingdom for general readers which

has yet been produced.”--=Nature.=

ANCIENT PLANTS

A SIMPLE ACCOUNT OF THE PAST VEGETATION OF THE EARTH AND OF RECENT

IMPORTANT DISCOVERIES IN THAT REALM OF NATURE STUDY

BY MARIE C. STOPES, D.Sc., Ph.D., F.L.S.

Lecturer in Fossil Botany, Manchester University; Author of ~The Study

of Plant Life~

Fully Illustrated. Demy 8vo, 4s. 6d. net

“Dr. Marie Stopes has made a name for herself in this special line.

Anyone who takes an intelligent interest in the subject cannot fail to

be charmed with the pleasant manner in which Dr. Stopes conveys her

information.”--=Athenæum.=

NATURE STUDIES

(PLANT-LIFE)

BY G. F. SCOTT ELLIOT, M.A., B.Sc., F.L.S., F.R.G.S.

Formerly Lecturer in Botany, Glasgow and West of Scotland Technical

College

Author of ~A Naturalist in Mid Africa, Flora of Dumfriesshire~, &c.

Illustrated by Drawings, Photographs, Microscope Specimens, &c. 3s. 6d.

THE SCIENCE OF LIFE AN OUTLINE OF THE HISTORY OF BIOLOGY AND ITS RECENT

ADVANCES

BY J. ARTHUR THOMSON M.A.

Regius Professor of Natural History in the University of Aberdeen

Cloth, 2s. 6d.; bound in Leather for Presentation, 3s. 6d.

A FIRST COURSE IN PRACTICAL BOTANY

BY G. F. SCOTT ELLIOT, M.A., B.Sc., F.L.S., F.R.G.S.

Formerly Lecturer in the Glasgow and West of Scotland Technical College

Crown 8vo, cloth, 3s. 6d.

A combined course of flower-study, experiments, microscope work, and

explanation, with over 150 illustrations.

“We may say at once that this work is one of the best of its kind in

English. The illustrations and diagrams, with which the book abounds,

are of the highest character.”--=Guardian.=

THE STUDENT’S INTRODUCTORY TEXT-BOOK OF SYSTEMATIC BOTANY

BY JOSEPH W. OLIVER

Lately Lecturer in Botany and Geology at the Birmingham Municipal

Technical School

Fifth Edition. Crown 8vo, cloth, 4s. 6d.

“The author has wisely chosen the natural and sensible method of

commencing with the lowest forms of vegetable life, and tracing the

gradual evolution of the plant upwards to its most complicated forms,

and he has further given excellent descriptions of readily accessible

types, so that the student will easily be able to verify for himself

all the more important statements. The book is, moreover, copiously

and well illustrated.... For the student, for whom it is written,

it is calculated to be of great service, and we can most cordially

recommend it.”--=Oxford Magazine.=

ELEMENTARY BOTANY

BY JOSEPH W. OLIVER

~New Edition, revised and enlarged~

BY W. B. GROVE, M.A.

Lecturer in Botany at the Studley Horticultural College and the

Birmingham Municipal Technical School

F’cap 8vo, cloth, 2s.

“Mr. Oliver deals first with general morphology, next with the

anatomy of plants, and then with their physiology. From this point he

proceeds to deal with flowers--their morphology and physiology--and

in the concluding chapters we have the classification and description

treated. The illustrations are very plentiful, and there is a capital

index.”--=Education.=

THE PRINCIPLES OF HORTICULTURE

A SERIES OF PRACTICAL SCIENTIFIC LESSONS

BY WILFRED MARK WEBB, F.L.S.

Lecturer on the Principles of Horticulture under the Surrey County

Council

Illustrated. F’cap 4to, cloth, 2s. net

BLACKIE & SON, LIMITED, 50 OLD BAILEY, LONDON, E.C.

Transcriber's Note

The following apparent errors have been corrected:

p. 17 "(~see~ Chap. VI.)," changed to "(~see~ Chap. VI.)."

p. 40 "actually the case" changed to "actually the case."

p. 61 "adventititious" changed to "adventitious"

p. 84 "B. Primrose" changed to "B, Primrose"

p. 101 "places we do not not need" changed to "places we do not need"

p. 107 "ordinary leaflets" changed to "ordinary leaflets."

p. 142 "stem and leaves" changed to "stem and leaves."

p. 165 "them Did you ever" changed to "them. Did you ever"

p. 197 "Anther, 80, ~81~" changed to "Anther, 80, 81"

p. 198 "179, ~152~ 181" changed to "179, ~152~, 181"

p. 199 "without CO_{2} 20" changed to "without CO_{2}, 20"

p. 200 "twining of petioles, 107" changed to "twining of petioles, 106"

p. 201 "Seeds, maize, 10" changed to "Seeds, maize, 9"

Archaic or inconsistent language has otherwise been kept as printed.