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THE GREAT

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WORLD'S FARM.

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SELINA GAYE

Cornell University

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3 1924

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Cornell University

Library

The original of this book is in
the Cornell University Library.

There are no known copyright restrictions in
the United States on the use of the text.

http:/Awww.archive.org/details/cu31924001115306

THE GREAT WORLD’S FARM

THE

GREAT WORLD’S FARM

SOME ACCOUNT OF NATURE'S CROPS
AND HOW THEY ,ARE GROWN

BY

SELINA GAYE

Author of ‘The World's Li Lumber-. Room, -
‘Coming,’ ete.

WITH A PREFACE BY

G. S. BOULGER, F.LS., F.G.S.
Professor of Botany & Geology in the City of London College

* The world is one vast aes, bringing forth crops of the most
luxuriant and varied kind, century after century, and millennium
after millennium. Yet the face of Nature is nowhere furrowed by
the plough, no harrow disintegrates the clods, no lime and phos-

hates are strewn upo its fields, no visible tillage of the soil

improves the work on ¢he great world’s farm.’
H. Drummonp, “ Tyvopical Africa”

New Dork

THE MACMILLAN COMPANY
LONDON: MACMILLAN & CO., Lrp.

1899

[Att Ricuts REsERVED]

PREFACE

‘By G. S. Boutcer, F.L.S., F.G.S.
Professor of Botany and Geology in the City of London College,

Ir cannot be too often insisted upon that knowledge,
and not ignorance, is the true parent of reverential
wonder. Our appreciation of the beauty of a flower is
-heightened, and not lessened, by the knowledge that
each curve in its outline and each spot of colour on its
petal has a definite utility in the plant-economy. Our
admiration of a landscape is intensified, and not
diminished by the thought that hill and dale owe their
contour to the excavating power of rain and rivers
operating through ages of time, and that the vegeta-
tion which clothes them has definite relations to the
composition of the soil and to the character of the
climate.

It has, therefore, been wisely recognised by all our
modern authorities on the subject of education, that
the study of some of the sciences should occupy an
early and an important place in our school curriculum.
It may be that those universal favourites, the flowers,
which can anywhere be readily obtained, are to be the
subject of study; or the innate love of experiment is
to be fostered and directed in the chemical laboratory;
or, perhaps better still, the physical features of the
world around us, of sky and sea, of mountain and
river, of crystal and pebble, are to be presented, not

vi Preface

as isolated facts, but as the offspring of constant and
universal law.

In the attempt, however, to employ the teaching of
science as a means of education, to develop, that is,
the innate mental faculties of a child, there are several
dangers to which we are exposed: we may, for instance,
make our subject so uninteresting that it becomes an
irksome exercise of patience and memory, and so loses
all its distinctive educational value; or, again, we may
give much useful information, and even teach valuable
lessons of observation, accuracy, and method, but fail
to impart a sense of proportion, to show the inter-
dependence of Nature as a whole, or the relation of
our particular subject of study to as of equal
importance.

Hence arises the great value of a such as the
present, which, while simple enough to be understood
by unscientific readers, and so accurate as to teach
nothing that will afterwards have to be unlearnt, are
also extremely attractive in their selection and mar-
shalling of facts.

A ‘dry book’ may do much mischief, for it may
choke the promising but tender seedlings of curiosity ;
and if, as the proverb says, ‘necessity is the mother
of invention,’ curiosity is certainly the mother of
knowledge. Young people are generally provided by
Nature with a plentiful supply of curiosity. They may
yet, however, be very far from learning the funda-
mental methods of scientific inquiry. Scientific know-
ledge, it has often been explained, differs from other
knowledge only in being accurate and in being syste-
matic; and neither of these mental qualities seems to
come altogether, like Dogberry’s reading and writing,
‘by nature.’ The lesson of how to observe, and how
to discriminate truth from falsehood, is one that we all

Preface vii

have to learn. Scientific observations, too, demand
sustained attention and very generally repetition and
interpretation | by such intellectual processes as com-
parison and Classification. The reasoning faculties,
by which such processes must be performed, require
the guidance of more mature intelligence, not only to
train them but even to bring them into operation at
all. Nor does mental orderliness come more naturally
than attention or discrimination.

We find, then, that we must interest, we must
stimulate the power of observation, and we must elicit
and guide the reasoning faculties. One never-failing
method of effecting these three objects is to bring the
young directly in contact with nature. To pick a
bunch of flowers, to chip fossils from the quarry, to
be shown some of the more conspicuous constellations
on a starry night, or the moon’s surface through a
telescope, is sure to arouse interest, and no competent
teacher need then fail to find lessons that will not only
instruct or impart information, but will also teach the
art of reasoning. So, too, though most of the. leading
truths of physical geography can be illustrated any-
where, we might wish, in order to exhibit to the mind
all the facts upon which those principles are based,
to take the young student on extensive travels in
many climes whilst his mind is still in its most im-
pressionable stage. Failing this, nothing is so likely
to produce a powerful and life-like realization of the
true facts of nature as the word-pictures of eye-
witnesses. For this reason the writer of the present
work seems to have acted wisely in culling, without
pretence of originality, from many of the most accurate
works of travel of modern times, and setting before her
readers in detail the inferences to be drawn from the
facts which she describes.

viil Preface

Readers of more mature years can hardly fail to
find in this volume some facts that are new to them,
some suggestions of a wider interpretation of nature
or of a more accurate perception of its inter-relations,
or some fresh cause for intelligent wonder. If Newton
could look on himself as a boy playing with pebbles
on the shore of the great unexplored ocean of truth,
every student of nature may well recognise that, what-
ever his years, his experience or his learning, he will
remain but a student, and will never have learnt all
that nature has to teach.

In looking upon nature as a great farm, there is,
however, another and a more important lesson than
any teaching of accuracy or of admiration. We read
of steam-ploughs, of hoeing-machines and mechanical
sowing, reaping and threshing machines; but, though
much labour may be replaced by automatic processes,
the controlling intelligence of the farmer co-ordinates
all the operations of the farm to his one end. It is
wisely said that

‘The undevout astronomer is mad,

and Napoleon’s tribute to the Higher Power, when he
asked the sceptical members of his staff ‘Who made
all these ?’ is only the natural testimony of intelligence.
Truly those minds are to be pitied that fail to see
more than the blind operation of mechanical forces
even in the simplest of natural phenomena; but when
these phenomena are studied separately, there is
undoubtedly a danger that we may ‘fail to see the
wood for the trees.” When, however, we contemplate
the marvellous co-ordination of all the forces of nature,
the balance of vegetable and animal life and their
mutual dependence, we must be blind indeed if we
refuse to look ‘thro’ Nature up to Nature’s God.’

CONTENTS

CHAPTER PAGE
PREFACE e ° . . » > Vv

_ EL INTRODUCTORY . . ae , ° ° i
II. PIONEER-LABOURERS .- : ’ e e «6&5
Ill, SOIL-MAKERS . . , ® » 29
IV. SOIL-CARRIERS .o : « e ° e 4!
V. SOIL-BINDERS . : . e e e 50
VI. FIELD-LABOURERS . 1 . e e 60
VII, FIELD-LABOURERS—continued « 2 . « 73
VIII, WATER « ‘ ‘ . ‘ ° * 90
IX. DESERTS . . . . ® e 105
X. ROOTS .« . . . ® . e 124
XI. FOOD FROM THE SOIL. ’ . ‘ + 139
XI], LEAVES AND THEIR WORK . . e » 157
XII. CLIMATE . . . . e . 177
XIV. BLOSSOM AND SEED . ’ . . » 190
XV. THE GOLDEN RULE FOR FLOWERS . ’ » 208

XVI. GUESTS WELCOME AND UNWELCOME., e 2° 227

x - Contents

CHAPTER

XVII. SEED-SCATTERING . .
XVIIT. SEED-CARRIERS . . .
XIX. CHANCES OF LIFE . .

XX. FRIENDS AND FOES.
XXI. NATURE'S MILITIA 5 .
XXII. MAN’S WORK ON THE FARM «

INDEX. ‘ i .

PACE
246

261
277
300
313
337
361

LIST OF ILLUSTRATIONS

ee ee eee eee FP

PAGE

FLOWER VISITED BY A HUMMING BIRD + ~ Frontispiece
SNOWDON : - - - - - - 26
LICHENS ON A ROCK - : - - - - 32
DELTA AT THE HEAD OF THE LAKE OF GENEVA = - 46
MANGROVE SWAMP - - - - - - 54
THE GREAT ANT-BEAR . - - - - 88
BARREL CACTUS AND DESERT VEGETATION IN UTAH - 98
DATE PALM ON THE EDGE OF THE DESERT - 4
SUNDEWS, PITCHER PLANT, AND VENUS’S FLYTRAP - 150
RAFFLESIA ARNOLDI - : - . - - 104
WELCOME GUESTS - - - - - - 216
WINGED AND FEATHERED SEEDS-~ - - « - 256
SEYAL ACACIA AND SPINES - ° - - - 306
ASH STEM BORED BY LARVA OF A BEETLE - - 310
NUTHATCH FEEDING HER YOUNG - - - 320

LONG-EARED OWL BRINGING FIELD-MICE TO HER YOUNG- 334

The Great World’s Farm

INTRODUCTORY

WuaT would the learned writer of the old Eton
geography, of sixty years ago, say to the statement that
the whole earth is one great farm or garden, almost
everywhere covered with vegetation, and ‘bringing
forth crops of the most luxuriant and varied kind’?
This was certainly very far from being his own idea;
for he informed his students that at least one of the
‘quarters’ of the world was little more than ‘a vast
sandy desert.’ |

Such was his description of the great continent of
-- Africa, where, according to him, there was no cultiva-
tion, except in the immediate neighbourhood of a river
or spring, ‘all the rest being one wide tract of utter
desolation ’; and he went on to say: ‘These cultivated
places, appearing like islands or oases in the great
desert, caused some of the ancients to compare the
whole continent to a panther’s skin, dotted, as it were,

I

2 Introductory

with spots of fertility surrounded by a brown and burning
desert.’

As a matter of fact, nothing could ‘more wildly mis-
represent the truth’ than this description; but it was
written before the interior of Africa had been explored,
and the old geographers, feeling, it would seem, obliged
to say something, were very much in the habit of
writing ‘desert’ across those regions of the earth which
were to them ‘unknown.’

These imaginary deserts, which once occupied so
large a space in our maps, are, however, fast shrinking
and dwindling away before the face of the explorer,
until there are few, if any, left. The last so-called
desert in America was that to the west of the United
States, and that vanished some five-and-twenty years
ago, when Mr. Hepworth Dixon said of it: ‘It has
retreated further and further, and has taken its last
stand behind the Missouri, where I faced it, and now I
can assure you that I have been right through the Great
Prairie, and desert there is none. The prairie is the
pasture-land of the world’ —all ready prepared, that is,
to afford an ample livelihood to man’s flocks and herds
as soon as he should choose to make use of it; and
certainly, therefore, no desert, though ‘ owly an Indian
hunting-ground ’!

But still, it may be said, there is a wide difference
between a desert and a farm. If the prairie is not
bare, at least it is uncultivated; and the word ‘farm’
suggests the idea of ploughs and harrows, orderly
crops, sheep and cattle. Very true; but because
nature farms in ways of her own, on a large scale and
without fuss, while man farms in his way on a small
one, and lets all the world know what he is doing, is

Introductory 8

that any reason for denying to nature the name of
‘farmer’?

How much of the earth has man brought under
cultivation? In Europe, where he has done most, the
proportion varies from little more than a twentieth (in
Sweden), to a little more than one-half (in Belgium).
Supposing that he farms, or ‘improves,’ one-tenth of
the land all the world over—and he certainly does not
do more at present—what becomes of the other nine-
tenths? It is not a desert, it does not lie idle; with
but few exceptions, indeed, it is covered with crops of
one sort or another; for the world is a green world,
not a brown one.

But, where crops are grown century after century,
millennium after millennium, no matter whether they
be wild or not, there must needs be tillage, and
that of the most thorough kind, fully deserving
the name of farming, though it may be carried on
without steel ploughs, and so quietly as to escape our
notice.

There are vast pasture-lands here, there are exten-
sive forests there; there are woods, jungles, heaths,
moors, downs, but they have all been planted; and
the soil was prepared in the first instance, and
has been renewed since, by labourers who are not
less truly deserving of the name of labourer than
the ploughman, though they do not work with his
implements.

When Captain, afterwards Sir Francis, Head,
travelled goo miles across the Pampas, he saw to his
surprise, first, 180 miles of the most luxuriant clover
and wild artichokes ; then an unbroken stretch of long:
grass, 450 miles wide, without a weed; and finally,

4 Introductory

growing up to the base of the Cordillera, a grove of
low trees and shrubs.

Man had had no hand in preparing the soil for this
grass and clover, man had neither sown them nor
cared for them in any way; yet there they were, just
as good food for his cattle as if they had been grown
on the most orderly of human farms. Surely, then,
the lands of the Pampas had been ‘farmed’ most
successfully, by one means or another. For the
word ‘farm’ is said to be derived from an Anglo-
Saxon verb which means ‘to supply with food,’ and
certainly, in this sense, the lands which man still
leaves to nature’s labourers have every claim to be
considered as one vast farm; for they grow, many
of them, the most luxuriant crops, and they feed more
live-stock than can be numbered.

Man grows for himself and his live-stock a few
vegetables—about two hundred and fifty species—and

he has adopted, and partly domesticated, about_two

hundred avimals. But on the great natural farm
things are done on a very much grander scale. Here
the species of crops grown number not much less
than a hundred and forty thousand; and the different
species of live-stock amount to some millions.

With so many animals to feed, and so many crops
to grow, nature’s farm-labourers do not allow of
‘deserts’; and wherever there is an unoccupied
surface, they hasten to take possession, and if possible
sow something upon it, if it be but a lichen. They
sow even the little heaps of dust which collect in
sheltered nooks, on the leads of the church-tower, on
walls, in the angles of masonry, and make them bear
at least a blade or two of grass, and often quite a crop

Introductory . 5

of various green things. Generally speaking, it is only
by recent lava-fields, and the loftiest, bleakest peaks of
rock, that these energetic labourers are baffled, and
then it is only for a time.

Over and over again, as Mr. Ball says, he was told
in different parts of the world that such and such a
spot was entirely devoid of vegetation, or, in other
words, a desert, and over and over again he found it to
be quite a mistake. On the so-called ‘bare’ peaks of
the Dolomite Mountains he always found a ‘fair
number’ of plants hidden in cracks and crevices; even
at Suez, on the exposed, burnt-up face of the mountain
Djebel Attakah, he still found something, and in the
northern part of the great Sahara, though vegetation’
was scanty, it was difficult to find many yards together
that were actually bare. -

In fact, Mr. Ball had come to doubt the existence of
‘deserts’ altogether by the time he reached the
‘rainless zone’ of Peru, and was once more told that
he would find no vegetation at all. Certainly this was
more barren than any part of the world which he had
seen yet, except indeed the drifting sands above Cairo;
yet even here there were plants, stunted bushes in the
gullies, and tiny vegetables in the depressions where
the scanty rain rests longest; but they wanted looking
for, as there was scarcely one so much as three inches
high. The labourers had done their best; they had
prepared the soil, and they had sown, but they had
been hindered from growing anything like a luxuriant
crop by want of water. And at one place, Tocopilla,
they had been entirely baffled; for here at last Mr.
Ball found his desert—an altogether barren spot
where hot a single green thing was to be seen, and

6 Introductory

not so much as a lichen was to be discovered, even
‘with the help of a microscope.

But this is quite an exceptional state of things, due
to the extreme rarity of the rain; and such utterly
barren surfaces are not only very few, but very small
compared with the whole extent of the farm-—mere
spots, in fact, in the midst of generally luxuriant
crops.

In most cases the so-called deserts are deserts
only for want of water; the soil has been carefully
made ready, and in the Great Sahara and the deserts
of Egypt it is extremely rich, though at present covered
with sand. What it might be, and how easily it might
be made to ‘blossom like the rose,’ we can to some
extent guess, when we find that the passing showers,
which are all that visit the deserts of Egypt, are
sufficient, scanty as they are, to awaken ‘the green
things on the yellow surface’; though we may well
wonder how the seeds ‘could germinate after months
of exposure to the burning sun.’

And then, again, while it is quite certain that
such vegetation as exists in these regions is grown
entirely by the natural labourers, there seems also
good reason to suppose that man actually does much
to hinder their work.

If, for instance, man and his domestic animals were
banished from the Arabian and African deserts, it is
believed by Mr. Marsh that many parts of them would
soon be covered with forests, and with forests would
come rain, to the enormous benefit of the whole region.
Acacias of several species are constantly being sown,
and they sprout up plentifully around the springs and
winter water-courses, while grasses and shrubs grow

Introductory 7

up under their sheltering shade. But these latter are
mown down as fast as they grow by the hungry cattle
of the Arabs; and even the trees do not escape, for
the goat devours the seedlings whenever it has the
opportunity, and the camel will bite through thorny
branches as thick as the finger, and unfortunately it
has a particular liking for the twigs, leaves and seed-
pods of the Acacia; so that between them, the tree of
the desert has but little chance. If only they were left
undisturbed for a few years these spots would be
covered with groves, which would gradually extend
where now little can grow but the foxglove and
colocynth.

Still, even now, these deserts cannot be called bare,
though their crops are scanty. As we have said before,
the labourers on the great farm do not allow any
surface to be bare, if they can help it, and they work
as if it were their one object to grow as many crops as
possible. The very snow-fields and ice-fields are not
allowed to lie idle, for there is soil even here, and it
must not be wasted.

Dust, meteoric dust from the higher regions beyond
our atmosphere, is constantly falling all over the earth,
to the amount, it is believed, of more than 500,000 tons
every year; and though, being scattered evenly over
the whole surface, it must be spread very thin indeed ;
still, where there is no other minera] matter, as on the
snow and ice-fields of the Arctic régions, it is quite
perceptible, and it is enough for the growth of such
humble vegetables as the ‘Red Snow,’ which in
summer covers the white surface with a flush of rose-
colour many miles in extent. Nor are this and other
similar minute plants grown to no purpose. These

8 Introductory

‘barren fields’ are also part of the great world’s farm,
an outlying part, it is true, where the produce is not
large: but, such as they are, the crops are needed,
for there are glacier-fleas and other live-stock even
here, and these tiny vegetables supply them with
food.

Nature’s labourers are such zealous and thrifty hus-
bandmen that they are always on the watch to occupy
every inch of space where anything can be grown the
moment it is vacated, and even before. They will
overrun our gravel paths, and grow grass in our streets
if allowed, and they will take but a very short time
to convert the most highly cultivated garden into a
wilderness without any trace of a path in it, if it be
given up to them. This is true even in such temperate
climates as our own, but in warmer latitudes the
incessant struggle of the wild crops to invade and
recover the ground which they have lost is still more
marked.

At Par4, in Brazil, for instance, we are told that
every lane, yard, and square is a battle-ground. Even
the roofs and cornices of some of the public buildings
are occupied by plants or small trees, which wave their
feathery heads aloft like flags of triumph in defiance of
the enemy. The city is hemmed in by a wall of tropical
forest, consisting of giant trees, palms, and tangled
creepers, which ever and anon send out skirmishers to
try and effect a lodgment in the enemy’s territory ; and
so well do they succeed where circumstances favour
them,-that a large square, which was cleared and turfed,
but left unguarded, was covered in five years’ time with
a tangled mass of vegetation fifteen feet high, and
denser than the virgin forest.

Introductory 9

For there is no lack of labourers on the great rarm.
They are employed by the million in all parts of it, and
though they are always ready to reclaim any portion
which has been taken from them, they nevertheless
attend impartially to the whole —the small part which
man has taken under his own care, as well as that
which he leaves at present entirely to their manage-
ment.

And a very sorry condition the human farmer’s fields
would be in if they were left to himself alone, in spite
of all his improved modern appliances and scientific
knowledge.

‘It is an easy error to consider that he who has tilled
the ground and sown the seed is the author of his crop.’
And for the most part, perhaps, the farmer realizes but
little of the vast debt which he owes to the unseen,
-. unnoticed, and often abused labourers, who are inces-
santly at work for him.

Of course, he knows very well that he cannot do
without sun and rain, and he will readily allow that
dew, frost and wind are useful, and that at present he
could hardly do without them; but grant him these—
and what are they after all but labourers borrowed
from the larger farm—and surely his improved ploughs
and harrows, and his patent manures, will be able
to manage the rest. In the days when a forked
stick was the best plough, no doubt things were
different, and the farmer was more dependent upon
what the natural labourers were pleased to do for him,
but now !

Well, let him try! There is an island just risen
above the waves here, or there is a stream of cooled
lava there—nice, fresh, virgin surfaces both of them,

10 Introductory

where nature’s husbandmen have not yet been at work,
so that he may keep either to himself, and show what
he can do when he is not interfered with. Let him
try his modern steel plough, driven by steam, too, if
he will, upon either of these.

But there is no soil! Of course not; is the soil put
ready for nature’s labourers? Do they not have to
make it, and out of these, or similar materials? But
one cannot plough the bare rock, even with the help of
steel and steam; and before these can do anything
with it, it must be broken up and crumbled by other
workers, much more humble and feeble in appearance,
most of them absolutely noiseless, some quite invisible,
and yet—far more powerful.

Wonderful things, no doubt, are being done with
machinery, and the time may possibly come when we
shall be able to grind up the rock without too great
expenditure of time. and labour; but even then,
powdered rock is not soil, and will not grow any
crop worthy of the name. It must be mixed as
well as pounded before it can be converted into
fertile soil, such as the farmer will find it worth
his while to cultivate. And who is to mix it? It
will not pay him to attempt the work himself
on any large scale; but it has been done, and is
constantly being done, on all parts of the great natural
farm.

On the whole, then, the farmer will probably find it
best, at least for the present, to accept what has been
done for him, and to cultivate the soil which he finds
ready made.

‘Ready made?’ but doesn’t he still have to plough

Introductory II

it, and harrow it, and manure it? To be sure; but
this is no more than has to be done, and is done, by
the natural husbandmen also all the world over. Crops
cannot be grown year after year, for many years in
succession, without constant labour. For every crop
takes something from the soil, and the loss has to be
made good. The clods must be broken up, too, or the
air and rain cannot enter freely, and the roots cannot
make their way through the soil. And this the farmer
must do as best he can, with his plough and harrow;
but these are at best only clumsy instruments, and they
are not enough by themselves. If the fields were
deserted by the ‘natural ploughmen,’ the worms and
others, the farmer would speedily find that his ploughs
could accomplish only the rough part of the work.
And it is much the same with the harrows; they can-
not do the fine work of the great * natural harrow,’ the
frost, which crumbles the soil grain by grain, till it is
reduced to the condition of dust and ashes, ready for
sowing.

And now surely the farmer may put in his seed and
feel that if only seasonable weather be granted him
he may be quite independent of further help from his
humble fellow-labourers. The ‘if,’ to be sure, is
rather a great and important ‘if,’ and altogether
beyond his own control; but, granted the weather,
may he not go on and prosper ?

Not unless he is prepared to pay a whole army of
boys to keep off marauders; and even then he would
probably find himself worsted in the battle with slugs,
and snails, and grubs, for these creatures have an
especial fondness for seedlings, wild and cultivated.

12 Lnutroductory

We are told, for instance, by the Rev. F. Morris, that
out of 504 grains of rape planted as an experiment,
200 were eaten or injured. And how many even of
these would have escaped if ‘nature’s militia,’ the
army of birds, had withdrawn their services? Very
few, probably, for the farmer has not yet invented any
satisfactory substitute, and if he be wise he will cer-
tainly welcome them in his fields, and be glad that
they do not limit their care to the wild crops of the
farm. :

But when the crop has escaped these serious
perils and dangers, what then? Even then the
farmer will not in many cases have any harvest,
unless nature again comes to his help and lends him a
fresh set of workers different trom any hitherto em-
ployed in his service. This is especially true of the
fruit-farmer and the market-gardener. The orchards
and gardens may be a mass of blossom, but if they
are left to themselves at this critical time there will be
few apples, strawberries or raspberries, and absolutely
no melons or cucumbers, no matter how favourable the
weather may be. And the same holds good with
regard to many another crop. Help is needed if they
are to bring their fruit to maturity, and this help the
grower is, generally speaking, quite unable to give.
That is to say, he may be able to give it here and there
in a few instances, but he would be powerless in an
orchard, and would not be able to afford the time
necessary to do the delicate work required in a single
strawberry bed. Again, therefore, he must look to
Nature’s labourers for assistance.

Take the following example, for instance; In his

Introductory 13

-- garden at Santo Domingo, Nicaragua, Mr. Belt, the
naturalist, sowed some scarlet-runner beans. The soil
was good, and the climate was favourable to bean-life,
and the scarlet-runners grew and flourished, and finally
blossomed abundantly.

But it was finally! for here their career ended.
They did not produce a single bean among them,
simply because the right labourers were not at hand to
give the requisite help.

The garden in which the beans grew had been
recently taken from the forest, by which it was still
surrounded ; and that the labourers in this part of the
farm were not idle was quite evident from the abundant
luxuriance of the vegetation. But it was tropical
vegetation, and as it did not include scarlet-runners,

__ these were in the position of foreigners, whose appeals
for assistance were not understood. It was in vain
they put forth the bright flowers, which were well-
known signals in their native land, and would there
have brought’ them the helpers they needed—no one
noticed them. They were made welcome to the soil,
the rain and the sunshine, and then they were left to
themselves and their master, with the result already
mentioned—no fruit!

And who were the gardeners whose absence proved
to be of such vital importance? Humble bees, only
humble bees! and, indeed, only the particular species
of humble bees which wait upon scarlet-runners.
There were plenty of others, but they did not under-
stand, though very probably they would have come
to do so in the course of a few seasons. As it was,
however, failing these insect labourers, there was

14 Introductory

nothing to be done—nothing to take their place.
Man has not yet discovered any substitute for the
bee.

In the following chapters we shall consider in more
detail the various ways and means by which the work
of the great farm is carried on by the natural labourers;
and also some of the changes made in it by the work
and unconscious influence of man.

II.
PIONEER LABOURERS

No one needs to be told that all living things require
food of one sort or another to keep them alive; but
some people have fancied, even within the last hundred
years, that vegetables had such delicate appetites as to
need nothing but air and pure water for their susten-
ance.

If this were so, then, of course, one sort of soil
would agree with them as well as another; and, in
fact, it would not be wanted at all except as a protec-
tion to their roots, and as a means of fixing them to
one spot and enabling them to stand against the wind.

As a matter of fact, however, no vegetables live upon
a diet of mere air and water.

But then, what of the seaweeds which float about in
the ocean? Are there not vast meadows of weed far
away from soil or even rocks of any kind? Does not
the ocean, moreover, swarm everywhere, from the
Polar regions to the Equator, with microscopic vege-
tables ? and is it not a fact that no seaweeds, not even
those which cling to the rocks, receive any of their
nourishment through their roots, and therefore must
live upon water ?

16 Pioneer Labourers

Quite true that they do not feed by means of their
roots—indeed, no seaweeds possess true roots; and it
is quite true, also, that they live upon what they obtain
from the water, but surely the taste of it is sufficient to
prove that it is not mere water.

There is no such thing as pure, absolutely pure,
water in nature; and sea-water, which is much heavier
than fresh water, contains thirty-five parts of solid
matter in every thousand. The rivers are constantly
pouring into it small quantities of every sort of mineral
substance that can be dissolved, while the sun draws
up from it almost pure water, leaving the salts behind
to accumulate and help to feed the crops of seaweed,
besides providing material for the skeletons of corals
and sponges and the shells and bones of other sea-
creatures.

All plants, then—whether they tower aloft like the
giants of the tropical forest, or send out streamers two
or three hundred feet in length like the Giant Kelp of
the Atlantic Ocean ; whether they are so minute as to
be altogether invisible to the naked eye, and whether
they live in earth or in water—are alike in this, that
they live upon other food besides mere air and
water.

We may easily satisfy ourselves of this by burning a
bit of wood, a few grains of corn, or any other vege-
table matter. When it has burnt as long as there is
anything to burn, and all the gases and water it con-
tained are driven away, a small quantity of ash will
remain, consisting of salts, or compounds of various
metals. The whole amount is usually very small—so
small that we might perhaps be disposed to think it
could not be of any very great consequence.

Proneer Labourers 17

If, for instance, we were to burn a hundred grains of
wheat so thoroughly that nothing but ash remained,
we should find the whole amount of this to be equal to
about two of the grains, or less; while if we were to
take peas or beans, the amount in a hundred of each
would be equal to less than three peas, and less than
four beans.

There would be more in the straw or stems of all
three kinds of plants, but still. the quantity appears so
small that one might doubt its being absolutely essential
if one did not know that it was so.

However, ‘many a mickle makes a muckle,’ and
when we consider, not single plants or a handful of
grain, but a whole crop, the amount of mineral matter
becomes large enough to look important. Thus, while
a pinch or two of dust might represent the entire
amount of ash of all sorts in a single turnip or carrot,
there are, on an average, about 40 pounds of lime alone
in 22 tons of turnips, more in proportion in the carrots,
and very much more in an equal weight of clover.

The mineral substances chiefly taken up by plants
are sulphur, phosphorus, silica, potash, soda, lime, iron,
magnesia, manganese, together with mineral compounds
of the two gases chlorine and fluorine. All these are
contained in the rocks; but the question is, How are
they to be made available—how is the plant to get
hold of them? There is abundance of food, but as
long as it is stored in the rocks it might as well be
locked up so far as most of them are concerned, for
they cannot get at it or make use of it. Of course, we
all know that seeds cannot grow, though they may
sprout, upon a slab of bare stone, even though it may
be rich in the very food they want. The stone must be

2

18 Pioneer Labourers

converted into soil before they can turn it to account ;
and how is this to be accomplished ?

If man had to make his soil from the rocks before
he could grow his crops, he would have to begin with
crowbars and pickaxes, if he did not first resort to
blasting with gunpowder or dynamite, and even then
his progress would be slow and laborious.

Nature usually works in a much more quiet and un-
obtrusive fashion, but there are times when she, too,
has recourse to blasting as a preliminary measure. She
mines the rocks and shatters them by means of the
earthquake, compared with which the power even of
dynamite is insignificant ; and if these rough measures
do but little towards preparing the soil, they unques-
tionably make things easier for the army of labourers
who follow.

But it is the noiseless and often invisible workers
who accomplish most, for they are at work, some or
other of them, incessantly during every moment of
every hour, day and night, summer and winter, through-
out the whole year.

Usually the first of the silent labourers to begin work
upon the rocks are also the invisible ones—the gases of
air and water, which wear away the very hardest rocks
by degrees. They are not able to work equally fast
upon all rocks, but where they can be employed, there
the work goes on most rapidly. Those rocks which are
best able to resist them decay more slowly, even though
they be actually softer and yield more readily to such
labourers as wind and rain. In other words, the un-
seen chemical workers produce more effect on the rocks
than do the seen, mechanical workers.

The two gases which do the chief part of the chemical

Pioneer Labourers 19

work are oxygen and carbon dioxide, formerly called
carbonic acid. -Rocks containing much iron are espe-
cially open to the attacks of the one, and those con-
taining lime, potash, soda, to the attacks of the other.
We are all familiar with the fact that iron and steel
become covered with rust if left exposed to the air.
Keys rust if left in their locks, and even polished fire-
irons often rust in the summer, unless they are oiled or
greased and so protected from the air. What happens
in these cases is that the oxygen, always present both
in the air itself and in the watery vapour floating in the
air, lays hold of the metal and combines with it to form
a compound substance—an oxide—which is looser and
softer, and takes up more room than the metal alone.
At first the rust is a mere reddish-brown stain; but as
the oxygen eats deeper and deeper, and more and more
oxide is formed, it swells up unevenly above the sur-
rounding surface, and feels rough to the touch. It is so
soft that it may be partly rubbed off by the finger, and
when the rust is cleaned away there will be scars and
indentations left, showing how much of the metal has
been removed.

Now it would take a much harder blow to break a
piece of iron than it would to shatter a flint ; but if the
two were left exposed to the air, the metal would waste
away long before any impression was made on the stone.

Very many rocks contain iron, as, for instance, the
slates, sandstones, granites, and basalts, some more,
some less, but hardly ever in a pure state. The basalt
of the Giant’s Causeway contains so much iron that,
on those sides which are most exposed to the weather,
it not only looks rusty, but is also softer on the surface
and less compact within, for nature’s labourers do not

20 Pioneer Labourers

generally work singly and alone, but in union one with
the other, and the great ally of oxygen is moisture.

Let us take basalt as an example, and see how this
rock is crumbled into soil. In perfectly dry air, at the
ordinary temperature, oxygen is powerless to do even
so much as tarnish iron in the mass, though it would
have no difficulty in reducing it all to oxide—that is,
rust—if the same mass of iron were exposed to its
action in the form of powder. Fireirons do not rust
in winter, or when in constant use, because the fire
keeps them dry; they do rust when unused in summer,
because natural air is mever perfectly dry, even on
the driest summer day, not even in the midst of the
parching desert.

But, if iron quickly rusts when exposed to the damp
air of such a climate as ours, we all know how much
faster it does so when actually wetted ; and therefore
it is not surprising to find that basaltic and other rocks
containing much iron decay more rapidly on the side
which faces the rainiest quarter. Not that the force
of the rain makes so much impression on them as on
softer rocks, but that the wet enables the oxygen to
work faster. The decay is not confined to the surface,
moreover, for all rocks, even those which are most
close and compact and are called impervious, absorb
some amount of moisture, and this also finds entrance
through the cracks and joints, from which no large
mass of rock is ever entirely free. These joints are es-
pecially well developed in the basalt—an ancient lava—
which, in cooling down from the molten state, has
shrunk and contracted into columns having from three
to nine faces, and measuring from a few inches to
several feet across, The rain, of course, easily finds

Pioneer Labourers a1

its way in between these columns; but patches of wet
and brown stains are also found actually inside the
columns themselves, when these are broken open,
showing that moisture has been sucked up by the
rock.

Now, water in the natural state always contains
some amount of air dissolved in it, and, wherever the
water penetrates, there the oxygen of the air penetrates
also, and lays hold of any iron that comes in its way,
as we see by the stains that it has done in this instance.

The iron of the basalt is not, indeed, pure iron, being
already combined with some amount of oxygen, but it
does not acquire the reddish-brown colour of what we
familiarly call ‘rust’ until it has absorbed as much
oxygen as it can hold. In this condition it is, of
course, heavier, and, as we have seen, softer than
before, and is therefore more easily washed or blown
away from the surface. But it is also more bulky, and
takes up more space than it did before, so that if it
be formed inside the rock where it has not room to
expand, the rock is cracked by it. This, of course,
opens the way for more water and more oxygen to
enter, and so the work proceeds, and the decay goes
deeper and deeper.

We have chosen iron-rust as a sample of the way in
which oxygen works because it is one of which we all
know something, but it must not be forgotten that this
is only one of many oxides formed in the rocks ; and that
whenever oxygen combines with any other substance
in a rock to form an oxide, it makes that substance
take up more room than before, and so the rock is
cracked and crumbled. The other gas, carbon dioxide,
works in a different way, though it also helps the

22 Pioneer Labourers

oxygen to rust iron faster than it could do alone. But
when it works on its own account it is by combining
with such substances as lime, potash, soda and mag-
nesia, which it makes much more soluble than they
were before.

Some rocks are said to be impervious, or ‘ water-
proof,’ but this only means that they allow water to
enter so very slowly that, unless they are actually
soaking in it for some time, hardly any is taken up.
And so, in a similar way, some minerals are called in-
soluble, which again means only that pure water has
very litile effect upon them, dissolves them so very
slowly that it hardly seems to do so at all. For some
effect it has upon every known mineral, unless it be
perhaps upon gold and platinum. But water in nature
is never perfectly pure; how can it be, since it dis-
solves some, though it may be only a very minute
quantity, of everything through, or over, which it
passes? Its dissolving powers are greatly increased,
too, by the addition of carbon dioxide—the gas we are
now speaking of—which is being constantly produced
both in earth and air, by the decay of vegetable matter
in the one, and by the lungs of animals, fires and
furnaces, in the other.

The rain, as it descends from the clouds, washes
down with it some of this gas, and if it comes in con-
tact with such a rock as limestone, soon makes an im-
pression upon it. Chalk, limestone and marble, are all
composed of carbonate of lime, softer or harder, the
lime being already united with a certain quantity of
carbon dioxide. But in this condition it dissolves so
very slowly as to be called insoluble in pure water.
When it comes in contact with the gas, however,

Pioneer Labourers 23

whether in air or water, it takes up double the quantity
it had before, and is converted into a double, or
bi-carbonate, which is easily dissolved and washed
away. Marble slabs which are exposed to the weather
in such a climate as that of Edinburgh are com-
pletely destroyed in this way in less than a hundred
years.

Even rocks which consist only in part of carbonate
of lime are open to the attacks of carbon dioxide. For
instance, there are the sandstones. The grains are
hard enough, being composed of silica, and if they are
cemented together with silica, too, the stone is one of
the most durable that can be found, neither water nor
gases, together or separately, being able to make much
impression upon it. But if the grains are cemented
together by iron oxide, or by carbonate of lime, it is
quite another matter. Oxygen or carbon dioxide may
get to work on the cement, and as that is removed the
grains fall apart and become sand.

Then, again, there are the granites, composed of three
minerals, quartz, mica, and felspar; the first is silica,
like flint, and equally hard, and if the rock consist
mainly of -quartz, as some granites do, it is of course
extremely durable, for, besides resisting the action of
the gases, it also admits very little water. If, on the
other hand, the felspar predominates, the rock is softer,
and water finds an easier entrance; but, besides this,
the felspar—which is clay without the water, and in a
crystallized form—contains either potash or soda, and
often lime as well, and any one of these is easily
attacked and made soluble by union with carbon
dioxide. Once converted into carbonates, or bicar-
bonates, as the case may be, these are easily dissolved

24 Pioneer Labourers

and washed away by the next shower. As for the
single carbonate of potash, it does not need even a
shower to help it, but melts away in the moisture of
the air, as anyone may know who has ever tried to keep
it wrapped in paper.

The carbonates being thus removed, and the clayey
part of the felspar softened and washed away to form
beds of clay elsewhere, the crystals of quartz and mica
must needs fall apart, and so the work of breaking
down the rock goes on.

But nature’s labourers proceed upon the principle
that ‘ union is strength,’ and they so constantly work in
company that it is a difficult matter to apportion the
result of their labours exactly each to each. We have
already seen how water dissolves; we must now look
at it in another capacity, and see how it acts the part
of crowbar and pickaxe, and even at times of dynamite.
A cubic inch of water, when converted into steam,
“occupies just 1,728 times as much space as it did
before, and it expands with such violent force as to
shatter the rocks beneath which it is confined. Such
explosions as this sometimes occur during volcanic
eruptions, water having found its way down through the
earth till it has come into contact with some mass of
molten lava, which has converted it into steam, and
made it a powerful engine of destruction.

But water expands also, though in a less degree,
when it is converted into ice, and it is under this aspect
that we are most familiar with its doings. Ice occupies
only one-fifteenth more space than the water from
which it is formed, and, compared with the expansion
which takes place in the formation of steam, this
increase may sound insignificant. But its effects are

Pioneer Labourers 25

very far indeed from being insignificant the force which
it exerts being simply irresistible.

Water, as we have said, finds entrance everywhere,
more or less, in one way or another, and wherever it
is sufficiently near the surface to freeze, there it has the
effect of a multitude of crowbars and chisels of all sorts
and sizes wielded by an invisible army of workmen. It
widens every crack in which it is formed, prizing up
large masses of rock many tons in weight, loosening
and eventually forcing them off, and also doing finer
work, such as chiselling off splinters and particles of all
sizes, large and small. The immense piles of rubbish
which strew the surface of the glaciers, and consist of
sand, grit, and fragments of all dimensions, are due
mainly to the action of the frost, which in mountain
regions recurs not merely every winter, but every night
throughout the year.

Even in England, where frosts are less frequent, as
well as less severe, and therefore penetrate to a less
depth, the tops of the higher hills are often buried
some feet deep with wreckage of the frost’s making ;
‘only very often we fail to realize what is going on
because the loosened fragments are being constantly
washed away by the rain. In more severe climates the
waste is immense, the hill-tops and mountains being
crowded with great blocks and slabs wedged off by the
frost; and this is the first step towards their being
crumbled into soil. The more water a rock absorbs,
the more easily, of course, it is cracked and splintered
by the frost; and though we may not, many of us, have
much opportunity of observing the work done in this
way upon the rocks, we all know something of glasses
and pipes cracked by the freezing of the water in them.

26 Pioneer Labourers

We may have seen, too, how fence-posts ure sometimes
lifted out of their places, simply by the heaving of the
soil beneath them; the water in the pores of the soil
having frozen and swelled, and forced them up.

But even where there is no rain, and no ice can
therefore be formed in their cracks and crevices, the
rocks themselves feel changes of temperature; and
where these changes are sudden, severe, and often
repeated, no rock is strong enough to stand against
them. The rocks of the Sahara and other similar
regions are crumbled into sand simply by the intense
heat of the day and the sharp frost at night. The one
causes them to expand and the other makes fhem
contract; and between thetwo the outer grains are being
constantly loosened and forced out of their places.

When the ‘Glass Road’ was being made in the
famous Yellowstone Park (Wyoming, U.S.A.), sqme
huge blocks of obsidian, or volcanic glass, were found
to come in the way; and as they were too hard to be
either hewn or drilled, and could therefore not be
blasted, the engineer in charge had large fires lighted
on the top. When the rocks were scorching hot, a
sudden deluge of cold water was poured upon them
from the neighbouring lake, and by these means they
were thoroughly shattered. This is of course a very
extreme instance of the effect produced by changes of
temperature, and such as would seldom, if ever, occur
in nature; but it may serve to show how very real
these effects are.

Of the other ways in which the rocks are broken up,
it will not be needful to say much. We must pass
over with brief mention the work done by sand, set in
motion by wind or water, which cuts and polishes the

Pioneer Labourers 27

very hardest rocks when driven against them by the
former, and, when driven by water, has produced the
great cafions, or narrow gorges some thousands of feet
in depth, with which we are familiar in California.
Nor will it be necessary to dwell upon the hammering,
battering effects of the rains, which are sufficiently
obvious even in our climate, and are of course greatly
intensified in tropical regions.

But a few words must be said about the glaciers,
those frozen rivers, which are among the mightiest of
nature’s grinders. Looking down upon a glacier, and
seeing it strewn with the blocks of stone and vast
heaps of rubbish which have fallen upon it from the
cliffs above, dislodged by the frost, we should be dis-
posed to think it a very rough labourer indeed, merely
engaged in carting away the wreckage made by others.
But this would be a great mistake. A little brawling
stream makes, it is true, far more noise and fuss, and
even more show of work, as it rolls the pebbles over in
the bed which it is perpetually deepening and widen-
ing; but the glacier is a giant mill-stone, pressing
upon the rocks beneath with a power which is simply
irresistible.

Glaciers move on in solemn silence, it may be at the
rate of perhaps only an inch or two in the twenty-four
hours, but they go on steadily and noiselessly, and as
they go, they grind the rocks beneath to a powder so
fine, that when at last it escapes from the glacier-mill
in the stream, which flows out from beneath, it has
been reduced to nothing but mud.

One other grinder, equally mighty and thorough,
but by no means silent, must be mentioned in con-
clusion. This is the volcano, which, besides pouring

28 Pioneer Labourers

forth streams of lava, often buries the surrounding
country many feet deep in the finest dust and ashes,
or in mud, if the eruption be accompanied, as it often
is, by rain.

Such, then, are the principal pioneer-labourers
employed in breaking down the rocks. By the com-
bined efforts of the gases and moisture of the atmo-
sphere, by heat and frost, wind and rain, by rivers and
streams, by glacier and volcano, the rocks are gradually
split up, worn away, and reduced on the surface toa
condition of softness.

In tropical regions, where the air is always moist,
and the rainfall large and violent, some rocks are
decayed and softened to a depth of a hundred or two
hundred feet. In drier climates, the work proceeds
more slowly and to a less depth, the rock beneath
being to some extent protected from the weather by
the looser material above, when this is left to accu-
mulate.

But the labourers which we have been thus briefly
considering are only pioneers. They accomplish only
the rougher work of preparation, and very much
remains to be done before anything that can properly
be called ‘soil’ is ready for the crops.

III.
SOIL-MAKERS

STANDING before some bare expanse of hard rock, we
might well wonder, if we knew nothing of the subject,
how it should ever be converted into a surface fit for
the support of vegetation. There may be vineyards
close by showing that it has been done in other
instances ; but what is to be the first step ?

Ploughs, even steam ploughs, are quite useless here,
and man must wait until the work is done for him, as it
will be, and very thoroughly, too, in the end; but it
will be done deliberately, without hurry or bustle,
and it may take years or centuries. Meanwhile, it is of
no use for him to look with longing eyes upon the
rock; he can’t plough it, and he would be mad to sow
it, for any seed he could sow would be washed or blown
away.

And yet if he were to look closely at the seemingly
bare surface, he might, and in most cases would, find
that it was not altogether bare and barren. He might
need a microscope to show him the truth, but if he
understood what he saw, he would discover that the
rock had been sown.

The pioneer labourers, far from finishing, have
hardly begun their work here, but seed has been

30 Sotl- Makers

scattered in this unlikely place; and if we look at what
has been done in other similar places, we shall see that
it has not been wasted.

Floating about in the air, invisible, but in countless
multitudes, are—what answer to the seeds of other
plants—the spores of those strange forms of vegetation
called lichens, which, except in towns, are to be seen
beautifying every old wall, roof, and tombstone. They
are so light that they cannot settle at all, except when
the air is still, and even then the least breath would
disturb them.

But they are sticky, and this stickiness enables
them to cling. fast even to the bare rock. Once
settled, they begin to grow, and are the first traces
of vegetable life to make their appearance upon recent
streams of lava. They may truly be called ‘traces,’
for the first-comers are nothing more than helpless-
looking stains, or dust, hardly noticeable except by
those on the look-out for them; and one would have
said anything but dangerous to the rock, for they look
not only perfectly inactive, but entirely lifeless.

Just so a stranger to the tropics, newly-arrived,
would see with perfect unconcern a single small ant
making its way across the floor of his room, a helpless
insignificant insect, which he could crush with a
finger. But the native knows better. He could crush
the one, but behind it isa mighty column of ants two or
three hundred yards long coming to take possession of
the house, and there is nothing to be done, as he knows,
but to give it up to them and retreat for thetime. The
ants come and go again when their work is done; but
the lichens come to stay until displaced by other and
more important members of the family, for they are the

Sotl-Makers 31

advance guard of the vegetable host, and their appear-
ance signifies that the fate of the lava surface upon
which they have settled is sealed. Nature has marked
it for her own. She is going to break down the hard,
barren surface sooner or latter, and convert it into a
fertile, productive soil, fit for field or vineyard.

The lava has resisted for some time. For years it
did not even cool, and it has scorched innumerable lichen
spores to death in their attempt to settle upon it. Even
when the surface had cooled there was for a long time
heat enough within to dry all the life out of them ; while
multitudes have found the glossy surface too glossy
even for their powers of clinging, and have been blown
away as fast as they came. There are some streams of
lava which are as glossy now as when they were first
poured forth three or four hundred years ago, and no
lichens have as yet managed to gain.a footing there.
But they are not generally kept so long at bay. They
return to the charge again and again, helped by the
pioneers who have also been at work meantime, and
have gradually roughened the surface a little, or at
least have taken off some of the glossiness; and at
last the spores manage to, settle and fix themselves
so firmly that neither wind nor rain can dislodge
them, and they begin to grow and spread at their
ease.

Then, in spite of what was said in the previous
chapter, these vegetables, at all events, must live on air
and water ?

Not at all! Lichens are very substantial feeders
indeed, and consume more mineral matter in propor-
tion to their size than any other plants.

But if it is locked up, and not available until the rock

32 Sozl-Makers

is crumbled down and softened enough for the roots ta
penetrate into it, how can they get at it?

In one respect lichens are like seaweeds, for they
have no roots through which to take up food. But
they are unlike them in another, for they do feed upon
the rocks; and even these first-comers, the humblest
members of the family, mere stains in appearance,
contrive to make a living wherever they can gain a
footing. Not, of course, that they take up farticles of
stone, but, being all of them strongly acid, they are
able to dissolve it first and then absorb what they
need; and though they are at first so minute as to be
almost microscopic, no rock can resist them.

The ‘stains’ spread and grow and decay, and by
degrees there is formed from their remains a thin film
of soil, in which lichens of a much larger growth are
able to flourish. They are all more or less harsh to
the touch ; and the ashy, steely grays, and rusty browns,
and the brilliant yellow and orange of their colouring
remind one more of minerals than of vegetables, which
is not surprising, considering that often a fifth part of
their substance, and sometimes much more, consists
of solid matter eaten from the rocks.

When the lichens have had possession for a time,
and have prepared the way, they are followed by mosses,
which absorb much moisture from the air and-help to
decay the rock by keeping the surface damp, for, as we
have already seen, where water is there frost and gases
can get to work. The mosses grow and die in their
turn, and their remains, with those of lichens and
loosened particles of rock, as well as the dead bodies
of such minute insects as may have found a dwelling
among them, together form something deserving the

SR

Sozl-Makers es

name of mould, which will support plants of quite
large size. These are followed by dwarf shrubs, whose
roots help on the work more rapidly ; and in a century,
more or less, the stream of lava is usually converted
into soil fit for the planting of vineyards and gardens. ~

Lichens attack not only lava, however, but also
granites, slates, and even hard crystalline quartz-rock,
wherever there is sufficient moisture. No rock is
proof against them; almost any climate suits them,
hot or cold, moist or dry, and they are the last signs of
vegetation to be lost sight of by the mountaineer as he
ascends towards the region of perpetual snow and bare
peaks, whither even they are unable to follow. But
they flourish best and do most work where there is
moisture.

They quickly make their appearance upon any
freshly exposed surface of granite, though we may
often need a microscope for their detection. In one
instance, at least, however, their brilliant colouring and,
what is more unusual, their sweet scent betray them.

The so-called Violet-stone found on the summit of
the Brocken is nothing but bare granite, covered with
a film of what looks like scarlet dust, which smells like
violets, especially on being rubbed. It looks so per-
fectly harmless, that one can hardly believe it possible
it should affect the solid granite in any way. Yet it
does; toa very small extent, indeed, but just sufficiently
to prepare the way for two large brown lichens, which
are the next to make their appearance; and then the
work proceeds more rapidly in the way already
described, until at last tall pine-trees rear their heads,
and find sufficient food and foothold, where but a few
years before there was nothing but a bare surface.

3

34 Sowl-Makers

The pines are much more imposing in appearance,
and look capable of much greater exertion (as they are
in some ways), but they could not have done what the
lichen does; and, but for the lichen, they could never
have grown here at all.

We see, then, that nature makes large use of the
humbler vegetables in preparing the way for the crops
which are eventually to be grown; but it must not be
forgotten that the process of preparation is an exceed-
ingly complicated one, performed, not by one set of
labourers, but by many, all working together.

Even a very scanty covering of vegetation does
something, it is true, to protect the rock below against
the battering of the rain and against changes of
temperature; but, on the other hand, it keeps the rock
damp, and moisture not only dissolves on its own
account, but attracts gases from the atmosphere, which
greatly increase its powers in this respect. Then, too,
the powerful gas, carbon dioxide, is also formed in the
soil itself by the decay of vegetable matter, besides
being given off by living roots, and this greatly enhances
the dissolving power of water.

Lichens, as we have said, are able to eat into the
rock, as oxygen eats into iron, and by similar means,
for both are strongly acid; and on removing lichens
from a stone one sees indentations, similar to those
left on a piece of iron by the removal of rust. But
what is true of lichens is true in a degree of all
plants. The roots of all plants, that is to say, are
acid, though in a less degree, especially the young,
fine, hair-like roots; and if these find their way
through the thin soil to the rock beneath, they eat
into it, leaving a distinct impression of themselves

Sozl-Makers 35

upon it when they are removed. The finest hair will
leave its mark.

The amount of acid contained in a delicate little
rootlet, or even in a lichen, is, of course, very small—
quite insufficient, one would say, for the work it has to
do; and so i¢ is in our hands. That is to say, if we
get from the chemist and apply the self-same acid in
similar quantities, we cannot do with it what the
lichen and other plants do; we cannot make as much
impression upon the rock. For the lichen, though it
may look dead, is alive, and the roots are alive; and
living things, however humble, produce wonderful
effects, such as dead matter never can.

But roots also exert a powerful influence upon the
rocks in another way. A very common method of
breaking up the rocks in use with quarrymen is to
drive into them plugs of very dry wood. These plugs
are then watered, whereupon they swell with such force
as to split even the hardest granite. Roots act ina
similar manner, though less violently ; and by swelling
in every direction, they gradually widen any cracks
into which they have found their way, and actually
wedge off large slices from the sides of hills and cliffs.

In the neighbourhood of Mount Etna people make
the roots of the prickly pear work for them in this way,
for they want to hasten the breaking up of the lava, in
order that they may turn it to account as soon as

possible. The lava cracks as it cools, and in every
crevice that appears they insert a branch of this cactus,
which not only lives, but soon begins to grow, thanks
to the warmth, sunshine, and moisture of the genial
climate. Its roots cannot, of course, penetrate the
lava, but they can and do make their way into every

36 Soil-Makers

crack and cranny within reach, and as they grow and
swell they break up the rock into fragments.

As to what the plant lives upon in the absence of
soil, it must be remembered that often a very little
mineral food is enough for a plant, if only it is able to
make the most of what there is and has plenty of
water; then we must remember, too, that lava is
especially rich in the materials required by plants, and
that water flowing over it, or draining through it,
would certainly dissolve some of these materials and
bring them within reach of the roots, which would
obtain them in this way quite as well as from soil;
and then, finally, the whole cactus family, like the
lichens, are furnished with large quantities of acid,
by which they take up an altogether unusual amount
of mineral matter, and they are apparently able to
take it up, as the lichens do, from the solid sub-
stances, at least, to some extent, for in their native
land, America, they are to be seen growing out of
the rocks. j

Though we may not have had the opportunity of
noticing how roots split the rocks, we are all probably
familiar with the power which they exert on a smaller
scale and upon humbler material. Who that has
* gardened,’ even to the extent of growing a few ferns,
but has some time or other known a pot cracked by
the efforts of the roots to find room when they have
outgrown their domicile ?

But we have now to consider other means by which
nature prepares the soil. Hitherto we have confined
our attention to what is done with the rocks on the
spot, the soil being left where it is made; but this pro-
ceeding is attended by certain disadvantages: the soil

Soil-Makers ey)

rarely attains any great depth, for one thing, as the
rock below is protected more or less from frost ; and
then, again, generally speaking, one kind of rock alone
does not contain all that is necessary to make a really
fertile soil rich in all the various mineral matter re-
quired for luxuriant crops. If we look at those soils
which are acknowledged to be the richest in the world
we shall find that, as a rule, they have been much
mixed. We say,as a rule, because most of the lavas
are rich enough in the minerals which plants require,
and are also so well drained, thanks to the cracks and
fissures within, that they do form most productive soil
when simply crumbled down.

With the granites, however, the case is very
different : they are poor in the necessary minerals to
begin with, and what they do possess is, as we have
seen, dissolved; and in great part washed away.
Granite slopes are poor and sandy, therefore, while
the clay deposited at their feet is too stiff and compact
to be fertile; and nature seems to tell the farmer as
plainly as she can that in most cases he will not find it
worth his while to try and grow wheat either on the
hills or in the dales of a granite district. Of course,
where granite decays on the level, and its various
minerals remain, all crumbled down and mixed to-
gether, it is naturally more fertile than where the best
of them are washed away; and thus we find that
the granite soils of the Scilly Isles are far more pro-
ductive than those of the Scotch hills, and are capable
of bearing good crops of corn, in part, at least, because
less of the potash has been washed away from them.
But some thanks are also due to the more genial
climate, for on the granite highlands of Dartmoor

38 Sotl-Makers

there is no vegetation but heath and coarse grass, and
though one has heard of labourers attempting to culti-
vate portions, and not without some success, it is im-
possible to say that the soil is naturally adapted for
either field or garden crops. The moor is flat enough,
indeed, to prevent the separation of the sand and clay,
and such minerals as the granite possesses are fairly
enough mixed without much loss by washing; but the
natural poverty of the rock is aggravated by its elevated
situation on the one hand, and by the shallowness of
the soil on the other, and the soil therefore labours
under the two great disadvantages of a cold climate
and want of drainage. To the latter of these are due
the many bogs which abound, not only on Dartmoor,
but on the granites of Scotland, and the serpentine
rocks of the Lizard as well—everywhere, in fact, where
the soil lacks depth and the underlying rock is so close
and compact that water collects on the surface instead
of draining through.

These moorlands and bog-lands are accordingly-
dubbed ‘ waste’ by those who look at them only with
the eye of the farmer, and are reckoned among the
twenty odd million of uncultivated acres in Great
Britain, thirteen million of which are pronounced alto-
gether irreclaimable.

Waste lands! because the farmer cannot profitably
bring them under his plough and harrow! as if that
were the only end for which soil could possibly be
wanted, and as if man and his domestic animals were
the only creatures requiring to be fed. Waste lands!
where grouse and black game feed upon the heath
buds, where bog and moor are the summer haunt of
curlew and plover, not to mention the countless other

Sowl-Makers 39

feathered fowls, not classed as ‘ game,’ which yet form
part of the live stock for which nature grows the varied
crops of the ‘ great farm.’

The soil of the chalk-downs is like that of the granite
table-lands in one respect, that it is derived chiefly
from the rock beneath, and has had little advantage of
intermixture with others; but—and this makes a vast
difference—the underlying chalk absorbs water readily,
like a sponge, so that bogs have no chance of forming.
The downs grow excellent pasture, and are especially
adapted for sheep-farming; but if people will plough
up the soft fine herbage of nature’s providing and try
to grow corn and turnips instead, they must not be
surprised if they get poor crops in return for much
labour. The soil wants mixing before they can be
grown to much purpose; and since the other minerals
necessary are not upon the spot, the farmer must fetch
them from a distance before he can grow a satisfactory
crop—and this is expensive.

But nature has labourers at her command who can
do what the farmer can never accomplish, no matter
what his wealth and appliances. Nature’s soil has been
transported wholesale, not once only, but over and over
again, and has become so much mixed in the process
that no soil is absolutely pure, even though it be pro-
duced by the crumbling down of one kind of rock only.
For every rock that meets our eyes was formed from
others more ancient still.

Most of the richest soils of the world have been
mixed, either by the work of rivers, or by that of other
labourers to be considered by-and-by. And besides
being mixed, they have in many cases been transported’
from situations where they were comparatively useless,

‘40 Sotl-Makers

to others where their good qualities can be turned to
the best account.

The richest soil in the world is of little use on a lofty
mountain-top, for none but lowly plants can stand the
cold and exposure, and anything to be called luxuriant
vegetation is impossible. Take even the case of the
Cheviot Hills. They cannot be called lofty, but their
more elevated parts are too exposed, too bleak, for
successful cultivation, in spite of the rich soil, which
would be invaluable for farming purposes if it could be
transported to a more genial climate. To yield its full
value, this soil must be brought down to a lower level,
and for that we must wait nature’s time. :

But in numberless other instances this is what has
been done. Soil has been brought down from the
mountains, where it must have been comparatively
unproductive; it has been mixed and prepared, and
finally spread out in extensive fields ready made to the
farmer’s hand, in situations where his crops can have
the warmth and moisture which are essential to them.
- It certainly does appear perverse, therefore, that
men should persist in trying to grow crops where they
seem plainly meant to feed their sheep; and that they
should want to plough up moors and deer-forests which
could never make productive fields, when by long and
most elaborate preparation thousands and millions of
acres have been provided which would yield abundant
gharvests with less than half the labour.

IV.
SOIL-CARRIERS

WE have now seen by what means the rocks are
crumbled -down; but in many: cases much besides
crumbling is necessary to convert rock into good soil.
On a bleak hill-top the crumbled materials will be of
little use owing to the climate, though they may be
most valuable when brought down to the lowlands.
But, more than this, nearly all the soils which we look
upon as especially fertile have been made so by being
mixed. We have now to see how this mixing has been
effected, and how the crumbled matter of the rocks has
been transferred from one place to another.

When we consider which are the best corn-producing
regions of the earth, our thoughts naturally turn first to
Egypt, once the granary of the world.

And what is Egypt? ‘The gift of the Nile,’ as the
ancient historian says. The soil which produces such
wonderful-crops has not been produced by the decay
of the rocks upon which it rests, but is a mixture of
soils brought in great part from the lofty mountains of
‘ Abyssinia, hundreds of miles away. The only fertile
tracts in Abyssinia itself are due to the sediment
washed down from these mountains, which are rich in
the minerals most desired by plants, but, like the

42 Sowl-Carriers

Cheviot Hills already mentioned, unproductive, owing
to their height and the consequently severe climate.

The top of this magnificent chain of mountains is a
vast table-land, upon which the rains descend heavily
and incessantly during some three or four months of
the year, the fall being so abundant as to supply five
tremendous mountain-torrents, which rush down the
sides of the mountains with the force of cataracts, and
carry with them enormous quantities of rock, which is
ground up by degrees into the finest mud and poured
into the Nile. The river rises so much in consequence
that it overflows its banks, inundating the plains of
Lower Egypt during four months of the year, and
wherever the flood comes, there it leaves behind it a
thin film of rich mud, which needs but little labour on
man’s part to make it produce most abundant harvests.
So large is the amount of sediment brought down by
the river—which those who like statistics may be inter-
ested to know is about equal in bulk to a solid cube
measuring more than five feet each way transported in
every second—that the river-bed is gradually rising, and
the inundation therefore extends further and further ;
and very, very slowly, but still surely, more of the
desert is being converted into fruitful soil. Left upon
the Abyssinian mountains, the materials of which this
sediment is composed would have had little or no value
—for man’s purposes, at least—but, transported to the
magnificent climate of Egypt, and mixed with other
matter, they form a soil which is the very perfection of
fertility.

The sediment is not all deposited on the land or in the
river-bed, however; much is carried into the Mediter-
ranean, where another delta is being gradually formed,

Sotl-Carriers 43

equal no doubt to the old one in richness, and capable
of bearing crops as abundant, should it ever rise above
the waters. A delta is possible only where there is
little or no tide, or current, to carry the sediment
away.

But it must not be forgotton that something more
has been done than merely to transport this wonderful
soil. It has also undergone much mixing, and con-
sists not only of mud washed from the Abyssinian
mountains but of sand, which is blown into the river
in vast clouds from the desert. The Nile itself, too,
has done a great deal of grinding, and sand- and mud-
making, as well as its tributaries. Sand, driven by
water, will wear away the hardest rock by degrees ;
and by means of the sand which the wind blows into
it, the river has cut its way through the rocks, scoop-
ing out for itself a wide deep bed. The solid mass of
rock thus removed, grain by grain, has also contributed
in no small degree towards the formation of the Great
Delta.

But even this is not all. No soil can be really
fertile, however rich in mineral matter, unless it con-
tain some amount of animal or vegetable matter.
And this, too, has been supplied to the Delta in an
interesting and remarkable way.

Nile-water, like that of all rivers more or less,
contains a vast number of microscopic animals and
vegetables, the lowest and simplest forms of life, which
are not only left behind with the mud, but are killed
in myriads where they come in contact with salt water.
The Mediterranean being a tideless sea, this wholesale
destruction cannot take place except at the mouth of
the river, and for a certain distance beyond it in the

44 Sowl-Carriers

sea. Fresh water being lighter than salt, flows over
the latter at first, before the two mingle; and, as sea-
water abounds in these minute forms of life to a much
greater extent than river-water does, and as fresh
water is as deadly to the one as salt to the other, the
destruction wherever the two come in contact must be
wholesale.

At present it is the delta of the future which chiefly-
benefits; but the present delta was slowly formed in,
like manner under water, and has therefore received
an abundant share of this fertilizing matter in ages
past, some amount of which is also brought and left
with the mud every year.

But where rivers are affected by the tide, there the
salt water flows up under the fresh, for many a mile
above their mouths, carrying with it a living freight,
which must to a large extent perish and be left behind ;
while the microscopic inhabitants of the river-water
are destroyed with equal certainty wherever they come
in contact with that which is salt, or even brackish—
that is, partially salt.

Hence the great fertility of large districts on both
sides of the Thames, at the mouth of the Humber, on
the shores of the Wash and Bristol Channel.

The remarkably productive ‘carses’ of Scotland
owe their fertility to the same apparently insignificant
cause; and the soil of Holland is rich for similar
reasons, having been to a large extent formed by the
Rhine, Meuse, and other rivers.

The whole of Southern Louisiana, with its extensive
cotton and rice-fields, was made in like manner by the
Mississippi, which becomes a deuse yellow torrent
after it is joined by the Missouri, and brings down

Soil-Carriers 45

with it a heavy load of mud, ground from mountains
3,000 miles away, which it has deposited in some
places to a depth of 300 feet.

And so again, on a smaller scale, the low plain at
the head of the Lake of Geneva is formed of mud from
the mountains, which the Rhéne has brought down
and deposited in the lake, adding to it year by year,
until it has risen above the water, and Port Vallais,
which stood on the margin of the lake in Roman times,
now lies a mile and a half inland.

Inundations are caused usually either by excessive
rain, such as that which falls periodically in Abyssinia,
or by the melting of the snow in spring; but passing
mention must here be made of certain inundations
brought about by very different causes, and which,
though on a very much smaller scale than these others,
are yet said to have altered some of the valleys of
North America to a quite incredible extent.

These inundations have been caused by the beaver.
The beaver is retreating further and further before
man; and though it still inhabits the North of Europe
and Asia, it is nowhere now so plentiful as here in
North America, where, also, the effect of its work in
the past may best be observed.

But the beaver once abounded in England and
Wales, and indeed throughout the greater part of
Europe, as the names of many places, such as
Beverley, Beverstone, Biverbike, and many others,
plainly show. What we see of its work in America,
therefore, is probably only a specimen of what it has
done wherever it has been undisturbed. Here, at all
events, thousands of acres of land have been sub-
merged, at one time and another, as the result of its

46 Sol-Carvriers

labours. As is well known, the beaver is in the habit
of building dams; and these are often so solid and
extensive as to stop up the streams and rivers in
which they are constructed, causing them to over-
flow and form shallow lakes.

But local floods were only the first result of its
work; for the streams brought down with them the
usual sediment, which was spread over the inun-
dated surface, gradually raising its level, until the lake
became a marsh covered with marsh-plants. Then,
as the sediment still accumulated, the marsh-plants
by degrees. found the situation too dry for them, and
died off; their places were then taken by grasses, and
the lakes were thus converted into meadow land,
fertile, as river-formed soils usually are, and enriched
by the decay of the marsh plants.

The value of river-mud is abundantly seen in Egypt ;
and in Hungary the broad river Theisz is left uncon-
trolled by dikes in its upper part, because the yearly
spring-floods which lay the whole neighbourhood under
water, though inconvenient, are found to be of such
great benefit to the soil.

Rivers, then, must be reckoned among the most
important makers and carriers of soil. But the wind,
too, does much good service, though also occasional
damage, from man’s point of view, as nature’s labourers
are apt to do, in these disorganized days.

On the Lincolnshire Wolds, for instance, and on the
coast of Norfolk, where the soils are light and sandy,
the whole of the finer portion, as well as the seed sown,
is sometimes altogether blown away by the equinoctial
gales. One field near Cromer was sown three times in
the course of a single spring, and was finally left to

Soil-Carriers 47

itself, all the upper portion of the soil being banked,
like a snow-drift, against the hedge.

But for the hedges the wind would no doubt have
spread the soil fairly over the neighbouring fields. Its
efforts on this occasion were, however, certainly mis-
directed. ;

But when the wind is able to raise dust from the
fields high in the air, as it does at times, it may carry
it great distances—miles, and even hundreds of miles
—and so do real service to the soil elsewhere.

There is naturally most dust in winter and early
spring, when the fields are bare, more or less, and
especially during the dry March winds. Clouds of
dust are raised from ploughed land, and in dry weather
even from grass-land. Large quantities are transferred
in this way from the high lands to the lower.

But dust may be blown uphill as well as down, and
it may be carried over dry sands, or absorbent rocks,
where water would be sucked up so quickly as to be of
no use as a Carrier.

It has been suggested that much of the fertility of
our own land may be due to the east wind, for which
few people have a good word to say. The east wind is
a dry wind, and undoubtedly a dusty wind, as we know
it; but when the climate was colder it must have been
sharper, and drier, and dustier still; and it may well be,
therefore, that it has helped to bring about that mixture
of the soils to which they owe their fertility.

As to the enormous distances which fine dust is often
carried, we have positive proof in the brick-red or
cinnamon-coloured sirocco dust which falls thickly upon
vessels in the Atlantic at certain seasons of the year,
and is carried to Europe as far inland as the Tyrol.

48 Sowl-Carriers

This dust, which is exceedingly fine, has - travelled
thousands of miles on the wings of the wind, the greater
part of it having been borne across the Atlantic from
the banks of the Orinoco and Amazons. Its value as a
fertilizer is recognised by the North American farmers,
who use a similar deposit of ‘flint-earth’ to mix with
some of their heavy soils. Very fertilizing also must be
the volcanic dust, which, being carried high up into the
air, at times probably far above the cloud-region, is
conveyed enormous distances before it finally sinks to
the earth.

The most tremendous volcanic outburst on record is
that of Krakatoa in 1883, when millions of tons of
matter were hurled into the upper air, and dust, to
the depth of two inches, fell a thousand miles off.
The vegetation of the neighbourhood was, of course,
utterly destroyed, being deeply buried in ashes and
pumice-dust; but the great farm is so extensive that
occasional ruin here and there is of little moment
compared with the benefits which follow in the long
run, especially when the ravages made are so quickly
repaired as they sometimes are. In this instance it
took less than five years to cover up the dismal scene
of desolation with a fresh growth of tropical luxuriance.
Just so Vesuvius is said to smother and destroy the
crops in its neighbourhood every eighth year ; but it is
this very fact which makes the soil so wondrously
fertile during the other seven.

However, we are concerned just now chiefly with
the work done by the wind, and must glance at one
curiously interesting sample of it which has been
observed in the valley of the Limagne, in Auvergne.
Here there is no active volcano to furnish dust, and

Sowl-Carriers 49

yet the fields seem to get it—and that, too, without the
drawback of being suffocated every few years. Where
does it come from ?

The wind blows chiefly from the west and south-
west, across the mountain-chain of the Démes. The
air on the western side of the mountains is bright and
clear, but that on the Limagne side is generally slightly
hazy, and the haze seems to consist of fine dust. And
when we inquire about the mountains, we find that
they are extinct volcanoes, and are widely strewn with
volcanic ashes, the relics of ancient eruptions, rich in
‘the minerals which make the most fertile soils, and
just in the condition in which plants can most readily
make use of them.

It seems, therefore, that the inexhaustible fertility of
the Limagne is in great part due to these constant
supplies, which are carried across the country by the
sometimes severe wind, and naturally fall when it sub-
sides, besides being brought down by rain and snow.

The English proverb declares that ‘a peck of March
dust is worth a king’s ransom,’ and there can be no
doubt that the clouds of dust blown upon the fields
from the high-roads are most valuable. So, too, in
spite of all their drawbacks, are the dust-storms which
occur from time to time in certain regions—as, for in-
stance, in Western Iowa, where the air is filled for
days together with dust of the finest description.

Vv.
SOIL-BINDERS

THE materials being ground up, mixed, and in some
cases transported, there are still two important matters
to be attended to before anything strictly to be called
‘soil’ can be formed.

First, these materials have to be bound to the
spot where they have been deposited ; and, secondly,
before they can grow any but poor crops they in
many cases need the addition of animal or vegetable
matter.

Nile-mud, and river-mud in general, already con-
tains some proportion of this, and does not consist of
mineral matter only.

But the first thing is to make the future soil
settle down, since nothing of value can grow in a
wandering sand-drift. The deposits, whatever they
be, need protection against the washing of the rain
and the drying of the wind, which will not only dry
the surface, but blow it away in clouds if it is left
exposed.

Even to this day the plains of Hungary suffer from
dust-storms, though they have long been covered with
vegetation; and we may easily imagine how much

Sotl-Binders 51

worse these must have been when sun and wind had
full play, with nothing tc check them.

It is clear, too, that where sand or volcanic ashes
‘have been brought by the wind, the same wind may
in many instances scatter them again. And where ©
mud has been brought down by a river and deposited
within reach of the tide, there it will be liable to be
washed away, unless some means be taken to fix it to
the spot.

Let us even look, for instance, at a railway embank-
ment. It has been piled by human hands with a
special object, and is a far more solid mass than if it
had been merely blown together; but yet it to some
extent wastes away. Its bare, exposed surface is
washed and wasted by the rain, dried and blown away
by the wind ; for there is nothing to protect it from
either, to begin with. But this state of things does not
last long. There is always plenty of seed floating in
the air, ready to sow itself on any bare space it can
find; so that in two or three years’ time the embank-
ment is overgrown with grass, whose roots are so
matted together that further shifting of the soil is to a
large extent prevented. .

Of course, where seed is sown even before the soil is
made, as we have seen in the case of lichens, there the
mould as it is formed is kept in place and protected,
and is able to deepen undisturbed. But where sand
has been heaped together by the wind, or mud de-
posited on the coast, there something is needed to give
it firmness, or else it will be dispersed again.

The sandhills on the plains of Venezuela, for example,
are still constantly moving to and fro, here to-day and
there to-morrow, except in one district where they

52 Sotl-Binders

have been consolidated into a low range of permanent
hills by a curious grass with tall, cutting, sword-edged
blades, which grows so closely and with such rapidity
that any paths made by travellers are quite covered up
and destroyed by it in a few days. In itself it is of no
use—that is, it cannot be used as fodder for flocks or
herds, though no doubt it affords shelter, and possibly
food, to wild animals; and where it grows, there other
more useful plants have no chance, being simply over-
powered and choked by it.

But then useful grasses and other fodder-plants would
be quite unable to spring up while the sand was shift-
ing about; they could not grow fast enough to stop it
from smothering them. Their turn may come by-and-
by, when generations of this coarse grass have improved
the soil.

The plants which are most useful for this work of

‘binding the soil and giving it its first firmness are those.
which, besides growing quickly, also send out especially
long roots, runners, or underground stems, often mis-
called roots, which are pegged down at frequent in-
tervals by real roots, much in the same way as the
thatcher binds down the straw on the rick-top. The
couch-grass and others have long underground stems
of this sort, as the gardener knows to his sorrow; and
then there are the bindweeds, most appropriately so
named, for they send out long, trailing runners above-
ground, having roots at each joint, which make them
extremely difficult to get rid of when once they have
established themselves in a garden. Their tropical
relatives, the ipomzas—plants of much larger growth,
but bearing similar convolvulus-blossoms of more bril-
liant colour—are among the plants which render most

Sotl-Binders 53

useful service in the Bermudas by stopping the fine
white coral-sand of the coast from invading and bury-
ing the neighbouring gardens.

Plants of the convolvulus family are equally useful
on the coast of Ceylon, where the rivers, flowing
rapidly down from lofty hills, bring with them heavy

-loads of sand and mud. Under ordinary circumstances,
since the Bay of Bengal is not, like the Mediterranean,
a tideless sea, these would be carried away and de-
posited some miles from the coast. But this is pre-
vented by the ocean-currents, which set towards the
island, and not only drive back what the rivers bring
down, but add to them similar loads of their own.
Accordingly, the sand and mud of the rivers, unable to
escape further, are piled up in bars along the shore,
and these, when once begun, rapidly increase in size
until they rise above the water, and form long em-
bankments reaching for many miles, with the river
flowing behind, and occasionally bursting through
them.

These bars, though a mile or two and even more in
width, are not very solid at first, but they are presently
sown with such plants as do not mind salt water, and
the roots soon penetrate and mat together in sucha
way as to prevent the soil being washed away. The
drier sand on the top of the bank is protected from
wind and rain by creeping plants, among which is one
of the great bindweeds already mentioned, which covers
the surface down to the water’s edge, with its long,
trailing branches pegged down at each joint, as already
described.

When the sand has been consolidated and improved
by the growth and decay of these and such-like plants,

84 Sozl-Binders

there follow shrubs and small trees, such as do not
object to the saltness of the soil; and finally, when the
way has been carefully prepared, the once barren
sand-banks are covered with groves of coco-palms.
It is a fact never to be lost sight of, that here, as so
frequently elsewhere, the first all-important work is
done by comparatively feeble instruments; the dust-
like lichen prepares the way for the pine, and the
insignificant salt-worts, and weak-stemmed, creeping
bindweeds make ready for the palm. The pine could
not have found foot-hold or sustenance on the granite,
nor the palm on the sand-bank, but for these indis-
pensable fore-runners.

The mangrove, like the coco-palm, thrives in salt
water, but is unlike it in being able to grow without
any preparation, and itself does much to consolidate
the mud in which it grows. A mangrove-swamp is not,
by all accounts, a delightful place, and is strongly
suggestive of malaria and fever, but it must be regarded
as only a first step towards arresting and cultivating
the mud in many tropical regions.

The mangrove is a low-growing tree with widely-
spreading branches, and is wonderfully adapted by its
peculiarities to the situations in which it grows. It is
found on many tropical coasts, growing between high
and low water-mark, and in river estuaries washed by
the sea during one part of the day, and left exposed
during another. From its branches it sends down
long roots which, on reaching the mud, fix themselves
firmly in it, and become independent trees; and the
seed, which begins to germinate and grow while still in
the fruit and on the bough, also sends out branches
and roots sometimes long enough tn touch the ground,

Sozl-Binders 55

before it falls. The fruit-roots, branch-roots and stems,
together form a tough, closely-woven net-work, in which
the mud of the river is caught and entangled, and
converted into solid, or something like solid, land, very
much more quickly than it would be without their
help.

In Holland, the people have taken a leaf out of
nature’s book, and carefully plant the sea-dikes, on
which the very existence of their land depends, with
the ‘sharp rush,’ whose multitude of roots mat to-
gether near the surface, besides striking deep into the
soil.

The horse-tails, too, which thrive there to such an
extent that we used to import them under the name
of Dutch rushes, have underground stems of extra-
ordinary length, and so much interlaced that they
seem exactly intended to bind the loose soil.

Then there is the sea-sedge, an insignificant little
grass-like plant, but a few inches high, which does not
look capable of much at first sight. But it grows with
marvellous rapidity—always an important advantage
where loose sand is concerned—and it covers extensive
tracts in a very short space of time, sending out, only
just below the surface, long, creeping stems, which are
firmly pinned down by frequent root-fibres.

The growth of the sea-reed is even more remark-
able. It will grow in the very driest soil, and has
been planted in the Hebrides to cure sand-drift. Its
runners are often as much as twenty feet long, and
so tough and strong that they have been used for rope-
making.

Some quite fragile-looking roots are indeed remark-
ably tough, and capable of resisting an immense strain

56 Sozl-Binders

without breaking. The roots of the Lucerne clover
are said to be often as strong as those of an ash-tree,
though, of course, very much finer, and looking much
weaker; and they have at times given unmistakable
proof of their strength, not merely by resisting the
advance of the ploughshare, but by actually break-
ing it.

It is this wonderful tenacity which makes roots so
useful in binding the soil together, and in keeping the
banks of streams and rivers, as well as sea-dikes, from
being seriously undermined.

Qn mountain slopes, too, the roots of trees and
brushwood serve to keep in its place the soil which
must else slip down by its own weight, even if there
were no rain to wash or wind to blow it. And where
people have been so short-sighted as to cut down
mountain forests, there they have had to lament
not merely the ruin, but the actual loss, of the fields
in their vicinity, which have been carried bodily
away.

In some parts of the French Alps half the cultivated
ground has been washed away, owing to the reckless
destruction of the pines; and this is not all, for when
the forests are gone, not only does the soil follow, but
so do the avalanches; or rather they come! plunging
down from the heights above and overwhelming every-
thing in their way. The trees, and the trees only,
were strong enough to resist them.

It is remarkable what a very slight obstacle is often
enough to stop the onward motion of a sand-drift, a
few oleanders, by no means very sturdy shrubs, being
often found sufficient for the purpose in the Bermudas.
A sand-drift cannot, of course, compare with an

Soil-Binders 57

avalanche, but it has also been found possible to stop
formidable snow-drifts by means of rose trees !

In the wide plains of South Hungary, where the
wind has nothing to break its force, the railway lines
are often in winter blocked with snow-drifts, which
there seemed to be no means of preventing, until in
one part the experiment was tried of planting hedges
of Provence roses on each side. The hedges are
of the height of a tall man, and the lines were kept
clear during some exceptionally heavy falls of snow a
few years ago where they were invariably blocked
before.

On the south-west coast of France there is an
extensive sandy region known as the Landes, which at
one time seemed likely to be converted into a veritable
Sahara, and was saved from this fate by nothing else
but the planting of pines. |

It is a sandy region still, and the fine dust arising
from it in windy weather givés it the appearance of
being overhung with clouds. The sand rattles inces-
santly against the carriage-windows as the train
advances southwards; but in the last century the
sand-dunes were always in motion, constantly changing
their places, ebbing and flowing like the tide, but
creeping gradually further and further inland. When
the storm-wind blew from the west it caught up
the sand and scattered it over the adjacent country,
where it fell like volcanic ashes, doing equal damage
and none of the good, for it consists to a large extent
of fine white quartz, the most hopelessly barren sand
there is.

In ancient times this district is said to have been
fairly well covered with oak woods, remains of which

58 Sozl-Binders

are yet to be seen; why, and when, they were destroyed
seems to be unknown, but the results were disastrous
and even alarming. At length, however, the happy
thought came to an engineer named Brémontier, in
1787, that where trees had grown, trees might be
induced to grow again, and the attempt was made,
not with oaks, for they could not have borne the sand,
but with the maritime pine. Over and over again it
was tried and failed, owing to the shiftiness of the sand ;
but at length, by dint of immense perseverance, the
seed was induced to take root, and then the worst of
the battle was over.

The pine-roots spread little by little, entangling the
sand and putting a stop to further rovings; one dune
after another was brought to a standstill, and that
which threatened to become a desert has gradually
been converted into profitable pine-woods, with inter-
mediate stretches of vigorous heather and furze ten feet
high, and here and there a thick growth of hawthorn
and holly.

We may conclude this chapter by mentioning the
curious origin ascribed to certain patches of grass
which occur frequently all over the bison region of
North America. These patches are said to be evidently
due to the bison’s habit of wallowing in the dust, and
were, in fact, the wallowing places of the herd. The
repeated wallowing of a number of animals created
shallow hollows or depressions which the rain converted
into pools, where the water lingered and into which it
drained from the surrounding soil. Even when the
water had drained away the hollows would continue
damp for some time, and grass-seeds falling upon them
would readily spring up. The grass-plants would

Soit- Binders 59

speedily weave a network of roots over the whole,
forming in time a thick mat by which the soil would
be effectually held together and consolidated, and the
bison who wanted a dust bath in future would have to
choose a fresh wallowing place for himself and his
companions. But the soil would have been won for
vegetation, and, once covered with green things, it
would not easily be given up again.

CHAPTER VI.
FIELD-LABOURERS

THE field-labourers, whose work we are going first to
look at, are somewhat rough in their ways, it must be
confessed, and not such as the farmer generally cares
to see at work upon his land. For when he has taken
possession of the beds of soft earth ready prepared for
him, his ploughs and harrows come in very usefully,
and he is of opinion that he can manage the tillage of
his fields himself. ;

Nature, however, has no steel ploughs, and her fields
must be tilled by other means, for they need it as well
as the farmer’s. And her labourers work in all parts
of the farm, giving man a vast amount of help, for
which he is often not as grateful as he might be,.for he
and they do not at present understand one another;
and though he may tame a lion he cannot control a
worm.

But though they may often be troublesome where
man has taken possession, it is to the long-continued
services of some of these natural labourers that he
owes much of the fruitfulness of some of his richest,
lands.

The wonderful fertility of the lands in Manitoba

Field-Labourers 61

for instance, is due, not only to the fineness of the
soil, but to the long ages of undisturbed animal and
vegetable life by which it has been deepened and en-
riched.

Every now and again, perhaps, there has been a
prairie fire, laying waste wide tracts of country, but
leaving a large supply of most valuable ashes behind ;
and of the value of ashes as a manure, the farmers
of Flanders have so high an opinion that they say,
‘He who spends nothing on ashes is sure in the
end to pay double.’ Season by season, too, leaves
have fallen, and annuals have withered and decayed,
adding their remains to those of countless former
generations.

No soil is really fertile, whatever the mineral matter
composing it, unless it also contain some amount of
organic matter—matter derived from organized, living
things, whether animal or vegetable. Organic matter
alone is not enough to make a fertile soil; but with
less than one-half per cent. of organic matter, no
soil can be cultivated to much purpose. Even with
this quantity it will not grow corn of any kind
successfully, but it will grow wild crops with less ;
and these in time add what is required, if they are
let alone for many generations. The Black earth of
Russia, which is jet black when wet and brown
when dry, owes its colour and much of its fertility
to the finely divided and well-mixed vegetable matter
which it contains, the remains of countless genera-
tions of wild plants, which held undisturbed posses-
sion there for ages, but have now made way for their
betters.

All soils contain some amount of organic matter,

62 Field-Labourers

animal or vegetable, but chiefly vegetable ; and this is
true even of such as seem to consist only of sand, clay,
or chalk. For wherever it is possible for a plant to
grow at all, thither something suited to the situation
is sure to find its way. The wild crop may be a very
poor one, perhaps only some coarse, wiry kind of
grass—for there is hardly any soil so poor but that
grass of some kind will grow in it—and when this has
improved the soil a little, other better sorts may
follow.

The Black earth is of a very dark colour even when
dry; but it is not always so easy as in this case to
judge of a soil by its appearance. Sometimes the
organic matter, being only imperfectly decayed, may
be visible enough ; sometimes it may be reduced toa
fine brown powder; in some cases it may.have more
or less entirely lost its colour; and then, again, it
may be so thoroughly decayed as to be even soluble
in water.

Whether visible or not, however, there it surely is in
every soil, in larger or smaller quantities.

But it is the effect of animal life that we are now to
look at. Animals, large and small, benefit the land by
manuring it; but this is so obvious a benefit that we
need not dwell upon it further than to remark that
coprolites—the fossilized droppings and bones of
animals of former ages—and guano, the droppings of
birds, are among the most valuable manures which the
farmer can use, and where they are not to be had upon
the spot he finds it worth his while to bring them from
adistance. When, therefore, we consider the abundant
animal life which for ages occupied many of the lands
now brought under the plough, we can understand one

fueld-Labourers 63

cause of their fertility—they have been regularly
manured for ages.

But besides manuring the land during their lives, the
animals must have left their bones to enrich it also,
whenever they escaped being devoured. Small dead
bodies must have been covered up by leaves, or buried,
as we shall see, either by the castings thrown up by
worms or by the burying beetles, whose office it
especially is to act the part of sexton to the smaller
wild animals.

Burrowing animals have also been especially useful
in more ways than one. In the first place, they have
added to the organic matter of the soil, and, in the
second, to the mineral matter also; and besides this
they have done much to drain the soil, and expose it
to the influences of the sun. and air.

The organic matter which they have added, besides
their own droppings, consists of the materials which
they use to line their nests, principally leaves and
grass, and also the remnants of their food, nuts,
grain, acorns, and sometimes the whole of their winter
stores.

They have added also to the mineral matter of the
soil by helping on the decay of the underlying rocks.
These are seldom at any great depth beneath, for the
loose materials with which they are covered are but as
a film of dust compared with the thickness of the solid
mass. The soil at its very thickest is measured only
by feet, while the solid crust of the earth is measured,
at least, by hundreds of miles; and in most cases the
soil is actually only a few, often a very few, feet
thick.

Burrowing animals often carry their tunnels down

64 Field-Labourers

several feet, and in this way make it easier for the rain
and the air to reach the rock below; and wherever
these penetrate, there, as has been already shown,
decay must surely follow, slowly or rapidly, according
to the nature of the rock. In this way, therefore,
burrowing animals, whether rabbits, ground squirrels,
or even worms, have helped to deepen the soil; and
by the lives and labours of these and similar animals,
long continued, some of the most fertile lands have
been prepared.

We will now look at their work more in detail.
All over the Pampas of South America there are
frequent groups of holes excavated by the bizcacha, a
curious, rabbit-headed animal, as large as a badger ;
and in South America also, but chiefly in the moun-
tain valleys, dwells the bright-eyed, soft-furred little
chinchilla, not much larger than a squirrel, whose
burrows are found together in such large numbers as
to cause almost as much inconvenience as those of the
bizcacha.

In the western regions of North America, from
Mexico to the Arctic Ocean, as well as in the northern -
parts of the Old World, there are a large number of
small animals called by the general name of ‘ ground-
squirrels,’ and resembling tree-squirrels in many
respects, though some of their habits are very dif-
ferent. Like the tree-squirrels, they lay up stores
of food, but, unlike them, they burrow in the ground,
and live together in large villages instead of in
pairs. ;

One of these, the Chipmunk or Hackee, abounds in
parts of North America, where it makes very extensive
excavations, considering its size, which is less than that

fField-Labourers 65

of a tree-squirrel. It has a large nest lined with leaves
and grass; and the storehouses of one burrow have
been found to yield a grand supply of food—a quart of
hazel-nuts, nearly a peck of acorns, two quarts of
buckwheat, and smaller quantities of other vegetable
food.

The Prairie-dog, of the same family, is rather larger,
and something between a squirrel and a marmot in
appearance. Its ‘ villages,’ ‘towns,’ or warrens cover
many square miles, and in some parts are so extremely
numerous as to have undermined extensive tracts of
pasture-land, much to the inconvenience and danger of
horses, not to mention their riders.

The dog-towns, so-called, are ruled by a ‘ big-dog,’
who sits on a mound in front of his burrow, apparently
directing the affairs of the community.

The Gopher, or Canada pouched-rat, too, is to be
found in the Prairie, where it dwells not merely in
thousands, but in hundreds of thousands, and has so
- completely taken, perhaps we should rather say kept,
possession, that in some parts other quadrupeds are
almost excluded. The Gophers extend over hundreds
of thousands of square miles, and have honey-combed
millions of acres. One may indeed ride for days
and even weeks through some districts, finding them
everywhere as plentiful as if the whole district
were one vast warren. If ever the lands should be
settled, the first husbandmen will have a hard fight
for possession with the present owners, whose diligence
in burrowing is wonderful, for they work both night
and day, though they do not go nearly as deep as the
‘dogs.’

The burrows will’ just admit a man’s arm at the

5

66 Field-L abourers

mouth, growing narrower farther down, but they make
up in numbers for what they lack in size. Each Gopher
lives alone in a burrow of its own; there are separate
burrows to hold the winter stores, and large numbers
seem to be made either for temporary refuges, or from
a pure love of digging which can never be satisfied, for
the deserted burrows are many more than can be
accounted for by the size of the colonies.

Other burrowers, better known in the Old World,
are the marmots, which make very large and rather
complicated burrows, and have quite riddled the rocks
in Turkestan, in some parts of which they abound;
and others again of the same great family of rodents,
or ‘gnawers,’ the Gerboas, have honey-combed the
sides of mountains in South Africa, and possess such
strong teeth that in the north they even gnaw through
the thin layer of stone beneath the sand, and thus do
some of the very first work of the pioneer labourers.

Every country, indeed, seems to have its special
burrower or burrowers, and everywhere their work has
similar results, often troublesome enough, where man
has established himself, but doing a useful and im-
portant part of the work of the farm, of which man
reaps the benefit in after years.

In England the field burrower with which we are
most familiar, unpleasantly familiar, too, is the common
mole. No matter where he lives, the mole’s labours are
not anywhere looked at with a friendly eye by farmer
or gardener; and so fierce is the war waged against
him that it is matter for wonder how he has managed
to escape extermination. Mole-catchers boast of having
slain many tens of thousands, one declaring that he
had trapped twelve hundred in six months. Yet still

Freld-Labourers 67

the mole lives on; lives and labours, as some say, in
the service of ungrateful man.

The sins alleged against him are: that he drains the
soil so thoroughly by his network of underground
galleries as to render it dry and barren; that he
damages the crops by uprooting them, and by ex-
posing, destroying, or eating their roots; and, finally,
that he uses such a large quantity of spring corn, as
much as a couple of hundred blades, to make his
bed, that where he abounds one-eighth of the crop is
lost.

These are serious accusations; but the mole is not
without friends, enthusiastic friends even, though pro-
bably not farmers or gardeners, and these declare that
the damage done is slight compared with the service
rendered. The soil is greatly benefited, say they, by
being upturned and lightened ; and they claim that the
mole takes high rank among nature’s field-labourers,
and should be honoured accordingly, not only for his
work as ploughman, but also for his extraordinarily
large and voracious appetite for smaller animals of all
sorts, which do far more injury to the crops than
himself.

It is, however, too much to expect that any gardener
of tidy mind should look favourably upon an animal
which throws up earthworks in the middle of his neat
paths and borders. The mole has occasionally done
even worse damage than this by burrowing through
dams and dikes, thereby causing inundations, which,
though they have their use in fertilizing the soil, are
not generally desirable where man has taken over
nature’s fields, and would prefer to cultivate them in
his own way.

68 Field-Labourers

Putting aside for the present the mole’s services as a
devourer of injurious insects, which are certainly great,
we may perhaps admit that we do not now need him as
ploughman, as we have our own ways of doing his
work. But it would be very rash to say that we could
dispense with him altogether; and even if we could
now, this need not make us overlook the share which he
has had in the past, and in unoccupied lands still has,
in preparing the soil for our use.

Wherever a mole lives the organic matter in the soil
must be continually receiving increase, for it lives
almost entirely on animal food—such as worms, grubs,
insects, as well as mice, dead birds, lizards, frogs; and
as it is extraordinarily voracious, large numbers of these
must be consumed, their remains, digested or riot,
being left in the earth: Large quantities of vegetable
matter are also carried into its nest by. every mole
every year, and there they are, of course, left to decay.
When, therefore, one thinks of the thousands of moles
still existing, and the many more thousands and mil-
lions of past countless generations, every one of which
lives, or lived, the same sort of life, always burrowing,
always feeding, and always making nests year by year,
it is evident that their effect upon the soil—in places
where they are, or have been, plentiful—can certainly
not be small.

Some might like to be rid of them now, though pro-
bably, if they had their will, they would find cause to
regret it; but in unoccupied land the mole has cer-
tainly done much service.

And now we turn to another very different set of
workers, most unlikely ones we should say at first
sight, who are helping to improve and prepare some of

Field-Labourers 69

the limy mud-flats of the East Indian Archipelago.
At present, we believe, their work has been watched
only on the Keeling or Coroz Islands; but what crabs
are doing now crabs may have done, and have most
probably done, in the past, so that some part at least
of the present fertility of other mud-flats, perhaps of
coral islands, may be owing to them.

But what, it may be asked, can crabs do? They
burrow, for one thing; and they make their homes so
close together that as many as a hundred and twenty
of these narrow, corkscrew holes have been counted in
a space only two feet square, so that the ground is very
thoroughly perforated indeed. And they not only
burrow, but are incessantly busy carrying down twigs,
bits of seaweed, scraps of coco-nut shell, seeds, and so
forth, with the object of making themselves comfort-
able, it is to be supposed, and yet it almost seems as if
they laboured, some’ of them, in this industrious way
simply and solely for the sake of improving the soil.

One of these crabs works so near the water that its
burrows are covered at high tide; another works a
little further in, and a third further still, where the mud
is dry; but what is curious about this last is that as
soon as the white, chalky mud has been turned into
dark vegetable soil, which it is bythe decay of the
various things dragged into it—at once the crab goes
off to another fresh spot,.and begins all its work over
again. Perhaps it does not like decayed vegetable
matter; but the result is that it is always at work, and
must get through a good deal of digging in the course
of its life.

Further inland still, the soil is dry and turned up to
the sun and rain by the ‘great coco-nut crab,’ one of

70 Field-Labourers

the largest that live on the shore, whose deep tunnels
are larger than rabbit-burrows, and are lined with
coco-nut fibre.

Beetles, again, are most useful workers, almost all
the world over, and on some of the wild hill slopes of
Ireland all the patches of good grass are said to be
their work. Cows are kept on these wastes, and are
attended by numbers of large beetles. Three or four
of these together set to work at a patch of cow-dung,
burrowing into the soil beneath, and bringing up little
heaps of clay until they have covered it three or four
inches deep. Their object, no doubt, is to-make a
suitable place in which to lay their eggs, for the grubs
when hatched live upon this food; but they at the
same time provide a suitable bed for grass-seeds, which
is quickly taken possession of.

The Dumble Dor beetle, or Flying Watchman, the
slow, hump-backed, bluish-black creature, which is
often found lying on its back, goes to work in a
different way, and in spite of its slow movements gets
through what is really an amazing amount of work for
its size. We all know it probably, though we may not
all have watched its operations. It, too, is an attendant
upon cattle, and works so expeditiously and in such
large numbers as to clean a meadow tenanted by cows
in three or four days. Instead of bringing up earth to
cover the droppings, it removes them altogether, pellet
by pellet. It digs its way down between the grass-
roots, carrying with it as much as it can to a hole a
foot deep, where it lays one egg; after which it crawls
up again for more, over and over again, making many
journeys. As many as forty or fifty burrows have been
counted in one square foot.

Field-Labourers 71

In tropical countries, where animal life is abundant,
dung-beetles of many species are especially plentiful.
The great Scarabeus of Egypt, which is common
throughout Africa, as well as in the south of Europe,
may be looked upon as the head of the family, some of
the members of which are of very large size. Some of
the family, like the Carrion-eaters, bury the dead
bodies of small animals, which, though small, are many
times larger than themselves.

Burying beetles, of one species or other, are every-
where plentiful, so plentiful indeed that we very seldom
meet with the dead bodies of bird, mouse, or mole, or
any other animal, in our walks in field or wood. All
have been cleared away and buried several inches,
sometimes nearly a foot, underground, where they
benefit the soil, besides providing food for the beetle’s
family—this latter being of course the only object which
the beetle has in view. They work sometimes singly, -
sometimes in company, scraping the earth away from
beneath the carcase with their forelegs, and then care-
fully covering it up; after which they burrow down and
lay their eggs. .One beetle alone has been known to
bury a mole forty times its own weight; while four
together have been seen burying a crow; and if we
consider for a moment what a task it would be for a
man, alone and unaided, to bury an animal weighing
forty times as much as himself—say four hundred
stone—we may gain some idea of the vast amount of
work performed by these insects. Four beetles which
were kept and watched for fifty days, buried in that
time four frogs, three small birds, two fish, one mole,
two grasshoppers, the entrails of a fish and two pieces
of ox liver. But even rabbits are not too large for

72 Field-Labourers

them; and one foreign species will bury a snake in a
few hours.

Burying beetles of the many carrion-feeding species
abound especially in temperate climates, for there it is
that there is most work for them to do, since there
dead bodies decay but slowly. In those parts of the
tropics where great heat is combined with extreme
dryness—as, for instance, on the Pampas of South
America or in the African deserts—a body is dried up
so quickly that it can hardly be said to decay at all.
A dead horse can even be used as fuel, and there the
carrion-feeders are comparatively few. They are little
needed as scavengers, and, unless covered up imme-
diately, the dead body of any small animal such as
they could bury would supply little food for their
grubs.

VII.
FIELD-LABOURERS—continued.

‘THE plough is one of the most ancient and most
valuable of man’s inventions; but long before he
existed the land was, in fact, regularly ploughed, and
still continues to be thus ploughed, by earthworms.’

Earthworms are continually busy about this work
over pretty nearly the whole world, ‘reversing the
earth’s crust, turning it over and over, from year to
year,’ as the ploughman does, ‘only much more
slowly, and much more thoroughly, spadeful by spade-
ful, foot by foot, and even grain by grain.’ And the
earthworm’s work has another great advantage over
that of the ploughman. It is not only more thorough,
but it can be, and is, carried on even while the crops
are growing, and that without any material injury to
them.

We have learnt much about the earthworm of late
years, thanks to Mr. Darwin; but long before ‘ Vege-
table Mould and Earthworms’ was written—more
than a hundred years ago, in fact—Gilbert White, the
naturalist of Selborne, had a very good idea of the
worm’s importance as one of nature’s field labourers.
‘A good monography of worms,’ he wrote, ‘would

74 Field- Labourers

afford much entertainment and information at the
same time, and would open a large and new field in
natural history.’ ‘ Vegetation would proceed but lamely
without it, so great are its services in boring, per-
forating, and loosening the soil, and rendering it
pervious to rains and the fibres of plants, by drawing
straws and stalks of leaves and twigs into it, and, most
of all, by throwing up such infinite numbers of lumps
of earth, which is a fine manure for grain and grass.’

Gardeners and farmers hated the worm in his day,
as the former at least do still; but he remarks that
they would find ‘the earth without worms would soon
become cold, hard-bound, and void of fermentation,
and consequently sterile.’

The earthworm is an animal possessed apparently
of more than the traditional nine lives, and endowed
with a wonderful power. of adapting itself to the most
diverse and most adverse circumstances. Bodilyinjury
affects it but little, so far as life is concerned. One
worm is said to have been behéaded eight times in
succession, and to have perseveringly grown a new
head each time; another was cut into fourteen pieces,
thirteen of which became perfect worms, while only
one died.

Earthworms closely similar in appearance to those
which we know in England are found in soils of the
most various kinds and in almost all parts of the world.
The English species is extremely plentiful on commons
and chalk downs, where the soil is poor and the grass
short and thin, and it is almost equally abundant in
some of the London parks, where the soil is rich.
But their numbers may vary in different parts even
of the same field, showing that they have their pre-

Fiield-L abourers 75.

ferences, though it may not always be easy to discern
the reason for them. Moisture, however, they cannot
do without, and hence, while they avoid dry sand and
heaths, they frequent paved yards near houses in large
numbers.

On the mountains of North Wales and on the Alps
they are rare, owing perhaps to the lack of sufficient
depth in which to make their winter burrows; but
they are found in Scotland on hills 1,500 feet above
the sea; near Turin, at a height of 2,000 or 3,000 feet;
on the Nilgiri Mountains of South India, and on the
Himalayas. They have, indeed, an enormous range,
occurring in the most isolated islands, abounding in
Iceland, and found in the West Indies, St. Helena,
Madagascar, New Caledonia, Tahiti, Kerguelen’s Land,
and the Falkland Islands, though how they reached
these is at present a mystery, since sea-water is abso-
lutely fatal to them. In the United States they are
plentiful; in Venezuela, common in gardens and fields;
in South Brazil the soil, to the depth of a quarter of a
yard or more, looks in most parts of the forest and
pasture land as if it had repeatedly passed through
their bodies. Even in the dry soil of New South Wales
their castings abound, and in the hot, moist jungles of
Bengal they occur almost everywhere.

Strange to say, they seem to be either absent or
uncommon in the Canadian prairies—that is, they
never seem to have come in the way of the surveyors ;
but, after all, this does not prove much.

Almost the whole surface of every moderately damp ©
country is covered with a layer of fine, dark, vegetable
mould; it is only a few inches thick at most, from four

76 Field- Labourers

or five to perhaps twelve inches, but no matter what
the nature of the soil beneath, there it is. One may
see it in any railway cutting, or on the top of any bank,
be it chalk or be it sand; and this black earth, or
humus, is, to a very large extent, the work of worms.

In a very loose soil worms can move easily, but,
generally speaking, as their bodies are soft, and cannot
pierce through anything at all hard or close, and, as
they have nothing but their mouths to work with,
they are obliged to eat their way through the ground.
No doubt they are fed, to some extent, by the animal
or vegetable matter contained in the soil, but their
primary object in swallowing it does not seem to be
food; to swallow it is the only way they have of
getting rid of it, and their real object is to make a tube
or burrow in which to live.

Where other food is scarce, or absent, they must,
of course, live on what they can get from the soil, and, ©
in purely mineral soils, they are rare accordingly, as
they could not find sufficient nourishment in it in case
of necessity.

The effect produced upon the soil by its passage
through their bodies is very marked: it is not only
rendered extremely fine, but its colour is gradually
altered, becoming darker and darker, until, after re-
peated swallowing, it is turned almost black. The
layer of dark mould which covers our fields is dark just
because it is composed of the castings of worms,
castings which have passed through their bodies over
and over again, times innumerable..

The worm has no teeth, and its mouth is a mere
opening, but it has the power of flattening its head and
extending it on each side of this opening so as to form

Field-Labourers 7

two lips, with which it is able to grasp leaves and
other things firmly enough to drag them into its
burrow. Sometimes, however, it seems to vary its
manner of proceeding, and, instead of grasping the
object it wishes to move, it presses its mouth upon it
until it adheres firmly by mere suction.

Worms are omnivorous: they will eat anything
eatable, and will feed daintily upon half-decayed
flowers and almost any kind of vegetable matter, or
coarsely upon their own dead comrades, or meat when
put in their way. But their chief food consists of half-
decayed leaves, enormous quantities of which are
pulled into their burrows, torn into small shreds, and
then swallowed and digested; and it is this vegetable
matter which changes the colour of the earth which
the worms swallow with it, and converts it into ‘mould’
—vegetable mould.

Two worms kept in a large pot of sand, well
moistened, of course, but consisting only of mineral
matter, converted the top layer into vegetable mould
four inches deep, simply by the help of the leaves
strewed on the surface.

In woods the fallen leaves are being constantly
covered with worm castings, and thus converted into
rich soil; and in Sumatra the ground in the forests is
almost as rough as a field which has been literally
ploughed, so thickly is it covered with large worm
heaps eight inches high, often thrown up in a single
night. There may be as many as ten or twelve of
these in a square yard, and the creatures seem to be
incessantly at work bringing up soil and burying leaves,
twigs, etc.

As to the actual amount of soil swallowed by worms,

78 Field-Labourers

it varies, of course, according to their size, in which
they differ very greatly. There is a worm in Ceylon
about two feet long; in the Nilgiri Hills, already
mentioned, they are twelve or fifteen inches long and
as thick as a man’s little finger; while on the Amazon
there are some as much as two feet and a half long
and thick in proportion, and able therefore to do much
work.

Seeing only the little dark heaps of soil thrown up
by worms on grass-plots and gravel-paths, heaps which
are soon washed down again by rain, one has some
difficulty in realizing the vast amount brought up in
the course of a year. But Mr. Darwin reckoned that
near Nice this amounts to from about fourteen to
eighteen tons to the acre; this is supposing them to be
as numerous and active over the whole of a field as
they were in the one square yard chosen for observa-
tion; but it is also supposing them to work for only
six months of the year, which he considered a low
estimate. The largest amount was brought up on very
poor pasture, where leaves were probably scarce, and
‘the worms had to swallow much earth in order to
obtain sufficient food.

On the whole it seems probable that they bring up
more than ten tons of soil to the acre in many parts of
England year by year, and that the entire mass of
mould—the dark surface-soil of every field—passes
through their bodies in the course of a few years, and
is by these means sifted and rendered extremely fine,
besides being thoroughly impregnated with vegetable
and animal matter. Moreover, bones, twigs, leaves,
shells, are constantly being covered with castings, and
these further help to enrich the soil by their decay ;

Field-Labourers 79

whereas, left upon the surface, they would benefit it
but little. Large earthworms sometimes bring up
soil from a great depth: in’sandy soils, for instance,
their tubes go down from three or four to six feet, and
are then continued horizontally; and the whole
contents of these tubes must, of course, be brought to
the surface.

Estimates differ so much that it seems hopeless at
present to try and calculate their numbers. But this
one thing we know, there are many thousands in every
acre of moderately damp land, and, grain by grain, the
whole surface is literally ‘loughed and saturated with
fertilizing juices.

So far from being over-rated, as some have thought,
the earthworm is now proved to be an even more
valuable field-labourer than was supposed, and it is
said that, in estimating the value of land for farming
purposes, no satisfactory conclusion can be arrived at
unless the number of worm-holes be taken into the
account.

Besides grinding up the soil in the process of
digestion to a state of extreme fineness, besides adding
to it vegetable matter and darkening its colour, worms
are most useful in another way: they prepare channels
through which the roots of plants are able to spread
with ease. Plants evidently prefer, when they can, to
take advantage of ready-made passages, and worm
burrows which have been in existence some little time
are usually found lined to the very end with fine roots
and rootlets, the latter covered with fine hairs, through
all of which the plant absorbs food.

Roots of red clover have been found running down
six feet, or more, into the ground by means of these

80 Field-Labourers

holes, and the plant of course gains by this. The
longer the root, the larger the surface with which it is
brought in contact, and the larger the supply of food
which it can extract; and it obtains this food more
quickly where it can run through a tube than where it
has to force its way through close soil, and con-
sequently the plant grows more rapidly.

Much of this will be more readily understood when
we come to speak of how plants feed and grow; but
we may mention here that plants which are able to
send down roots to any considerable depth have the
advantage of reaching soil which is quite fresh and
unexhausted; they have also plenty of room in which
to develop their roots, and, more important still, their
roots are kept warm and well supplied with moisture
at all times, even when the surface of the ground is
frozen hard. Dig through the frozen surface, and you
will always find moist earth beneath; so also even in
drought, there will be more moisture below than on
the surface; and this moisture plants are enabled to
reach by means of the worm-tubes, instead of spread-
ing their roots only, or chiefly, through the surface-
soil as they might otherwise do.

However, as we have observed already, man may
tame a lion, but he cannot control a single worm—
cannot make his wishes understood or respected by
one of these insignificant creeping things; and so, as
the worm’s proceedings are at times exceedingly irre-
gular, he blames the worm, and sometimes goes so far
as to deny that it does any good at all.

Their way of top-dressing lawns and paths does not
improve the appearance of either, we must admit; top-
dressing may be all very well in a meadow, or in the

Field-Labourers 81

rice-fields of Bengal, which are very soon studded with
worm-heaps after they have been flooded, but in a
garden we are inclined to think it out of place, And
it is true that, in the Botanic Gardens of Calcutta, the
lawns are covered in a single night or two, if they are
left unrolled, with tower-like castings, which weigh
some ounce and a quarter each, and are anything but
sightly. aa

Sometimes, too, the earthworm may disturb seed-
lings by burrowing, but it does not eat them. Neither
does it touch living roots, as it has been suspected of
doing, at least when these are growing in the open
ground ; though what it may do when confined in a
pot, and pressed by hunger, is perhaps another matter.

In spite of some drawbacks, however, it would be
not merely hard but absolutely impossible for man to
contrive any substitute for these natural ploughmen if
he could succeed in banishing them.

But people are never all satisfied; and among the
malcontents are some who find fault with the worm,
not for doing too much, but for doing too little! It
works, say they, only for a few months of the year,
and therefore does not deserve so much credit and
gratitude after all.

The poor worm cannot work in dry soil. Indeed,
moisture seems to be the one thing essential to it; for
though it can stand much bodily ill-usage, it is actually
killed by exposure to the dry air of a room for even a
single night. In hot countries, such as Bengal, there-
fore, it can only work during the cool season, about
two months, after the rains; and even in the moist
climate of England it cannot work near the surface
during the dry weather of summer, any more than

6

82 Field-Labourers

in hard frost. Gilbert White remarked that worms
worked most in spring; but he added that they were
by no means torpid during the dead months, and were
in fact out, even in winter, on every nmild night.

There is, however, another and much smaller animal,
which, as some people think, has done much work
hitherto attributed to the overpraised worm. Ants
have not generally had the reputation of being useful
to the agriculturist, however clever some of them may
be as agriculturists on their own account; but in
Ireland, aecording to at least one observer, they do
appear to have been most useful; and if in Ireland,
then why not elsewhere ?

These Irish hill-building ants love what the worm
cannot bear, a dry, sandy, or peaty soil; and they are
busy at work from early ‘spring to late autumn, all
through the hot weather, when the worm is compara-
tively idle. Yet even so, they do not work for more
than about five months of the year; whereas the worm
works on an average at least six, and in mild, damp
winters often much more.

However, whatever their respective merits, the ants
work where and when thé worms cannot do so, and
are most useful where there are crags, or large stones,
with patches of sandy peat; for the hill-building ants
always choose rock to build upon, and gradually cover
the surface with soil. These patches are at once taken
possession of by grass and other seeds, and so the soil
is kept in place. During the winter there may be a
little loss by wind and rain, but the greater part is
held together by the roots, and a patch of permanent

vegetation is formed where previously there was only
bare stone.

Field-Labourers 83

A single colony of ants seldom covers less than two
Square feet, and sometimes more than three; and
as they generally choose a fresh place every year,
they really do a great deal towards clothing bare
places.

The ants which work on the sandy moors seem to
keep to the same spot year after year, but their hillocks
are much taller, sometimes as much as four feet high
and a yard across at the base, all composed of soil
brought up from below mixed with refuse vegetable
matter, and in this way much of the unprofitable peat
is converted into good soil.

In some parts of Ireland the work done by ants is,
if not larger, at least much more noticeable than that
done by worms, and it is believed that the space
covered by the work of the two is about equal.

But in the tropics worms are, of course, quite power-
less during the greater part of the year, the soil being
either baked to a brick or dried to dust. In the burn-
ing deserts of Nubia a worm was never seen or even
heard of, and even in a tropical forest during nine
months of the year the soil is so hard as to be quite
unmanageable by its jaws.

In the sub-tropical parts of South America and India,
worms swarm out in endless numbers when the rain
comes, but in the tropics proper, except in the moister
regions, they are on the whole few. Not one was seen
by Professor Drummond in Central Africa, even during
rain, and he suggests that their place is taken in these
parts by the termite, commonly, though erroneously,
called the white ant.

The white ant lives underground, and being quite
defenceless, it has such a dread of exposure that when

84 Field-L abourers

obliged to come out for food it brings some of the earth
with it, and builds a tunnel within which it always
remains.

The food of the termite is dead wood, and, not
content with what it finds on the ground, it climbs the
trees in search of it, toilsomely carrying earth for its
tunnels wherever it goes. There may be perhaps a few
feet of dead wood at the end of a long branch some
thirty feet from the ground, and the whole distance
must be covered in if the termite is to reach it. But
as it does not know exactly where the food desired is
to be found, it more often than not covers the whole
tree with tunnels and galleries made on speculation.

The extent to which this tunnelling is carried, and the
amount of earth brought up, are something incredible. .
In some districts of tropical Africa there are millions
of trees covered with tubes, every one of which must
be plastered over with many pounds of soil. The
tunnels generally are about the size of a small gas-pipe,
some occasionally larger, and here and there are large
chambers covering nearly the whole trunk for some
feet. Every branch, every twig has a tunnel, and as
for the dead wood which falls to the ground, none is
ever to be seen, as it is at once encased in soil. At
first sight the traveller may think he has found a faggot,.
but on closer inspection it proves to be nothing but a
cast in mud, a very perfect cast, with all, even the
minutest, knots reproduced.

But of trunks, branches, boughs, or even twigs lying
about on the ground, there is nothing to be seen. All
are eaten up.

The outside texture of the termite galleries is like
that of coarse sand-paper; but being intended for

Field-Labourers 85

temporary purposes, only they crumble into dust after
a little exposure. But the dust, brought up from the
sub-soil in the first instance and now returned to earth
again or scattered abroad by the wind, has been altered
in character; it has been powdered for one thing, and
it has been to some extent mixed with animal juices for
another, since the only ‘mortar’ at the termite’s
command is its own saliva, by means of which it makes
the grains adhere together. So far, then, the soil which
the termite has brought up from below is richer than
before ; but the chief point gained seems to be that the
soil is being constantly turned over and over.

Some districts are more especially favourable to the
termite than others, and in one of these there are miles
of trees all covered with.its earthworks. ‘The soil of
the tropics is therefore in a state of perpetual motion.
Instead of the upper crust being converted into a paste
by the autumn rain and then baked to adamant, the
under soil being hermetically sealed up from light and
air, there is a slow constant transference, grain by
grain.’

But the tunnels do not represent nearly all the
termite’s work, though they are much. Besides these,
there are the nests, mounds of earth of huge size,
which are a common feature of the African landscape,
and can be seen for miles. In India they are seldom
more than a couple of feet or so in height, but in
Central Africa they are from ten to seventeen feet high
and contain many tons of earth, while the excavations
beneath are many feet and even yards deep.

The mounds are not solid, but composed of many
tunnels, chambers, and galleries, yet they are so strong
that they will bear the weight of a man on horseback.

86 Field-Labourers

The exterior is, indeed, brick-like or stone-like in its
hardness, but with all its strength it must give way at
last beneath the fury of the tropical rains, which
continue off and on for two or three months at a time,
and thus the soil is returned to the earth enriched by
its admixture with animal matter.

Ants, true ants, as well as white ants, abound every-
where within the tropics, but they also do a large
amount of work outside, though their numbers gradually
diminish as we go further and further north and
south.

There are ‘ ant-cities ’ in Pennsylvania, each of which
contains more than 1,600 nests of various size, the
largest being fifty-eight feet round the base and forty-
two inches high, with galleries some sixty feet long
leading to the feeding grounds.

The muscular power of these ants is truly wonderful.
The loads they carry are twenty-five times their own
weight, and they carry them what, for their size, is an
enormous distance. It is as if a man of ordinary size
were to carry a weight of 4,000 pounds from the bottom
of a coalpit to the top of the Great Pyramid. And they
have not merely to carry these loads, but first to prepare
them.

The ant begins work by scratching with her forelegs
like a dog; later on she bites, cuts, or twists off pellets
of earth, during which process she often works like a
collier on her back, and then she compresses the
particles into a ball and carries them out. The only
implements she has for her work are her mandibles,
or first pair of jaws, which are placed outside her
mouth, each jaw being furnished with seven teeth.
These powerful jaws serve as pick, shovel, crowbar,

Freld-Labourers 87

saw, axe, and cart, all in one, and as the little creature
grows old her teeth are gradually worn down by the
hard work they have done, just as a workman’s tools are
worn.

The number of these ants is simply enormous; and,
besides enriching the ground by the quantity of leaves
with which they fill their storehouses, they also per-
forate it to a considerable depth. Some of their sub-
terranean galleries have been traced down fifteen feet,
and found to be still descending. Whatever the depth
may be, from it they bring up the soil with which they
build their mounds ; and in Brazil there are very large
deposits of earth which have been raised to the surface
entirely by the ants.

Thus not only is fresh soil continually exposed to the
action of air and rain, but ways are opened by which
the same air and rain may penetrate to the underlying
rocks and carry on the decaying process, as described
in an earlier chapter. Nor must it be forgotten that
wherever there is decaying vegetable matter, there
carbon-dioxide and other gases are formed, which are
absorbed by the rain in its passage through the earth,
and increase in a very high degree its power of acting
upon the rocks beneath.

The ants’ store-rooms, the worms’ burrows with
their quantity of decaying leaves, the ground-squirrel’s
hoards, and the beds made for themselves or their
young by mole, marmot, and the like, all increase the
organic matter and the supply of carbon-dioxide in the
soil; while their various burrows, large and small,
make an easier passage for the rain.

We cannot attempt to give more than a sketch, and

86 Field-Labourers

The exterior is, indeed, brick-like or stone-like in its
hardness, but with all its strength it must give way at
last beneath the fury of the tropical rains, which
continue off and on for two or three months at a time,
and thus the soil is returned to the earth enriched by
its admixture with animal matter.

‘Ants, true ants, as well as white ants, abound every-
where within the tropics, but they also do a large
amount of work outside, though their numbers gradually
diminish as we go further and further north and
south.

There are ‘ ant-cities’’ in Pennsylvania, each of which
contains more than 1,600 nests of various size, the
largest being fifty-eight feet round the base and forty-
two inches high, with galleries some sixty feet long
leading to the feeding grounds.

The muscular power of these ants is truly. wonderful.
The loads they carry are twenty-five times their own
weight, and they carry them what, for their size, is an
enormous distance. It is as if a man of ordinary size
were to carry a weight of 4,000 pounds from the bottom
of a coalpit to the top of the Great Pyramid. And they
have not merely to carry these loads, but first to prepare
them.

The ant begins work by scratching with her forelegs
like a dog; later on she bites, cuts, or twists off pellets
of earth, during which process she often works like a
collier on her back, and then she compresses the
particles into a ball and carries them out. The only
implements she has for her work are her mandibles,
or first pair of jaws, which are placed outside her
mouth, each jaw being furnished with seven teeth.
These powerful jaws serve as pick, shovel, crowbar,

Freld-Labourers 87

saw, axe, and cart, all in one, and as the little creature
grows old her teeth are gradually worn down by the
hard work they have done, just as a workman’s tools are
worn.

The number of these ants is simply enormous; and,
besides enriching the ground by the quantity of leaves
with which they fill their storehouses, they also per-
~ forate it to a considerable depth. Some of their sub-
terranean galleries have been traced down fifteen feet,
and found to be still descending. Whatever the depth
may be, from it they bring up the soil with which they
build their mounds ; and in Brazil there are very large
deposits of earth which have been raised to the surface
entirely by the ants.

Thus not only is fresh soil continually exposed to the
action of air and rain, but ways are opened by which
the same air and rain may penetrate to the underlying
rocks and carry on the decaying process, as described
in an earlier chapter. Nor must it be forgotten that
wherever there is decaying vegetable matter, there
carbon-dioxide and other gases are formed, which are
absorbed by the rain in its passage through the earth,
and increase in a very high degree its power of acting
upon the rocks beneath.

The ants’ store-rooms, the worms’ burrows with
their quantity of decaying leaves, the ground-squirrel’s
hoards, and the beds made for themselves or their
young by mole, marmot, and the like, all increase the
organic matter and the supply of carbon-dioxide in the
soil; while their various burrows, large and small,
make an easier passage for the rain.

We cannot attempt to give more than a sketch, ang

88 Field-Labourers

that a very slight one, of the work done by nature’s
various field-labourers; but, slight as it is, it would be
incomplete without some mention of the very curious
animals known as ant-eaters, which are found through-
out the tropics.

These creatures have very long, thin, pliable tongues,
looking like red earthworms, and as if they were en-
dowed with independent life; and when they can get
at them they lick up the ants with marvellous rapidity.

The ants, as we have seen, dwell, many of them,
within walls almost as hard and strong as if built of
stone or brick, capable, one would think, of defying the
attack of almost any animal. But ant-eaters are armed
with tremendously powerful claws—so powerful that
with them they are able to dig and tear down even
these strong citadels; and this done, they sweep up
the terrified inhabitants by thousands.

Ant-eaters of the Manis family, long-tailed and short-
tailed, which are found in Africa and Asia, are covered
with horny plates, sharp-edged and overlapping, the
points turned to the tail and raised, so that they have
the combined advantages of scale-armour and the
hedgehog’s bristles.

The Aard-Vark, or Earth-hog, of South Africa, is a
very different-looking animal, covered with coarse,
bristly hair, and about five feet long with its tail—
altogether too large, one would have fancied, to be
satisfied with such very small food as ants. Its fore-
limbs are very powerful, and armed with long, hoof-
like claws, with which it digs through the hardest
mounds and burrows in the hard-baked earth faster
than a man can dig with a spade.

The great Ant-eater, or Ant-bear of tropical South

Field-Labourers 89

America, is like the Aard-Vark, but larger, and is so
bold that it will sit up and fight even a ‘tiger,’ or more
properly jaguar, with the very long curved claws of its
fore-feet. Yet, notwithstanding its size and strength,
it lives chiefly on ants.

By these and other ant-eaters the hills and mounds
of the ants are demolished, and the earth which they
have excavated with so much labour is returned to the _
soil. And it is returned in an altered state, much finer
than before, and enriched to some extent at least by
what has been added to it, and so is better fitted for
the support of plant-life.

VIII.
WATER

THE soil may have been ground and mixed, perhaps
transported long distances, and otherwise prepared by
the various labourers already described ; but even then
no crops, whether wild or cultivated, can thrive in it
without moisture. In perfectly dry soil they must
starve in the midst of plenty; for they can no more
get at the food around them, however abundant it
may be, without water, than if it were locked up.
To them, indeed, under such circumstances, it is
locked up.

Of course, we all know, as a matter of fact, that
plants fade and wither, and eventually shrivel and die,
if they be kept without water. We may know, too,
that three-quarters of the weight of most plants, and a
great deal more of many, is made up of nothing but
water. But when once they have had a supply of
water, why should they need more? Cannot they keep
it? and if not, how do they lose it? Why do they
need constant watering ?

A potato is watery: only one-fourth of its weight is
solid matter ; the rest is all water. An artichoke con-
tains still more water, and still less solid matter; a

Water 91

turnip is more watery still; and a pumpkin contains
only five and a half per cent. of solid matter.

And yet, when we have stored our potatoes and
turnips, or our pumpkins, we do not find it necessary
to water them. They do not shrivel; they keep their
moisture. Why does not a plant do the same?

The only answer to this question is, simply because
it can’t. It cannot shut the many mouths by which it
is constantly losing moisture. We human beings can-
not prevent the escape of water through the pores of
our skin, or in the breath which we breathe; and the
plant is in similar case. It is constantly giving off
water, and if the loss is not made up it must needs be-
come dry and shrivel.

_Almost every part of a plant which is exposed to the
air, and not covered by a layer of cork or of thickened
skin, is constantly losing moisture in ordinary air; and
unless the roots can suck up enough to make the loss
good, it droops, flags, withers, and dies.

The potato and the pumpkin ave protected —the one
by cork, the other by thick skin—and they are there-
fore able to retain their moisture for a considerable
time. In a similar way, the stems of most woody
plants and trees are protected by layers of cork, and
often of fibrous bark as well, which almost, though not
altogether, prevent the escape of water. It is the
young, green stems, the growing parts, and the leaves
by which it is chiefly allowed to go off into the air;
and these are just the parts which especially need the
mineral food, the food derived from the soil, which the
roots are constantly preparing.

How are the roots to convey this food to the growing
parts of the plant? Of course, they cannot do so;

92 Water

they can only make it ready, and then it must be
pumped up to where it is wanted. Accordingly, as the
water is drawn off, so to say, above, the sap from below
—that is, water containing food from the soil—rises to
supply its place.

A constant current, therefore, rises from the roots
upwards; but a great deal of this would be lost during
its passage before it reached the young shoots but for
the fact, already mentioned, that the trunks or stems
through which it passes are protected against the air,
and moisture can escape but very slowly through bark
or cork, though it does still escape to some small
extent.

When the sap reaches the green parts of the plant
it passes off into the air as invisible vapour; or,
rather, the water of the sap passes off in this way,
and the food from the soil, the mineral matter, is
left behind. But even from the green stems and leaves
the water is not allowed to escape quite unchecked,
else it might pass off too fast—faster than it could be
supplied.

For anything moist, whether it be moist earth or
wet clothes, dries when exposed to the air. The air
sucks the moisture out of all, and the drier the air,
the more quickly it sucks. Without some protection
against this thirsty air, therefore, leaves and green
stems would also be sucked dry, like anything else,
and accordingly their outer skin is more or less
thickened; and it often contains, or is covered by, a
waxy deposit as well. We may perhaps have noticed
how drops of dew lie upon the leaves without soaking
in, so that when the dew is shaken off, the leaves are
dry. This is especially noticeable on some shiny

Water 93

leaves, but also on some mealy-looking ones, as, for
instance, cabbage leaves; and in both cases it is the
waxy substance in or upon the skin of the leaf, which
not only prevents water from soaking in, but also
prevents all but a very small quantity of moisture from
being drawn out.

Then, if water is constantly passing off, and that in
considerable quantities, how does it escape? A little,
as we have said, passes off through the whole surface,
but the bulk finds its way out through special openings,
pores, or mouths, to which the name of ‘ stomata’ has
been given. These pores aré extremely minute open-
ings in the outer skin of leaf and stem, and vary very
greatly in size and number in different plants. It is
through them that used-up air and water in the form
of vapour are allowed to escape.

The process by which vapour is given off through
the leaf pores is called ‘ transpiration,’ and is not the
same thing as evaporation, though like it, it proceeds
more quickly in hot dry weather. But evaporation
goes on—or, in other words, the air sucks moisture—
from the whole surface of a plant—from trunk, stem
and leaves more or less, and would suck much more
than it does if it were not prevented.

Transpiration, on the other hand, is confined to the
leaf-pores, and is the process by which the plant parts
by its own action, so to say, with its superfluous
moisture. In evaporation the plant is merely acted
upon by the air; the moisture is sucked out as it is
sucked from a wet sheet hung out to dry, or a piece of
dead wood. In transpiration the moisture passes out
through the proper openings, and the plant itself acts,
or at least discharges one of the natural functions of

94 Water

its being. Evaporation may continue in a dead plant,
but only a living plant transpires.

Both processes are affected by the weather, however,
and both in a similar way.

Nothing, we know, dries on a very damp day,
because the more moisture the air contains, the less it
can take up; or, in other words, evaporation proceeds
slowly in moist air. So, too, transpiration almost or
quite ceases in damp weather, or when the leaves are
wet. But both go on more briskly in the sun, in dry
air, and more especially in a drying wind.

The leaf-pores by which transpiration proceeds are
usually more abundant on the under surface—the
shady side—of the leaves, and are few or altogether
wanting on the upper surface, where they would be
exposed to the sun, and water might pass off too
rapidly. In moist, shady situations there is no danger
of too much transpiration, and plants growing in these
not only have more leaf-pores than others, but can
also have them without risk, both on the under and
upper surface of the leaves, for here transpiration goes
on more slowly, and the loss of water is also easily
made up.

Thick, fleshy leaves have the fewest leaf-pores, and
thick, fleshy leaves are particularly characteristic of
hot countries, where plants can afford to lose but
little of the scanty supply of water which comes to
them.

Many leaves which are alike on both sides have
about an equal number of pores above and below; but
when there is any difference, as, for instance, where
one side is dull and the other glossy, the dull side,
which is also the under side, has the larger number of

Water 95

pores. The leaves of the laurustinus have no leaf-
pores at all on their shiny, upper surface, neither have
those of the lilac; while those of the carnation, which
show no such difference as these do, have about an
equal number on each side. Some leaves have as
many as 170,000 pores to the square inch, but this
seems to be the largest number. An apple leaf
of ordinary size has about 100,000 a alto-
gether.

The size of the pores varies very much, but at their
largest they are so minute as entirely to exclude the
very finest dust. Those of the white lily, for instance,
which are called ‘remarkably large,’ measure only one
4,250th part of an inch across.

Hard, evergreen leaves, such as those of the pine,
are like the thick, fleshy ones in this, that they have
but few leaf-pores, and lose but little water except
through these openings. _ For pines grow in very dry,
sandy soils, and often in elevated situations, where the
air, though cold, is exceedingly dry and drying, and
they therefore need as much protection as plants
which grow in hot, dry climates.

Many and various are the devices by which evapora-
tion is checked and controlled, even in temperate
latitudes, lest the plant’s need of water should exceed
the supply. For it must be remembered that air has
an immense appetite for water; the drier it is the
more it takes up, but it goes on sucking, if allowed, as
long as it is in contact with anything containing
moisture until it can hold no more.

It is this which makes the misery of an east wind,
which is a very dry wind, as well as a cold one, and
sucks up moisture wherever it can, not only from vege-

96 Water

tation, but from the bodies of animals, drying the skins
of human beings, as the hot, dry air of the desert dries
them, though in less degree.

Since three-fourths of the weight of most plants, and
more of many, is made up of water, the air would be
always sucking at them, if not prevented. As things
are, however, though some, generally very small,
amount of water is sucked by the air from the whole
surface of a plant, as we have said, its escape is con-
fined, as far as may be, in most cases, and especially in
dry climates, to the legitimate openings, the pares
made for this purpose.

Soft, thin leaves lose water by evaporation from the
whole surface, and have a large number of pores as
well, but they grow in situations where they can
easily make up the loss. All leaves, however, have
some protection more or less in the skin which
covers them, this skin being, moreover, as we have
said, impregnated with wax, which, though com-
monly invisible, often appears as a shiny coating, or
as ‘bloom.’

A cabbage, for instance, has a mealy look about it,
as if it had been dusted with flour; many grasses,
acacias, and the now well-known Australian gum-tree
or eucalyptus, have a similar appearance, and when
this ‘bloom’ is examined it is found to consist of
minute rods, or needles, of wax. The substance forms
a regular incrustation on the stem of the Peruvian
wax palm, whose native land is one of the most rain-
less regions of the earth; and there is nothing more
effectual than wax for excluding air and preventing
evaporation. Honey stored in wax-cells is, as it were,
hermctically sealed up and preserved.

Water 97

With the wax is often associated resin, which acts in
a similarly protecting way apparently. No explanation
indeed has hitherto been given of the use to the plant
of gums, resins, caoutchouc, and the strong-smelling
oils frequently found in leaves ; but, as water in which
gum or any other substance is dissolved evaporates
more slowly than pure water, it seems not unlikely
that one at least of the uses of these substances is to
check the escape of water. And this seems the more
probable when we consider that aromatic, as well as
gum and resin-bearing, plants are especially charac-
teristic of deserts and dry regions, hot or cold. Thus
the pine-tree of the north has its turpentine, the
eucalyptus of hot, dry Australia its oil, and the acacias
of Africa their gums.

Many trees and shrubs in hot, dry countries are
protected also by having either small or very few
leaves, or even none at all.

Where the air is constantly damp, as it is in many
parts of the tropics, there the trees may boldly venture,
as the plantain does, to spread broad leaves many feet
square to the sun, for the water-supply never fails, and
the air is not outrageously thirsty, as it is in the desert.
But in those parts of Australia where rain is scanty and
droughts are frequent, there the leaves are not only
small, as we have said, but they, most of them, also
protect themselves by turning only their edges, not
their broad sides, to the sun; for they have to economize
their resources as much as possible. This is par-
ticularly the case with many species: of Eucalyptus,
some of which turn one leaf-edge to the earth and the
other to the sky, or stand erect, turning one edge
towards the stem and the other away from it, in each

7

98 Water

case exposing themselves as little as possible. Their
leaves, too, are for the most part narrow, and so
scantily distributed over the branches that an Aus-
tralian forest has none of the deep shade which the
word naturally suggests to us.

But when the eucalyptus is transported to other
lands, where it has plenty of deep, rich soil, and
moisture in abundance, then it puts on more foliage,
showing that it was only the dry heat of its native
climate which made it so sparing of its leaves.

Most of the many species of acacia found in
Australia go even a step beyond the eucalyptus in the
way of economizing their foliage, and give up having
any true leaves at all as soon as they are full-grown.
They keep their leaf-stalks indeed, but there are no
leaves at the end of them, and instead there are
‘wings,’ or narrow, leaf-like margins, growing out
from each side of the stalks. Even these ‘wings’ do
not venture to face the sun, but turn their edges to
earth and sky.

Acacias are especially the trees of deserts; they are,
indeed, the only timber-trees of the Arabian Desert,
and they abound in Africa, as also in Australia. But:
wherever they grow they are characterized by the
lightness of their foliage; and of the Australian species,
which number something under three hundred, two
hundred and seventy drop their leaves altogether when
they are grown up, and merely flatten out their leaf-
stalks as described.

None of the Cactus family—which are natives of
the hot, dry regions of America, North, South, and
Central—make any attempt at having leaves or even
‘wings,’ but their stems are flattened out and do

Water 99 |

duty instead. The stems, too, are protected against
evaporation by being enveloped in a peculiar leathery
skin, which is thickest in the species inhabiting the
hottest and driest regions; and they lose little water
therefore, except through the pores, which are but
few in number. Thus protected, they not only exist,
but flourish, in dry sand, where for three-quarters of
the year they are exposed to the blazing, parching
sun.

The tall, fluted columns of the species of cactus
called the ‘Torch Thistle,’ sometimes fifty feet high,
are to be seen springing out of crevices in the hard
rock, and standing up like telegraph-posts on the
mountains and in the rocky valleys all over the hot,
parched, almost desert regions of New Mexico.

This tall cactus seems to be so fully protected by its
thick skin that it may venture to expose its whole
surface to the sun without risk; but other species are
less bold, and keep close to the ground, growing in the
form of large cushions or great globular masses, and so
diminishing the extent of exposed surface. Some, too,
are set all over with long, slender, needle-like spines,
and are also covered with what look like dense masses
of floss silk, both of which protact the plant from the
hot air and sun.

But though these special means of defence are more
striking in the tropics than elsewhere, they are em-
ployed more or less everywhere, our own moist land
not excepted. Besides the bark, and the cork, and
the more or less thick skin of the leaves, and the wax,
which we have already mentioned as the ordinary
means by which evaporation is checked, these other
measures are also frequently adopted for securing the

roo Water

same end. Our plants do not indeed go so far as to
drop their leaves altogether, but some of them do
greatly diminish both their number and size ; and some
clothe themselves with hairs, partly, as it would seem,
lest they should be deprived of too much moisture,
though partly also, probably, as a protection against
insects. An example or two of these must suffice, and
we will take, first, that of the Amphibious Persicaria—
a particularly interesting plant, as it grows both on
land and in water, and adapts itself to its situation in
a very marked manner. When it grows in water,
where, of course, it does not matter how much it may
lose, it has smooth, lance-shaped leaves; but when it
grows on land the leaves are narrower, and not only
this, but they are covered as well with a quantity of
long hairs, pressed close upon the surface, which they
protect against evaporation.

Then there is the Sweet Woodruff, whose lance-
shaped leaves grow in whorls of eight, for the plant
dwells in moist, shady places, where there is no risk in
having many leaves. But look from this to another
member of the family, the Quinsy Wort, and what do
we find? The leaves are very narrow, and there are
but half as many of them. Why? Because this little
plant grows on dry banks, where many and large
leaves would be dangerous to its welfare.

It has been already mentioned that the Pine family,
which thrive in dry, sandy soils, have hard, needle-like
leaves, with few pores, and therefore give off but little
water, either by evaporation or transpiration ; and it is
for this reason that the air in a pine forest in summer
has none of the coolness which one finds in a forest of
what the Germans call ‘leaf-trees, The ‘needles’ of

Water IOI

the pine they do not consider worthy the name
of leaves.

Leaf-trees are continually cooling the air by the
moisture which they give up to it; but the -pine-
needles have so few pores, and are so very much
protected, that the little water they part with is not
enough to produce any appreciable effect upon the air.

It is, perhaps, hardly necessary to do more than
remind our readers that the evaporation of water
is always accompanied by the absorption of heat, or,
in other words, that water cannot be converted into
gas or vapour, which it is when evaporated, without
using up heat. Whether it be the heat of a fire or the
heat of the sun, it is all the same. A certain amount
of heat is required to make water pass from the liquid
to the gaseous state, and if this heat be taken from the
air, the air is necessarily by so much the cooler.

And this brings us to another part of the subject,
the question, namely, as to the amount of water given
off by trees and other plants, notwithstanding the
various ways in which, as we have seen, they are
protected.

We have distinguished hitherto between the two
processes of evaporation and transpiration, because
they are distinct; the one being due to the action of
the air, and the other to the action, so to say, of the
plant. Evaporation takes place whenever air comes
in contact with anything moister than itself; whether
it be animal or vegetable, whether it be wet earth or
damp clothes, from all it draws water, and by its own
heat converts this water into vapour. The other
process, transpiration, is that by which, through the
pores—the openings left in the skin of stem and leaf—

102 Water

the plant gives up, in a regular, systematic manner,
the moisture with which it would else be overcharged.

But in both cases the water passes off into the air in
the form of vapour; and in both cases it passes off as
nearly pure water, all mineral matter being left behind ;
in both cases also, the amount given off varies with the
weather, there being more loss on a hot, dry, sunny,
or windy day, than ona damp, dull, still one. When,
therefore, we consider the amount of water which
passes off into the air from a plant in a certain time,
it is generally impossible to distinguish between that
which comes through the whole surface and that
which comes through the pores; and both processes
are frequently spoken of together as transpiration or
evaporation. The quantity transpired is, however,
usually very much larger than the quantity evaporated.

In some plants it is occasionally possible to see the
moisture coming from the leaf-pores, as it escapes
faster than the air can evaporate it. This is the case
with many grasses, especially the maize, which may
be seen studded with actual drops of water.

A grass-plant gives up its own weight of water in
the course of twenty-four hours, in hot, dry weather;
and a square foot of turf will yield more than 1} pints
of water in this time. But a square foot of long
pasture-grass gives off nearly 42 pints, or as much as
106 tons of water to the acre!

The larger the surface, the larger of course the
amount of water which passes off from it; and there-
fore the extent of surface exposed is a matter of great
importance, though it is also one which we are very
likely to overlook, at least in many cases. Of course
we can all see that a tropical plantain with its broad,

Water 103

large leaves, has a considerable surface exposed to sun
and air; and so with other conspicuously large-leaved
plants. But when, instead of a few large leaves, a
plant has many small ones, it is not so easy to realize
what the whole surface may amount to.

A sun-flower, for instance, has leaves of a good size,
and yet it is rather surprising to find that in a plant
only three feet and a half high, the whole leaf-surface
may amount to more than thirty-two square feet!
One specimen of this size was found to give up from a
pint toa pint and a half of water during a day of twelve
hours. The sun-flower is quite outdone by the cabbage,
however, one specimen of which gave off nearly two
pints and a half in twenty-four hours, and that from
leaves which, had they been spread out, would have
covered only nineteen square feet. We have seen how
well the cabbage is protected by its wax coating against
evaporation, so that almost the whole of this amount
is given off by the plant’s own action. The camellia is
much less thirsty; it has fewer pores, and its thick,
glossy leaves are so efficiently protected, that half an
ounce of water, Zs pint to the square foot of foliage,
was all that one plant gave up in a day and night.

These calculations are comparatively simple; but,
when we come to trees, who would venture to guess at
the extent of surface exposed to the air and sun by the
leaves upon an elm? We look up at the quivering
multitudes, and feel as if it were hopeless for anyone
even to attempt to count them; it is too bewildering!

Yet the calculation has been made, and the leaves
on a not very large elm-tree are said to be about
47,000,000, which would give a surface of about 200,000
square feet, or five acres!

104 Water

From the whole of these five acres of green surface,
water passes off into the air in the form of vapour, to
the amount of seven tons and three-quarters during
each twelve hours of clear, dry weather.

But if this is the quantity returned to the air by a
single tree of only moderate size, how large must be
the amount received from a wood or forest, containing
hundreds or thousands of trees |

IX.
DESERTS

FRoM what has been already said, it is evident that
every tree, every plant, every spire of grass indeed, is
a pumping apparatus on a larger or smaller scale, by
which a portion at least of the water which descends
from the clouds begins to mount up again almost as
soon as it has fallen.

Plants give up to the air, chiefly by transpiration
through their leaf-pores, but partly also by evaporation
from their whole surface, nearly as much water as is
taken up by their roots—nearly, but not quite—for, as
long as they are growing, they need some water for
the formation of new shoots and leaves. The quantity
is not much in itself, though water makes up a large
part of the weight of most plants. But it is quite clear
that, without water, they cannot grow at all.

Provided a plant has a plentiful supply of water,
enough, that is, to make up for what it loses, it does
not seem to matter how much it transpires. Some
plants thrive perfectly well in dry air—where they give
off moisture constantly and rapidly—if only their roots
be kept in damp soil; and others thrive equally well in
comparatively dry soil, provided the air be damp enough

106 Deserts

to check transpiration and allow them to retain most
of the moisture they draw up. But, when once a plant
has thoroughly flagged, the case is different. Then,
nothing short of water supplied to the roots will be
sufficient to revive it. Damp air will be of no use;
neither will the heaviest dew avail anything. The
roots, and the roots only, can furnish the necessary
supply.

Of course every substance—even, as we have seen,
the hardest rocks—will absorb some amount of water
when actually steeped in it; and so, if a withered shoot
is kept soaking in water, it will absorb a certain quantity
in time, as any piece of dead wood does. But leaves
and stems have little or no power of absorbing moisture
from the air.

This is the general rule, to which there are a few,
but only a few, exceptions; lichens, which have no
roots, do draw moisture from the air, and would be
badly off if they could not, considering the bare rocks
upon which they grow. Mosses, too, which grow
where there is little or no soil, also supply themselves
with moisture from the air to a great extent; and so it
is believed do plants, such as the mistletoe, which grow
upon others.

But still the general rule holds good; leaves have
little or no power of absorbing moisture either from the
air or from water poured upon them.

And yet, how the drooping leaves revive on a dewy
evening, or in a shower of rain, or even under the
influence of a shower from the watering-pot! The
water cannot surely have had time to reach the roots,
and then to travel up the stem.

Water certainly does travel upwards with amazing

Deserts 107

rapidity in some plants, as will be seen presently ; but
when leaves revive on a dewy evening, or during a
shower, it is not because they have drunk in any of
these fresh supplies. Moisture is constantly passing up
to them in larger or smaller quantities from below ; but
they part with it nearly as fast as they receive it
generally, and faster than they receive it in dry weather.
It is the want of sufficient moisture which makes them
droop and renders them flabby. But when the dew
falls on them transpiration ceases, or nearly so; they
are able to keep nearly all the moisture sent up to
them, and so they swell out again and stiffen, and hold
themselves up.

A similar effect may be seen even in cut shoots which
have been allowed to fade, and are then placed in very
damp air. No moisture is taken up; quite the con-
trary; the continued decrease in their weight shows
that moisture is passing off into the air, little by little,
all the time; but stem and leaves are losing it very
much more slowly than they did in ordinary air; and
as water from the lower, older parts of the stem con-
tinues to rise, as it did before the shoot was severed
from the tree, so the younger parts at the top, the
leaves and buds, are refreshed and revived. Ofcourse,
this can go on only for a time, so long, that is, as any
of the original moisture is left in the stem; and when
this is exhausted the leaves droop as before, and at last
wither entirely.

And now to gain some idea, if we can, of the rate at
which water travels upwards from the roots to the
leaves ofa plant. This of course varies enormously in
different plants, because some transpire so very much
more than others; and it also varies greatly at different

108 Deserts

seasons of the year, according as the plant is growing,
or putting out buds and leaves, or not.

Experiments made by watering plants with coloured
solutions are not very satisfactory, because the colour-
ing matter may be caught and entangled, while the water
moves on without them. Still, it is interesting to learn
that in the case of a white iris, which was watered with
a blue solution, the white petals were streaked with
colour in from ten to fifteen hours.

A more trustworthy experiment made upon a willow
seemed to show that the water in this case rose from
the roots at a very much more rapid rate—thirty-four
inches an hour. But the willow, having its roots always
in or near water, has no need to be economical.

In a plant of maize, whose roots were in earth, the
rate was much less, being little more than 14 inches
per hour; in a sunflower it was 25 inches; but in a
tobacco-plant it was 474 inches per hour. The tobacco
transpires so freely that its leaves droop as soon as
gathered, and these experiments were made in such a
way as to encourage transpiration to the utmost.

In some plants the sap rises with extraordinary
rapidity; as, for instance, the Water-liana. This is
one of the many gigantic, rope-like creepers or ‘vines’
of tropical America, and owes its name to the fact that
clear, cool water fit for drinking can be obtained from
its stem—by those, at least, who know how to pro-
ceed.

These climbers mount up among the trees far over-
head, so that to cut off the top of one is quite im-
possible. A length of some seven feet has to be cut
out where it is within reach, and this piece will yield
about a pint of water; but it must be cut first at the top,

Deserts 109

otherwise, if cut first near the ground, almost the whole
of the water will have rushed away into the vine high
overhead before the second cut can be made.

This plant therefore seems to dispose of a pint of
water in less than a minute, and almost all by tran-
spiration, since the quantity evaporated and the
quantity required for growth, in one minute, must be
exceedingly small. At this rate the liana pumps up
from the ground 60 pints of water in an hour—720
pints, or go gallons, in a day of twelve hours.

In early spring, when the sap is beginning to rise, the
sugar-maple will sometimes yield as much as seven or
eight gallons every day for three weeks, and this, of
course, does not represent more than a small portion
of the water which the tree has taken up, as it is only
tapped, not drained of moisture. But the maple is
far outdone by the Black Birch, another of the
American trees from which sugar is made; for one
specimen of this yielded, in four or five weeks, the
extraordinary quantity of about 1,890 gallons. And —
this, like the sap yielded by the maple, is only a part,
and a small part, of the moisture which the tree has
drawn from the earth, and would in the natural course
of things return to the air, diminished only by the small
supply needed for fresh shoots and leaves.

But the amount of water which a plant takes up does
not depend solely on the soil and climate in which it
grows, but also on the plant itself. There is a
wonderful difference in the power which plants possess
of supplying themselves with food and water. Just as
one man will live, and even thrive, where another would
starve, so it is with vegetables. The lichen makes a
living off the bare rock, where nothing else can grow;

110 Deserts

and the ice-plant carpets some of the most arid rocks
of Greece, even after months of drought, and looks,
too, just as deliciously cool as ever, its fleshy leaves
being still covered with their characteristic ‘frosting,’
against which the hottest sun is powerless. On closer
examination the coating of ‘frost’ turns out to be
composed of innumerable globules of water contained
in the surface-cells—the skin—of the leaf. A prick with
a needle shows that these globules are just tiny bladders
filled with water; but this skin is so exceedingly thin,
and so perfectly transparent, that it is a mystery how
the plants manage to keep their moisture; and it is
often no less a mystery how they manage to obtain it
in the first instance.

An English meadow, again, would wither and turn
brown if it were left unwatered beneath the fierce heat
of a tropical sun, but the grasses of the Kalahari desert
of South Africa remain surprisingly green, though
they get but one or two falls of rain in the course of the
whole year. Sometimes they get no rain at all for a
twelvemonth; but even then, when they are the colour
of hay, they are equal to hay of ordinary quality as
fodder for cattle, and hence are of course still very
valuable. The wonder is how they manage to keep
any life at all, and any nourishment in them, after so
many months of burning drought.

In parts of Texas, where also rain is quite the ex-
ception, the grass is often destroyed during the hot
months; but other green things contrive to exist, and
these supply its place to the cattle. Timber is scarce
in these parts; but within the last twenty years
thickets of ‘mesquite’ have sprung up, and now cover
miles of prairie, where formerly there were none. And

Deserts Ill

4 most valuable tree the ‘mesquite’ is, not only for
fuel, fences, and for the framework of houses, but for
food. Its light foliage takes the place of grass during
the hot season, while its beans supply the cattle with
abundant food in winter; and it is enabled to bear the
drought by the fact that it has huge roots, which weigh
hundreds of pounds when the tree is only a few feet
high.

But the Prickly Pear cactus is almost equally useful,
so far as the cattle are concerned, and it covers
prairies so vast that the supply is simply inexhaustible.
In spite of drought, and heat, and dry soil, the thick
stem-like leaves, or leaf-like stems, hold an enormous
quantity of moisture, and when the thorns have been
burnt off even sheep can live and grow fat upon it.
For horses and cows it is split open, and they eat out
the inside, which is so succulent as to answer the
purpose of drink as well as food. One can hardly
imagine any other way in which water could be so
successfully stored in these arid districts as within the
thick leathery skin of the cactus.

But the gourd family are almost as wonderful in the
way in which they manage to appropriate and keep
‘possession of water, even under the driest circum-
stances.

A pumpkin is all water, with the exception of five
and a half per cent. of its weight ; and yet large pump-
kins may be seen growing in what looks like nothing
but sand. To be sure, their thick rinds enable them to
keep the water when they get it, and sand is liberal in
the way of parting with its moisture; but even so,
knowing how very watery they are, it is strange to see
them growing in such dry soil. Plants of this kind,

112 Deserts

however—gourds and melons—are especially charac-
teristic of so-called ‘ desert’ regions, which are exposed
to long-continued droughts.

Whenever there is more rain than usual vast tracts of
desert land in South Africa are covered with melons,
which provide food and drink both for man and beast.
The sama, or wild water-melon of the Kalahari, grows
in great abundance in many parts of this desert; and
the fruit, which remains good for a year in dry seasons,
affords the natives almost their only supply of water
when they are journeying across this rainless region.
Evidently, therefore, the sama is able to make the
most of its limited opportunities, and can not only
appropriate, but also keep, moisture, where most plants
would simply perish of thirst.

Trying as are the droughts of the South African
desert, they are less severe than those of Australia, for
at all events such rain as does fall is kept, and sinks
into the sub-soil, there being no rivers to drain it away ;
whereas in Australia the rivers quickly carry it off
again. Even here, however, some trees, and among
them the eucalypti, manage to store water in their
roots; and from this supply the natives were in the
habit of helping themselves in time of need. The long
side roots were laid bare, as much as twenty or thirty
feet, and divided into short lengths, from which water
dripped at once, clear, cool, and free from any
unpleasant taste or smell.

How the water remains so cool, buried only from
six to twelve inches beneath the burning surface, is one .
of the many mysteries connected with the great mystery
of life.

Water in a pipe, from which there was little or no

Deserts 113

evaporation, and water in a dead root, would speedily
grow warm under similar circumstances. Water in a
porous vessel keeps cool, indeed, in the hottest sun,
‘because the vessel 7s porous, and water is constantly
passing through it and being turned into vapour; with
the result that the air immediately surrounding the
vessel is being constantly cooled. The water is turned
into vapour by means of the heat abstracted from the
air.

But the water in the roots of the eucalyptus is not
kept cool by evaporation; else, in time of drought, it
would be evaporated altogether. Besides, the juice of
the hard, leathery-skinned pomegranate is cool on the
hottest day; so, too, is that of the melon, with its
thick rind; and the abundant juice of the thick-skinned
mango feels as cold as iced water, even under the
blazing sun of Ceylon; though the evaporation from
any one of these must be very slight indeed.

“Moreover, the coolness lasts oly while the fruit
remains on the plant, and disappears in a few minutes
after it is gathered. It must, therefore, be quite
independent of evaporation, and the temperature of a
living plant’s juices must be like the temperature of
‘the blood in men and animals, quite independent of
climate.

The ordinary temperature of the blood of human
beings (98° F.) remains the same whether they live
under the equator or in the Arctic regions.

And so it is with plants. They are cold-blooded, so
to say, and cold-blooded they remain, even when sur-
-rounded by hot air, as long as they are alive. When
they are dead their temperature soon rises or falls,
according as the surrounding air is hot or cold. But

8

114 Deserts

if, while alive, the temperature of their sap were
affected by climate, or by the changes of summer and
winter, day and night, then not only would it be con-
stantly frozen in the far north, and not far short of
boiling in the tropics; but the sap of an acacia of the
desert might freeze by night and almost boil by day—
a sudden and violent change, which, as has been
shown, wears out the very rocks.

But to return to the ‘deserts,’ by which we are to
understand those regions where water is scarce,
drought frequent, and where vegetation, though seldom
or never entirely absent, is more or less scanty, and
more or less peculiar, because it is especially adapted
to the special circumstances of its situation.

The soil of the desert may, or may not, be poor, but
it is the want of water which renders these regions
comparatively barren.

Well-watered, the Kalahari desert might, it is said,
be one of the richest grazing lands in the world; and
the utter barrenness of certain tracts of the Sahara is
owing merely to the lack of rain, for the soil beneath
the sand is actually rich, and is not only quite capable
of supporting vegetable life, but is extremely fertile
wherever there is moisture.

The other marked characteristic of desert-lands is
the dearth, if not absence, of trees, and the question
we have now to consider is whether these two charac-
teristics—the want of water and the scarcity of all
vegetation, but especially of trees—are brought about
the one by the other.

Vegetation cannot thrive, though it may manage to
exist, without a regular supply of water; but does
vegetation bring rain or increase the rainfall ?

Spe
see

.
KS

SS

Deserts 115

There is no doubt whatever that where forests have
been recklessly destroyed there the climate has been
most seriously injured. The Ceylon coffee-planters
cut down forests to make more room for their planta-
tions, and many of them were ruined in consequence.
The trees were gone, but so, to a large extent, was the
rain also; and the additional space gained was value-
less, for the coffee could not grow for lack of moisture.

So, also, the destruction of the olive-trees in Pales-
tine has diminished the rainfall there, and with the
rainfall the productiveness of the land, for centuries
past. Now that trees have been planted again the
rain is said to be returning.

So much, then, is certain: cut down forests and you
will have less rain; and, though the natives of
Namaqua Land, South Africa, attributed the great
diminution in their rainfall to the presence of the
missionaries, others had no hesitation in ascribing it to
their own wasteful way of cutting wood.

But though loss of forest brings loss of rain, it is
difficult to say precisely how the change is brought
about, and whether rain is actually caused by transpira-
tion or not.

Wherever there is vegetation, be it grass or be it
forest, there, as has been shown, large quantities of
water are constantly passing off into the air in the form
of vapour. And the amount is large, not merely con-
sidering the means by which it is pumped up, but it is
large actually ; very large, when we compare it with the
amount of rain which falls.

For instance, from the record kept at Greenwich it
appears that during July, our wettest month, the
average fall of rain is something under three hundred

116 Deserts

tons to the acre, or under three inches—three hundred
tons during the whole month, or less than ten tons each
day. But an acre of pasture-grass actually gives up
more than ten times this quantity in the course of
twenty-four hours—106 tons—that is to say, in a single
day and a night. So that an acre of pasture which
has received three hundred tons of rain in a month,
gives up more than three thousand tons in the same
time.

The question as to where this immense quantity
comes from will have to be considered later. At
present we are concerned only with the fact that so
much water is returned to the air. Whether it falls
again on the same spot is another matter, and we have
no proof that it does so. It may do so under certain
circumstances, or it may be carried away by the wind
and fall elsewhere, perhaps close by, or perhapsa long
way off.

But if the air immediately over a certain district is
being constantly cooled by the evaporation day after
day of large quantities of water, does this produce no
effect upon the air above?

What happens when water is boiled over a fire?
Clouds of visible vapour rise from it, which we com-
monly call ‘steam.’ They are not properly steam,
however, for steam is invisible. These are clouds, true
clouds, consisting of minute globules of water, steam
made visible, converted into water again by coming
into contact with the air of the room, which is cooler
than that within the kettle.

As heat converts water into gas or steam, so cold
turns it back into water again. So when the earth is
chilled at night the moisture of the air is also chilled

Deserts 117

on a large scale, and dew is formed—first on grass and
leaves, because they are cooler than the soil.

If this be so, then when a current of warm moist air
comes in contact with the cool air over a forest, or
over acres of pasture, will not some of its moisture be
condensed into a cloud, as the steam from a kettle is
condensed into a cloud when it escapes into the air,
and may not this cloud discharge itself upon the grass
or the trees ?

Of course the cloud may be carried away; but it
seems likely that, in some cases at all events, it will
water the district above which it is formed.

There is a further question as to whether trees
actually attvact the clouds or not, and this still waits
for a satisfactory answer ; but it is certainly the popular
opinion that they do, and it is a very common thing to
hear it said that the clouds have gone over to a neigh-
bouring park or wood, when the farmer would have
been better pleased that they should water his fields.

As we began by saying, the subject is a difficult one ;
but though we may not be able to explain precisely
the how, there is no doubt at all as to the fact that the
presence or absence of all vegetation, not of trees only
does very greatly affect climate, and the climate in its
turn affects vegetation.

For instance, Tacitus, the Latin historian, writing
some eighteen hundred years ago, mentions that not
even a cherry would ripen on the banks of the Rhine;
and he certainly would not have believed that in cen-
turies to come the same region would have become
warm enough to be famous for its vineyards. But
in his day forests abounded all about the river, and
it is the removal, or great diminution, of these which

118 Deserts

has raised the temperature. A similar, but in this case
disastrous, result has been produced on the southern
slope of the Pyrenees, where what once were wide
fertile tracts, covered with vegetation, have been turned
into wastes by the destruction of the forests too reck-
lessly carried out.

Wooded countries certainly seem on the whole to
receive most rain; and the clearing away of any kind
of vegetation, be it herbage, brushwood, or forest-trees,
may be, and often has been, attended by evil canse-
quences. For vegetation protects the soil from
evaporation, enabling it at least to keep what water
it receives, and, as this accumulates, springs, or
reservoirs, are formed, from which the plants in their
turn may derive supplies when rain fails or is
insufficient.

Then again, vegetation preserves the soil from the
assaults of wind and rain, a matter of no small im-
portance, especially in mountain regions, for, as we
have already seen, the earth on the slopes may be
clean washed or blown away, and the fertility of cen-
turies may be thus destroyed.

But even this is not all. The soil gone, what
remains ?

Bare rock or subsoil, which is dried and heated by
the sun, growing drier and therefore hotter, till it is
quite parched. Buta dry, hot surface heats and dries
the air above it, for hot air, being lighter than cold,
rises.

From a wide expanse of dry hot sand, such as that
of the Sahara, therefore, there must be a constant
upward current of hot air, and this, again, must act
like a furnace upon any moist current with which it

Deserts 119

comes in contact. The moisture has no chance of
condensing into a cloud, or rain, as it might if it
met with cool air, but is dispersed—drunk up and
evaporated by the hot, thirsty air from below. No
wonder, therefore, that the Sahara is a rainless region.

The island of St. Helena, again, is a notable instance
of what man can do in the way of reducing a luxuriant
garden to a barren waste, simply by his ignorant or
reckless destruction of its natural vegetation. When
first discovered, the island, though very mountainous
and bounded by tremendous precipices rising some two
or three thousand feet above the sea, was very fertile,
and possessed a luxuriant growth of forest. For it is
astonishing what a thin film of soil is enough for seeds
to sprout in, if only it be moist; and it is astonishing,
too, how little soil will suffice even for hardy evergreens,
birches, and other small trees, whose roots often grow
in immediate contact with the rock. But one thing is
absolutely necessary. If the soil be shallow, moisture
must be abundant.

The soil of St. Helena was rich, being formed by the
slow decay of volcanic rocks, but it was not deep, and
was only kept in place by the roots which held it fast.
The Portuguese brought goats to the island, and by
these destructive animals the luxuriant vegetation was
in great part destroyed, for they multiplied by
thousands. There was a wanton waste of wood, too,
on the part of the human inhabitants, though some
were far-sighted enough to predict that the island
would be ruined when the ‘Great Wood’ was
destroyed. And so, sure enough, it was.

Gradually the soil became more and more exposed,
and whenever this was the case, it was washed away

120 Deserts

by the violent rains, leaving bare rock and utter barren-
ness behind. Still the destruction was allowed to go
on, until, as the timber rapidly vanished, not only did
the soil follow, but the vain deserted it also, and the
Governor, taking alarm, reported that the island,
hitherto abundantly watered, was beginning to suffer
from drought.

But the authorities—the island was then in the
hands of the Hon. E. I.C.—were not to be persuaded
that there was any connection between the loss of
trees and the want of rain, and returned for answer
that the goats were more valuable than the ebony-
trees, and were not to be destroyed. So the goats
stayed, and the ebony-trees went; and the general
aspect of St. Helena became that of a dreary rocky
desert.

On the other hand, a change greatly for the better
has taken place in the region round about the Suez
Canal. Here there was formerly hardly a blade of
grass to be seen, and the land was a desert. But the
cutting of the canal has brought water into the midst
of the parched land; this soaks through the sandy
soil, and everywhere herbage is springing up along the
banks. Rain is still rare, but the air is moister; for
the blazing sun draws up from the canal large volumes
of water, which, though it is only invisible vapour by
day, is chilled and condensed into water again by the
lower temperature of the night, and falls upon the
thirsty land as a heavy, refreshing dew.

But the very fact that it is a sandy district is in its
favour in one way, for water soaks easily through it,
and is thus brought to the roots of all plants growing
within reach,

Deserts 121

Then, again, in the Delta of Egypt there is much
more cultivation than there was some years back.
There are more cornfields, more pastures, and even
little forests are springing up, so that its general aspect
is quite altered, and this change is accompanied by a
change for the better in the climate also. Alexandria
has rain, even to excess; and Cairo, which used to
have at most five or six light showers a year, now has
three or four times as much. The increase in the
rainfall seems to be distinctly traceable to the increase
in the amount of vegetation.

So impressed are the Americans of the West with
the connection between want of trees and want of rain,
that they now set apart a day in each year, which they
call ‘ Arbor-day,’ and dedicate to the planting of trees.
Before this idea was started there had been such reck-
less cutting of wood in the mountains and timber
regions as to cause quite a dearth even of fire-wood,
especially in what is called the ‘arid-region’ of the
Western States. Now, however, more than six million
trees are said to be growing on formerly barren lands,
and Kansas alone has 250,000 acres of artificial forest
growing up—a change which it is expected will so
benefit the whole region that it will cease to be arid.

In this land we have little idea of the magic change
produced in the appearance of the landscape by rain
falling upon the hot, parched surface in southern lati-
tudes. There, growth is so rapid that, in Ceylon for
instance, a green hue begins to colour the saturated
ground after a single day’s rain, almost between dawn
and sunset, where all before was dreary brown.

But the change which takes place in the desert of
Nubia is far more wonderful. During the dry season

122 Deserts

not a blade of even withered grass is to be seen; trees
and bushes have shed their leaves—their very bark is
cracked by the fierce heat. The Atbara—that mighty
tributary of the Nile, to which its yearly inundations
are due—has altogether ceased to flow, and is con-
verted into a barren waste of glaring sand, four or five
hundred yards wide, interspersed with a few pools
here and there. And yet the tremendous torrents
which pour down into it from the Abyssinian highlands
have never ceased to flow; but the whole of their
waters, to the last drop, have been evaporated on the
way by the intense heat, or have been absorbed by the
desert-sand which has accumulated in the bed of the
river. Everything is parched, scorched, gasping; not
only the sand, but the air is burning.

Such is the state of things towards the end of June:
the Atbara is dead !

Then one night, when everything is suffocating,
there comes, suddenly, without warning of any kind,
a sound as of distant’ thunder, a continuous roll and
roar, which means that the river has arrived !

There, where there was only sand the day before, it
flows five hundred yards wide, a mighty flood, and
already fifteen to twenty feet deep; for the rain is
pouring down upon the great table-land of Abyssinia,
and it will continue to pour for two or three months
to come.

And the change in all the bare and withered trees
and shrubs, how rapid and how marvellous it is! In
two days’ time they show signs of bursting into leaf,
having previously looked as dead as they do with us
in winter; and as for the mimosas—their light,
feathery foliage is already, beginning to afford shade.

Deserts 123

Yet there has not been a drop of rain, or even of
dew. The air no doubt is moister, for evaporation
from this wide expanse of water must go on at a
tremendous rate. But at present it is too hot and
dry to part with a single drop; and it is from the soil
that the trees have received their fresh supplies, so
quickly does the water soak through the sand. But
this is not all that they will get. All nature seems to
expect a change, for the wind is blowing from the
south, and rain is surely coming!

The natives of South Africa say that the wind
‘smells of green grass’ when the wind blows from a
quarter where rain has fallen, though this may be
hundreds of miles away; and thousands of cattle will
start off sometimes and travel immense distances, in
the endeavour to reach the fresh pastures of which the
wind tells them. So keen is the scent of men and
animals in lands which suffer from long drought.

X.
ROOTS

PLaNntTs, as we have seen, need a constant supply of
water for transpiration and for growth. They cannot,
as a general rule, take this in by their leaves, and
therefore must take it in by their roots; and without
water the roots cannot take up and supply to stem,
branches, leaves, flowers, and fruit that mineral matter
without which the plant cannot exist.

Before examining the way in which the roots perform
their work of supplying all parts of the plant with
liquid food, we must briefly consider where the water
comes from.

For if, as has been said, the ordinary rainfall in
England for the whole month of July is about 300
tons, and if an acre of pasture-grass transpires more
than 3,000 tons in the same time, it is quite evident
that the demand far exceeds the supply from the
clouds. Moreover, the grass does not get even the
full benefit of that which does fall, for a very large
proportion is either at once evaporated from the
soil, or is drained away into ponds, lakes, streams, or
rivers.

Of the rain which falls in England between April 1

Roots 125

and October 1, it has been calculated that go per cent.
is evaporated from the soil and returned to the air.
From the air, however, the soil again absorbs it; for
though leaves do not absorb moisture from the air,
the soil does.

We speak commonly of the air as being ‘damp’
or ‘dry,’ as the case may be; but in point of fact
it is never absolutely dry, for nothing could live in
it if it were. It always contains some amount of
watery vapour, and, whether it be large or small,
soil which has been dried during the day regains some
degree of moisture by night by the simple process
of sucking it from the air. The air sucks it from
the soil by day, especially during sunshine or dry
wind, and the soil thus dried sucks it back again at
night.

Some soils suck much more moisture from the
air than others, and some are also able to keep it
much longer than others. We all know that a sandy
soil, for instance, is a dry soil: it takes some time
to grow really damp, and it dries again very quickly.
Indeed, pure quartz-sand seems as if it could not be
moistened by anything short of rain or dew, being in-
capable of sucking any moisture from the very dampest
air.

A chalk or limestone soil, on the other hand, acts like
a sponge, and, though it may dry on the surface, keeps
its moisture a long time within. The subsoil of the
Kalahari Desert, already mentioned, is limestone; and
this is probably one reason why the grass there is able
to remain green so long without rain. Such water as
is received is kept for some time, stored up in the sub-
soil.

126 Roots

Of all kinds of soils, it is those containing most
vegetable matter which take up most moisture, and
also remain damp the longest.

It is a curious fact, however, that the soils which are
least ready to part with their moisture to the air are
also those which are least ready to part with it to the
roots of plants. There may be actually more moisture
in vegetable mould than in sand; but the latter, at all
events, makes the plants welcome to what there is, and
lets them have almost every drop; while the mould
may have more to give, but also keeps back more. If
the two contained an equal amount of water, there-
fore, plants would actually be better off for moisture
in the sand than in the mould; but this is not the
case.

An experiment made for the purpose of trying
different soils with regard to their readiness to give
up their moisture to the roots of plants gave some
very interesting results: the soils chosen were three
—1, loam; 2, a mixture of vegetable mould and
sand; and 3, coarse sand alone; the loam held two
and a half times as much moisture as the sand, and
the sand and mould mixed held more than twice as
much.

In these three soils were placed some tobacco plants,
which are very thirsty and very watery—four-fifths
water, indeed. Their broad, tender leaves begin to
droop as soon as gathered owing to their rapid tran-
spiration. The sand gave up the whole of the water
it contained with the exception of one and a half per
cent., and it was not until it had reached this dry state
that the tobacco planted in it flagged ; the other plants
flagged when the loam still contained eight per cent.,

Roots 127

and the vegetable mould and sand a fraction over
twelve and a quarter per cent.

The supply contained in the sand was exhausted
first, of course, because it contained so much less to
start with; but, though the other soils were not nearly
as dry, the plants flagged because they could not get
hold of the water which they still contained.

Some plants, such as rice, grow equally well in soil
or water, but most plants are injured by having their
roots kept in water for any length of time, and are, as
a rule, in better health when allowed to take up the
moisture they need from that which is contained,
invisibly, in the pores of the soil, when it does not look
actually wet at all, and no moisture could be squeezed
out of it.

But our main point now is to show that soil may,
and does, become damp without rain. It may be dried
_by sun and wind by day, but it makes up for this by
drawing moisture from the air by night, and it is this,
partly, which enables plants at least to live through a
time of drought, though their very stunted growth
shows that the supply has been insufficient for their
needs.

The moisture which the soil thus draws from the air
does not remain on the surface, but, like the rain and
dew, sinks into the ground, penetrating deeper and
deeper, and moistening the soil until it is used up, or
stopped by meeting either with damp soil, or with soil or
rock through which it cannot pass. Rain falling upon a
porous soil, such as sand, or even soil containing much
sand, passes quickly through it until it meets with a
bed of stiff clay or rock, which prevents its going
further; and then what is left, over and above what the

128 Roots

soil has taken up, accumulates, and may in time form a
spring, or even a sheet of water. In some places there
are known to be very extensive underground lakes, and
these must do much to keep the soil above them moist
in the absence of rain. The springs, or underground
streams, too, do the same, and in some cases they flow
such long distances that it seems not unlikely the
Kalahari Desert may have some such subterranean
supply of waier, which enables the plants to live
through the long terrible drought.

But, it may be asked, what is the use to the plants
of water so far beneath as to be quite beyond the reach
of their roots? The answer to which is that it does
not remain beyond their reach, but is brought up to
them.

The water in the soil, visible or invisible, is like a
stream which is never at rest; it is in constant motion,
always either rising or sinking according as the surface
of the soil is damp or dry.

When the surface is wet from rain, the rain goes
on sinking down and down till it is either absorbed
by the soil through which it passes, or accumulates
at some greater or less depth below. But when the
sun shines out again, or a dry wind blows, the
moisture of the surface is evaporated, the upper soil
grows dry again, and, the moment it is drier than the
soil below, the damp soil begins to give up its moisture
to this drier bed immediately above it. Thus the
stream of moisture at once begins to ascend, and will
continue to ascend until the surface is wetted again;
it moves, in fact, either up or down, to the drier parts
of the soil, whichever these may be, the movement
being exactly like that of the oil in the wick of a lamp;

Roots 129

as fast as the oil is consumed, more rises to take its
place.

In time of drought the soil may appear quite dry
even to some depth, but, as we have seen in the case
of the tobacco planted in sand, plants can continue to
draw moisture from the soil long after all trace of
moisture has vanished, so far as can be seen. To find
it at all we should have to dry the soil by artificial
heat; but it is there, and the plant manages to draw it
out.

In very long droughts, even the springs near the
surface may fail, all their water being drawn away
from them by degrees; but still, at a greater or less
depth, some water there is, for the deeper wells do
not fail though the shallow ones may; and, unless
this water be buried under some bed through which
it cannot pass, it will continue to rise to the sur-
face.

The water which plants need, therefore, for growth,
and to supply the small loss by evaporation and the
large loss by transpiration, comes to them from rain and
dew; it is also very largely absorbed from the air by
the soil; and the large stores accumulated in the
ground are also drawn upwards as they are needed-—
chiefly, of course, during the spring and summer. In
autumn, when growth ceases, transpiration is less; in
winter, when the trees are bare, there is next to none,
so that they have little need of water. In spring and
summer, on the other hand, they need much, and
receive it, in part, from the accumulated stores of the
other months.

All the water which plants transpire—in many cases
a very large quantity, as we have seen—is taken up by

9

130 Roots

their roots, and their roots alone. And these roots we
must now look at a little more closely.

A root is a very wonderful organ, much more won-
derful than a passing glance would lead one to suppose.
And, indeed, the most important parts cannot even be
seen, without careful examination.

The root serves two purposes : it keeps the plant in
one place, enabling it to stand against the wind; and
it collects from the soil food and water which the
plant can obtain in no other way, and without which it
can neither grow nor exist.

Some plants have a single fleshy root, like that of a
carrot, which descends straight into the earth, and has
no branches, but only a few fibres growing from it. A
carrot needs a good pull to uproot it; but an onion is
easily lifted from the earth, as its roots are only fibres
growing from the base of the bulb; while a dock may
resist the full strength of a man.

Water-plants have few roots, as their food comes to
them already prepared, without their having to search
for it ; bog-plants have more roots, as they have more
work to do; and land-plants have most of all, as their
roots frequently have to explore the earth for a con-
siderable distance in search of food.

In a fertile soil, where there is plenty of food, roots
are generally short and much branched. They branch
out, in fact, where the food is to be found. Butina
poor soil they have to go further to find what they need,
and are usually long and slender.

But the mere mention of so many feet gives no idea
at all of the real length of a plant’s roots; for besides
the long main roots, there are rootlets innumerable
branching from them, and these rootlets, though they

Roots 131

may be mere threads themselves, are covered with
millions of hairs, generally so minute as to be hardly
visible without the help of a microscope.

But here again, as we have seen in various ways
before, it is the small, insignificant workers which are
of the most importance. It is through the younger,
threadlike rootlets, and through these millions of
minute hairs, that food is chiefly taken up; and this is
why, in moving a plant, the gardener is careful to keep
a ball of earth round its roots, that the small, deli-
cate rootlets may not be injured, and its food-supply
lessened.

The root-hairs are being constantly produced in
fresh millions, for each individual lasts but a few days.

It is difficult in any degree to realize what length of
root a plant possesses, for to do this one must measure
not only the main root, or roots, but the branches,
rootlets and fibres as well; and even then, the fringe
of hairs will have to be left altogether unreckoned.

An oat or barley plant, for instance, has roots
several feet long; but when we say several feet, we
merely mean that they stretch several feet down-
wards through the soil. Their real length, if the
many roots are measured end to end, branches and
all, is a very different matter. A_ barley - plant
grown in a very small quantity of rich porous soil,
was found to have a total length of root of 128
feet! This measurement included the fibres, but not °
the hairs. In loose soil, such as this, roots can make
their way easily; but in closer soil, growth is more
difficult, and so slower, and a plant grown in soil of
the latter sort had roots only 80 feet long. Only 80
feet; but both the 80 feet and the 128 feet were packed

132 Roors

into the fortieth part of a cubic foot of soil, a quantity
which would be contained in a box between three and
four inches square and equally deep.

Of course, if these roots had had their liberty they
would have been much less branched, and would have
spread much further. They would, so to say, have
gone much further ahead, without running up so many
by-paths. But being prisoners, they had to make
the most of what they had, and so explored most
thoroughly the small space at their command. Every-
one knows what a mat of roots and fibres there will be
when a plant is taken out of a pot too small for it; such
a mat that the earth is often completely enveloped.

Now, of course, it is not natural for a plant to grow
in a confined space, with its roots crowded together in
this way, and when left to grow as it likes, in the open
ground, its roots often roam to great distances, and
therefore require much more soil than they make use
of as food. The poorer the soil the farther the roots
spread in their endeavour to find nourishment, and a
maize-plant in sandy soil will send its roots out a dis-
tance of ten or fifteen feet.

It is supposed that only a very small portion, perhaps
a hundredth part, of the soil helps to feed the plants
growing in it. And this is probable enough when we
consider it; for the soil, however fine, still consists of
solid particles, which the roots cannot swallow; and
though it is being constantly dissolved by water and
gases, the process is a slow one. Where the soil is
coarse the process is slower still. For, as a lump of
sugar takes much longer to dissolve than the same
quantity of sugar when reduced to powder, just so it
is with the soil; when it is fine the water has a very

Roots 133

much larger surface to act upon, and,can act more
quickly. And this is one reason why finely-ground
soils are so generally fertile.

But this is not the only reason; for, besides drink-
ing in the moisture of the soil, with whatever may be
dissolved in it, the roots do much dissolving on their
own account. And it is for this purpose, apparently,
that all, down to the smallest fibre, and even hair, are
more or less acid.

What food comes to them ready dissolved may be
brought from a distance from the soil above or below
the roots, but it 7s brought. The particles of soil, on
the other hand, do not move, and the roots must go to
them, and actually touch them, and that very closely,
for the acid to be able to act upon them. A rich
morsel which is a foot, or even an inch or a half-inch
away, is of no use, except so far as it may be dissolved
by water. The roots can do nothing with it unless
some part of them, fibres or hairs, are near enough to
get hold of it and press close to it, as the lichen adheres
to the rock.

And it is this which makes it so important that a
soil should be not only finely ground, but well mixed,
so that all the ingredients may be within reach of the
roots of each plant.

Most soils distinguished for their fertility contain a
large proportion of fine matter, and to this is largely
due the extraordinary productiveness of some of the
lands of Ohio, which have borne heavy crops of wheat
and maize for sixty years in succession. A-consider-
able part of the soil here consists of particles which
measure from the five-hundredth to the thousandth
part of an inch across, The same thing is to be

134 Roots

observed in the Black earth of Russia, and again in
the mud brought down by the Nile and other rivers :
all are distinguished for the fineness of their particles
and their thorough mixture.

Why is it that a block of granite is able to support
only a few lichens and mosses? Chiefly because it 1s
a block, into which roots cannot penetrate. It would
not make a really fertile soil even if it were crushed
into coarse gravel, but it would grow more than it does
now; and if it were ground to fine powder and kept
well watered it would grow even corn—not perhaps
good crops, though even granites differ in fertility, but
still corn—whereas not a stalk can spring up while the
granite remains a block, no matter how diligently it be
watered.

By way of testing this point, an experiment was
made with some barley sown in a soil consisting ot
pure felspar. Felspar is that one of the three minerals
of which granite is composed, which, when finely
powdered and washed away, forms beds of clay. In
this case it was first only coarsely powdered, and the
barley grew to a height of fifteen inches; moreover,
the ears formed, one ear ripened, and two seeds were
perfected. In the second instance the felspar was finely
powdered, and the stalks were very much stronger.
One grew to a height of twenty inches, and perfected
four seeds.

Felspar alone, though a compound of several
elements, could not in any case produce a good crop;
for the stiffest clay soils under cultivation have been
not only well ground, whether by ice or water, but
also mixed besides, and contain sand and other in-
gredients.

Roots 135

It is, of course, possible for the soil particles to be
too fine, as they are in pure clay, which is so close in
texture as to exclude what is as necessary to the plant
as food and water, namely, air. A plant’s roots need
air as much as any other part of it, for they are con-
stantly taking up oxygen, and hence all specially fertile
soils contain a large proportion of sand, which makes
them light and porous; for, though fine, it is not nearly
as fine as the particles composing the clay, and does
not turn into a stiff paste when mixed with water.

In a stiff, heavy soil roots make their way with less -
ease and with less rapidity than in a light, loamy one
containing a large proportion of sand, and therefore
they must needs collect food less rapidly. Moreover,
both air and water penetrate a heavy soil less easily
than they do a light one, and hence not only is the air
which the roots need less able to reach them, but less
water can enter also, and consequently less soil is dis-
solved and made ready for their use. The ‘loamy
soil’ which a farmer loves contains from forty to
seventy per cent. of sand.

Here, again, we see the great usefulness of earth-
worms. In sand they, like the roots, can make their
way so easily that they have little need to remove the
soil by swallowing it, the only means at their disposal.
But in a stiffer soil they are obliged to do this, and
thus they let in both air and water, to the great
advantage of the plants, while they also spare the roots
much labour by preparing for them airy passages,
down which they can run with ease.

But though roots take advantage of these ready-
made channels, and are evidently all the better for
them, they do not let go their hold on the soil,

136 Roots

but keep a close grasp of it, lining the worm-
burrows with thread-like fibres, which cling fast to
the: sides. -

Roots coming in contact with a piece of limestone
will leave upon it a perfect impression of themselves,
even to the hairs with which they are fringed, showing
how, like the lichens, they have eaten their way into
the solid substance.

How do they do it? Wecan hardly do more than
conjecture; but it seems probable that the acid in the
roots acts much as acid contained in a bladder would.
If a glass tube is filled with water made slightly acid
with vinegar, and then covered with a piece of
moistened bladder strained tightly over the mouth,
and in contact with the liquid, this will represent the
root, though the resemblance would, of course, be
closer if the tube itself were of bladder. This, how-
ever, seems to be the only practicable way of trying
the experiment. The acid is very weak, as the acid in
the roots is weak; but if salts, such as phosphate of
lime, and others found in the soil, are now strewn
upon the bladder, they will in a short time begin to
pass through it into the tube, being dissolved by the
weak acid in its pores.

The acid in the roots acts, it is supposed, in a
similar way, and thus the dissolved minerals are
sucked in. But, as before said, living things have
more power than dead ones; so it may well be that
roots, like lichens, dissolve more than the weak acid
alone would do.

The roots take up what they themselves dissolve
from the particles of soil immediately surrounding and
closely touching them, and also what the water in the

Roots 137

soil has dissolved for them, with the help of carbon-
dioxide and other gases.

The water thus taken up—for what is dissolved by
the roots and what is dissolved by water and gas are
taken up together—the water thus taken up is a very:
weak solution of various salts—phosphates, and others
—so weak that it may fairly be compared with ordinary
drinking-water.

No water in nature is or can be perfectly pure, as
has been said, because it is constantly dissolving some-
thing wherever it goes. And though, even with what
the roots have dissolved, the solution is still so weak as
to pass for ordinary water, yet it must be borne in
mind that the roots are constantly sucking it in, and
that the leaves are as constantly returning the water
to the air—only the water, however. The salts remain
behind and accumulate day by day.

The same sort of thing on a vast scale goes on with
the rivers and the ocean. River-water is generally
tasteless, though it, too, contains various salts dissolved
in it. This small proportion of salts is, however, being
constantly poured into the ocean, while the sun is
constantly taking away by evaporation almost pure
water. The -salts, therefore, accumulate, and sea-
water is salt and bitter in consequence.

The salts left in a plant do not usually make it salt
or bitter, because the quantity is altogether extremely
minute in proportion to the plant’s size; and as they
are distributed through the whole of its substance,
there is a continual demand for them while the plant
is growing or putting forth fresh leaves.

But if a plant is stunted by drought it may become
actually bitter A cabbage, for instance, which has

138 Roots

not reached perhaps a quarter its proper size for want
of water, will be quite bitter; and the reason seems to be
that the salts, which would have been enough for a large
cabbage, are compressed into a very small one. Or, in
other words, the roots have not been able to find
enough -water to dilute the food which they have
gathered, as well as to keep pace with the transpiration
of the leaves, and to allow of their proper growth.

XI.
FOOD FROM THE SOIL

IT is but a very small part of their food after all which
plants, generally speaking, draw from the mineral
matter of the soil in which they grow; and yet this
small quantity is not merely important, but absolutely
necessary. It is dissolved by water and gases, and by
the action of the plant itself, and is then taken up by
the roots, especially. the younger, finer roots, and root-
hairs, by which it is passed on to the stem, and so is
conveyed to every part, not only to branches, leaves,
and buds, but also to flowers and fruit. Every part
of a plant needs some amount of mineral matter, and
the plant cannot obtain it without water, for whether
dissolved by the plant’s roots or otherwise, it is in each
case taken up in a very diluted condition ; so diluted,
indeed, that the water containing it is hardly to be dis-
tinguished from ordinary drinking-water.

The plant could not be sufficiently nourished by
these very weak dilutions, especially while it is growing,
but for the fact that it is constantly receiving them.

Perhaps one of the most striking examples of the way
in which plants are fed by this very weak food is to be
found among the sea-weeds. Many sea-weeds contain

140 Food from the Soil

large quantities of iodine, which, like the rest of their
food, they draw from the sea. With the smell of
iodine we are all no doubt familiar; but if we mix one
part of iodine with 300,000 parts of water we entirely
lose it. That is to say, no one of our senses is keen
enough to detect it. We can neither see, nor taste,
nor smell it. But of course it is there, and we can
find it again by adding starch, which is turned to a
brilliant blue by coming in contact with even this
minute quantity.

But the iodine contained in sea-water is less even
than this—it is less even than the hundredth part of
this infinitesimal amount. And yet the sea-weed
manages to extract it. And although plants take their
mineral food in such weak dilutions that we cannot
detect its presence either by taste or smell, and might
be inclined to think that it can matter very little what
it is, yet they are discriminating ; and their roots have
to some extent the power of choosing what they will,
or will not, take up.

This is evident from the fact that plants growing
side by side will take up different food, or take it in
very different proportions.

There is, for instance, the common reed and the
common species of moss, which both grow in bogs.
The soil is dissolved by water and gases equally for
both, and both take up a good deal of dissolved flint,
or silica; but the reed takes up also a very small
quantity of salt, a little more, but still a very small
quantity, of iron, no soda, a little magnesia, and a great
deal of phosphoric acid; whereas the moss, which grows
close by, takes very little either of phosphoric acid,
magnesia or salt, but some soda, and much iron

Food from the Soil — 141

The same thing is also true of the farmer’s crops,
and it is for this reason that he varies them, not
growing the same crop year after year, or even two
years running, on the same soil, lest it should be
exhausted and unable to feed them.

Corn-crops, for instance, take up much flint, which
goes chiefly to give the hard, glossy coating to their
stems; and they want from a fifth to a tenth part as
much potash. Turnips and beet, on the other hand,
take in little flint, but more lime and potash; and
turnips and carrots will use up the sulphuric acid;
while clovers want little sulphuric acid, but much
potash, lime and soda.

All plants need more or less of several mineral sub-
stances, and even when it is ‘less,’ they cannot do
without this lesser quantity, be it never so small.
When, therefore, we say that corn-crops take up much
silica or flint, it is not at all meant that they do not
take some proportion of lime, potash, soda, sulphur, -
iron and phosphoric acid as well; for they use them
all, in larger or smaller quantities.

The amount taken up of each varies in different
kinds of corn; wheat, oats, barley, etc., have all their
special needs, and so, too, have different varieties of
the same kind of corn. More than this, different plants
of the same variety differ slightly in this respect, as
if they had their own individual preferences; but the
difference is very slight, and in plants of the same
species, the proportion always remains nearly the
same.

And this is true, no matter where the plant may
grow. If it grows at all, its ash—that is, the mineral
substances which it has taken from the soil—will always

142 Food from the Sot

be found to be pretty nearly the same; the proportion
will be the same, that is to say, for of course, in un-
favourable soil, the plant may be a dwarf. Grasses,
for instance, which are like corn in taking in consider-
able quantities of silica, will take up just as much of
this when they grow on the chalk soil of the downs as
when they grow ina soil containing much sand. Yet
chalk, pure chalk, does not contain a particle of silica.

As before remarked, however, such a thing as a
perfectly unmixed soil is hardly to be found anywhere.
Even on the mountains there is rarely less than ten
per cent. of soil which has been brought from else-
where, either by wind or water, or added to it by
animals. So it is on the downs, and the grass finds
there what it needs. ;

It would be rash to say of any plant that it will not
grow on any soil until it has been tried; but plants
certainly have their likes and dislikes in this matter,
though sometimes a good climate will make up for
poor soil.

Clover, for instance, loves lime; and cowslips and
primroses are poor and scanty where lime is deficient,
and luxuriant on chalk ; but the heather, in this country
at all events, shuns lime; and though it may be found
growing close by on a patch of sand, and though its
seeds must be scattered all around, it is not to be found
on the chalk downs. Here and there a stray plant
may be seen growing in a mixture of sand and chalk;
‘but as a rule it is conspicuously absent from chalk
and limestone in England, and in Wurtemberg it
actually disappears even from sandy soils, if marl
containing more than a fifth part of lime be added to
them. But the same thing does not hold good in

Food from the Soil 143

France, where heather is sometimes to be seen actually
thriving on a limy soil. :

Some plants have such peculiar tastes, or require-
ments, in respect of soils, that they must seldom, one
would think, be able to gratify them; and one almost
wonders where the seeds come from when the oppor-
tunity for growing does arrive.

Some, for instance, are never to be seen except after
forest-fires; apparently because they require wood-
ashes to growin. Other plants have similar likings ;
and it was observed that after the fires of London and
Copenhagen, plants of the same kinds grew among the

_ tuins of both cities.

It is very- remarkable, too, what slight, and even
imperceptible, differences in the soil will make very
great differences in the crops grown upon them. This
is especially noticeable in the case of vines. Tokay
wine, for instance, cannot be made except from grapes
grown in the one district from which it takes its name.
The vines may be grown elsewhere, but the wine is
different. So, too, in France; vineyards growing side
by side, and separated only by a narrow footpath,
having the same aspect, and apparently the same soil,
and cultivated in precisely the same way, yet produce
wine of quite different qualities and very different
values.

Plants differ, too, extremely, among other things, as
to the quantity of salt which they take up. To corn,
and most other plants, any large quantity is absolutely
fatal. Some, however, take up much.

On the west coast of France grow various species of
the small plants called, from their love of salt, salt-
worts, which are interesting because, though they are

144 Food from the Soit

entirely lost sight of as one moves inland, and are not
to be seen anywhere, all across Europe, except in the
neighbourhood of salt-springs, yet they do reappear
in some parts of Hungary, and in the great plains, or
steppes, of south-east Russia, where the soil contains
so much salt as to be often encrusted with it in
summer.

Here these plants thrive as well as on the coast, but
nothing else will grow, except a few such plants as are
nearly related to them; and in some places it is the
custom to cut and remove the whole crop of these
every year, by way of improving the soil. The plants
have some value in themselves, because they yield soda
—common salt being a compound of soda; but the
main object in cutting them is that, by this means, the
salt may be gradually removed from the soil, so that
other and more useful crops can be grown ir it.

And what is true of the saltworts is true of every
crop. That is to say, every crop takes away from the
soil, not one mineral substance only, but several, in
larger or smaller proportions; and the soil is to this
extent poorer than it was before. If the crop is cut
and carried, nearly the whole of what it has taken up
is lost to the soil; in the case of turnips and other
root-crops, the whole plant is taken away, and the loss
is so much the greater.

A meadow which is mown by a machine, too, loses
more than one mown with the scythe, as the machine
cuts closer; and horses are said to take more from a
meadow than either sheep or cows, tor a similar reason,
because they are closer feeders. But where a crop is
consumed by animals, it is not all lost to the soil.
On the contrary, so much is returned to it in their’

Food from the Soil 145

droppings, and returned, too, with increased fertilizing
powers, that the land is actually benefited, and needs
no other manure; whereas hay-meadows cannot go
on bearing crops year after year without being manured
or top-dressed, to make up for their yearly loss.

It is a different matter, of course, where the crops
grown by nature are concerned ; for these, being neither
machine-mown nor scythe-mown, so far from rendering
the soil poorer, really do much to enrich it.

Herds of wild cattle may eat off grass and herbage,
as they did for ages before man came and took posses-
sion of their grazing grounds, but they manured the
soil in return. And the same is true, in its degree,
of squirrels, monkeys, birds, bats—in fact, of all the
grain, fruit, and vegetable eaters.

The same is also true, though in a different way, of
the plants themselves. If they are left alone, they
return to the soil all that they have taken from it, and
more besides. For they give to it, also, that food
which they draw from the air, of which we have yet to
speak.

The roots of a tree are constantly bringing up sup-
plies from the deep subsoil, which, when the leaves fall,
are added to the surface-soil ; and the ancient forests
of North America, after flourishing for ages, and pro-
ducing enormous quantities of timber, left the soil,
not impoverished, but so rich that it was hardly
exhausted by a whole century of wasteful farming.

The ‘ yellow earth’ of China, a deposit of very great
extent, is believed to consist very largely of the ashes:
of plants, accumulated during more generations than
one can attempt to realize, for in some parts it is more
than 1,500 feet thick.

IO

146 Food from the Soil

It is the long-continued course of this green-manuring
which has so largely contributed to produce the extra-
ordinary fertility of the ‘Black earth’ of Russia and
the region of Manitoba. And so, too, with the Pampas
of South America, a still more interesting example,
because the process is going on under our eyes.

In the winter Captain Head found the ‘thistle’ part
of this region looking something like a rough turnip-
field intermixed with clover, so large and luxuriant were
the leaves of the ‘ thistles’—really wild artichokes. In
the spring, the ‘thistle’-leaves had spread, and had
overgrown the clover, but still had the appearance of a
rough crop of turnips. Less than a month later, how-
ever, they had shot up in the most surprising manner,
and were in full bloom. They were now ten or eleven
feet high, and formed such a close, impenetrable barrier
on each side of the track that nothing whatever could
be seen in any direction. The growth was so amazingly
rapid that an army might easily have been hemmed in
unawares by the thick, strong stems.

Before the end of the summer there was another
change. The heads drooped, the leaves faded, the
stems turned black and rattled in the breeze until they
were blown down by the periodical hurricane, when
they quickly rotted away, and the strong luxuriant
clover rushed up again.

The artichoke, as well as its near relation the true
thistle, requires a rich soil, and would be an exhaust-
ing crop if it were cut and removed, because it takes
so much food; but as the roots penetrate to a great
depth, it benefits the clover, and the clover in its turn
enriches the soil for the thistles.

Clover is found, indeed, to be such a beneficial crop

Food from the Soil 147

that farmers in America sometimes grow it in alternate
rows with wheat, and this is also the only kind of
green-manuring commonly practised in England. It
is in warm countries, where growth is rapid, that this
sort of manuring is chiefly useful; and in the Azores,
yellow lupins are very frequently sown among the corn
and ploughed in when it is reaped.

Lupins are plants which are especially active in
_ dissolving mineral matter; and the same is true of
other members of the large family of leguminous
plants to which they belong—clovers, vetches, beans,
peas. Moreover, not only these but other plants
dissolve more food than they need for their own
immediate use and leave it in the soil, making it
easier therefore for their successors to find nourish-
ment.

This, then, is another important service rendered
by the wild crops which have grown for ages past on
what are now the best soils in the world for the
farmer’s purposes. Whether these crops be trees, or
shrubs, or herbage, they have not only brought subsoil
up to the surface, but they have, at least in some
cases, dissolved more than they have used, and have
left it all ready for the crops which follow to make
use of. j

But even this is far from exhausting their very
important list of services. Indeed, the most impor-
tant of all has yet to be mentioned.

Animals cannot live either upon mineral matter or
upon gases, though they need both, until these have
been made ready for them, which they must be in the
first instance by vegetables.

Plants are more independent, for they can make use

148 Food from the Soil

of mineral matter, and of gases; but they, too, need a
little organic matter as well, either animal or vegetable.
Some plants need more than others; but no soil is
really fertile which does not contain at least some
small amount. As has been shown, however, no soil
is absolutely lacking in this important ingredient, for
wherever plants have grown, or animals, however
lowly, have lived, there they have left their remains.

Why plants should need organic matter is another
and more difficult question, which seems to be at
present unanswerable. All organic remains, of course,
contain some mineral matter; but this the plant can
get from the soil. They all also contain much carbon ;
but this the plant can get without their help from the
air. And finally, they all contain nitrogen in some one
or more of its compounds; and it is this nitrogen
which the plant wants, and cannot apparently get,
in sufficient quantity, except from organic matter.

There is an abundant supply of nitrogen in the air,
however, and why plants cannot help themselves to it
—when they can, and do, take up carbon dioxide fram
the same source—one cannot say; but such is the fact.
Both are gases; and, as nearly four-fifths of the air
consists of nitrogen, there is certainly no lack of it.
However, the plant takes the one up by its leaves, as
will be seen in the following chapter ; and does not
take the other, much as it wants it.

All animal and vegetable matter, then, contains
nitrogen; and as all plants, whether lichens and mosses,
or oaks and palms, must have some amount of it, they
most of them get it from this source—the decayed
organic matter in the soil.

But there are others which get it equally well from.

Food from the Soil 149

living matter. The mistletoe and other similar plants
get this, as well as other food, from the living trees or
plants upon which they grow. And other plants, again,
sometimes turn the tables on the animal world, and
actually devour living insects.

The plant called Venus’ Fly-trap is one of these
insect-eaters, and a very curious plant it is. Its leaves
end in two lobes, on each of which are three delicate
hairs, so placed as to form a triangle, and in such a
position that it is almost impossible for any insect
alighting upon the leaf to help touching them. As
long as the leaf only is touched, no harm is done, but
if but the tip of one of these magic hairs be touched,
the leaf closes instantly upon the victim, and does not
re-open until it has sucked it dry! The trap will close
equally upon a dead, dry fly, or any other substance
placed upon it, but it re-opens almost immediately,
when the plant, by some mysterious instinct, discovers
that the morsel is indigestible.

A large blue-bottle will be seized at once, and
squeezed so tight that escape is impossible. But a
meal of this sort seems to be very satisfying, for in one
‘instance the leaf did not open again for twenty-four
days, and when it did, though the dry remains of the
fly were removed, no attempt to catch more was made
until several days later. There was a similar result in
the case of caterpillars, raw meat, and spiders. All
are digested by means of an acid which the leaf pours
out upon them.

It is a curious fact, that the dropping of water upon
the trap does not make it close, unless the sun is
shining, or has been shining immediately before, upon
it. In this case, the plant, not being prepared for rain,

150 Food from the Soil

seems to be for the moment deceived. Rain usually
comes when the sky is cloudy, and then the leaf,
knowing apparently what to expect, takes no notice.
If it closed for rain, it would of course often lose a
meal.

One of these plants, having six leaves, has been
known to comfortably digest twelve flies, or twelve
good-sized spiders, at once, one for each lobe, after
which it was satisfied for some time.

Venus’ Fly-trap is found only in Carolina; but we
have carnivorous plants in England, and it seems very
possible that many plants, hitherto unsuspected of it,
feed upon insects when they have the opportunity.

The Sundews, British plants nearly related to the
Fly-trap, openly catch prey, and are frequently dis-
figured by the remains of insects. Their leaves are
fringed, as well as scattered over, with red hairs. Each
hair has a shining drop on its tip, which, lovely and
innocent as it looks, serves only to entrap the insect
touching it. Dragon-flies seem to be attracted and
fascinated by these glistening beads, for they have
been observed to hover over the leaf, and then to dart
down upon it and be hopelessly caught by the folding
of the tentacles. In the small space of one square
foot, six Sundews have been seen growing at once,
every one of which had secured a dragon-fly, while one
had even caught two. The plants were young, and
the leaves in some cases were smaller than the prey,
whose wings were two inches across, while their bodies
were an inch and a half long; but chance of escape
there seemed to be none for them.

The Bladderwort has been seen to catch newly-
hatched roach and also worms, by means of its

Food from the Soil 151

bladders; and the Butterwort catches its victims by
means of the sticky glands with which its leaves are
thickly covered, rolling up its edges over them and
undoubtedly eating them.

The various Pitcher-plants also feed upon the large
number of insects drowned in their receptacles, which
are from two or three to as much as eighteen inches
deep, and always contain water.

But, whether or no many plants are actual flesh-
eaters, it is certain that they all need nitrogen; and
other food, however abundant, will not be enough for
them, or enable them to grow properly, if they be
stinted in this respect. Their more usual way of
obtaining it, however, is from the soil, or from the air ;
but in neither case can they take the pure gas itself;
it must be in the form of a compound before they can
make any use of it.

By way of trying whether plants could do without
nitrogen, other than that by which they are surrounded
in the air, three pots were filled with a soil of sand and
brick-dust, from which all animal and vegetable matter
had been removed. A couple of sunflower-seeds were
planted in each, and all three were watered with pure,
distilled water, containing no food whatever.

The plants in the first pot turned out mere dwarfs,
as was to be expected; those in the second were not
much better, though they had had a small quantity of
clover-ashes given them; but those in the third were
almost as large as the finest specimens grown in the
garden, for they had been supplied with a compound
of nitrogen, in the form of potassium nitrate; and
while the two first had managed to get only about the
thirtieth part of a grain of nitrogen from the air, these

152 Food from the Sot

had taken sixty-six times as much from the soil. The
quantity is still very small, of course, only two grains
and a fifth; but it strikingly illustrates the immense
importance of small, and even minute quantities, since
it made the whole difference in the growth of the
plants.

The dwarf sunflowers obtained their small fraction
of nitrogen from the air; but this is no contradiction
to what has been previously said, for they did not take
pure nitrogen, but ammonia, which is a compound of
nitrogen and hydrogen.

There is always some very minute quantity of
ammonia in the air—about one part in a million—and
there seems to be no doubt that plants can and do
take this up by their leaves, for they thrive all the better
when the quantity is artificially increased. But they
take it up also, and in larger quantities, by their roots,
when it has been absorbed by the soil, or brought
down to it by rain, snow, and dew.

The quantity of nitrogen thus washed down in
combination with hydrogen in the course of the year
seems to be from about 2 lb. to nearly 21 lb. per
acre; but the average is about 43 lb. to the acre—
44 lb. spread over an acre of ground! Considering
that there are 7,000 grains in a pound, and that the
sunflowers, even when they had more within reach,
took up little more than a grain of nitrogen apiece,
perhaps the quantity may not sound so very small.

_ But an acre of wheat, yielding twenty-eight bushels,
takes up about 45} lb. of nitrogen; while an acre of
clover uses 108 lb. !

And even this does not at all represent the whole of
what is required; for the roots, however many, cannot

Food from the Soil 153

possibly be in close contact with all parts of the soil
at once, and they can no more make use of all the
nitrogen than they can of all the mineral matter, or
all the moisture; so that of this, as well as of the rest,
they need much more than they can actually use.

An acre of soil, one foot deep, weighs some
4,000,000 Ib.; and just a few pounds of nitrogen
equally mixed in this would be almost as difficult to
find as a needle in a haystack; and even if there were
actually as much as the crop required, the roots couid
not reach it.

A heavy wheat-crop needs, therefore, nearly 300 lbs.
of nitrogen to the acre, or about six times as much as it
actually takes up. And this it certainly cannot get from
the ammonia in the air, or from that which is washed
from it into the soil.

But when organic matter decays, whether it be
animal or vegetable, the nitrogen contained in it
combines with other gases to form not only ammonia,
but also nitric acid.

Much of the ammonia streams off into the air, but
the nitric acid remains and combines with potash,
soda, lime, magnesia, or iron, with which it forms
nitrates. These nitrates are easily dissolved, and it is
from them that the plants obtain their nitric acid—
very much diluted, of course, as is all the food which
they take from the soil.

As already remarked, plants have the power of de-
composing such salts, taking one ingredient and leaving
the other. The sunflowers which throve so well in the
experiment described, were supplied with potassium
nitrate, and from this they were able to extract the
nitric acid which they needed.

154 Food from the Soil

Nitrates are very soluble, and in damp soil they
are formed and dissolved so quickly as seldom to be
visible. But it is not so in regions where rain falls
either at certain seasons only, or very rarely. The
most fertile soils of Bengal, for instance, are often
covered during the dry season with a white crust of
some of these salts, chiefly potassium nitrate, other-
wise called nitre and saltpetre. The crust vanishes as
soon as the rain comes, being dissolved and washed
into the soil, which is so rich as to bear two or three
crops a year. :

Wherever these nitrates are formed, whether, as in
England, they are dissolved almost at once, or whether,
as in dry lands, they accumulate and encrust the soil,
they are formed by the decay of animal and vegetable
matter. And what, it may be asked, causes this
decay? Not the action of the air; for in perfectly pure
airy organic substances do not decay. The change is
brought about by the action of living organisms,
invisible, but very potent in their effects.

We have all heard enough about *germs’ of late to
know that they swarm in the air; but they also swarm
in all the moist places of the earth. Some few classes
of them are dangerous to man, and produce diseases
of various kinds; others are not only harmless, but
productive of the greatest good.

All decay, fermentation, or putrefaction, whichever
we call it, is their work; and when we say ‘ work,’ all
that is meant is their living, growing, multiplying,
which they cannot do without feeding. There is an
immense variety of them, and they produce different
results according to their different modes of feeding.
The yeast which’is put into dough, the ‘mould’ which

Food from the Soil 155

grows upon paste, or jam, are all of similar nature,
and all produce alterations in the substance which
they attack, When we like the result of these
alterations, we call the process ‘fermentation’; and
when we do not like it, we call it ‘putrefaction’; but
both are substantially the same, for both are the result
of decomposition. Grape-juice, apple-juice, and wort,
are converted by these ‘ferments’ into wine, cider,
and beer respectively; and another ferment again
alters wine yet further, and turns it into vinegar.

It is these living organisms which bring about all
decay of animal or vegetable matter, whether in the
soil or elsewhere.

Their work in the soil seems to go on chiefly in the
upper nine inches, and most rapidly when the weather
is warm and damp.

The multitudes of leaves drawn in by worms, the
old roots of former crops, or green crops which have
been grown only that they may be ploughed in—all
are decayed, and so converted into food, of which the
next crop can avail itself.

As has been more than once remarked, all soils
contain more or less organic matter; but unless the
amount is very large, as it is in the Russian Black
earth region, Manitoba, and elsewhere, not much of
the nitrates formed by its decay will be left in the
upper twenty-seven inches of the soil after a crop of
corn has been grown in it. Organic matter there will
still be, but decay is gradual, and nitrates take time to
form; so the farmer must supply the want in one way
or other.

In former days, till within the last century in fact,
his way of doing so was simple. He merely ploughed

156 Food from the Sott

up the field, and Jet it alone to recover itself; in other
words, he allowed it to lie fallow.

And what goes on in a fallow field? Generally
speaking it is, or was, both ploughed and harrowed
repeatedly, so that the soil might be exposed as much
as possible to the action of the air and rain, by which
the mineral matter would be dissolved ready for the
next crop. Then in the winter the soil would be yet
further broken up by the freezing of the moisture in
its pores, which would separate grain from grain,
reducing it to powder in a way that no plough or
harrow yet invented can do. The crumbling of the
soil would make it yet more easily dissolved by water,
as well as more easy for roots to penetrate ; nor must
it by any means be forgotten that while the land lay
idle the worms were busy, turning it over, also, grain
by grain, and enriching it as already described. And
though the farmer did not sow it, seeds were sown by
the wind, and a crop of weeds was certain to spring
up, whose half-decayed leaves the worms would drag
into their burrows. The whole wild crop, too, would
be ploughed in, and, with the roots of the farmer’s last
crop, would be gradually decayed. The soil when
damp would absorb ammonia from the air, and
ammonia would also be brought down by rain and
snow, and converted into nitric acid, which would
combine with some of the minerals already mentioned;
and in this way, as well as by the decay of the organic
matter left in, or added to, the soil, a fresh supply of
nitrates would be’ prepared.

XII.
LEAVES AND THEIR WORK

ALL the plant-food which we have yet considered is
drawn from the soil, with the exception of the minute
quantity of ammonia taken in by the leaves from the
air. But this latter is far from being all that the
leaves contribute to the food-supply.

The roots furnish food from the soil—mineral and
organic matter; and the leaves furnish food from the
air—the carbon, which makes up about half the dry
weight of a plant—half its weight, that is, when all the
water has been removed from it. Roots and leaves,
therefore, supply about an equal amount of food.

But the leaves do more than merely supply food;
they prepare it for the whole plant, both that which
they themselves take up, and that which is procured
by the roots. Leaves are the food-manufacturers ;
and it is they which combine the various materials,
and distribute food to the several parts.

Nitrogen, the food derived from organic matter,
which we have last considered, is needed in some
combination or other by all parts of a plant, but
especially by the seed. No one needs to be told
that grain is more nourishing than straw; but the

158 Leaves and their Work

reason why it is more nourishing is that it contains
more nitrogen, in the form of nitrogenous or albu-
minous compounds, commonly called albuminoids,
because they resemble the albumin, or white, of an
egg. There is albumin in the liquid part of blood, and
there is albumin in the seeds and juices of plants.
There is fibrin in flesh and in the thick red part
of blood; and there is vegetable fibrin, a sticky
substance usually called gluten, in flour. There is
casein in milk and cheese, and there is casein in beans.

These various substances are all jelly-like, and are
very similar in composition, whether they are obtained
from animal or from vegetable matter. They are
called nitrogenous because it is the nitrogen they con-
tain which gives them their especial characteristics
and value as food; but the nitrogen in them forms
less than a seventh part of their substance, more than
half of which consists of carbon. In addition to this
large amount of carbon, most of the nitrogenous com-
pounds contain sulphur, besides hydrogen and oxygen,
and most of them phosphorus as well. They could
not therefore be formed without the help of mineral
matter from the soil, and of carbon from the air; the
nitrogen being obtained both from the nitrates in 1 the
soil and from the ammonia in the air.

All the corn crops, as well as the clovers, beans,
peas, and other leguminous plants, require much
nitrogen, especially when their seeds are forming and
ripening; but by the time they have done blossoming,
they have taken up all they want, and it is being pre-
pared and compounded by the leaves, to be gradually
passed on by them to the growing seeds as they need
It. Grass, therefore, is not cut for hay until after it

Leaves and their Work 159

has blossomed, because it then contains most nitrogen
and is most nutritious. For the nitrogenous com-
pounds are the flesh-forming part of all food, animal
or vegetable. ©

They are very much alike in composition, as has
been said, and substances which are closely similar
may be obtained both from a beef-steak and a cauli-
flower ; from the white of an egg and from a cabbage ;
from milk curd, and from peas and beans, of which the
Chinese do actually make a vegetable cheese.

Quantity for quantity, a cabbage is, indeed, less
nutritious than the white of an egg; but the
cabbage contains a similar substance. It would, how-
ever, be necessary to eat a much larger weight of
cabbage to obtain as much flesh-forming food as is
contained in an egg.

And then, again, though the nitrogenous compounds
obtained from flesh and vegetables are similar—so
closely similar even as to appear almost identical—they
are not absolutely identical, and it would be rash,
therefore, to conclude that they are equally nutritious.
For, if one thing be more plain than another, from
what has been said in the previous pages, it is the
immense importance belonging to little things—to
trifles so minute as almost, or quite, to escape detec-
tion.

Let us remember the vineyards growing side by side
—the treatment the same, the soil so apparently the
same, that the difference cannot be detected—and yet
the wine from the one is worth, and fetches in the
market, twenty times as much as the other! The vines
being of the same species, and all other things being
equally enjoyed by both, it follows that the difference

160 Leaves and their Work

in quality must be caused by some slight difference in
the soil, which is so slight as to be undiscoverable.

If, therefore, so slight a difference in the vine’s food
can make so large a difference in its produce, it seems
altogether rash to conclude that the cheese of beans is as
nutritious as the cheese of milk; or that it makes no
difference whether one dines on cauliflower or beef.

All plants do not contain an equal amount of the nitro-
genous compounds; and even the same plant contains
very different quantities in different parts, and also at
different stages in its life.

Leaves and stalks are less nutritious than seed, and
the seed itself is most nutritious when it is ripe, as it
is then that it contains the largest amount of nitrogen.
Ripe ears of maize, for instance, contain ten times as
much nitrogen as green ears; but even then they con-
tain less than either rye, oats or wheat, and less than
half the amount contained in peas, beans, or lentils.
Lentils, indeed, are among the most valuable of the
seeds used as food, for nearly a fourth part of their
substance consists of albuminous, or nitrogenous, com-
pounds. As for potatoes, they are very low down in
the scale of food, for they are chiefly water, and the
amount of flesh-forming food which they yield is only
two parts in a hundred, less, that is, than meadow-grass
before it has blossomed.

We must now look a little more closely at the work
done by the leaves, for it is they, as has been said,
which supply the plant with carbon. Carbon is
wanted for the nitrogenous compounds; carbon is
wanted for the plant’s skeleton, and for its wood;
carbon is wanted for the manufacture also of starch,
gum, sugar, oils, acids, and the various aromatic

Leaves and their Work 161

compounds to which plants and flowers owe their
fragrance.

And this carbon the leaves have no difficulty in pro-
viding, so long as the roots do their part; but if they
fail, the leaves must fail too. For the plant is a whole,
a body, of which every part is dependent upon the
rest. But while the roots can do their work in the
dark, the leaves are perfectly helpless without light.

Give the plant light, however, together with the
proper food which the roots collect from the soil, and
then the leaves have no difficulty in adding the carbon
which is their share.

And why, it may be asked, should they have any
difficulty ? Since the whole plant wants it, and has to
get it through the leaves, surely it would be more
strange if the leaves could not find it, since they live in
the air, where it is.

Perhaps; but the proportion in the air is extremely
small, though the amount sounds large; and leaves
cannot wander in search of food, as roots do. The
food must come to them, as they cannot go to the
food. Carbon exists in the air, combined with oxygen,
as the gas carbon-dioxide, or carbonic acid; and there
are about three billion four hundred million tons of
the gas in the atmosphere of the whole globe. The
figures convey little to one’s mind, but, at all events,
the amount sounds comfortably large—sufficient, at
least, to preserve the vegetable world from all risk of
a dearth of this species of food.

And yet it has been calculated that, if used at the
present rate, the whole of this enormous supply would
be exhausted in about a hundred years, after which

II

162 Leaves and their Work

not so much as a blade of grass could exist until the
supply were renewed.

Let us put it in another way. The amount is large
in itself, but it is enormously diluted—so much diluted,
indeed, as to be hardly reckoned at all! That is, in
speaking of the air, we commonly say that it consists
of about four-fifths nitrogen and gne-fifth oxygen,
leaving the carbon - dioxide out of the account
altogether. For, except in confined spaces, and under
special circumstances, one part in twenty-five thou-
sand is all the carbon-dioxide that the air contains,
so vast is the space through which the gas is dis-
tributed. There is just enough carbon-dioxide in the
air to furnish twenty-eight tons to every acre all over
the globe—twenty-eight tons of gas, or eight tons of
carbon !

But an acre of beech-forest would use up the whole
of this allowance in about eight years; and it would
not last an acre of bananas much more than one year.

All plants do not, it is true, use up carbon at these
rates; but it is evident that the supply needs pretty
constant renewing. And it is renewed day by day,
hour by hour; nor, so long as animals breathe, and fires
burn, and vegetable matter decays, is there any danger
that the supply will run short.

Whenever carbon unites with oxygen it is what we
call burnt, and carbon-dioxide is produced. The
carbon disappears, but it is not destroyed—it has only
been made invisible by combining with oxygen. When-
ever, therefore, animal or vegetable matter decays, the
carbon which it contains is slowly burnt, and the gas
passes off into the air as it forms, unless prevented,
as it is, ina great measure, when produced underground,

Leaves and their Work 163

Again, when animals or plants breathe, the oxygen
which they inhale unites with, and burns, part of the
carbon of their food, and the gas is breathed back into
the air. The air we inhale contains but one part in
twenty-five thousand of carbon-dioxide; but the air
we exhale contains much more—from three to six per
cent. Plants, however, breathe very much more
slowly than any warm-blooded animals, and give off
less carbon-dioxide in proportion.

Whenever carbon is burnt by combining with oxygen,
whether in food, coal, wood, gas, oil, candle, or in
decaying vegetable-matter, there carbon-dioxide is
formed. It is being constantly poured into the air,
therefore, by men and animals, by the chimneys of
factories and houses, by volcanoes, and by the soil.

But it is not produced in anything like equal quan-
tities in all parts of the world. Very little is returned
to the air above the ocean, and that little chiefly by
passing vessels ; and as there is more ocean than land
in the southern hemisphere, much less is produced
there than in the northern hemisphere, which is chiefly
land.

Then, again, the eastern hemisphere is much more
densely populated than the western, besides having,
of course, many more factories, furnaces, and engines
of all sorts, which are constantly burning carbon. It
might seem not improbable, therefore, that some parts
of the world, such as the islands of the Pacific, should
be at times in danger of not having carbon-dioxide
enough to supply the wants of their vegetation,
especially when we consider that bananas, which need
such large quantities, form an important item in their
crops.

164 Leaves and their Work

But the fact is not so; for the supply is equally
distributed. More fires are kept burning, and more
carbon-dioxide is produced in winter, when the trees
are leafless and do not want it, than in the summer,
when they do. And yet we are not choked by it, or
even inconvenienced by it, in the winter months, so it
must be got rid of somehow. For, if there were two
per cent. in the air, we should have severe headache,
and ten per cent. would suffocate us. What, then,
becomes of it? Roughly speaking, we may say that
the carbon-dioxide produced during the winter of the
north goes to feed the vegetation of the south—the
thistles, clover and grass, for instance, of the Pampas,
which are flourishing in all their luxuriance while
winter prevails with us. And it goes, to some extent,
at least, because the leaves of the southern hemisphere
draw it thither.

The ocean of air which surrounds the world is not,
it must be remembered, a compound, but a mixture.
If we could see it we should find oxygen, nitrogen,
carbon-dioxide, ammonia, all perfectly mixed, but
perfectly distinct. The combination of two gases,
oxygen and hydrogen, makes water—a liquid entirely
different from both; but there is no such combination
and alteration in the gases of the air. Each keeps its
own character ; but, though all are of different weights,
they are so thoroughly and perfectly mixed that, except
under special circumstances, there is but little appreci-
able difference in the air of different parts of the world.

Carbon-dioxide is the heaviest of these gases, and it
is more than twice the weight of the mixture of these
gases which we call the air. Where it is poured out from
cracks in the earth, as it is largely in some volcanic

Leaves and thety Work 165

districts, its weight keeps it down for a time near the
ground, but gradually, in obedience to a mysterious law,
it rises and spreads through the air. Its weight draws
it down to the earth, or, more correctly speaking, the
earth attracts it to itself more than it attracts either
oxygen or nitrogen. It is heavy, because the earth
attracts it, just as a stone is heavier than a feather.
But it rises.

We should be surprised to see a stone thrown from
our hand continue to mount upwards instead of falling
to the ground, but this is precisely what carbon-dioxide
does, and we can but state the fact without explaining
it. Gases, no matter what their weight, are obliged to
mix one with the other.

Put into a bottle first some heavy carbon-dioxide,
then some oxygen, which is lighter, nitrogen, which is
lighter still, and, lastly, hydrogen, the lightest of all,
which is so light that it has to be poured upwards, and,
though at first the heaviest gas will be at the bottom,
before long all will be perfectly mixed, and there will
be as much hydrogen at the bottom as at the top.
Carbon-dioxide moves more slowly than hydrogen,
owing to its weight, but move upwards it will, and that
without any shaking.

All, or part, of. the carbon-dioxide might, however,
be removed from this mixture without affecting the
other gases, if a piece of caustic potash were intro-
duced; for this substance has the power of attracting
and absorbing this particular gas. Each of the other
gases might also be removed by similar means, one by
one substance, and another by another.

Leaves, then, act upon carbon-dioxide in some such
way as caustic potash does, They attract it to them-

166 Leaves and their Work

selves and absorb it; but, by su doing, they are con-
stantly diminishing the amount of the gas in the air
immediately surrounding them; and as, according to
the law of their being, gases must mix equally one with
the other, more carbon-dioxide flows in to supply the
place of that which is absorbed. Streams of the gas
are therefore constantly flowing towards each leaf,
even when the air is still; when there is wind the
whole air is, of course, in motion.

We have now to see what becomes of the carbon-
dioxide when the leaves have taken it up. As has
been said, in most plants nearly one-half the dry sub-
stance left when the water is removed consists of
carbon, of which charcoal is an impure form. Carbon
enters into the composition of every animal and vege-
table substance, no matter how minute. It is to be
found in every part of a plant from the root upwards,
but especially in the seed. In the grains which we use
as food the quantity of carbon amounts to some forty
or fifty per cent. of the whole; and, though the car-
bon compounds are not, like the nitrogenous com-
pounds, flesh-formers, they are equally important as
fat-formers, and as supplying fuel to maintain the heat
of our bodies. The carbon of our food is oxidized,
burnt, by the oxygen of the air we breathe; heat is
thus produced, and the greater part of the carbon is
given back to the air as carbon-dioxide.

One pound of wheat-flour contains about nine and
a half ounces of starch, and starch is a compound of
carbon, oxygen and hydrogen ; but it also contains two
ounces of gluten—one of the nitrogenous compounds—
and half of this is carbon; and besides these it con-
tains smaller quantities of sugar, gum and fat, and

Leaves and their Work 167

these are all carbon compounds; so that altogether
the pound of flour contains some seven ounces of
carbon.

Some of the palms, as the sago palm, use very large
‘quantities of carbon in forming the starch of their
pith: one tree, for instance, often yielding the extra-
ordinary amount of 800 lbs. of starch. All the sugars,
oils, gums, caoutchoucs, of the vegetable world, contain
large quantities of carbon, and so also do the fibres
of cotton, flax, hemp and others.

But, as already said, carbon forms part’ of the

Surface leaf-cells, with pores, magnified,

structure of every portion of a plant from root to seed,
and it enters largely into the composition of the
skeleton, or frame-work, both of stems and leaves ; for
a plant’s skeleton consists of fibre, identical in com-
position with the fibres of the cotton and other plants
used for weaving purposes.

Now, both the skeleton and the flesh of a plant,
every part of it, indeed—roots, stems, leaves, flowers,
fruit, seed—consists either of a single cell, or of an
assemblage of cells, which may be compared with the

168 Leaves and their Work

rells of a honeycomb, except that they vary extremely
in size and shape.

Some cells are so minute as to be altogether invisible
to the naked eye; as, for instance, the spores of
lichens and fungi, the ‘ germs’ already mentioned, and
certain minute water plants, each and all of which
consist of a single cell, filled, like the honey-cells, with
more or less fluid contents.

But the cells in the flesh of a lemon are gigantic by
comparison, being half an inch long; the cells of

Transverse section of a leaf, magnified.

fibres are often much longer than this, and there are
cells of all sizes between these, the most usual size
being from y/55 to sty of an inch across. Cells are of
almost every. possible shape, too—globular, square,
six-sided, twelve-sided, or quite irregular, with their
outlines beautifully zigzagged or waved. But, whatever
their shape and size, their walls, thick or thin, are
composed of the skeleton material mentioned above,
which is called after them ‘cellulose.’

This material, like cotton and other fibres, is com-
posed in great measure of carbon, and, as all plants in-

Leaves and their Work 169

crease in size by the multiplication of cells, it is evident
that they could not grow at all in air containing no
carbon-dioxide. Neither can they grow if deprived of
their leaves, for these are the chief manufacturers of
cellulose and other food. A ‘tree stripped of even half
its leaves will be unable to make much wood, though it
may manage to live.

The skin of a leaf usually consists of a single layer of
cells, not green, but colourless and transparent, and
beneath these are other cells containing, besides other
things, ‘leaf-green,’ or colouring matter. It is in these
lower cells that the manufacture of the plant’s food is
carried on; and, though the process cannot be ex-
plained, one or two facts are certain—it cannot, in
most plants, go on without light, or in any without the
leaf-green.

The gases of the air are able to pass through the
cell-walls, both in and out. It must not be forgotten
that plants need air for breathing, as well as carbon-
dioxide for food; and though they breathe as well as
feed by means of their leaves, the two processes are
quite distinct.

What the plant does with the carbon-dioxide is to
separate the carbon and keep it, and to let go most of
the oxygen. The two have to be torn asunder, and
this is done in the cells containing leaf-green. But the
leaf-green itself cannot be developed either without
light, or without iron; and when developed it cannot
act in darkness.

For the supply of iron the leaves are, of course,
dependent upon the plant’s roots, and if the roots can-
not find it, the leaves and young stéms remain yellow
or colourless. Compounds of iron are, however, so

170 Leaves and their Work

very general in all the rocks composing the earth’s
crust, that it is almost impossible to find any soil quite
without them.

But the iron may be taken away by artificial means,
and when this is done the leaf-green turns yellow, as
human beings do when their blood contains too few
red particles, and for precisely the same reason. Both
stand in need of iron. Iron oxide is reddish when
it contains the full amount of oxygen possible, and
green when it contains less. Give the plant iron
and keep it in the light, and the grains of leaf-
green at once begin to turn their proper colour, and
tiny grains of starch form within them.

A very little light, barely enough to read by, will be
sufficient to make a plant begin to turn green, but not
sufficiently green to enable it to separate the carbon;
and therefore in dim light no starch grains can be
formed. In ordinary daylight, however, whether the
sun be shining directly upon the plant or no, these
starch-grains are being continually produced; but the
brighter the light the more briskly the manufacture
goes on, up to a certain point—provided, that is, that
the air contains carbon-dioxide wherewith to furnish
the necessary supply of carbon. If it does not, no
starch, of course, can be formed, no matter how bright
the light, or how green the leaf-green.

But all air, unless artificially deprived of it, contains
enough to furnish what the plant requires in this
respect, thanks to the supplies which are being con-
stantly furnished to it. Ifthe supply of carbon-dioxide
were not renewed, however, it would be exhausted, as
already mentioned, in about a hundred years by the
present vegetation of the globe. But if the world were

Leaves and their Work 171

covered with beech-forest, all this gas, even though it
amounts to billions of tons, would be gone in eight
years! For one acre of beechwood takes about a ton
of carbon every year; and to supply one ton of carbon,
three and a half tons of carbon-dioxide gas are neces-
sary. This is taken up not only by the leaves, but
by all the green parts of a plant, leaves, buds, stems,
and fruit, so long as these remain green ; for it is only
in the cells which contain leaf-green that starch is
manufactured from the gas. These green cells lie im-
mediately underneath the thicker-walled but transparent

Surface leaf-cells, with pores, magnified.

cells of the surface which compose the skin; and through
the skin the gas finds its way into them.

The leaf-pores, by which water escapes, are openings
in the skin formed by two curved, lip-like cells, which
gape open in hot, bright weather, and close more or
less in rain, damp, and darkness; and it is when they
open most widely that the manufacture of food goes
on most briskly. For it is then that most carbon
is separated, and most food is pumped up from the
roots, as that is the time when the plant transpires
most, and in this way both kinds of food are received
together. When there is much transpiration, and water
containing dissolved food is pumped up rapidly, then
also much carbon is received, and vice versd.

172 Leaves and their Work

Such plants as the cactus, which have no leaves, very
few pores, and skin so thick and leathery that evapora-
tion is prevented, transpire very little, and grow in
consequence very slowly. The tall Torch-thistle cactus
of Mexico is said to take some hundreds of years in
attaining its full size; whereas the thin-leaved gourd of
the East is noted for its very rapid growth.

How the food from the soil and the food from the
air are combined, and distributed from the leaves to all
parts of the plant, is unknown; but from them each
part does receive its due share of nourishment, one
more of this sort, one more of that.

But without the leaves no food can be prepared,
except where the stems take their place; and without
light the leaves have no power to act. Hence the
plant’s whole life depends upon the sun.

In the autumn, when the plant has finished growing,
no more leaf-green is formed, and the leaves begin to
change colour; for instead of manufacturing food, they
are giving up their own stock to feed the young fruit.

Some plants, such as lichens, copper-beeches, and
others, might be supposed to possess no leaf-green,
because it is not visible; but they have it all the same;
it is merely concealed from view, hidden by other
colouring matter.

But some plants never have any leaf-green under any
circumstances, and, therefore, being non-manufacturers,
they have to live by the labour of others. Among
these are the fungi, which grow and feed entirely upon
organic matter, animal or vegetable, and are inde-
pendent of the light. Mushrooms, for instance, may
be grown in cellars; toadstools spring up in the night ;
for their food of all kinds—mineral food, nitrogenous

Leaves and their Work 173

compounds, carbon compounds—has been made ready
for them in the light, by the dead vegetable matter
upon which they grow. Perhaps it is the fact of their
not having any work to do which enables them to grow
with such extraordinary rapidity, as they devote all
their energies to feeding and increasing in size. The
cells of the puff-ball; for instance, multiply at the rate
of three or four hundred million in an hour, and the
plant will attain the size of a large gourd in a few days.
The curious brown Bird’s-nest orchis is another plant
which has no leaf-green, cannot provide its own food,
and lives upon dead vegetable matter.

But there are other plants devoid of leaf-green, which
prey, not on the dead, but on the living; sucking their
juices, and profiting by their labours in earth and air.
Among these may be mentioned the broom-rape, a
brown, uncanny-looking plant, which attaches itself to
the roots of living plants, clover and others, and draws
all its nourishment from them.

In one way or another, then, all plants obtain car-
bon ; and when they have to do it by their own exer-
tions they must have leaf-green, and they cannot
usually have leaf-green without light, or, in any case,
without iron.

But, it may be said, seeds, most of them, begin to
grow in darkness, underground, and so do bulbs; and
they are usually pile yellow at first. If they have no
leaf-green, as they evidently have not, then, if cells
cannot be multiplied without carbon, and carbon they
canndt get for want of this leaf-green, how do they
manage to grow? —

In the same way that other plants do which are also
without leaf-green. They make use of the carbon stored

174 Leaves and their Work

by others. That is to say, they live for a time, seedlings
—upon the material stored in their seeds—bulbs, upon
the material stored in the bulbs, which are buds, not
roots—all of which has been prepared by means of leaf-
green, and in the light.

In the case of bulbs, the leaves go on collecting food
long after the plants have-done flowering, in readiness
for the blossoms of the next spring; and if the leaves
are cut off before they have finished their work, the
bulbs shrivel, and have not the means of supplying
next year’s blossoms at all. The autumn crocus comes
up and blossoms, without its leaves, but it is dependent
upon them for the means of putting forth its blossoms ;
for the leaves have been busy months before, in the
spring, storing the necessary material in the bulbs.

Seedlings, in like manner, when first they germinate
under the soil, before they are provided with leaf-
green, live upon the food stored up within them; but
if, when this is exhausted, they are still kept in dark-
ness, they will not only remain yellow, but will lose,
instead of gaining in weight, and that though their
roots may be busy collecting food from the soil.

But why, it may be asked, should they dose in weight ?
Without carbon they cannot, of course, use the food
from the soil, they cannot grow; but provided they
have water, why should they not remain as they were?
What are they doing to make them lose weight ?

Well, they are doing just what all living things do,
and must do, if they are to remain living ; they are
breathing ! breathing as animals do, though they have
no lungs, and though they breathe very much more
slowly. That is to say, they are taking in air.

In breathing, as has been said, part of the oxygen of

Leaves and their Work 175

the air inhaled combines with, and burns up, part of
the carbon taken in sas food, converting it into the gas
carbon-dioxide, which is breathed back into the air.
Warm-blooded animals breathe much more vigorously
than plants do, but the process is the same in both.

Plants, however, breathe more or less through their
whole surface, though chiefly through their leaves, and
from the leaves, the air finds its way to every part.

Probably the breathing of plants may be fairly com-
pared with the slow breathing of cold-blooded animals ;
but though feeble it is always going on, night and day,
in light and in darkness, though more vigorously in
light ; and, therefore, as the stock of carbon is gradu-
ally burnt, or oxidized, and breathed out, if it is not
replenished it must be gradually exhausted, and the
plant must lose weight.

To prove this two beans of nearly equal weight were
planted at the same time, one being kept in the dark,
the other in the light. At the end of twenty-six days it
was found that the seedling kept in darkness weighed
more than a third /ess than the original bean, and the
other weighed more than a third move. The one had
breathed away some of the carbon contained in the
thick seed-leaves without being able to extract any
from the air to feed upon, while the other had obtained
food enough for growing and breathing, too.

There is some difference in the breathing of the
leaves and the blossoms of a plant. The blossoms
breathe faster than the leaves, especially when they are
just opening ; and they are therefore slightly warmer—
in some cases, indeed, so warm that the heat may
actually be felt! And the same is true of sprouting
seeds when there are many together. The sprouting

176 Leaves and their Work

barley, for instance, from which malt is made, gives off
quite a high degree of heat.

As the plant, like the ‘animal, must breathe in order
to live, it must needs have a constant supply of air for
breathing, as well as feeding, purposes. And this air is
necessary, more or less, not only for leaves and blos-
soms, but for all parts, including stems and roots. It
breathes through all, though chiefly by its leaves and
blossoms; and the roots are always breathing out
carbon-dioxide into the soil. If the soil be too close,
or baked on the top, the roots cannot get enough air to
breathe properly, and the plant is sickly. And the
same thing happens when soil is piled up round the
stem, for the air is then kept away both from it and
from the roots, and many a tree has been killed in
consequence.

Leaves covered with dust, or smoke-particles, cannot
possibly thrive, for they are choked, just as much as an
animal would be if kept without air; and besides being
unable to breathe, they are also unable to take in food.
The whole plant, therefore, suffers, and unless relief
came from time to time in the shape of rain to wash
the leaves, it must die of suffocation.

The patient, laborious Chinese, who were the first to
attempt market-gardening in the sandy environs of
Melbourne, were so well aware of the fact that plants
cannot thrive when choked with dust or sand, that they
were in the habit of washing their vegetables, leaf by
leaf, three times every day to keep them in health.

XIII.
CLIMATE

THE plant’s whole life depends, as we have seen, upon
the sun, for without sunlight it cannot obtain carbon
from the air and must starve. And this is equally true
whether the plant manufactures its own food or
whether it feeds upon what has been manufactured by
others. The parasite sucks the juices of plants growing
in the light; the fungus feeds upon dead vegetable
matter which has grown in the light; the seedling
lives at first upon food stored in the seed, by the leaves
which waved in the sunlight, and so on.

But plants require of the sun something more than
light; they must have some degree of heat as well—a
very small degree in some cases, but this small degree
is essential to bring them to maturity. Even those
lowly plants which grow in snow and ice cannot dis-
pense with some amount of heat, and though they
contrive to exist in the lowest temperatures, they
remain dormant during the winter, and only wake up
when the summer sun begins to shine.

Many seeds will even begin to grow while it is
freezing, though they cannot make much progress;
and wheat has been known to germinate when actually

IZ

178 Climate

upon ice, and to send out roots into it. Barley and
oats will also send out roots with the thermometer |
down to freezing-point, but they cannot develop seed-
leaves without a few degrees of warmth. Maize, as
might be expected, requires more heat than any other
corn, and will not start until the thermometer shows
about 153° above freezing, and even then grows but
slowly; and cucumber-seed shows no sign of life
without still more heat.

But, though many seeds will make a start in cold
weather, even in frost, it does not follow that they will
do more than start; for a plant requires different
degrées of light and heat at different times in its life.
And if it does not receive enough at the important
period when it has done growing, and is going to
blossom, the chances are that it will bear no fruit.
For fruit cannot do much towards feeding itself, and
though it does take up carbon from the air, it is chiefly
dependent for nourishment upon the leaves, the great
food manufacturers. But, in acold summer, the leaves,
instead of passing on their stock of food to the fruit,
and themselves turning yellow, as they ought to do,
seem to be quite thrown out of their calculations. They
keep their food to themselves, and remain green and
juicy, while the fruit is starved, and its development
checked. In very bad cases, the plant puts out new
shoots, and the crop never comes to perfection; for
the heat which is quite sufficient for the growth of
stems and leaves is not sufficient for the growth and
ripening of the fruit.

If, on the other hand, the piant gets too much lignt
and heat at an early stage in its life, it grows up and
ripens its fruit too quickly, before it is properly

Climate 179

developed; and this is what takes place when crops
are sown too late in the year. In the ordinary course
of nature, seed generally drops and sows itself as soon
as it is ripe, and begins to grow forthwith. But it
cannot go on growing. Winter comes and checks it,
and it is obliged to put off bearing fruit till the following
summer. Plants grown in this, the natural way, are
generally the stronger, if they manage to survive the
winter. But they are exposed to more perils than
when the seed is sown in spring, and of course they
are much longer in coming to perfection.

Barley sown early in August and September, as soon
as it is ripe, has been found to take two hundred, and
two hundred and forty days, to come to perfection,
which is just eight times as long as it often does in
Egypt, where it is sown and ripened not only the same
year, but quite early in the year.

Provided, however, the seed be not sown too late,
the crop seems to be equally good whether the seed be
sown in autumn or spring. Barley sown for experiment
on the 21st of April came to perfection in eighty-eight
days, that is, by the 18th of July; whereas that sown
five weeks later ripened, indeed, in an equal number
of days, but prematurely, before the grain was properly
developed, because it had been over-stimulated—too
much hurried, in fact, during the J0n5; light, warm
days of June.

Of all the influences by which the plant is surrounded,
none affect it so powerfully, for good or evil, as light,
temperature and moisture, or, in one word, climate.
Where the climate is favourable, the quality and
quantity of the soil are of comparatively little import-
ance, for the plant manages to make the very utmost

180 Climate

of what it has. But, where the climate is unfavour-
able, no soil, however good and abundant, can make
up for it, though it may do something to lessen the
evil consequences.

As we have already seen, the richest soil is unable
to supply the place of water; while in Guiana, on the
other hand, where moisture is abundant, and the
climate genial, groups of trees may be seen growing on
a spur of the great sandstone mountains, wherever
there is just sand enough to afford them a foothold.
The sand is, of course, not mere sand, though it may
look like it; but the soil is undeniably poor and
shallow. Yet, helped by the climate, the trees thrive,
as they could not possibly do without that help.

We are naturally accustomed to look upon the sun
as the source of light and heat to our planet; but
temperature does not depend solely upon the sun; for
if it did, the same temperature would prevail all along
the same parallel of latitude, which it certainly does not.

Rhine grapes, for instance, will not ripen in England ;
laurels and camellias flourish all the year round on the
coast of Cornwall, while in the same latitude on the
continent, only the hardiest trees can stand the
winter. The vine can hardly flourish at the mouth of
the Loire; yet it comes to perfection in Tokay, which
lies a degree further to the north; and Astrakhan, in
nearly the same latitude, has summer-heat enough to
ripen the southern fruits of Italy, and even of the
Canary Islands, though its winters are so severe that
no vine-stock would be able to live through them
without being buried several feet deep in earth.

In Germany, where the summers are much hotter
than in England, roses, and other trees and shrubs,

Chmate 181

which we do not think of protecting, are matted up
like mummies for the winter.

Then again, myrtles will flourish out of doors all the
year round in Ireland, as well as they do in Portugal ;
but plums and pears do not usually ripen well, though
they will do so perfectly on the continent, in the same
latitude.

It is evident, therefore, that the climate of a country
does not depend solely upon its position with regard
to the equator. Indeed, the great characteristic of the
equatorial climate is, not so much its heat, as its
wonderful uniformity. Hot it is, of course, though
not as hot as the plains of North India; but there is
nothing to be called change of season, and there is
seldom more than 16° or 17° of difference between day
and night. Itis not often that the thermometer stands
above go’ or gi” F. by day, or falls below 74° F. by
night. And the temperature of the soil varies but
little, too. Four or five feet below the surface it never
varies at all, and remains constantly at 80° F., just
about half-way between the temperature of night and
day.

Where the temperature of the air varies more, there
the temperature of the soil varies more also, and toa
greater depth. At the equator, the sun affects only
the upper four or five feet of the soil, the change
between day and night being unfelt below this; but in
England the change between summer and winter is
felt to a depth of fifty or sixty feet probably ; and below
this the temperature remains steady at but a little
above 40° F.

40° F. is about the mean temperature of the air in
England, as 80° F. is that of the equatorial region—

182 Climate

half-way between the two extreme points to which the
thermometer rises and falls.

But this fact, that the depth at which the tempera-
ture of the soil remains always the same is so much
greater in one case than in the other, has much influ-
ence upon the two climates; and for this reason:
whenever a hot body is in contact with a cold, or cooler
one, it at once gives up some of its heat to this other,
and continues to do so until there is no difference be-
tween the two. .-

When, therefore, the sun warms the surface of the
soil, the upper layer parts with some of its heat to the
one below it, this to the next below, and so on, until
that depth is reached where the temperature is always
the same. At the equator, therefore, the heat, having
only four or five feet of soil to travel through, soon
raises the temperature of the whole mass equally, and
then, as it cannot descend any lower, it goes on adding
to the heat of these upper layers, in which it accumu-
lates. At night, when the sun is gone, the surface of
the soil cools, and the reverse process begins: the heat
stored during the day gradually passes up again to the
surface, and from the surface into the air, so that both
earth and air are kept at a more even temperature than
would otherwise be the case.

But where, as in England, the sun has forty or fifty
feet of cool earth to warm, naturally it is much longer
about it, and the whole mass is consequently not
warmed equally through till summer is at its height.
Then, and not till then, the whole mass being warm,
heat begins to be ‘stored during the day in the upper
layers, and is given-up again, when the sun is down, to
warm the air at night. Hence we have warm nights in

Climate 183

July and August; and winter is less cold than it would
otherwise be, thanks to the heat gradually given back
by the great mass of earth.

But the heat given back to the air in this way would
quickly escape, and benefit us little, were it not for the
moisture in the air, which acts the part of a blanket,
and keeps it near the earth. .At the equator, the air is
generally in a very moist condition all the year round ;
and this moisture, while serving the part of a blanket
by night, acts as a veil or parasol by day, and prevents
the sun’s rays from being too scorching.

It is to the large quantity of moisture in the air that
the region of the equator owes its very even tempera-
ture, therefore.

In the dry plains of North India the heat is scorch-
ing, much greater than at the equator, just for want
of this veil ; and the nights are often so cold that water
is frozen, because the heat received by day all escapes
again through the clear air.

Everybody knows that a clear night is a cold night,
while a misty or cloudy one is comparatively warm.

Among other circumstances, therefore, which greatly
affect the climate of a country is its nearness to or dis-
tance from the ocean. For where constant evaporation
is going on, on a large scale, as, of course, it is from
the ocean, there the air must needs be loaded with
moisture, with the consequences already mentioned :
the nights are warmer, the days cooler, the winters less
severe, the summers less scorching. In qne word, the
climate is more equable. Moreover, the ocean is
warmer than the land, in winter and by night, while
it is cooler, in summer and by day; and this tends to
further equalize the temperature.

184 Chimate

Winters are colder and summers hotter in Germany
than in England, mainly for this reason—because the
air is so much drier owing to the greater distance of
the ocean. For the same reason, plants and shrubs
need protection there during the winter which they do
not here; and, on the other hand, grapes will ripen
there when they will not here.

But, besides these general circumstances, there are
also various local circumstances which affect climate
more or less. Thus, if the neighbourhood of the ocean
tends to equalize climate, the neighbourhood of any
large expanse of dry soil does exactly the reverse, inas-
much as it dries the air.

If the Sahara were covered with water, the climate
of the South of Europe would be many degrees less
warm than it is; for the wind passing over it would be
cooled, instead of heated as it now is. It would alsobe
moistened, and so more snow would fall in the Alps,
and less would melt in the summer.

Then, again, there are the many ocean currents, hot
and cold, which also influence climate to a considerable
extent. Western Europe would be far colder than it
is without the Gulf Stream, which brings about 166,000
cubic miles of hot water from the tropics to the North
Atlantic in the course of each year. And this tre-
mendous volume of steaming water, besides warming
the air, loads it with moisture; so that it is easy to
understand why the winter climate of Ireland should
be mild enough to allow of myrtles flourishing out of
doors, and yet why the summer heat should not be
sufficient to ripen fruit, owing to the thick veil of
vapour which screens it from the sun.

Other local circumstances which affect climate in a

Climate 185

greater or less degree are the presence of forests,
rivers, lakes, mountains, which cannot now be dealt
with in detail.

But plants are also affected in a minor degree by the
colour of the soils in which they grow.

Dark substances absorb more heat than light ones
do; and snow will melt more quickly if a piece of black
cloth be stretched above it, even though the two do
not touch one another. In the Arctic regions the ice
melts much faster wherever a small dark-brown plant,
of the same family as the Red Snow, grows, because it
attracts the heat. So, too, in some parts of Switzer-
land the peasants hasten the departure of the snow by
strewing it with black powdered slate.

Dark soils are therefore usually warmer than light
ones; and it is not an uncommon thing for gardeners
to sprinkle a light-coloured soil with peat, charcoal, or
vegetable mould to warm it, for these all act as sun-
traps.

Melons are thus ripened, even in the coolest summers,
at Freiberg, in Saxony, by means of a layer of coal-
dust.

Grapes, too, in the Rhine district, ripen best where
the ground is covered with fragments of black slate;
and the vines are purposely kept near the ground, that
they may have the full benefit of the heat which the
slate absorbs by day and gives up again by night.

The difference in temperature between two sub-
stances, one of which is white and the other black,
when both are equally exposed to the sun, is very re-
markable. There will be as much as thirteen or fourteen
degrees difference, for instance, in the temperatures of
a piece of lamp-black and of a pie e of magnesia.

186 Climate

But though colour makes such an important differ-
ence in the power to absorb heat, it has no influence,
apparently, upon the power to retain it. Indeed,
though sand may absorb heat less quickly than a
darker soil does, when once it is warm it remains warm
longer than any other. The coarser it is, too, the less
quickly it cools ; and as coarse gravel, once thoroughly
heated, retains some degree of heat even through the
night, it is found useful to put it round grape-vines to
keep them warm.

Great, and especially sudden, changes of temperature
are particularly trying to most plants, though such as
grow in deserts have become so accustomed to being
scorched by day and frozen by night, as at least to
manage to keep alive. But though an even tempera-
ture is in some ways most desirable, it does not by any
means follow that all plants would thrive in the equa-
torial region. That region, as has been said, is charac-
terized less by its great heat than by its remarkable
uniformity of climate. It knows no change of seasons:
it is always summer, always spring, and always autumn
there, and many trees bear both flowers and fruit at
the same time. But this constant activity, though it
suits the trees and plants accustomed to it, is too
much for our European fruit-trees and other plants;
for these are in the habit of taking a winter sleep, and
cannot get on without it. Transported to the equa-
torial region, they grow, indeed, freely enough, but too
freely; for they become evergreen, putting out fresh
leaves all the year round, and are so exhausted for
want of their customary rest that they are unable to
ripen their fruit. This is the case even when they are
taken to the cooler hill-country of Ceylon; and it is

Climate 187

true even with regard to the vine, which, though a
native of warm climates, still is not a tropical plant,
and is accustomed to shed its leaves year by year. In
the tropics, however, its leaves remain green, instead
of giving up their stores to feed the fruit as they ought ;
the grapes fall off almost unformed, and the vine puts
all its energy into growing leaves instead of fruit, not
having strength for both. The one thing which it lacks
is rest—the rest which in winter it is compelled to
take.

It being, however, impossible to provide the vines
with winter-cold in Ceylon, it was suggested that heat
might perhaps be made to answer the purpose as well,
and the experiment was tried of laying the roots bare
for a time to the strongest sun. This had the effect of
checking the flow of sap as effectually as frost could
have done: the leaves dropped, the vines had their
sleep, and awoke from it so refreshed and invigorated
that they were able to bring their crop to maturity ;
and this plan has been adopted with success both in
Ceylon and Bombay.

In those tropical regions, outside the equatorial belt,
where there are periodical rainy seasons and long
droughts, the latter answer all the purpose of winter,
and are, indeed, winter, so far as vegetation is con-
cerned, in spite of their intense heat. Trees and shrubs
are as leafless in the desert of Nubia, for instance,
before the rains set in, as if it were mid-winter, in spite
of, or, rather, in consequence of, the terrible heat ; and
thus a time of rest is secured to them.

In the far north we have a very different state of
things. Here, instead of its being necessary to secure
that the plants shall have rest, the great thing is to

188 Climate

provide that they shall make the utmost of the very
short spring and summer which are all that fall to their
lot. Their time of sleep lasts on an average ten
months, and during the remaining two months they
have everything to do, so that it is most necessary that
they should make the most of their time. The days
are of course very long, which is a help, while the
nights are so light as to be hardly like night; and if
Professor Nordenskjéld’s observations be trustworthy,
it seems that the plants do indeed turn every moment
to account, by growing all night as well as all day.

But many of them do a great deal of growing in
advance, so that as soon as the summer comes their
blossoms and fruit, which need heat more than the
leaves, may be ready at once to take advantage of it.
These plants, that is to say, make very large, strong
buds, which are packed full of leaves and blossoms in a
more or less undeveloped state, but with all their parts
ready, before the winter sets in. Directly the growing
time comes round again, therefore, they can burst out,
and begin to gather food from the air at once, and the
plant is able to blossom very early, thus ensuring as
much time as possible for the perfecting of the fruit.

Most of the plants ripen their fruit, but some few are
not able to do so, except now and then, when the
summer is hotter or longer than usual ; and some which
are annuals further south become perennials here, as
they would not have time to grow from seed, and ripen
seed, in one short season.

During the long winter many are of course protected
by the snow; but there are wide surfaces here and
there left quite bare of covering, and yet even here
plants manage to survive, some without any protection

Climate 189

whatever, others because they are buried. under a deep
layer of dead leaves and stems.

But though they bear the intense cold without
injury, it is quite evident that even these dwellers in
the Arctic regions enjoy a little warmth when they can
get it, for they are most abundant on sunny slopes and
in sheltered nooks and corners. Many of them, indeed,
crouch close to the ground, and few venture to raise
their heads very high; trees there are none, the bushes
are dwarfs, with few and small leaves, and the vegetation
generally is on a miniature scale. Still, there is vege-
tation ; and whether in ‘ deserts’ of ice or ‘ deserts’ of
sand, it would be equally difficult to find any spaces of
large extent where vegetable life of some kind or other
does not exist, at least during certain seasons of the
year.

XIV.
BLOSSOM AND SEED

PLANTs, even the very humblest and lowliest, have, as
we have seen, many requirements in the way of food of
various kinds, water, air, light, and warmth. But
having seen them duly provided with all these, we
might fancy that now at last all their wants were
satisfied, and that nothing more remained but for them
to make the best of their opportunities and—grow.

But all depends upon what we consider to be the
plant’s object in life. For instance, we may be quite
satisfied to grow orange-trees for their blossom merely,
or maize for use as forage, and palms for the sake of
their foliage, in climates where it is impossible for any
one of them to ripen their fruit. And provided they
throve and answered these purposes, our object would
be attained.

But plants in the natural state grow to bear and
ripen fruit. All the rest of their lives is merely a pre-
paration for this one grand end. The roots draw food
from the soil, and the leaves do the same from the air,
all for the purpose of feeding and maturing the fruit—
the one aim to which everything tends.

Of course, where man comes upon the scene it is

Blossom and Seed Ql.

quite another matter, as he can take cuttings of some,
divide the roots of others, and fetch continual supplies
of seed from the ends of the earth, if necessary. But
the wild plant has not these resources to fall back upon,
and if its race is to continue, it must as a rule be able
to perfect its seed, otherwise it will merely thrive for a
time, longer or shorter, according as it is an annual
or a perennial, and then it will perish without
descendants.

But in very many cases the plant, like Mr. Belt’s
scarlet-runners already mentioned, is quite unable to
perfect seed without the help of what we may call
nature’s under-gardeners. The plant does much for its
offspring ; it collects and stores food, it drains itself
of its own life-juices for their benefit, but it cannot
always do everything; and if these under-gardeners
were banished from the earth, some plants would
speedily vanish also.

Both blossoming and fruit-bearing are processes more
or less exhausting to the plant, for neither flowers nor
fruits do much, though they do something, towards
feeding themselves. Annuals blossom and bear fruit
once and then die entirely, roots and all, their leaves
and stems being drained of nourishment by the end of
the season. Others, perennials, die down, but their
roots remain alive; and others again, merely shed
their exhausted leaves, and grow fresh ones, for several
or many seasons in succession. Others again, take
more than one season to store food before they venture
upon the expense of having blossoms at all; and others
take many years to prepare for this great effort, and
when it is at last accomplished, the great end of their
lives, they die of mere exhaustion.

192 Blossom and Seed

The food of blossom and fruit is, as has been said,
very generally accumulated in the leaves and stems of
the plant ; but sometimes the root serves as the main
storehouse. The turnip, for instance, like other
biennials, spends the first year of its life in doing
nothing but gather a store of food by means of its roots
and its tuft of leaves. It does not shoot up, and it
makes no attempt to blossom; and as the farmer does
not want turnip-blossom, and does want roots, he takes
the latter while they are plump, and well-filled with the
food intended for the seed. If he waited till the next
year he would see his turnip-plants shoot up rapidly
and blossom; and very thriving they would look, no
doubt ; but all this time they would be sucking away at
the roots, which would be losing their plumpness, and
growing gradually hollower and more hollow, until, by
the end of the second year, they would be reduced to
nothing but fibre, and be quite useless.

We have spoken already-of bulbous plants, such as
crocuses, whose blossoms are nourished on the food
previously stored for them in the bulb, by the leaves,
which, in most cases, do the chief part of their work
after the blossoms have faded. But in some instances,
as in that of the colchicum, or meadow saffron, they
come up and make their preparations in the spring,
for the blossoms which do not appear till the autumn,
long after the leaves have vanished. In these cases.
the food for the blossoms is stored in the bulbs;
and if a tidy gardener unwarily cuts off the leaves
before the bulb is properly stocked, he starves the
blossoms.

But some plants take years to prepare food sufficient
for the supreme effort of their lives.

Blossom and Seed 193

The American aloe, for instance, which was sup-
posed to blossom only once in a hundred years, though
it does not wait quite so long as this, does actually
wait five or six years in its own country, and from fifty
to seventy in ours, before it attempts to send up a
flower-spike. But when it does begin, it grows with
such tremendous energy—at the rate of a foot a day
even in our conservatories—that one can well under-
stand its need of a large store of food ready for im-
mediate use, since it would be impossible for leaves
and roots to collect, manufacture, and supply it as fast
as it is wanted.

The aloe does not, however, always die of its effort,
and may live to blossom again, some years later; but
the Talipot palm, though it attains a great age, spends
its whole life in accumulating food for its progeny;
and having once blossomed, it is quite exhausted .and
perishés.

Blossoming, then, is a serious matter for all plants,
and not to be undertaken without due preparation.
But it is a curious fact that the size of a plant’s blos-
soms is often quite independent of the size of the plant
itself. Many a forest-tree, for instance, bears flowers
which are quite minute and insignificant; others, as
some of the palms, bear spikes of blossom several feet
in length and leaves in proportion. As a rule, how-
ever, trees have small leaves, small dull blossoms, and
small seeds for their size; but they bear all three in
large numbers. A diminutive cactus, only a few inches
high, on the other hand, may boast a glorious crimson
flower, measuring two or three inches across; but,
then, it has to be satisfied with one or perhaps two.
The beautiful night-flowering cactus attains some size,

3

194 Blossom and Seed

but it is a conservatory plant, not a tree, yet its blos-
soms measure half a foot across and it bears at times
as many as twenty or thirty together.

The largest known blossom, however, is that of the
extraordinary Rafflesia Arnoldi, a native of Java and
Sumatra, which, much more truly than even the orchids,
is ‘all blossom,’ for it has neither branches, leaves, nor
roots. Of course, therefore, it must needs be a parasite,
living by and sucking the life-juices from others; and
it produces a huge blossom, more than a yard across,
mainly at the expense of the vine-like plant upon
which it fixes itself.

It is not by any means a beautiful object, and its
petals, which are thick and fleshy in texture as well as
flesh-coloured, have the smell of tainted beef. This
monster takes several months to come to perfection,
and then weighs about fifteen pounds; after which it
begins, in a few days, to wither away.

An ordinary, complete, simple blossom, whether
large or small, brightly coloured or inconspicuous, con-
sists of two sets of parts, or organs, an outer and an
inner set. It is the function of the inner set to form
the seed; and it is the function of the outer set to
protect the inner from all injury, and also, in many
cases, to attract the under-gardeners already referred
to, whose good offices are required for the development
of the seed.

The perfecting of the seed is the great thing to be
accomplished ; and those parts of the blossom which
contribute to this object are placed in the centre, as
far out of harm’s way as possible. If we examine, for
instance, a common primrose, splitting it carefully

Blossom and Seed 195

upwards from the base of the flower, we shall see in
the very centre a hair-like stalk, with a knob at the
upper end and a hollow swelling at the lower end. On
splitting open this hollow part, we find that it contains
a number of very-minute grains, ovules, or little eggs,
which, in the ordinary course of things, would be con-
verted into seeds.

This central organ is the pistil, which consists of

Section of Fuchsia-blossom.

one or more bodies, named carpels, each with its
hollow case, or ovary, below, and its stalk, or style,
above; and these are either distinct one from another,
or combined into one organ.

Outside the pistil stand the dust-spikes, or stamens,
—stalks bearing each a double sac, or anther, which
is filled with the dust known as pollen. Pistil and

196 Blossom and Seed

stamens together form the inner and more important
set of organs.

The outer set consists of a double envelope of leaves;
the inner, or petals, more delicate in texture and more
varied in colour, forming the corolla; and the outer,
or sepals, generally green, and forming the calyx. A
perfect flower has all these parts, and some have
double rows of each. Naturally our eye is attracted
chiefly by the brightly coloured part of a blossom, and
we think little about the inner organs, which are often
almost or quite hidden from our sight. But it is
these inner organs which are really the only absolutely
necessary parts of a blossom.

Many flowers have no calyx at all; some have no
petals; but, provided they have stamens and pistil, they
can still accomplish all that is necessary for the perfect-
ing of their seed. Even pistil and stamens, however,
may be, and often are, reduced in size and deprived of
their stalks ; but dust-cells there must be, and ovules,
or grains to be developed into seeds, there must be if
the plant is to bear seed at all.

Now all these organs, the inner set as well as the
outer set, are really Jeaves—leaves whose appearance
and duties in life have been altered. The calyx still
looks more or less leaf-like usually, and it is not
difficult to believe that the petals might be leaves too,
though more delicate and more daintily coloured. But
it is less easy to believe the same of stamens and
pistil. Let us, however, look for them in any double
blossom, and we shall find few if any, for they have
been changed into petals. It is blossoms with many
stamens, such as the rose, ranunculus, anemone; or
blossoms with many florets, such as the daisy and

Blossom and Seed 197

dahlia, which are most commonly doubled by cultiva-
tion.

Nature does not grow many double flowers, for
wild plants need seed, and double flowers produce little
if any, seed being sacrificed to petals. Geraniums,
which have only ten stamens, are among the plants,
however, which have a tendency to increase the
number of their petals; and, among the single blossoms,
one may often be seen with a petal or two more than
the rest, of an extra small petal, which is half way
between a petal and a stamen. If the seed from this
blossom were saved, some of the next generation of
plants might have still more petals and still fewer

Pollen of the Melon, magnified.

stamens, and by carefully cultivating those having
these peculiarities the gardener would at last obtain
quite double blossoms. The orange day-lily, too, may
sometimes be seen with one or more stamens enlarged
into small petals and bearing an imperfect anther.

But we have now to see what it is which changes
the little immature grains in the hollow part of the
pistil into seeds, capable of growing into independent
plants. At first they are mere specks of matter to all
appearance, and so they will remain unless they are
brought into close contact with some of the dust con-
tained in the sacs borne by the stamens. This is the
special stimulant which they need to make them

198 Blossom and Seed

develop, and if it be kept from them they will simply
shrivel and die, for nothing else will do instead.

This dust, or pollen, is contained in the anther,
which is usually seated, or more often perched, and
apparently very loosely perched, too, on the end of a
stalk.

When the pollen is ripe, that is, ready for the use of
the grains contained in the pistil, the chambers open
and it is discharged. The pollen consists of hollow
grains, varying very much in size and shape in different
plants, though always alike in the same plant.

Pollen-grains are very beautiful objects when seen
through the microscope, though they look like nothing
but powdery dust to the naked eye. Their colour is
usually yellow or brown, but they are also red, green,
blue, whitish, and even black; and though their
general shape is round, or egg-shaped, they are of many
other forms, wonderful in their great beauty and
variety, and reminding one of microscopic shells.

Some pollen-grains, for instance, are covered with

-ridges or grooves; others, such as those of the holly-
hock and aster, with spines; others again with hairs
or thorns; those of the thistle are many-sided; of
the fuchsia and evening primrose, triangular; of the
chicory, six-sided; and, if we could see, we should no

. doubt find a reason for every change of form and
colour, and discover that each was exactly adapted
for its own special purpose.

Every pollen-grain is delicately coated with oil, pro-
bably as a protection against damp and wet, and all
have upon them markings, like pores or slits, to some
of which there are lid-like covers. Usually each grain
consists of a single cell, though sometimes there are

Blossom and Seed 199

more, and the cells are filled with a liquid of a most
nutritious kind, consisting partly of starch, partly of oil,
and partly of some jelly-like nitrogenous compound.

It is pollen which is the’ flesh-forming food of the
bee. It may live on honey, which is mainly sugar—
not nitrogenous—during the winter, when it is doing
no work, but when it is taking long journeys to and
fro, it needs something more nutritious to make up for
the waste occasioned by so much muscular exercise,
and it eats pollen, besides carrying it home to make
bee-bread for the young grubs.

But our concern now is with the ovules, the possible

Pos.en of Wheat. Pollen of the Hollyhock.

seeds, lying enclosed in the ovary at the base of the
pistil, while the pollen, which is to make seeds of them,
-is in the anther-sacs above, and, as it would seem, out
of, and beyond their reack. The question is, how are
the two to be brought together ?

In describing the primrose, we mentioned that the
top of the pistil ends in a knob; and this knob is a
matter of great importance. It is called the stigma,
and is of all sorts of different shapes in different
flowers ; sometimes merely a point, sometimes large
and divided into lobes, sometimes feathery, as in most
of the grasses; but whatever its shape, it has no
covering of outer skin, as the stalk on which it is
borne has, and it is more or less sticky, and often
crowned with a bead of nectar. This bead is so large

200 Blossom and Seed

in some plants—as, for instance, the white lily—that it
may be taken off; and if then a few grains of pollen
from the anther be sprinkled upon it, we shall see that
these will in about half an hour begin to swell and
grow. Each grain will put forth a slender tube, very
minute, of course; but in an hour or two it will have
lengthened out, and the fluid contained in the pollen-

Throwing out the Pollen Tube.

grain may be seen passing down one side of the tube
and up the other. Pollen-grains may also be grown in
a solution of gum or sugar.

Now this is exactly what takes place when pollen
falls upon the sticky stigma at the tip of the pistil, only
that instead of growing in an objectless way, each grain

Blossom and Seed . 201

sends out its tube, or sometimes several tubes, in the
most business-like manner, and with the most precise
and definite aim. The object is to reach one of the
ovules below, and to do this the tube, in many cases of
more than hair-like fineness, pierces its way downwards
through the stalk of the pistil, and makes straight for
its aim with unerring exactness, entering one of the
ovules by an opening in it which exists for this
purpose.

Sometimes the tube may take months to reach the
ovule, but more usually it accomplishes its purpose ina
few days or hours. As soon as it has made its way into
the ovule, it begins to pass into it the fluid contents of
the pollen-grain, and the ovule begins to grow.

But the ovule does more than grow, it acquires a new
character. At first it was a mere speck of matter, con-
taining a germ-cell, indeed, but no germ, no rudi-
mentary or embryo plantlet, such as one may see on
splitting open a bean, pea, nut, or any other seed large
enough for the purpose. The tube sent out by the
pollen-grain enters the ovule, and the germ is developed
and vivified by the liquid which passes down it. The
seed, which before was unfertile, and could never have
germinated and produced a plant, is now fertilized,
made fruitful, and if allowed to come to maturity it will
be capable of producing a plant like that by which it is
borne.

It is quite possible in certain cases for ovules to grow
and even to attain the size of seeds without being seeds,
without having within them any living germ capable of
independent life and growth. For each ovule is at-
tached to the walls of its nursery, as one may see by
looking at the peas in a pod, and is fed from the leaves.

202 Blossom and Sceea

But unless it receives also the liquid contained in the
pollen-grain, it remains lifeless, and sooner or later
shrivels and perishes.

The quantity of pollen prepared and needed for the
ovules varies very greatly in different plants. The
violet, for instance, produces about a hundred grains in
each blossom, and the poppy more than three million
and ahalf. Some ovules need only two or three grains
of pollen to quicken them, and others several; some of
the foreign orchids bear as many as seventy-four
million seeds, and though they are very small, each
seed requires the contents of about twenty grains of
pollen to fertilise it; so that the quantity produced is
necessarily very large. Moreover, a good deal more is
required than the plant itself needs, as a considerable
margin must be allowed for waste, some being blown
away by the wind, some washed away by rain, and not
a little consumed by bees and other insects.

Since the pistil with its sticky tip stands in the
middle of the blossom all ready to catch and hold fast
the pollen which is discharged by the surrounding dust-
spikes, it would seem that there could be little difficulty
about the matter, and that stamens and pistils might
safely be left to manage it without help. But there are
various obstacles in the way of this apparently simple
arrangement.

In the first place, even though stamens and pistil be
most conveniently placed, as it might seem, for the very
purpose of giving and receiving pollen, it does not
follow that they are so. For where is the use of their
being within easy reach of one another if they are not
both ready to act at the same time? And this is a
thing which happens very frequently indeed. Some-

Blossom and Seed 203

times the pistil is ready first; its tip is unfolded and
sticky, and waiting for pollen, before that of the sur-
rounding stamens is ripe enough to burst from the
anthers. But the pistil cannot go on waiting, and if
pollen does not reach it at the right time, it is of no use
its coming at all; the time is gone by, and the ovules
are left to shrivel.

Often, too, the pollen“is ripe first and all scattered
before the pistil is ready for it; and here again the
ovules must perish, unless pollen ‘is brought from else-
where. Even when pollen and pistil are ripe together,
they may be out of one another’s reach ; for tlie pistil
may be taller than the stamens, or the anthers may
open outwards instead of inwards, and in neither case
will the pollen be scattered on the pistil-tip, or be of
any use to the ovules.

But there are more difficulties even than these. A
perfect flower, as has been said, consists of a double
set of outer and a double set of inner organs; but very
many flowers are quite imperfect. One or both of the
outer set of leaves may be altogether wanting, and one
or other of the inner set may be also wanting. Thatis
to say, some plants grow the pistil in one blossoni and
the stamens in another, but never both in the same
blossom ; and others go a step further than this, and
grow their pistils and stamens not merely in different
blossoms, but on different plants.

Those plants er blossoms, which bear stamens only,
are of course barren, for they possess no ovules, as they
possess no pistils; and those which bear pistils only
are, or may be, fertile, since they possess ovules, which
may become seeds provided pollen be brought to them
from another blossom or plapt, but not otherwise.

204 Blossom and Seed

And then, again, even when a plant bears perfect
flowers with both pistils and stamens, it not unfre-
quently happens that pollen from their own blossom,
or from another blossom on the same stalk, does not
suit the ovules. Some which are fertilized by the pollen
of their own blossom, close-fertilized, as it is called, do
well, and the seed is plentiful; but in most cases it is
poor and even worthless. Sometimes the pollen from
a blossom on the same stalk actually has the effect of
poison, and when applied to the pistil-tip, causes it to
shrivel and decay, and makes the petals drop; some-
times, again, it does neither good nor harm directly ;
it does not poison and it does not fertilize, but—which
is equally injurious—it prevents any other pollen re-
ceived afterwards from having any effect, so that in
either case the ovules are equally sure to shrivel.
Then, further, there are some plants, as, for instance,
certain of the passion-flowers, whose ovules cannot be
converted into seeds unless they receive pollen not
merely from another plant of the same species, but
from another plant of a different species—a passion-
flower, but a different species of passion-flower.

Such, then, being some of the many arrangements by
which it is made difficult or impossible, for ovules to be
fertilized by pollen from their own blossom, or from a
blossom on the same stalk, one must conclude that
there is some reason for them, and that seed is the
better for being cross-fertilized—fertilized, that is, by
pollen from another plant. And so, indéed, it proves ;
for if cross-fertilized and self-fertilized seeds be sown
together, it generally happens that the former grow up
so much the stronger as quite to overpower the rest.

As a rule, then, cross-fertilized seed produces much

Blossom and Seed 205

more vigorous plants than self-fertilized seed does. But
still, as wild plants have to keep their own place in the
world, which they cannot do without offspring, it is
better for them to have some seed, even poor seed,
rather than none at all. And to ensure this some
plants manage to bear seed of both sorts; some fer-
tilized by the pollen of its own blossom, some if possible
by that brought from outside, so that if by any chance
the latter should fail, they may still have something to
fall back upon.

There is, for instance, that ubiquitous little plant,
the common chickweed—weak-stemmed and _fragile-
looking, but not in the smallest danger of dying out,
for it goes on sowing itself through many months of
the year. Its first crop of seed is fertilized quite early
in the spring, so early that the plant is left to itself,
and has to make the best of its own pollen, which it
does in the most thrifty way possible. ‘ The pollen is
never scattered, so there is no waste, but, while still in
the anther-sacs, it sends out tubes in the direction of
the pistil-tip, which it reaches without fail. This pro-
cess takes place while the flowers are still only buds, so
that pollen and tubes are carefully protected.. The
seed thus produced may be poor, much of it may even
be useless, but at least what there is, is better than
none; and later in the season, if circumstances are
favourable, better seed will be produced by pollen
brought from other plants.

Generally speaking, pollen grains do not begin to
swell until they actually touch the moist tip of the
pistil, but in these early blossoms of the chickweed
and some other plants, they never leave the anthers.
The sweet violet, in like manner, bears some buds,

206 Blossom and Seed

smaller than the rest, which never open. These pro-
duce but a few grains of pollen, as there is no waste
to be allowed for, and they send out long tubes without
leaving the anthers.

The dog-violet, on the other hand, as it does not
resort to this device, is quite seedless, unless pollen be
brought to it; and other plants are much worse off,
and can never set seed at all in this country, being
unable to make use of their own pollen, and not find-
ing here the messengers which, in their native land,
bring them pollen from other plants. The Greater
Periwinkle is one of these, and never has seed.

As has been mentioned, some blossoms have pistils
so much longer than the stamens that it seems impos-
sible for the pollen of the one to reach the tip of the
former. This is the case with the colchicum, whose
mauve-coloured blossoms are much like those of
the crocus. But when the pollen is ripe and the
anthers have burst, some of the dust is rubbed off
upon the inside of the petals when the flower closes,
as it does every night several times in succession.
Meanwhile the petals lengthen so much that, when the
blossom closes for the last time, the first spots of
pollen are brought up to a level with the tip of the
pistil and are pressed against it, with the result that
some of the grains adhere to the sticky surface and
soon begin to grow, at the rate of something more
than an inch in an hour.

In the case of the colchicum, the ovules are a very
long way from the pistil-tip—as much as thirteen
inches—but they are reached in about twelve hours,
This takes place at latest at the beginning of
November; but, for some reason, perhaps because it

Blossom and Seed 207

needs warmth, the germ or embryo does not begin to
form in the ovules until the following May.

The ovules of the American oak wait almost a year
after the entrance of the pollen-tube before they begin
to develop, and then take another year to ripen.

Why should the pollen-tube always grow with its
end directly towards the very narrow opening by which
it is to enter the ovule ?

For the ovule is often far away—what, considering
the size of the pollen-grain, may be called, without
exaggeration, hundreds of miles away—while the door
by which alone the tube can find entrance is the
merest point. Indeed, the ovules themselves are often
mere specks, and usually they are placed in what looks
like a most inaccessible position, quite enclosed in the
ovary. Often, too, there are hundreds, and even
thousands, of ovules in one ovary, each of which
receives at least one pollen-tube, in some cases more.

Even when it has taken the first turn downwards
in the right direction there is plenty of room—either
on its way down the pistil stalk or when it reaches the
ovary—for the tube to goastray. But instead of doing
so it makes unerringly for its mark, and we can only
conclude that some definite arrangements exist by which
it is directed into, and kept in, the right way.

XV.
THE GOLDEN RULE FOR FLOWERS

‘Get fertilized! cross-fertilized, if you can, self-
fertilized if you must,” that is nature’s golden rule for
flowers.’

We have mentioned only a few of the curious and
interesting arrangements by which the pollen is in
very many cases prevented from coming in contact
with the ovules of its own blossom; but enough has
‘been said to show that this ¢elf-fertilization is generally
discouraged, and made in many cases either difficult
or altogether impossible.

We have now to see how cross-fertilization is
provided for, and by what messengers pollen is con-
veyed from one blossom to another. These messengers
are wind, insects of many kinds, birds, and even in
some instances that most unlikely of gardeners, the ill-
reputed snail.

Plants which depend upon the wind for bringing
them the needful pollen have small, inconspicuous,
and generally scentless blossoms ; bright colours, sweet
scents, and honey, being usually confined to those
plants which need the services of birds and insects. The
pistil-tips or stigmas of the former are also especially

The Golden Rule for Flowers 209

adapted for catching and holding the grains of pollen
blown upon them, for they are either divided into
plumes or feathers, or are plentifully beset with hairs.
Grasses and sedges are chiefly wind-fertilized ; and so,
too, are many trees, such as the oak, beech, hazel,
birch, elm, poplar and pine, all of which blossom early
in the year, often before there are any leaves to inter-
fere with the scattering of the pollen; and they mostly
bear pollen and ovules in separate blossoms, some on
the same tree, some on different trees.

The pollen-bearing, or staminate blossoms of these
trees grow together in large numbers, in the form of
tassels or catkins, which wither and drop when their
pollen is scattered and their work done.

The catkins of the hazel contain more than a
hundred blossoms, having no petals, but ten or twelve
stamens each. The blossoms containing the ovules
grow on the same tree, but they have no petals either,
and are so small as almost to escape notice, for they
look like nothing but small scaly buds, with tiny crim-
son tufts on the top. These crimson tufts are the
stigmas, outspread on purpose to catch the grains of
pollen as they float by.

Pines, on the other hand, have not only no petals,
but no pistil-stalks, and not even stigmas either; all
that there is of the pistil being the ovary, which is
scale-shaped and open, so that the pollen falls directly
upon the ovules within it. As the ovules develop into
seeds and grow, the scales that bear them grow also,
and ripen into fir-cones.

Pollen which has to be carried by the wind is light,
dry and powdery, and is produced in very large quanti-

14

210 The Golden Rule for Flowers

ties to allow for the unavoidable waste. It is carried
far and wide, and the air is often filled with it, espe-
cially in the neighbourhood of forests. Masses of pine-
pollen are often found in America as much as three or
four hundred miles away from any trees which could
have produced it. Of course, where plants are depen-
dent upon the wind for pollen, they are liable to have a
great variety of it brought to them; but this does not
hurt them, for unless the right kind comes it simply
has no effect whatever. But as it is of great import-
ance to these plants not to miss any chance of the
right pollen, and as the wind blows at all times, night
and day, they never close, many being unable to do so
from want of petals, so that they are always ready to
receive it.

Among the trees which are fertilized at least in part
by the wind are the palms, whose blossoms are small
and dull-looking, and enclosed—thousands of them
together —in a sheath, something like that of the
arum. But some of the palms are very strongly
scented, and when the sheath opens it is a centre of
attraction to a buzzing cloud of flies, small beetles and
other insects.

The date-palm bears ovules and pollen on separate
trees; and when date stones are planted it is found
that instead of coming up half of one sort and half of
the other, there are more of the fruit-bearing than of
the unfruitful trees among them.

However, one pollen-bearing tree is well able to
supply more than one ovule-bearing tree, and in their
wild state the trees have no difficulty in obtaining all
that they want. But when they are cultivated then

The Golden Rule for Flowers 211

they require help, though trees of both kinds grow in
the same plantation. The fact is mentioned by many
writers, from Pliny downwards, though without expla-
nation ; and in all the plantations part of the work con-
sists in climbing the trees, first to collect pollen-bearing
blossoms, and next to dust with them the little ovules,
which are about as large as peas, and lie exposed in the
centre of the other blossoms, not enclosed in an ovary.
If this is not done the date crop fails.

During Napoleon’s campaigns in Egypt, the natives
not having much leisure to attend to husbandry, the
plantations about Cairo were neglected, and although
the trees blossomed as usual the eatable dates were few.

In the East dates are such an important article of
food, and the failure of the crop such a serious loss,
that nations at war, and desirous of inflicting as much
injury as possible upon one another, were in the habit
of cutting down, not all the palms indiscriminately, bur
those bearing pollen. On one occasion it is said that
the Persians, fearing they might be injured in this way
during a civil war, took the precaution of collecting the
pollen from the trees, kept it in close vessels for nine-
teen years, and made successful use of it when peace
was restored.

The Arabs are said always to keep some of the
unopened sheaths containing pollen from year to year,
in case of any failure in the blossoms.

It has been mentioned that pollen may often be
‘borne long distances by the wind, and this has been
exemplified ina remarkably interesting way by the case
of a date-palm growing near Otranto. The palm is not
a native of Italy, and though introduced, does not grow

212 The Golden Rule for Flowers

wild ; and this specimen, being the only one of its kind
in the neighbourhood, was barren for years. But at
last, one year, the young dates, instead of shrivelling
as usual, remained on the tree and grew to their
proper size; and then it was found that a date tree
had flowered that same year for the first time at Brin-
disi, some forty odd miles away, and had borne pollen-
blossoms. This pollen, therefore, had no doubt been
carried by the wind to the tree at Otranto.

The case of another solitary date-tree, growing at
Martinique, in the West Indies, is also interesting,
though in another way. For this tree bore eatable
fruit without being fertilized, but though the dates
might be eaten the stones would not grow, for the
seeds were imperfect, and contained no germ.

The fruit of a plant, botanically speaking, is the
ripened pistil, or rather that part of the pistil which
contains the ovules. Sometimes, as in the case of the
various kinds of corn, it is the ripened ovules, the
seeds, which are the eatable part of the fruit, the ovary
in which they are contained being a mere husk. In
the various gourds, on the other hand, the ovary itself
grows enormously and becomes fleshy. So, too, with
apples, pears, peaches, nectarines, plums and oranges,
the swollen, ripened ovary containing the seed is the
part best worth eating ; and it has, therefore, been the
gardeners’ object to increase its size and improve its
flavour. In the almond, the ovary remains a mere
woolly skin without edible flesh ; in the horse-chestnut
it is a tough, thick and prickly skin, equally uneatable ;
in the filbert and beech-nut it is a hard shell; and in
the coco-nut it consists of fibre. Whether husk,

The Golden Rule for Flowers 213

shell, skin, flesh or fibre, however, the whole ovary
with the ripened ovules is properly the plant’s
fruit.

Generally speaking, the growth of the ovary, as well
as of the ovules, depends upon pollen, and when the
ovules are fertilized and begin to grow, the ovary
begins to develop also, and not until then.

But it is not always so. Among the plants belonging
to the order of Liliaceze, which includes, besides lilies,
the hyacinth, tulip, garlic, onion, and others, it is a
common thing for the ovary to begin growing actively
before the pollen-tubes have reached the ovules—before
they are fertilized, therefore—though not before the
tubes have begun to penetrate downwards through the
style. In these cases the ovary seems to be excited to
growth by the pollen, though not in the usual way, and
before the ovules are affected.

But in many plants the ovary, and even ovules, may
be fully developed, altogether without pollen; though
in this case the ovules do not become seeds any more
than the ‘stones’ of the Martinique date become seeds,
and no plant can be raised from them.

Among the plants which ripen the ovary without the
help of pollen are the Zante ‘currant’ (really a small
grape), many Maltese oranges, and some kinds of apple.

While some ovules are so independent as to be able
to grow to the size of seeds, and even to assume the
appearance of seeds, without being fertilized, there are,
on the other hand, some—as, for instance, those of the
orchids—which are not even formed until the pollen-
tubes begin to grow towards the place where they
should be. The pollen in these cases not only fertilizes

214 The Golden Rule for Flowers

them, but, though still at a distance, is the means of
bringing them into being.

Of course, as pollen is so light, and easily blown
about, many plants may at times be fertilized by the
wind, besides those which are especially dependent
upon it. Not many, one would suppose, are fertilized
by water; yet there are one-or two instances of this
too curious to be passed over.

One of these is that of a small water-plant, nearly
related to the duckweeds, which bears two blossoms
enclosed together in a boat-shaped sheath, which floats
upon the water. In the upper part of the sheath is a
perfect pistil, with its ovary, short stalk, and stigma ;
in the lower part are the anthers containing pollen,
which cannot by any possibility reach the stigma unless
rain happens to fall when it is ready. If it does, the
sheath is gradually filled with water, and the pollen is
floated up till it reaches the right place.

There is a still more curious arrangement in the case
of the Vallisneria, which grows in the ditches in Italy,
and is well known, though not in a flowering state, in
fresh-water aquariums. This plant bears its pistillate
and staminate blossoms on separate roots, which, how-
ever, seem to grow near one another. The pistillate,
fruit-bearing blossom grows on a long, slender stalk
twisted like a corkscrew, which uncurls and raises the
bud just above the surface of the water when it is
about to open. The barren, staminate, or pollen-
bearing flowers, grow in great numbers on short, up-
right stalks under water ; but just about the time when
the other blossoms up above opén and want their help,
these buds loose themselves from their stalks and rise

The Golden Rule for Flowers 215

up like little air-bubbles, opening suddenly when they
reach the surface. Here they float about on the water
among the pistillate blossoms in such numbers that
they often quite cover them, and by this means convey
to them the necessary pollen. When this has been
received, the corkscrew stalks, which are often as much
as ten feet long, curl up as before, and the fertilized
blossoms sink down again to ripen their fruit under
water.

We must now, however, turn to the insects, among
which bees have a foremost claim upon our attention,
since none are more generally useful in carrying on the
very important work of fertilization. Creeping insects
are not, as a rule, useful visitors for flowers, as any
grains of pollen which they may pick up by the way
are liable to be brushed off again before they reach a
blossom which might be benefited. But flying insects
of all kinds, even to the smallest flies and midges,
when once dusted with pollen, are almost sure to
convey a few grains to the next blossom upon which
they alight.

Pollen is of vital importance to the plants themselves,
besides serving as food to bees and other insects; but
nectar, so far as appears, is of no use to the plant
except as serving to attract useful visitors; and the
same may be said of sweet scents and brightly-coloured
petals. All these are, in fact, the one, baits, the other,
signals, which the plant puts forth to make known to
those who understand the language where pollen and
nectar may be found.

“Good entertainment for bees and butterflies’ is
what the bright colours mean ; and where, as is often

216 The Golden Rule for Flowers

the case, the nectar is concealed in some deep and safe
recess where wet cannot injure it, many flowers have
lines or dots upon some of their petals to point out
where it may be found, and so save their visitors’
time.

Many bees have a regular pollen-brush of thick hairs
under their tails, with which they sweep up the grains;
and even when their object: is nectar, not pollen, they
are almost sure to carry off a few grains by brushing
against the anthers of the blossom they are visiting.
For all bees are more or less covered with hairs, some
of which, being webbed, are especially adapted for
holding the pollen-grains; while the grains themselves
cling all the better for the spines and hairs with which
they are often beset.

Small insects are useful for fertilizing small flowers,
but they may light upon a large flower, creep in, and
even rob it of nectar, without coming into contact with
the pollen at all, which is almost impossible in the case
of the larger species of bees, with their hairy bodies. .
The bee, too, has another recommendation: it has to
visit many flowers before its crop is filled with nectar,
and both hive-bees and humble-bees, especially the
latter, seem generally, though not invariably, to confine
their visits to one kind of flower on each journey—a
very important matter, as, pollen of different sorts
would in most cases be useless.

Of course, the bee may, and does, convey pollen
from blossom to blossom of the same plant, which may
pfoduce self-fertilization of a sort; but when it has
visited all the blossoms on one plant, and flies off to
another, the jivst blossoms visited there must needs

The Golden Rule for Flowers 217

stand a good chance of receiving pollen from the last
of the former.

That the work thus done by bees is in many cases
absolutely indispensable there is ample proof, though
we may not always recognise it.

The bean-crop failed in Nicaragua just for lack of
the right sort of bee; and often when the young goose-
berries, or what should be gooseberries, wither and
drop in early spring, mstead of swelling as they ought
to do, it is not so much because they have been nipped
by the frost as that the frost has kept the bees at home.
For the pollen and pistils of the gooseberry-blossoms
ripen at different times, so that the one must be brought
to the other if the ovules are to be fertilized; and if
this is not done, neither they nor the berry containing
them can grow to their proper size.

One year there was a remarkable scarcity of holly-
berries in different parts of the country, which some
people thought was accounted for by the cold weather
in the early part of the year. But the holly is a very
hardy shrub, and grows in Norway as far north as 62°,
so that it was not likely to have suffered from an
English spring. On the other hand, bees were re-
markably rare that season; and, as the holly grows its
stamens and pistils mostly on different plants, the
dearth of berries was doubtless owing to the absence
of bees.

For, though holly-blossoms are insignificant, they
are fertilized chiefly by bees, and not by wind, pollen
having been observed by Mr. Darwin on many pistil-
tips, which must have been brought from a tree sixty
yards away, and could not have been conveyed

218 The Golden Rule for Flowers

by the wind, since it was blowing in the wrong
direction.

The year that the holly-berries failed, the crop of
clover-seed failed also in some parts, and no doubt
from the same cause. For though some clovers
manage to fertilize themselves more or less, there is a
very marked difference in the quantity of seed borne
by the plants, according as they are kept covered, and
out of the way of insects, or not.

A hundred heads of common red clover bear about
2,720 seeds among them; but a hundred heads covered
with a net on one occasion, to keep off the bees, had
not one single seed. This common red clover hasa
tube, too long to be sucked by the hive-bee until it has
been mown, when the second crop: of blossoms are
said to be rather smaller, and its first crop is dependent
on the humble-bee. A very slight difference in length
makes just all the difference as to the species of bee
which is able to extract nectar from the blossom. The
brilliant crimson-clover is frequented by the hive-bee,
its tube being shorter than that of the common red
kind.

Strawberry plants are altogether dependent upon
bees for the perfecting of their fruit, even where pollen
and ovules are produced in the same blossoms. In
one species of strawberry, the true Hautbois, they are
borne by different plants; and in the great market-
gardens of America, where this is grown, it is usual to
plant one row of barren plants to every three rows of
fertile ones, leaving the bees to do the rest.

A great deal has to be done to ensure the thorough
fertilization of the strawberry-ovules, for there are

The Golden Rule for Flowers 219

from a hundred to three hundred in each fertile
blossom, and there are an equal number of pistils.
The pistils are set upon a cone-shaped receptacle in
the centre of the blossom; each one contains in its
ovary a single ovule, and the ovary and ovule ripening
together, develop into a tiny nut, which is the fruit
properly speaking.

As the nuts grow, the conical receptacle on which
they are set grows too, and becomes soft, fleshy and
sweet, forming what we erroneously call the ‘berry.’

But if the ‘berry’ is to grow properly, every one of
the pistils must receive a few grains of pollen, and if
any are left out, the ovules belonging to them do not
grow, and the part of the receptacle which surrounds
them does not grow either, but remains hard. The
hard spots sometimes found in strawberries, with a
number of little ‘seeds’-crowded together, are due
simply to the fact that the ovules have not been
fertilized, and have withered instead of growing.

So, too, with the raspberry. Each one of the sixty
or seventy little fruits composing the ‘berry’ depends
upon pollen for the power of developing, not only its
seed, but also the sweet, juicy envelope surrounding
each seed. Towards the end of the season these. often
fail and wither, because the bees are either dying off,
or do not care to come out unless the weather is
tempting.

Then again with apples: one may often see an apple
which is deformed, having grown on one side; and
the reason here, too, is similar.

The calyx of the apple-blossom is a tube which
spreads out at the top into five leaf-like divisions.

\
t

220 The Golden Rule for Flowers

Inside the tube, and joined to it, are the ovaries,
which together form the horny core. When the
stigmas are all properly dusted with pollen, each
ovary, with its two pips, begins to grow; but, if
nothing else grew, there would be no apple, only a
horny seed-vessel, the only eatable part of which
would be the seeds. But the calyx enclosing the core
grows too, and so does the top of the stalk from which
it springs; and it is these which together form the apple.

If, however, one of the stigmas be by chance left
without pollen, then the ovary belonging to it, with its
two pips and the part of the calyx next to it, does not
grow, and the apple is misshapen.

There is a French apple called the S. Valery apple,
which is remarkable for having a double calyx and a
double core, with ten divisions, but no petals, and only
imperfect stamens, which produce no pollen. This
has to come, therefore, from different varieties, and it
is a regular custom for the girls.of S. Valery to go to
the orchards in the spring, taking pollen from various
other apple-trees, to, as they say, ‘make their apples.’
Tach marks with ribbons her own fruit, and the
different pollen produces apples of different flavour,
colour and size, according to the variety of apple from
which the pollen has been taken. ;

Occasionally one hears of an apple-tree which in-
dulges in the freak of bearing fruit, some of which is
of the ordinary shape, and some fear-shaped, both
sorts growing on the same twigs. In this case one
must suppose that the bees have been less particular
than usual, and have dusted the pistil-tips with pear-
pollen. So, too, an orange blossom crossed with

The Golden Rule for Flowers 221

pollen from a lemon will bear fruit which is partly
orange, partly lemon, with peel partly of the one, partly
of the other.

Among the many plants visited by bees, large or
small, are the foxglove, mallow, and campanula, all of
which, though they grow pistils and stamens together,
ripen them at different times. Anyone not knowing
this, and examining a campanula blossom, would be
puzzled to know what could have become of the
stamens, for when the flower opens they have generally
vanished ; the pollen is there still, however, having
been discharged upon the stalk of the pistil before the
bud opened, after which the stamens shrivelled away.
It is caught and held by the hairs with which the stalk
of the pistil is clothed, apparently for the very pur-
pose of holding it until the bees come and carry it off.
When the pollen is gone, the tip of the pistil unfolds
from three to five spreading branches which no pollen
can reach while they remain folded; and then, back
come the bees, this time in search of nectar, but
bringing with them grains of pollen in abundance from
other flowers.

Some pistils, as has been said, are actually poisoned,
and others unaffected by the pollen of their own sur-
rounding stamens. But there are others which carry
their likes and dislikes a point further still, and require
pollen, not merely from the blossoms of another plant,
but from blossoms whose stamens grow at exactly the
right height ; and if it comes from stamens too short,
or too long, they can make little if any use of it.

There is, for instance, the Great Purple Loosestrife,
whose tall, handsome spikes of blossom light up the

220 The Golden Rule for Flowers

river banks. The pistils and stamens of this plant are
of three different sizes, but they correspond exactly in
height, long pistils with long stamens, short with short,
and middle-sized with middle-sized. The long stamens
have emerald green pollen, the others yellow ; and the
grains vary in size with the length of the stamens, the
longer the stamens the larger the grains; for the
larger grains are destined for the longer pistils, and
have, of course, to send out longer tubes in order to
reach the ovules.

A bee entering a blossom in search of honey is
dusted with pollen on different parts of its body,
according to the height of the stamens, and when it
flies off to the blossoms of another plant, if the spots
of dust come in contact with pistil-tips of the proper
height they may be caught and kept.

The red Oxalis is another of the plants having
pistils and stamens of three sizes, and a large field in
Brazil containing many acres of this plant yielded not
a single seed, because, though pollen and insects were
both plentiful, all the plants chanced to be of the same
‘form,’ as it is called: all had long pistils and short
stamens, or vice versd, and the pollen was of no use.
Other plants possess similar peculiarities, but we will
mention one which all can examine for themselves—
the common yellow primrose.

The blossom of the primrose is a long tube flattened
out at the top into five divisions. If we look at a
bunch of primroses gathered from different plants, we
see at once that all are not alike. In some the pistil,
with a knob like a pin’s head, stands up just out of the
tube; in others no pistil is visible, but in its place,

The Golden Rule for Flowers 223

just at the same height, are five stamens standing up
like teeth, the stalks being so very short that they are
almost all anther. In spite of their shortness, how-
ever, the stamens are on a level with the long pistil of
the other blossom, for they are attached to the flower
tube; and for the long pistil their pollen is intended.
The pollen grains of the stamens which grow with the
long pistil—but out of sight, half-way down the tube—
are intended for the short pistil, whose knob is just at
their own level, and, accordingly, they are smaller.

All flowers which vary in this way, all which are
distinguished by colour, scent, size, or irregularity of
shape, are mainly indebted for fertilization to insects.
This is the case with all bell-shaped and tubular
flowers, also with the snap-dragon and foxgloves, and
with the dead nettles, lavender, thyme, and all
blossom of similar shape to these, besides many others.
In some the shapes of the blossom and of the insect
by which it is fertilized are as beautifully and ‘ exactly
fitted one to the other as the lock is to the key,’ and in
others there are endless different devices for securing
that the visitor shall not depart without doing some
service in return for the pollen or nectar which it has
consumed or carried off.

In the common stinging nettle the four stamens lie
folded down flat until they are touched, when they
spring suddenly up and scatter their pollen; a needle
inserted in the throat of the common purple lucerne
causes two stamens instantly to start up like a jack-in-
the-box, the anthers at the same time exploding and
discharging their dust. A similar explosion takes
place in the flowers of the whin and in many others. _

224 The Golden Rule for Flowers

In one plant the anthers act like a pair of bellows, and

,on being touched blow their dust out upon the insect ;
in another—the Kalmia, or American mountain-laurel,
the stamens rise up from the petals on which they
usually lie flat, and close round the insect, clasping it
and impressing their pollen upon its body.

But the various arrangements are so numerous that
it is impossible to do more here than give the merest
outline-sketch of them, and for fuller particulars the
reader must be referred elsewhere.

We have confined our attention hitherto chiefly to
bees, because they are the most generally useful of
insects, and few flowers seem to come amiss to them
if only they can reach the nectar. But there are just a
few flowers which they actually avoid. Bees of all
kinds, for instance, shun the Crown-imperial, though it
blossoms in March and April, when bee food is not
plentiful. Gilbert White noticed a small bird like a
white-throat running up the stems of this plant and
plunging its head into the bells in search of nectar, so
it may be that it is fertilized in this way, for it certainly
sets seed.

Other flowers disliked by bees are the passion-flower
and dahlia—which seem to stupefy and often kill them,
and, above all, the oleander, whose nectar is fatal. A
traveller in Hungary and Dalmatia, where the oleander
abounds, could not remember ever to have seen bee,
moth or butterfly visiting the blossoms. And yet their
bright rose-coloured petals seem to say, in the language
of flowers, that they need the help of insects, and
those, too, of a high order.

For colours have much meaning in the flower lan-

The Golden Rule for Flowers 225

guage, and show to some considerable extent what
kind of insects are wanted for the blossoms which
display them.

White, for instance, serves to attract insects of all
sorts ; but bright yellow seems to be especially favoured
by beetles, and blue by bees, though they do not, of
course, confine themselves to flowers of this or any
colour. What a flower lacks in colour may often be
more than made up for by its sweet scent and abound-
ing nectar. The dull pink sedum, for instance, which
blossoms in the autumn, attracts a swarm of humble-
bees and butterflies ; though, as its flowers are flat and
tubeless, the nectar is open to all comers, and bees are
not necessary to it.

Yellow is said to attract insects of the lowliest kind;
white, those a little higher in the scale; and pink, red,
lilac, purple, blue, rank higher and higher as to the
insects which they attract, that very superior insect,
the bee, being, as already said, especially pleased with
blue.

It is the fashion at present to say that the bright.
colours and sweet scents of flowers exist solely for the
plant’s own benefit, as the means of drawing to it
the insects which carry pollen from one blossom to
another. Nevertheless, man is gratified abundantly ;
and if this theory be correct, he may at least congra-
tulate himself on the fact that he and the insect-
world are of one mind as to what is agreeable and
attractive. ,

But are he and they altogether of one mind? The
butterfly will hover about a lavender-bush, attracted by
the perfume, and so far man shares its taste; but it
will also go and drink daintily at a drain, and, for any-

ID

226 The Golden Rule for Flowers

thing that appears to the contrary, an ill scent may be
as pleasant to it as a sweet one.

Ill-smelling flowers, as well as sweet ones, have their
admirers, and are certainly not especially avoided by
insects ; and flies will regale themselves upon honey or
filth, with apparently equal satisfaction. Ill-smelling
flowers are, however, comparatively very few; and as
their colours are generally deep yellow, orange, brown-
red, or brown, we may conclude that they are not
frequented by such high-class insects as bees.

XVI.
GUESTS WELCOME AND UNWELCOME

Bees do more, on the whole, for the fertilization of
flowers than any other insects; but, though plentiful
throughout the plains of Europe, they become fewer
and fewer as the traveller ascends the Alps; and in the
Tyrol, at a height of from 6,000 to 9,000 feet, he may
see hardly so much as a bee a day, and that of the
‘humble’ species only.

There is, it is true, the Ligurian, or yellow Alp-bee,
which is a mountain insect, and thrives in some of the
southern cantons of Switzerland up to a height of
4,500 feet ; but still, the higher one goes the fewer bees
there are of any kind; and though there are many
beetles and flies, and very many moths and butterflies,
there are, on the whole, fewer insects of all kinds in
these higher regions; and in the highest, bees are
almost entirely absent.

Yet the flowers of the high Alps are so intensely
bright in colour that it is pretty certain they must be
visited by insects of some sort ; and, besides being of
such vivid colours, the flowers here are made still more
striking by being massed together in large beds, instead
of being scattered here and there. For the fewer the

228 Guests Welcome and Unwelcome

insects, the more needful it is to economize their time
and labour, and to avoid the risk, which solitary plants
would run, of being overlooked altogether. Here, as
elsewhere, ‘ union is strength’; and the butterfly must
be blind indeed which could fail to notice these masses
of brilliant colour.

For the chief flower-visitors in these Alpine regions
are moths and butterflies, together with flies and
beetles ; and it is curious to see how flowers which are
visited by bees in the plains and lower mountain-
regions are modified to suit moths or butterflies when
they come up higher.

Of the many orchids, for instance, which grow in the
plains, all but very few—four or five, perhaps—are
visited by bees ; but in the Alps, out of five species, all
but one or two are dependent upon butterflies or
moths.

Flowers change in colour when they migrate to
these higher regions, on purpose to attract more notice
Our pale yellow primrose is fertilized almost entirely
by moths, but it might be overlooked among the bright
flowers of the Alps if it did not dress more gaily there,
so it wears brilliant pink and magenta. The wild pinks
also, which straggle about here and there in the low-
lands, sure not to escape notice among the many
visitors constantly flitting to and fro, here take the
precaution of growing larger blossoms, besides massing
themselves together in such a way as to catch the eye
of any wandering insect.

Large masses, large blossoms, brilliant colours—
these are the means by which the fewer insects of the
high Alps are guided without loss of time to the place
where they are wanted ; and flowers which might never

Guests Welcome and Unwelcome 229

be found out if they grew separately are ensured a-ainst
neglect by thus growing in company.

But, many and beautiful as are the moths and butter-
flies of the mountains, one must go to the tropics to
see them in their full glory of numbers, size, and
colouring.

Of all parts of the world, South America is richest in
butterflies, and the richest part of South America is
the region of the Amazons; where, also, the broad
belt of forest which surrounds the land-surface of the
earth almost continuously at the equator is denser
than anywhere else, and swarms with insects of many
kinds. :

There are some 1,200 species of butterflies in this.
region; but these gay insects do not care for the
solemn depths of the forest, where they find little or
no entertainment, and they are chiefly to be seen in
the more or less open paths, where there is more light,
and where, consequently, more flowers are to be found.

Here large blue butterflies, and many others, fly along
for miles, and always return if driven into the forest.
For this is gloomy and even musty, like a cavern; the
damp ground is not covered by herbage, there is little
beauty or brilliancy of colouring in the trees, and
flowers are rare.

The fact is that, according to the German proverb,
‘one cannot see the forest for the trees.’ They are so
crowded together, and they run up to such a height,
that there is little to be seen but trunks, canopied by
a mass of foliage so dark and dense that the sun is
quite powerless to penetrate it.

Many trees never blossom until they are a hundred
feet high, and it is only when a shower of bright petals

230 Guests Welcome and Unwelcome

falls from above that there is any sign of what is going
on overhead, or of the beauty, displayed to insects
only, outside the dark canopy. Beneath it the world is
dank, dull, gloomy, unrelieved by a ray of light; but
what a different world it is above! Here the sun is in
full blaze, and bees in swarms are humming cheerily
over the magnificent banquet of flowers spread for
them.

Bees do not like gloom, or even the chequered shade
which contents the butterflies, and they would have
missed the feast if the flowers had grown down below.

It is by the roadside, on the margin of the forest, in
the paths, and along the river-banks that the real
beauty of tropical vegetation is to be seen; for here
are bushes, shrubs, trees of every height, adorned with
festoons of creepers, and brilliant with bright flowers
and gorgeous butterflies.

Even here, however, there is nothing to surpass such
masses of glorious colour as are to be seen on our
heathery moors or gorse-covered commons; and though
tropical blossoms are undoubtedly splendid, they are
not as common as one is apt to fancy, and they gene-
rally last but a short time, beginning to fall almost at
once.

Bees abound in this region, but they keep in the
sun, among the blossoms borne high up overhead ; and
the butterflies float lazily along the paths which are
chequered with light and shade, but they keep for the
most part near the ground. If the smaller trees, there-
fore, followed the example of the giants of the forest,
and bore their blossoms on their tops, they would be in
danger of missing both classes of visitors. The bees
would know nothing about them down in the shade,

Guests Welcome and Unwelcome oat

and the butterflies would not rise high enough to find
them.

Under these circumstances, therefore, many trees,
such as the custard-apple, bear their blossom on the
trunks or larger branches, where moths and butterflies
can find them. The cacao is another which does so,
and when the large yellow fruit is ripe, the trunks of
some of the smaller trees are hardly to be seen, so
thickly does it cover them.

But, much as these insects do both in the tropics
and in the mountains, it must not
be supposed that their services could
be dispensed with even in temperate
latitudes and in the plains. Quite
the contrary. Most of the European
orchids are fertilized by bees, but
just a few species cannot get on
without the help of moths. There
is a large sphinx-moth which carries
pollen to and from one species of
orchid in a very curious way—on its .
eyes. The pollen of this flower ae
grows in two masses, each perched
upon a stalk which passes through its centre, and to
which the grains are united. At the base of the stalks
are tiny button-shaped discs, one on each side of the
stigma, face to face. When the moth presses its head
into the centre of the flower, the discs come into
contact with its eyes, and, being very sticky, they
adhere so firmly that the whole thing is dragged out
—stalk, pollen, and all. A very strange object one of
these moths is when it is thus adorned, for the stalks,
with their lumps of pollen at the end, at first stand out

232 Guests Welcome and Unwelcome

straight, like horns in the wrong place. In a minute
or so, however, they contract and bend down, and then
the pollen is in exactly the right position to be caught
and held by the stigma of the next blossom of the
same species, which the insect must, one would
imagine, be in haste to enter if it knows how it may
get rid of its undesirable appendages.

Orchid-blossoms remain in full beauty a long time,
whether cut or not, as long as they are not fertilized ;
but when insects are allowed to get at them, they fade
rapidly and go to seed.

Among the flowers specially attractive to moths in
Europe are the valerian, petunia, phlox, hop, nettle,
pink, ivy, clematis, pansy, jessamine, and honeysuckle,
the last being frequented, according to Gilbert White,
by a large sphinx-moth, which appears after dusk, and
feeds, like the humming-bird, on the wing, scarcely
ever settling, and making a humming noise with its
wings.

The jessamine is probably fertilized by the hawk-
moth, which hovers in like manner; but jessamine-seed
is rare in England, for hawk-moths are rare too. But
the want of hawk-moths may not be the sole reason
for the scarcity of seed. The humble-bees are also in
some measure to blame, for they come to the blossoms
in search of nectar, and finding no perch upon which
they can stand to suck in the proper way—the only
way to benefit the flower—-they get what they want
by gnawing through the tube of the corolla, which
soon drops in consequence.

Flowers which open at night are of course especially
dependent upon night-flying moths; and as colours
would not be seen, they are generally white or pale

Guests Welcome and Unwelcome 233

yellow, and have no lines to show where the nectar is,
for these also would not be visible; but they are often
so sweet as to be scented from afar. The large white
bindweed, though it opens by day, remains open at
night, when the moon shines, but not otherwise, to receive
the visits of moths.

Wherever, in any part of the world, there is a dearth
of bright-coloured flowers, there, as a rule, there is a
scarcity of insects, and vice versd, for, where insects
are wanting, there the flowers fertilized by them cannot
of course flourish.

The scarcity of both these is very conspicuous in the
Galapagos islands, situated on the equator, some 700
miles west of South America. In Juan Fernandez also,
which lies about 400 miles off Chili, ferns form the
larger part of the vegetation, as they do in most of
the South Sea islands. But there is no such total
absence of showy blossoms in Juan Fernandez as in the
Galapagos. One shrub which flourishes there bears
snowy blossoms, like those of the magnolia; another,
also plentiful, has dark blue flowers ;' arid besides
these, there are large patches of a white, lily-like bulb,
and there are two conspicuous yellow flowers as well.

Yet Juan Fernandez is poor in insects. It has but
one butterfly, and that is rare; there are only four
species of moths, and no bees at all, but some which
are very minute and of no more use to large blossoms
than the flies, of which there are twenty species.

But the poverty of the insect-life is made up for by
the presence of humming-birds, which are so abundant
that there are one or two in every shrub; and these
when killed are usually found with the front of their
heads covered with pollen.

234 Guests Welcome and Unwelcome

The group of honey-eating birds is so immense, both
in the islands of the Pacific, Australia, America—North
and South—the Moluccas, etc., that there can be no ©
doubt as to the large share they take in conveying
pollen from one flower to another.

The ruby-throated humming-bird frequents lilacs,
phloxes, portulaccas, morning glories, roses, honey-
suckles, snap-dragons, fuchsias, and many other flowers;
and in dry weather, before the spring begins, it will
even enter greenhouses and suck the fuchsias there,
which it does more rapidly than the honey-bee.

The Portuguese name for the humming-bird is
Beija Flor, ‘Kiss-flower’; but the little creature is
not so ethereal in its habits as its appearance and
poetical name have led people to suppose. It does
‘kiss’ the flowers, but with a view to something more
substantial than nectar merely, though that may be all
very well as an addition to its food.

Many a humming-bird has been starved to death in
captivity, owing to the mistaken notion that honey,
or sugar-and-water, was all that it needed; whereas
these living, flashing jewels possess tongues which are
exactly adapted for picking up imsects; and insects are
their principal food, though they take nectar as well.

The humming-bird’s tongue is long, and can be
stretched out far beyond its bill; it is very flexible, and
being cleft in two it can be opened and shut at will,
‘like a delicate, pliable pair of forceps.’

The humming-bird is, indeed, nearly related to the
swift, and its chief diet consists of the small insects
which are seldom wanting in the long-throated
blossoms of the tropics. The sheaths of the arums
and their kindred are generally full of insects too; so

Guests Welcome and Unwele me 235

are those of the palms, and the ‘ pitchers’ with which
many plants are furnished likewise afford insects in
abundance.

Whether the birds go for nectar or for insects, it is
all the same so far as the plant is concerned, for in
neither case can they help coming in contact with the
stamens and getting their heads and beaks dusted with
pollen.

‘The Marcgravia, for instance, is a plant which grows
a circle of flowers like the lamps of an inverted can-
delabrum. From the centre of tn's circle hang a
number of pitchers filled with a sweet., liquid, which
attracts swarms of insects. These, n their turn,
attract, not only humming-birds, but a variety of
others which cannot capture their prey without brush-
ing against the hanging stamens of the bell-flowers.

In Labuan large flocks of starlings are similarly
attracted to a flower with brilliant scarlet blossoms ;
and in the Malay and Molucca Islands much pollen-
carrying is done by the little brush-tongued lories,
small parrots, with unparrot-like tongues, which are
long, flexible, moist and hairy, and thus well adapted
for collecting honey from the tubes of the many large
blossoms which they visit.

Bees, butterflies, moths, birds—these are the most
conspicuous of the ‘under-gardeners,’ to whom is en-
trusted the important work of fertilization; but there
are others equally useful in their way, though their
sphere of operations is less extensive. Even the wasps
do something, for, in the absence of fruit, they suck
flowers, as Gilbert White remarked, especially those of
the ivy and small umbelliferous flowers; they are
especially attracted by the red and yellow blossoms of —

236 Guests Welcome and Unwelcome

the ‘ Poker-plant’ (Tritoma), which blossoms in the
late summer, and may be seen creeping quite into the
tubes; and they are also said to fertilize the dahlia,
which is shunned by bees.

‘ Where the bee sucks honey the wasp sucks poison,’
is a common saying, and as devoid of foundation as
such sayings often are. It is a libel on the wasp, and
too flattering for the bee; for if the bee does suck and
store honey, which last the wasp does not pretend to
do, it also secretes poison, and its sting is generally
considered much the worse of the two!

To small, flat flowers, whose nectar lies so near the
surface as to require little probing for, beetles and
small flies are almost as useful as bees, and may be
seen in crowds on such little blossoms as those of the
wild carrot, and others of the same family which grow
together in flat heads or umbels. Even the water-side
midges do their part among the small flowers of the
river banks.

All sorts of little flies, gnats and midges are attracted
also to the arums, some by the prospect of pollen and
nectar, others, as the carrion-flies, by. the flesh-like
appearance and smell of many foreign species, on
which they even lay their eggs, supposing that their
grubs will be well fed; another illustration of what
was said before, that if they existed solely for the
purpose of attracting insects, all flower scents might
just as well be what human beings consider disagree-
able.

The arrangements of the arum family are so curious
as to be worth a little special attention. We most of
us know the so-called ‘arum-lily,’ with its white flower
with the golden sceptre. The flowers of the arum are

Guests Welcome and Unwelcome 237

contained in a sheath, properly called a spathe, which
is snowy white in the ‘arum-lily’ and greenish in the
wild one. The real blossoms are clustered round the
sceptre, or spadix, which is golden in the one, and
purplish, or brown, in the other.

In some of the southern and foreign arums the lower
part of the sheath, which is enlarged and contains the
blossoms, is shut off by a ring of longish hairs which
point downwards and allow the visitors to enter easily,
but effectually prevent their coming out again until
they have done what is wanted of them. The lower
part of the spadix generally bears the flowers with
pistils, those with stamens being arranged ina ring a
little above. The lower blossoms are ready first, and
to them the insects, or some of them, bring pollen from
other flowers of the same species. Butit is not enough
for them to bring pollen, they must also carry some
away, and for this purpose they must be kept until the
anthers burst.

Meanwhile their prison is made very comfortable for
them: it is pleasantly scented—we are not speaking
now of the fleshy species—it is also warmed and pro-
vided with nectar. When the anthers burst, pollen is
added to the feast, and some of the captives devour it
so greedily as to be quite intoxicated. Enough, how-
ever, remains adhering to their legs and bodies to make
them acceptable visitors elsewhere, and, as soon as the
pollen is shed and there is no further reason for keep-
ing them, the hairs which prevented their escape
wither and die, and they are free to depart—generally,
but not always. The hairy arum of the South is said
to show her gratitude for the services rendered to her
by her visitors, carrion-flies, in a remarkable manner.

238 Guests Welcome and Unwelcome

She catches and devours many, digesting them by
means of the sticky hairs which cover the inside of the
sheath.

Most of the arums of the temperate zones blossom
early in the year, when the nights are still chilly
enough to make the prospect of a warm lodging
attractive.

Blossoms breathe more rapidly than leaves, and are
always therefore a little the warmer. Buds just open-
ing breathe so fast, if they are large, like those of a
cucumber, that when they are isolated under a glass
containing a tiny thermometer, the mercury may be
seen to rise sometimes nearly two degrees.

Many blossoms heat so much more than this, how-
ever, that the difference may be felt as well as seen.
This is the case with the arums, whose so-called
blossom is really an assemblage of many blossoms.
In the common wild arum, ‘lords and ladies,’ the tem-
perature rises several degrees, but in the heart-leaved
arum of the Isle of Bourbon the temperature of the
sceptre, or spadix, has been known to rise to 95° F.,
and nearly 102° F., and that, too, when the temperature
of the air was only 59° F.

But the common Italian arum outdoes even its
tropical cousin, and its spadix becomes hotter than a
hot bath, its temperature being nearly 110° F.

Arums are especially marsh-plants, and, though one
does not naturally associate the idea of warmth with
such cold creatures as snails, it seems that it is these
which are chiefly attracted to the arums of south
Europe, and, no doubt, of other parts of the world.

One of the foreign arums grown in hot-houses for
the sake of their handsome foliage was observed one

Guests Welcome and Unwelcome 239

day at noon to begin to blossom and grow warm at
the same time, its temperature rising beyond 100° F.
Suddenly it gave out a strong fragrant scent, between
that of cinnamon and musk, which filled the whole
house, and would no doubt have been a well-under-
stood signal in its own country, telling the small
marsh-snails that their night quarters were ready.
These would climb the stalk and find entrance by a
narrow opening at the base of the sheath, which would
soon after close upon them. Twenty-four hours later
the scent and warmth have much diminished, but then
the anthers open and drop down their pollen, not in
separate grains, but in chains or tassels of grains
adhering together, as much as an inch long, and far too
bulky therefore to be carried away by insects. On
coming in contact with the moist bodies of the snails,
however, the chains separate into grains, which adhere
and are borne away when the guests move on.

-And they are obliged to move on soon after the
pollen has fallen or else they would be suffocated ; for
the blossoms have been breathing vigorously in a con-
fined space, and so much carbon has been burnt, and
so much carbon-dioxide produced, that the bulb of the
sheath is completely filled with it, and a glowing match
held within is extinguished. Such visitors as stay too
long are therefore safely suffocated, and thus prevented
from eating the young fruit, which they would other-
wise do without fail.

The prudent snails, however, having enjoyed their
warm bed and nectar, do not outstay their welcome;
but, when these passing pleasures have come to an
end, they linger no longer, make the best of their way
up the sheath and down the long stem, and then

240 Guests Welcome and Unwelcome

proceed without delay to climb some other plant
whose blossoms are beginning to give fragrant notice
that another pleasant guest-chamber is ready for their
reception. Thanks to this diligence, therefore, pollen
is brought to the pistils, as soon as they are ready for
it, by the ‘ fastest snail-express.’

Hitherto we have confined our attention to the
welcome guests; but there are unwelcome ones also,
and the very snails last considered have two sides to
their character. Indeed, the beneficent side is not the
one with which we are familiar, being rather a recent
discovery, while their mischievous propensities are
well and widely known. Even the arums which
welcome them as pollen-carriers need some sort of
protection against them. They have to be tempted
to undertake what to them is really an immense
journey, by special attractions, otherwise, being
voracious eaters, they would simply begin to devour
the first leaf they came across. Then, when they have
started, all loitering by the way is sternly discouraged,
for arum-leaves are acid, and even poisonous; so there
is no temptation to make a meal of them.

Useful as they are to arums and arum-like plants,
they are not generally desirable as visitors, and are not
often found in flowers, bristles and prickles being
enough to turn them back at once. No wingless
visitors are generally welcome, for they craw! slowly,
lose pollen by the way, by getting it rubbed off them,
and are usually so indiscriminate in their tastes, that
they go as readily to one blossom as another, and it is
quite a chance what pollen, if any, they may bring
with them,

Guests Welcome and Unwelcome 241

It is, of course, not to the plant’s interest that its
pollen and nectar should be taken by insects which
plunder without making payment in return, as it is
thereby robbed of its means of attracting other and
more useful insects. But the useless ones are just as
fond of nectar as the useful, just as quick, too, to find
it out, wherever it may be hidden, so that many devices
are needed to baffle these unwelcome guests.

Human beings can, it is said, detect less than the
twenty-millionth part of a grain of musk; but in keen-
ness of scent they are far surpassed by the insect world.

Where is the man who can detect any difference,
by smell or otherwise, between cane-sugar and beet-
sugar, when the latter is properly refined ?—not, of
course, such as one meets with in continental hotels.
Yet the bees know well, for if the choice be given
them, they will take the cane and leave the beet.

And ants are not only as fond of sweets as bees,
but will find them out from an immense distance.
They have been known to make their way up from the
garden to the second story of a house, by means of
an outside bell-wire, all for the sake of some dried
fruit which they had scented out. They are sure,
therefore, to know where nectar may be had, as well
as the bees themselves; and yet, what with their
crawling, and their tidy habit of constantly cleaning
themselves, and their hard coats, which are not suited
for carrying pollen, they are some of the least welcome
guests that a flower can have.

When the ants do get a chance, they make the
most of it, and swarm in greedily; but on the whole
they are pretty well kept out, now by one means, now
by another.

16

242 Guests Welcome and Unwelcome

The snap-dragon, for instance, keeps her mouth so
firmly closed that none but the strong humble-bee can
force its way in, until, that is, the necessary pollen has
been brought. But then, when the seed is made sure,
and the ants can do no harm, the lips are unclosed,
and they are generously admitted to what remains of
the feast, an opportunity of which they do not fail to
make use.

Ants, like other wingless insects, prefer to avoid the
dew, and so are not astir very early. Some flowers,
therefore, unfold for only a short time during the first
hours of the morning and close again by g a.m.; and
in all probability there is a close connection between
the times when flowers open and close, and the hours
when their friends and enemies are abroad.

Plants such as the teasel keep off the ants by means
of the basins formed by their leaves, which catch the
dew as it trickles down their stems, and keep it so
effectually as to be seldom empty while the plant is in
blossom. Water is completely baffling to ants, and
if placed on the stem of a plant thus protected, they
run helplessly up and down, and then drop to the
ground.

Stickiness, too, of all kinds, is their abhorrence, and
is often fatal to them, whether in the form of sticky
hairs or sticky juice. The lettuce is one of many
plants furnished with a milky juice, which is especially
abundant near the flowers. If an ant crawls up the
stem, its hooked feet are so sharp as to cut through
the outer skin, and the juice which at once oozes out
hardens rapidly, gluing it to the spot, while the little
creature’s frantic efforts to clean itself only make
matters worse, and it seldom succeeds in escaping.

Guests Welcome and Unwelcome 243

Many of the plants belonging to the order which
contains the catch-flies, campions and pinks, are
provided with rings of sticky hairs, and as many as
sixty-four small insects have been found at once on
one flower-stalk of the red German catch-fly. One
can imagine how little nectar would have been left to
attract profitable insects, if these sixty-four had been
allowed to have their way. Ants are usually very wary
in their manner of proceeding, and feel their way
carefully up the stalk until they reach the sticky ring,
whereupon they generally turn round and come down
again; but if they do venture to proceed they are
surely lost.

Stickiness -is no impediment to slugs and snails,
however, for they overcome it by covering it with their
own slime. What they do mind are bristles and
prickles, which the armour-clad ant can afford to
despise.

Pricklets, hairs, and fringes inside the blossom, serve
often a double purpose, for they both keep out un-
welcome visitors and make the welcome ones reach
the nectar by the right way. Thus, insects wanting to
get at the honey in the spur of the garden-nasturtium,
are obliged to climb over the fringe on one of its three
lower petals, and this they cannot do without coming
in contact with anthers or pistil, which they might
otherwise pass untouched.

Plants sometimes need protection against even their
best friends the bees, for some of these, in spite of
their many good qualities, have a way of trying to.
reach the nectar by other than the right way—by
house-breaking, in fact, instead of by the front-door;
and others, though willing enough to come in properly,

244 Guests Welcome and Unwelcome

are too small to be serviceable to large blossoms.
We have already mentioned how humble - bees bite
through the tube of the jessamine, because they find
nothing to stand upon while they suck the blossom.
But as the jessamine is a foreign flower, this may be
thought excusable enough, as there are few insects
here able to reach the nectar in the right way.

But some bees really seem to be lazily inclined to
save time and trouble, for they always bite a hole in
the columbine, among others.

The bladder campion, however, successfully frus-
trates any such designs by growing a calyx which is so
inflated that no bee’s proboscis is long enough to reach
the nectar by means of a hole made in it. Others
have calyxes so hard and tough that even humble-bees
and ants are baffled by them.

But, then, the little bees—where big bees can enter,
why not little ones? The foxglove, for instance,
gapes widely open; and as stamens and pistil lie
close under the upper side of the blossom, they are
quite out of the way of the small bee, which would
pass in and out without touching them, if it were
allowed to find entrance at all. But an observer who
watched the flowers carefully throughout a season in
North Wales, where they especially abound, saw many
small bees make the attempt but only one succeed
the whole time. It looks easy enough, but the upper
part of the blossom is so smooth as to be actually
slippery, and affords no foothold; and the lower part
is beset with stiff hairs, which are very embarrassing
to smaller insects, though the humble-bee uses them
as rests for her feet and clings to them while she
sucks.

Guests Welcome and Unwelcome 245

It is interesting to watch the methodical way in
which a humble-bee visits and explores a spire of fox-
glove, always beginning with the lowest bell and
working upwards ; but it may not have otcurred to
all of us that, if she reversed her operations, the
foxglove’s hope of cross-fertilization would be gone.
So it is, however; for the foxglove-blossoms not only
open gradually, beginning with the lowermost, but the
pollen is ripe before the pistils are ready for it; and
consequently the pistils of the lower blossoms are
waiting for pollen—their own being safely gone—
while the anthers of the upper blossoms are dis-
charging it. If the bee began at the top, she would
only bring to the pistils pollen from the upper blos-
soms on the same stalk; whereas, leaving off at the
top, she carries pollen away to the lowest blossoms
on the stem of another plant.

Such are a few, and only a few, of the many marvel-
lous provisions for ensuring fertilization, for preventing
self-fertilization, for promoting cross-fertilization, and
for preventing the robbery of pollen and nectar by
insects which would not benefit the plant; and to
conclude with the words of Professor Asa Gray:

‘If these structures and their operations do not
argue intention, what stronger evidence of intention
in nature can there possibly be? If they do, such
evidences are countless, and almost every blossom
brings distinct testimony to the existence and pro-
vidence of a Designer and Ordainer, without whom,
we may well believe, not merely a sparrow, not even a
grain of pollen, may fall.’

XVII.
SEED - SCATTERING

THE great end of a plant’s life is to bear fruit. It
is for this that roots and leaves collect nourishment,
and that insects and birds are attracted to the blos-
soms by bright colours and the prospect of food.
So entirely, indeed, is fruit-bearing the aim of the
plant’s life, that many plants are dry and withered by
the time the fruit is ripe, having given up all their sap,
their very life, to bring it to perfection. In any case,
whether it last for one year or two, or many, the
plant’s life is devoted to making preparation for its
offspring. :

For this reason few wild flowers are double, as the
number of petals must be increased at the expense of
stamens and pistils, and without these fruit is im-
possible.

A cherry-tree covered with double-blossoms may be
very ornamental, but the gardener grows it for its
blossoms only, and does not, expect fruit from it.
When his object is fruit, however, he sometimes
interferes in another way, which has the same result,
so far as the plant is concerned; for he increases the
eatable part of the fruit, in some cases, as he increase¢
the number of the petals—at the expense of the seed.

\

Seed-Scattering 247

A plant’s fruit is the ripened ovary, containing the
seed; and when the seed is the part used for food,
man naturally devotes his attention to that, and cares
nothing for the case. From corn, for example, and
from nuts, he wants the seed, not the husk or shell,
and therefore he cultivates and increases the size of
the seeds. But the seeds of pears, grapes, pine-apples,
oranges, dates, are not what he wants; and in some
of the best sorts of all these he has so cultivated the
ovary, or fleshy envelope, at the expense of the seeds,
that these have almost, if not quite, disappeared.

He has done much the same thing, too, with some
of the best figs; only here he cares neither for seed
nor ovary, but for the receptacle; for a fig may be best
described as being, like a strawberry, turned outside in.

We may have seen young figs growing on the trees
in plenty, but who ever-saw a fig-tree in blossom ?

The first things to make their appearance on the
leafless branches in spring are not buds but miniature
figs. They have much the appearance of hard green
buds, but are in truth stems, hollowed out, and having
blossoms ranged*.round them inside, each pistillate
blossom having its own ovary, which ripens into a
minute nut—the true fruit. The stem or receptacle,
therefore, is the part which becomes sweet and fleshy,
and it contains within it many ovaries, just as, in
the case of the strawberry, many ovaries are placed
upon the receptacle. When the gardener increases the
size of the receptacle, then, and diminishes or does
away with the ‘seeds,’ he grows little if any frwit,
though plenty of jigs.

The fig is a tree nearly related to the mulberry, hop,
hemp, and stinging-nettle, none of which bear pistils

248 Seed-Scattering

and stamens in the same blossom; while some, as the
hop, bear them on different plants.

In the fig-tree the two kinds of blossom are borne
sometimes in the same ‘fig,’ sometimes on separate
trees. In the former case the pollen-blossoms are
above and the ovule-blossoms below, and there would
seem to be no difficulty about the fertilization. As we
have already mentioned, fertilization is not absolutely
necessary to ensure the swelling of the figs, in the case
of some varieties at all events; but still many growers
resort to what is called caprification, in order to ensure
their crop. That is to say, they take branches of the
wild fig, when its blossoms are ready, and place them
over the cultivated fruit. The wild fig is very much
frequented by a small insect, which deserts the wild for
the cultivated fig as soon as it gets its wings. Figs are
not entirely closed at the top, and through the small
opening left the insect makes its way, for the purpose,
probably, of laying its eggs. Whether it carries pollen
from the wild fig or from the staminate blossoms to
those below it in the same fig, or whether it helps
the growth of the fig merely by pricking it in order
to lay its eggs. seems to be a doubtful matter. But
some growers consider that the insertion of an oiled
straw answers the purpose equally well, and that,
if left entirely to themselves, the figs often do not
develop.

In England, however, where excellent figs ripen,
especially on the south coast, there are certainly neither
wild figs, nor the insects frequenting them, to give any
assistance; nor are any artificial means resorted to.
But whether the ‘nuts’ contain any germ or not is
another question.

Seed-Scattering 249

Whether they receive assistance or not, however,
most of the fig’s blossoins produce no ‘ nuts,’ and hence
the growth of the sweet flesh must be in some degree,
if not altogether, independent of them.

With many fruits, as already said, it is possible to
almost or entirely do away with the seed, and still to
secure, and increase the size of, its eatable part. This
the gardener-can afford to do; but nature cannot, for,
without seed, no offspring.

Such is the general law, the exceptions to which
have been already referred to. But, even when the
plant is left in a state of nature, and allowed to
produce seed in abundance, it often needs further help,
if its progeny are to grow up healthy, and vigorous
enough to hold their own among their many com-
petitors. The seed must be scattered.

The gardener often finds it advisable to get his seed
from some little distance, the plants raised from it
being distinctly" better than those grown from seed
ripened in the same place. This is one reason why it
is for the plant’s good that its seed should be scattered;
and here, of course, we mean by the ‘plant,’ the race,
and not the individual. But there are many other
reasons.

If seeds are dropped close round the parent-plant,
in a confined space, they grow up in a crowd, and
there is a desperate struggle for existence. Being all
of the same species, they all want the same kinds of
food, and none have much advantage over the rest.
A few seeds may have been a trifle larger, and may
produce seedlings a trifle stronger, and better able to
battle for what they want; but the difference is usually
slight, and the chances are that all will grow up weakly.

250 Seed-Scattering

Where seedlings are crowded together there must
always be a struggle as to which shall survive, but it is
much more severe where all are of the same sort.
Where they are mixed, some will have advantages.
They may be larger and stronger, or they may be
better fitted for the soil and situation. Whatever the
advantage may be, those possessing it will speedily
overpower their less fortunate rivals, and then, having
secured sufficient elbow-room, will grow up strong and
healthy.

Plants of different species, when crowded together,
are better off in another respect, for they do not all
want precisely the same amount of the various mineral
foods, and so there is more for all. For this reason it
is a very usual thing to sow a grass-field with seed of
different species; and the greater the variety, the
heavier the crop of hay, because the plants have had
a better opportunity of obtaining food.

On this account, therefore, as well as that they may.
have change of air, it is well for seeds that they should
be scattered, or otherwise dispersed. But there are
other reasons still.

Some plants need shelter, and are killed by sudden
exposure. If they had no means of dispersing their
seeds, not only they, the parents, but their whole
| progeny, might be exterminated by the removal of
trees, etc. Or again, by the draining of a pond or
drying up of a brook, plants needing much moisture
might be killed out of a neighbourhood, if all their
seeds dropped close round them, while they might
continue to flourish if they were able to migrate the
distance of only a few yards.

In some cases, too, the parent so exhausts the soil,

Seed-Scattering 251

that the children have no chance of thriving, if they
grow under its shadow; and then again, if cross-
fer‘ilization be an advantage to the plant, even where
not absolutely essential, it certainly seems—from ex-
periments made in crossing Indian corn and beans
with plants grown some miles away —that cross-
fertilization with plants at a distance is more beneficial
still, the produce being in each case very greatly
augmented.

Such, then, are the strong arguments in favour of
Nature’s plan of scattering her seed far and wide: the
plants gain change of air and change of soil; com-
petition is less keen, cross-fertilization is promoted ;
and, when driven by stress of circumstances from one
neighbourhood, they are able to gain a settlement in
another.

By one means and another seeds are widely scattered,
and there is not a bare patch of soil on railway-
embankment or mountain-side which is not speedily
sown.

At first sight it would seem that as plants are rooted
to the soil, migration would be impossible as well for
their offspring as for themselves; whereas, in reality,
they are more migratory, and wander further afield
than most animals, though these are free to come and
go as they will.

Winds, waves, birds, beasts, fishes, and even man
himself, are all pressed into the plant’s service, and
made to act as seed-carriers. But in some cases the
plant itself acts, and acts alone, sending her seeds to
quite considerable distances.

Many years ago, there was a certain bare, rocky
crag near Dunkeld, which the Duke of Athole desired

252 Seed-Scattering

to have planted with trees, though he was quite at a
loss how to accomplish it. For, as the place was
simply inaccessible, no one could climb up, either to
sow seeds or to plant saplings. The Duke mentioned
his difficulty to Nasmyth, and he, noticing a pair of
small cannon in front of the castle, ordered a number
of tin canisters, filled them with suitable seeds, and
fired them from the guns up the high face of the crag,
where they burst, and scattered their contents in all
directions. Some few years later there were trees
flourishing luxuriantly in all the recesses of the cliff.

Plants cannot perhaps shoot their seeds quite so
effectually as this, but in many the seed-vessels split
with so much of an explosion that the seeds are dis-
charged to distances which, at all events, remove them
from the danger of being squeezed to death in a crowd.
The Touch-me-not balsam is one of these. But the
Sand-box tree of Barbadoes is much more energetic.
Its fruit is rather like a small melon in shape, but hard
and woody, and when ripe it bursts with a loud report.
One of these—dried very gradually in the hope of its
remaining intact—exploded nine months after it was
gathered, and so violently as to break the wooden box
in which it was kept quite to pieces. The seeds were
scattered in all directions, but would of course have
been carried very much further had they been uncon-
fined. ‘

The fruit of the squirting cucumber has to be
bound round with copper-wire when ripe, to prevent
its shooting out its seeds.

The pods of the Chinese wistaria also explode with
a sharp, loud report, and the seeds may be carried at
least thirty feet; while those of the American wych-

Seed-Scattering 253

hazel are shot out to a distance of from twenty to
five-and-forty feet.

If, when these and other similar seeds are discharged,
a strong wind should happen to be blowing, they may
of course be carried much further; and even if it be
not to any really great distance, yet it will give them
an advantage; their descendants will advance further
still, and thus, in the course of generations, the plants
may spread over very wide areas.

Even individual seeds transported by the wind do
not always accomplish the whole of their journey ‘all
in a breath’; for the wind comes in successive waves,
not in one continuous blast.

Of a hundred seeds carried off by the wind, all will
be dropped when the first lull comes, and when the
next gust-or wave rises, probably not more than half
will be lifted up again to continue their journey; at the
third wave, perhaps ten will be caught up again, but
‘at the fourth or fifth, probably not a single one, for
they will have been dropped upon damp earth, or
water, into cracks, under bushes, or upon moss, all of
which act as traps, and, once caught, do not readily
give them up again, even to the most violent
blast.

Of course, the lighter the seeds, the better chance
they have of being carried far, unless they are caught
in these ways; and some few seeds, such as those of
the orchids, are so exceedingly minute and light, that
no mere lull in the wind is enough to make them drop,
for they manage to float even in the still, draughtless
air of a hot-house. In this respect they resemble the

spores of ferns, mosses and fungi, which can hardly
come to the ground at all except when the air is

234 Seed-Scattering

almost absolutely motionless, so extremely light are
they, being, in fact, rather like pollen than seeds.

Spores, owing to this extreme lightness, travel
immense distances over sea and land, and are to be
found in almost all dust, whether of town or country ;
but in damp weather they are not carried so far, and
some of the mosses keep the capsules in which their
spores are contained tightly closed, except when the
air is dry enough to ensure them a long journey.

Seeds, even the smallest, with very few exceptions,
fall straight to the ground when the air is still. Even
the tiny seeds of the poppy, campanula, and others do
this; but then, on the other hand, small as their
weight is, they require something of a shake to dis-
lodge them at all, and as they get this only when there
is a tolerably strong puff of wind, they must needs be
carried some little distance.

It might seem that large, heavy seeds would be at a
disadvantage in respect of wind transport; but as
they need a stronger shake to detach them, they do
not begin their journey till the wind is blowing with
some little force; and then again, being generally
borne by trees, and tall trees too, they start at a
favourable height, and are often carried a long way.

Seeds have, indeed, been raised as much as 5,400
feet in the air by the wind ; but hurricanes are usually
local, and do not convey what they snatch up more
than a few miles at the utmost.

But we have been looking upon seeds hitherto as if
they were themselves perfectly helpless and inactive,
which is very far indeed from being the fact. Many
of them have special means of their own for ensuring
or helping their conveyance from place to place ~

Seed-Scattering 255

means which vary according to the carriers upon
which they depend for locomotion.

Those which are carried by the wind, for example,
have elastic spines, wings, feathery tails, down, hairs,
all of which help to speed them on their way, and
make it more easy for them to be raised in the air, or
blown along the ground.

Generally as the lower part of the pistil ripens, the
upper part withers, having done its work of conveying
pollen to the ovules. But sometimes the pistil-stalk
remains attached to the ovary, and is turned to a fresh
use. In the wild clematis, for instance, so far from
withering it gvows, and not only lengthens out but
becomes: silky and feathery, ready to catch any puff of
wind, and very easily carried through the air. When
it drops, the heavier end, the ovary with its seed,
naturally touches the ground first, and is caught at
last, perhaps after two or three journeys, in damp soil
or moss, or some crack in the earth.

In the dandelion, it is the upper part of the calyx
which enables the seed to float through the air. A
dandelion blossom is composed of many small florets,
each having its own calyx and pistil. The lower part
of each pistil is entirely enclosed in its own small
calyx, and inseparably united with it. The upper part
of this calyx is divided into fine feathery hairs, which
at first form a crown to the ovary, and look as if they
grew from it. But later, as the ovary ripens, this
crown is pushed upwards on a fine stalk, and looks
like a miniature parachute, or an umbrella turned
inside out, and it catches the wind as easily, the merest
breath being enough to float it.

We need not do more than mention the down of the

256 Seed-Scattering

thistle and many other plants, the wing-like appendages
of the Seeds of the ash, maple, and sycamore, com-
monly called ‘keys,’ and the long, paper-like leaf-scales
attached to the flower-stalks of the lime, which answer
a similar purpose; or the wing-like expansions by
which many seeds are themselves bordered, and which
act the part of miniature sails.

The seeds of the water-pink of Ceylon are helped on
their way by other means; they are enclosed in circular
heads, measuring eight or nine inches across, and
beset with elastic spines which stand out in all direc-
tions. These heads are detached from the stalks
when ripe, and are whirled over the sands for miles,
bounding along on the spines, and dropping their seeds
by the way. Often, of course, they are whirled into
the water, and there they float, the upper spines
catching the wind, and acting as sails.

Water, indeed, plays a most important part in the
dispersal of seeds, many of -which, if carried only a
short’ distance by the wind to begin with, may con-
tinue their journey and travel much further if dropped.
into river or sea, especially if they happen to reach
one of the many ocean-currents.

There are not many seed-bearing plants which grow
actually in the water; but one of these, the arrow-
head, has seeds which keep afloat a long time, not
because they are so remarkably light, but because they
are so highly polished as to look and behave as if they
had been oiled. They do not even become wet, for
water runs off them ; and it is not until this polish has
been destroyed by much rubbing and long soaking that
they can be got to sink.

The seeds of: the water-lilies, white and yellow, are

Seed-Scattering 257

kept afloat for some time by means of air-bubbles.
Large fruits often float longer than small ones, and
could hardly be transported by any other means than
water.

Then, however, comes the all-important question,
how far the seeds are affected by remaining for some
time in water; and here again they vary considerably,
some being far more hardy than others.

The coco-nut, for instance, being enclosed in a mass
of fibre, floats well, and is able to stand immersion in
either fresh or salt water for an unusually long time,
without losing the power of germinating ; and coco-
palms, self-planted, are the first trees to spring up
upon any newly exposed coral-reef, the nuts having
been floated thither from some more or less distant
coast. When making experiments to ascertain how
long seeds might remain in salt-water without being
killed, Mr. Darwin was delighted to find that some
grew after twenty-one days’ immersion. Many ocean-
currents, as he reckoned, travel at the rate of a mile
an hour, so that these seeds might be floated five
hundred miles without being any the worse. But,
alas! he had overlooked one thing. The séeds had
been under water all this time; and as Dr. Hooker
reminded him, ‘If they sink, they won’t float!’ Seeds
vary much as to the length of time they are able to
remain afloat, and these seeds could not have been
transported at all by water, except under different
circumstances, such as while they were still enclosed
in their seed-vessels, or even attached to the plant or
branch on which they grew.

Some few seeds grew after being kept for 137 days
in sea-water; so that, if able to float, they might have

17

258 Seed-Scattering

germinated after a voyage of more than 3,000 miles—
a distance greater than that which lies between Europe
and America.

The question was, then, whether there were any way
in which they might float; and it was found that
though ripe, freshly gathered hazel-nuts sank directly
they were put in water, they would float for as much
as ninety days, and then germinate, if they were first
dried.

Now, in the natural state, seeds may often be dried
by exposure to sun and air before they are washed, or
blown, into the water; and they would, some of them
at all events, be then perfectly well able to float. A
plant of asparagus, for example, floated nearly as long
as the nuts, after being dried, and its berries germi-
nated ; and asparagus, being a plant which grows wild
on the sea-coast, would have especially good opportu-
nities, therefore, of migratirg.

Drying does not answer the purpose with all plants,
however; but out of ninety-four, upon which the expe-
riment was tried, eighteen floated more than twenty-
eight days, and some much longer, quite long enough,
in fact, to allow of their being carried from one con-
tinent to another.

For Mr. Darwin’s estimate of a mile an hour as the
rate at which ocean-currents travel, was a purposely
low one ; several of the Atlantic currents travel thirty-
three miles a day, and some as much as sixty miles a
day, so that any of these eighteen plants might have
been carried some hundreds of miles, and others from
three to five thousand, without their seeds being any
the worse for the voyage.

Some seeds appear to have no means at all of getting

Seed-Scattering 259

themselves transported from place to place; but it will
generally be found that these are seeds which have
been altered by. cultivation. The grain of wheat
and rye, for instance, falls quite naked from the ear
as soon as it is ripe, and sinks at once in water; and
this is one reason why neither is ever found wild. Rice
is a little better off, for each grain is enclosed in a
rough, hard case, which effectually preserves it from
injury, and probably in its natural state it was able
to float on water. But now that its size and weight
have been increased by cultivation, it sinks like the
others.

Many bean-like and pea-like seeds stand immer-
sion extremely well, and some of these, conveyed
3,000 miles or so by the Gulf Stream and cast upon
the Azores and on the Orkney islands, have been suc-
cessfully grown at Kew Gardens, though they could
not establish themselves in either group of islands
owing to the unsuitable climate of both.

Among the islands which have been especially in-
debted to ocean-currents for their vegetation, may be
mentioned the Bermudas, more than half of whose
flowering plants are supposed to be colonists. The
greater number of these belong to the tropics and
West Indies, and have been to a large extent brought
by the Gulf Stream, which is constantly throwing up
various objects on the shore—the seeds of trees among
the rest. The soapberry-tree, for instance, has been
observed to spring up in this way, from seeds thus cast
ashore.

Seeds may occasionally chance to be conveyed
across the ocean in drift-wood, without ever coming
in contact with the water at all; for stones and small

260 Seed-Scattering

quantities of earth are sometimes found perfectly
enclosed ; and from the earth thus entangled in the
roots of an oak, Mr. Darwin was able to grow three
plants.

But again, there is another way in which seeds may
escape contact with water: dead birds, having seeds
in their crops, may now and then escape being devoured,
and may be floated long distances by river or ocean-
currents; and, as many seeds retain their vitality after
being in a bird’s crop for thirty days, some may be
conveyed in this way from time to time.

The so-called ‘goose-wheat’ of Canada was first
sown from grain found in the crop of a wild goose
which was shot on its way, probably from Alaska, or
the Russian settlements on the other side of Behring’s
Straits. Migratory geese invariably take to the stubbles
when on their way to the south in autumn, and many
or most of them would probably be found to have grain
in their crops, though the chances of its getting planted
are small. In this case, however, the ‘wild-goose
barley,’ as it is also called, has become a permanent
colonist, and is still grown in Saskatchewan.

XVIII.
SEED-CARRIERS

Tue seed-carriers now to be considered are employed
-for the most part with as little reference to their own
wills, and often with as little knowledge on their parts,
as the winds and waves. The seeds simply make use
of them as carriers, whether they will or no, and that
no matter whether they be birds, animals, or even
men; for all are pressed into-the. service, and know,
for the most part, nothing of what they are doing.
Weare, of course, not here speaking of man’s voluntary
importations, but of his involuntary ones, which are
probably almost as many.

There are, however, some few voluntary carriers
among both birds and animals—carriers who, though
in one sense quite unaware of what they are doing, yet
for purposes of their own do carry seeds from one place
to another, not very far probably, but often the distance
of a few miles.

Some birds, for instance, take a positive pleasure, as
it would seem, in carrying things about for the mere
sake of carrying them; and the propensity is especially
strong in the crow tribe, including not only crows, but
rooks, jays, magpies and jackdaws, many of which
also have a great love of hiding as well as carrying.

262 Seed-Carriers

Rooks seem to be especially busy in this way, at all
events in America, where they are said to be per-
petually carrying things about. in their claws, with
which they are able to grasp even hens’ eggs.

On one occasion a large number of fowls, destined
for New Orleans, had been collected at some spot up
the river, and as the boat which was to convey them
was not ready, they were turned out into the woods
for about a week to shift for themselves. During this
time they laid about two thousand eggs daily, a fact
which seemed immensely to interest the rooks of the
neighbourhood. For, whether with a view to eating
them, or simply from a love of being busy, they devoted
themselves to carrying the eggs away, and burying
them in a field more than half a mile off on the other
side of a creek. A month or two later, when the field
was ploughed, the eggs were turned up in hundreds,
and being still perfectly good, supplied the labourers
with many a meal.

But now, supposing that the rooks had buried acorns
instead of eggs, and that the field had been waste
ground, where plough and harrow never came, might
not a small forest of oaks have sprung up? and may
not many a plantation of oaks, beeches, sycamores and
other trees, have been planted in a similar way ?

A certain pine-forest in Minnesota, for example, on
being cut down, was at once succeeded by oaks; and
a similar thing is said to have occurred in North
Carolina, with nothing in either case to account for it.
The oaks seemed to have grown of themselves; but
since oaks must certainly spring from acorns, it seems
at least possible, and indeed probable, that rooks may
have been the planters.

Seed-Carriers 263

Rooks are always busy in the wild state, and, as the
American writer before quoted remarks, on leaving an
oak-tree, the bird will often pluck an acorn, which- it
may carry perhaps five miles; then, if it alights upon
a beech, it will drop the acorn and gather nuts instead,
and so on, taking a fresh remembrance away wherever
it goes, and sowing seeds innumerable in the course of
its life.

But when the rooks assemble in their hundreds to
hold a ‘pow-wow’ or parliament, then is the time
when they do their sowing on a large scale; for, true
to their usual habits, many, if not all, bring and drop
something. The place chosen for the assembly is
always open, and more or less bare, and afterwards
the ground may be seen strewn with walnuts, hickory
nuts, acorns, sticks and other rubbish. This, at least,
is how rooks behave in America; and a field is
mentioned which, after being left to itself for some
time, was found to be full of young ‘bur-oaks,’ there
being no parent-tree anywhere near from which the
acorns could possibly have been carried, even by a
high wind.

Now, how could these have been planted, save by
birds? Pigs simply crunch up and eat nuts and acorns
where they find them; and though the squirrel some-
times carries them several hundred yards, it seldom
does more, while the field-mouse certainly does not
lay up her winter-store very far from where her crops
grow. Besides, neither tree-squirrels nor mice act in
concert, and planting on so large a scale must have
required a small army to accomplish it.

No doubt, however, both tree- and ground-squirrels,
as well as mice, are responsible for the planting of

264 Seed-Carriers

many a single nut-bearing tree; for sometimes they
may be startled, and made to drop their treasure
before they reach home; some may forget their store-
house, and some may die before it is empty. Still,
the result of any of these accidents will be rather
solitary trees than groves, or even groups; for in the
case of an abandoned store-house, though many might
sprout, only one or two would have a chance of
growing.

But the gray tree-squirrels may have done more,
for, unlike the red, and the ground-squirrels, they bury
their winter-store of nuts and acorns separately, one by
one, about a couple of inches deep; and though they
have such good memories as to be able to find them
again, even when buried under a foot of snow, no
doubt in many cases accidents have happened, and
their stores have been left undisturbed, and would
have excellent opportunities of growing. The number
of these little animals in North America was some-
thing extraordinary in bygone times; for in one year
(1749) 640,000 were destroyed in Pennsylvania alone.
They may well, therefore, have done a great deal of
planting, though they would probably not carry their
nuts far.

The nuthatch often plants quite a colony of young
beeches around its haunts; for it has favourite trees
to which it resorts, after twisting a cluster of nuts from
the bough; its object being to fix the nuts in some
crevice of the bark where it may hammer at them.
Very often, however, it fails in the attempt, the nuts
fall to the ground, and, under favourable circumstances,
germinate.

Monkeys, also, sometimes carry nuts and fruits to a

Seed-Carriers 265

distance before eating them; and if meantime their
attention be caught by something else, they will prob-
ably drop and forget all about them. Brazil-nuts,
for instance, are enclosed in such a very hard, strong
outer case that no monkey can get at the contents,
except by hammering it for a long time against a rock,
or a hard log of wood, neither of which is always to
be found close at hand.

So much, then, for the voluntary carriers, whose
work is but small and limited, compared with that
of the great army of involuntary carriers.

Look, for example, at a dog when he has been
hunting in a ditch, and see how the burdocks and
goose-grass, or cleavers, have taken advantage of him,
and made him act as carrier for them. Their fruits
are thickly set with tiny hooks, and with these they
have laid hold of his coat, entangling themselves in it,
and holding so tight, that though he may roll and
bite, and try in every way to rid himself of them,
he will often carry some about with him for days;
and if on some long expedition, might travel a good
many miles before he had freed himself from them
all.

Now, what is true of the dog in this respect is true
also of many animals, wild and domestic, including man
himself. The fleece of sheep, the fur and hair of other
animals, the feathers of birds, the clothes of human
beings—all answer the purpose of these hooked, barbed
and thorny fruits, by giving them something which
they can lay hold of. No doubt we have all noticed
the extraordinary way in which the seeds of the wild
barley work their way into one’s garments, and remain
for months unless picked out. The seeds of the porcu-

266 Seed-Carriers

pine-grass, too, cause positive annoyance by a similar
habit of sticking into socks and trousers.

This is the way in which seeds of these sorts get
themselves transported ; and accordingly it will be
found that fruits furnished with these means of laying
hold of the passer-by generally grow low enough down
to be within reach of some one or other of these means
of conveyance. Hides, fleeces, hair, wool, fur, feathers,
manes, tails—all are turned to account, and made
useful.

It is true that both birds and quadrupeds are
frequently cleaning themselves, and do not willingly
carry anything of the sort about with them; but when
once a bur has attached itself, it is very difficult to get
rid of again; and the animal which it has made use
of will generally be obliged to carry it for a time, how-
ever unwillingly.

We have abundant proof of this in the way in which
more than one plant has been introduced, not only
from one continent, but from one hemisphere, to
another, within recent times.

The ‘ Bathurst bur,’ among others, is a striking
example of the successful emigrant. Growing in
Patagonia, it got itself conveyed to Australia, where it
has flourished ever since in the most rampant manner.
The first step was to hook its burs into the tails and
manes of horses, which it did most effectually; and
then, as chance would have it, some of these same
horses were imported into Australia, burs and all, for
so thoroughly were they entangled that the animals
had not been able to shake or rub them ail off, even
during the voyage. Some no doubt were got rid of,
but enough remained to make a fresh start in the new

Seed-Carriers 267

country ; and they did it with such energy, that within
a few years it was found necessary to pass an Act of
Parliament ‘against the growth of thistles, and all
persons allowing them to remain on their land, or even
on their half of the road, were made liable to heavy
fines. ‘

The ‘ Bathurst bur’ was in fact, from man’s point
of view, a terrible nuisance; but from its own, it was
a peculiarly successful colonist. It had secured such a
change of air and change of soil as agreed with it
amazingly; it had made use first of the horses, then
of man, to attain its object; and finally, on reaching
the new continent, its downy seeds, being fully ripe,
had been launched on the winds, and borne hither and
thither to their new settlements. Their descendants,
again, had been carried yet further afield, and so with
giant strides it had advanced over the country—a most
successful plant !

The merino sheep has been similarly instrumental
in introducing another thistle-like plant to South
Africa. Indeed, plants with downy seeds have been
eminently successful, not only in dispersing their
offspring far and wide, but also in becoming natural-
ized—making themselves so thoroughly at home in
their new quarters that they are able to mature their
seed, and so to propagate their species without
artificial help.

But birds are the great carriers; and the migrants,
especially, transport such seeds as lay hold of them to
much greater distances than quadrupeds ever travel,
at least without the help of man.

There is a species of sedge which grows by the
water in the highlands of Jamaica, whose fruit is

268 Seed-Carriers

provided with long bristles, something like a shepherd’s
crook, the hooked part being so closely fitting and
elastic as to grasp the finest hairs, if drawn across the
back of the hand. It grasps them so tight, moreover,
as to pull them out, sooner than let go. The highlands
where this sedge abounds are the spots generally first
touched by migratory birds, and in some cases small
birds are caught and held so firmly by the sedge’s
hooks as to be quite unable to escape. Larger and
stronger birds of course get away, but must carry many
of the seeds with them; and these, as the bristles
wither and relax their hold, are dropped by the way.
Accordingly the sedge is plentiful all along the track
followed by these birds—the east coast of North
America, that is, and the adjacent islands, among
which the Bermudas are visited by large numbers of
these migrants.

Birds, such as the puffins, which burrow in the
earth, get their feathers covered with vegetable mould,
which is sure to contain spores and seeds, some of
which may cling long enough to be carried at least
. part of the way, when the birds leave their inland
nesting places for the coast, where they spend the
greater part of the year.

Birds, it is true, are generally very particular in
keeping both beak and feet clean, but still sometimes
they are found with little cakes of earth adhering to
them; and seeds are so very common in all soil, that
some no doubt are transported in this way. Indeed,
eighty-two plants have been grown from the earth taken
from the leg of a single partridge, and that after the
earth had been kept three years. This partridge had
carried as much as six and a half ounces of earth on

Szed-Carriers 269

its leg; and what one has done, others of course may
do, and probably have done. Still, dirt on feet and
beaks is rare.

The birds most likely to have muddy feet are
naturally the waders, and those which frequent the
edges of ponds and moist and muddy places. And
these, if they carry away mud, are certain to carry
away seeds also, for damp soil catches and keeps the
seed dropped upon it in a way that dry soil cannot.
From about a breakfast-cupful of mud taken from
under the water, and from the edge, of a small pond,
Mr. Darwin succeeded in raising 537 plants.

Now the birds which frequent bogs and marshes and
other muddy places, are also the very birds which
wander most, the migrants, in fact, chief among which,
for the wide extent of its journeyings, is the wood-
cock; for there is hardly any island, however remote,
but the woodcock finds its way thither, and no doubt
it has carried in its time many a seed, which has been
dropped again in soil as muddy as that from which it
was taken, and has therefore had a good chance of
establishing itself

But, though birds convey seeds both in their feathers
and in the mud on their feet, they no doubt convey
many more in their crops. There is no gastric juice
or anything else in the crop to injure the seeds in any
way; and when a large supply of food has been taken,
the grains do not all pass into the gizzard for twelve,
or even eighteen hours, in the course of which time a
good deal might happen. Birds, for example, are
occasionally blown the whole way across the Atlantic,
the wind carrying them on at the rate of thirty-five
miles an hour; and they might well, therefore, be

2470 Seed-Carriers

carried 500 miles before all the grain had passed out
of their crop, if they had just had a full meal.

Supposing them to be blown overland, instead of
over sea, or to reach land after a few hours, they might
then be pounced on by the hawks, who are always on
the look-out for weary travellers. These, like the owls,
bolt their prey whole, and after some hours disgorge
pellets of feathers and other undesirable matter, among
which might be the seed in the crop of their victim,
still uninjured. This, indeed, is no mere speculation,
for it has been found by experiment that such pellets
do contain seeds, such as oats, wheat, hemp, millet,
clover, and canary-seeds; all of which may be capable
of germination. Or again, a bird with seed in its crop
may be struck down by'a hawk after flying some
considerable distance, and the hawk in its turn may
be driven away from its prey before it has done more
than tear the crop open. In this instance, too, the
seed may fall where it will be able to germinate, and
the plant may be able to establish itself; and though
such cases are exceptional, one single successful seed
is enough to introduce a plant to an entirely new
neighbourhood, where, under favourable circumstances,
it may spread and become completely naturalized.

Seeds vary very much as to their power of resisting
digestion. Many are, for the most part, quite digested,
but there are others which are protected against
digestion by a covering so hard, or so tough, that it is
a real help to them to be swallowed, as they germinate
more readily when this covering has undergone some
amount of softening.

Seeds, for instance, which are swallowed, not for
their own sake, but for the sweet flesh surrounding

Seed-Carriers 271

them, are more or less hard, and some stone-like.
Even the seeds of elms, firs and ashes, often escape
not merely uninjured, but actually helped by being
swallowed; and the same is true, in a much more
marked degree, of the stones of the cherry, sloe, rasp-
berry, blackberry, and the seeds of the apple, and the
tiny nuts of the strawberry.

In some cases birds render a positive service to man,
also, by swallowing and scattering the seeds of plants
which he cultivates. The cinnamon-tree, for instance,
has been introduced in this way into the interior of
Ceylon from the gardens on the coast; and as the wild
trees are just as good as the cultivated ones for com-
mercial purposes, their shoots are regularly cut for the
trade.

So, too, with the pimento, allspice, or Jamaica
pepper-tree. All the present ‘pimento walks’ of
Jamaica, as the plantations are called, have been sown
by birds; for though the plants can be raised in
nurseries in large numbers by careful treatment, the
planters are of opinion that the seeds are better pre-
pared by the birds. And why should they incur the
trouble and expense of this ‘ careful treatment,’ when
the birds do all that is necessary ?

When a new ‘walk’ is wanted, all that is necessary
is to enclose a piece of waste ground near an old
‘walk.’ The birds eagerly eat the fruit when ripe, and
the seeds are dropped, with the result that twelve
months after the first rains abundance of young plants
are to be seen growing vigorously in all parts of the
new enclosure. If not enclosed, the plants would be
eaten off or trodden down by wild animals; but this
amount of protection is all that they require,

272 Seed-Carrters

Turkeys are employed to prepare the haws when
hawthorn hedges are wanted, in some parts of France;
for the bony cores are quite indigestible, and are
softened by being swallowed. Blackbirds, jays, and
others keep the haws in their crops for a time, and
then bring up the seeds clean and whole, with the thin
covering of flesh gone; and no doubt they are respon-
sible for the planting of many a thorn-tree.

Some trees seem to be entirely dependent upon
birds for getting their seeds scattered, and cannot
spread without them. The red cedar is apparently one
of these; for, though introduced into Indiana nearly
fifty years ago, it did not run wild, and was not to be
found in the forest, until some of the birds became
sufficiently familiar with it to venture to eat the seeds.
During the last few years numbers of young saplings
have made their appearance, and it is likely to be one
of the forest-trees of the future. The seeds of the red
cedar have so hard an outer covering that gardeners
find it well to scald them before planting; and it is
therefore, no doubt, a great advantage to them to be
swallowed.

How, except by being swallowed by birds, does the
mountain-ash berry get conveyed to the top of high
walls, where young trees may sometimes be seen
growing? How, save in this way, does the mistletoe
reach the top of the oak? or how do the wild-rose and
privet find their way to the walls of Cologne Cathedral ?
The reader may possibly be inclined to add another
‘how’ to the series, and ask how, when they get there,
do they manage to find soil to germinate and grow in?
But, as already remarked, a very little soil is enough
for seeds to sprout in; and this, in the case of build-

Seed-Carriers 273

ings, is provided first, probably, by the decay of lichens
and mosses and of the stone itself, and also by the
wind, which conveys many a little pile of dust into
sheltered nooks and corners. As for the mistletoe,
being a parasite and living by the labour of others, it
has no difficulty about soil, and makes itself at home
not only on the oak, but on other trees, above all on
the apple.

In the forests on the Amazons, plants without
number may be seen growing on the trees, some of
which, as the ferns and orchids, have no doubt been
sown by the wind; while there are others, such as the
fragrant pink-and-white clusia, which are equally surely
sown by the birds. The large, round, whitish fruit of
the clusia, called the ‘wild onion,’ is much eaten by
birds, and is to be seen growing on almost every other
tree.

Tropical birds, whether in the east or in the west,
are all chiefly fruit or insect eaters; while in temperate
latitudes, where there is much grass, seed-eaters abound,
and a mixed diet is more general.

The fruit-eating, and consequently seed-carrying,
birds of the tropics are the countless multitudes of the
parrot tribe, which usually feed in flocks of thousands,
and wander far in search of food; and, besides these,
there are many fruit-eating pigeons, hornbills, and
others. Nor must the inmense flocks of large fruit-
bats, or flying foxes, be overlooked; for their numbers
are so enormous that they often take hours to pass,
while their depredations in the orchards are carried to
such an extent as to make them one of the greatest
pests of the tropical fruit-grower of the East. In his
absence, however, the fruit-eaters have done, and

18

274 Seed-Carriers

do, much valuable service in the way of carrying
seeds.

Seed cannot be sown to any purpose until it is ripe,
and it would therefore be simply wasted if the birds
carried it off too soon. But it is safe enough from
them while it is unripe, for the eatable part, the flesh
surrounding the seed, is unripe too, as the birds very
well know, and they leave it severely alone. Green
fruit they do not like, probably because it is indiges-
tible ; for one would not suppose the flavour to be of
much consequence.

The fruits of the bird-cherry, hawthorn, ash, sloe,
and many others are of a size to be swallowed whole;
and as, to our taste at all events, they have no flavour
to recommend them even when ripe, a little unripeness
would not seem to matter much, except as regards the
seed. But for this it would matter greatly, and the
birds are therefore warned off until it is ready to
benefit by their attention. When the right time has
come, the fruit changes colour and becomes more con-
spicuous—a notice which is perfectly understood.

Red, yellow, purple, and black are the most usual
colours of ripe fruit, and these the birds seem, there-
fore, to understand best ; for they seldom touch white
currants till the red are gone, though the white are the
sweeter of the two; and they have been observed to
leave unnoticed a holly-tree bearing yellow berries,
while they stripped other trees near of their ordinary
red ones. Yellow holly-berries being uncommon, these
were probably considered to be still unfit for eating.

Though birds swallow their own small fruits whole,
they seem to appreciate the sweeter flavour of those
which man has improved by cultivation. But as seed-

Seed-Carriers 275

carriers they are distinctly out of place both in orchard
and kitchen-garden ; they are not wanted in that capa-
city, and, in fact, if they were, they are incompetent;
for, where cherries and plums have been so increased
in size that they can only be pecked at, not swallowed,
the flesh only is taken, and the stones are left.

Where plants are. cultivated for the sake of their
leaves or roots, not their fruit, the former are altered,
but the latter remains the same, with the same means
of getting its seed carried to a distance which were
possessed by the plant’s wild ancestors. The fruit of
the garden carrot, for instance, like that of the wild, is
covered with minute hooked bristles ; that of the par-
snip is winged ; and the seeds of the onion, tobacco,
and flax are just as easily scattered by the wind in the
cultivated as in the wild state.

But to mention, in conclusion, some of the other
seed-carriers besides the birds. Among these must
be reckoned fish, locusts, cattle, and, perhaps above
all, pigs.

Fish swallow the seeds of many water and land
plants, including even the large seeds of the water-lily;
but, being confined to their own pond, lake, or river,
their range is necessarily limited. When, however,
they, in their turn, are swallowed by herons, storks,
kingfishers, and other fish-eating birds, the seeds may
be conveyed to much greater distances and be dropped
quite uninjured. Some large seeds of the great southern.
water-lily, for instance, found in the stomach of a
heron, had probably first been swallowed by a fish.

The locusts which frequent parts of South Africa
are believed by the farmers tc have introduced there
various new plants which are injurious to the grass;

276 Seed-Carriers

and it is a fact that undigested seeds, capable of
germinating, are found in their droppings.

Cattle and pigs, but especially the latter, are respon-
sible for the rampant way in which apple-trees are
now running wild and forming extensive groves in the
Pampas. The pips are so well protected as to be
indigestible even by a pig; and the same may be said
of peach-stones, which have also been extensively
scattered in New Zealand and elsewhere, by simiar
nieans and with similar results.

XIX.
CHANCES OF LIFE

OF all the wonderful things in nature, surely a seed is
one of the most wonderful. How dead and helpless
it looks ; how very little it tells us about itself, and yet
how very much is wrapped up init! Seeds, especially
small seeds from the same plant, look just as much
alike as grains of sand. Indeed, peas have become
proverbial; and we say ‘as much alike as peas in a
pod,’ when we mean that things, or people, are quite
without individual character.

And yet each seed, even the smallest and most dust-
like, has a character of its own—-a character which
distinguishes it not merely from other seeds of different
families, but a character which distinguishes it also
from all its nearest relations, even from those which
grew in the same pod with it. —

Probably it is only want of sight which prevents our
seeing the difference between one seed and another,
for certainly even the most careless observer will
admit that he has never yet found two perfectly
identical plants. Not even two peas, taken from the
same pod, will grow up precisely alike.

But as long as the seed is kept from its natural bed

278 Chances of Life

in the earth, it not only looks dead, but is dead to all
intents and purposes, for it has no means of showing
that it lives—dead, however, with a possibility of life,
which generally grows less and less.the longer it is left
unburied. When the life has died out of it wholly,
it still looks much the same as before, at least to the
unpractised eye.

As to living seed, if it be one that we know, we can
tell at a glance what sort of plant bore it, and what
plant will spring from it. But if it is a seed that we
do not know?

Well, even then, we may be able to tell by the look
of it what family it belongs to, whether it is starchy
or oily, whether it will have two seed-leaves, like a
bean, or one, like corn. But our knowledge will not
carry us much further. In many cases it will not
even tell us whether the forthcoming plant will be a
tree, or a shrub, or a lowly herb. To the inexpe-
rienced, many of the smaller seeds especially look
very much alike; and there is certainly no such differ-
ence in their appearance as would lead one to guess
at the great variety-of plants which will spring from
them ; and even the wisest knows very little about the
why and the wherefore of the matter.

For why should the small seed of the elm produce a
tall tree, «nd the large seed of the gourd only a short-
lived, weak-stemmed, creeping plant? Why should
one bean grow to the height of a few inches only and
another climb up several feet? Why, again, should
an acorn always produce an oak and not some other
tree? All that we can answer is, an acorn has oak-
life in it. But we might as well say we don’t know,
for all the light this throws upon the subject.

Chances of Life 279

Look now at these seed-pods and seeds. We may
know that they have been taken from plants of the
great cabbage family; but the family likeness is so
strong between them that we should probably be
puzzled to.say which would produce red cabbages
and which green, and from which will come crinkle-
leaved savoys, curly-leaved kale, Brussels sprouts,
broccoli, or cauliflowers. All these are but varieties
of the cabbage, though they are so very different
in appearance; and as long as they are only seeds,
they are so nearly alike that their secret is quite safe
from ordinary people.

Even when we know that certain plants will spring
from certain seeds, we are in many cases quite unable
to tell what the colour of the blossom will be. There
is no difference at all to be detected in the seed, yet
one seed will produce blossom of one colour and
another of another. But why?

For instance, from the seed of the verbena, phlox,
and sweet-pea, we know, because it has been so in the
past, that we shall get verbenas, phloxes, and sweet-
peas; and we may go a step beyond this, and say that
there will be no quite blue flowers, nor any yellow
ones among them. This we know from experience.
We know, too, that, though the seeds of each sort
look so exactly alike, no two plants will be absolutely
similar, and the blossoms will vary much. Some of
the pea-blossoms may be pink of different shades,
others pink and white, or purple, though they grow
side by side; and there will be still greater variety in
the colours of the phloxes and verbenas, some of
which will also have white eyes and some not. But

280 Chances of Life

we cannot tell by looking at it which seed will produce
which blossom.

And even if, in some cases, we should be able to do
this, we are still not a whit nearer solving the mystery
of the how and the why. We may conclude that there
is some minute difference in the food which the roots
take up, according as the blossoms are of one colour
or another; for we know that the pink hydrangea will
turn blue if.supplied with an extra amount of iron;
and we may argue that, though the peas all look alike,
one has that within it which causes it to take up what
will produce pink blossoms, and another that which
will produce purple ones. But it is a mystery still.

We may prevent their growing at all, we may keep
them till the possibility of life has died out of them; or,
though we let them grow, we may prevent their blos-
soming ; but if allowed to grow and blossom without
interference, in their native soil, one will bear its pink, .
and another its purple blossoms without fail.

But if the seed tells us nothing as to the colour of the
blossom which will spring from it, it often tells us also
just as little as to the size of the plant which it will
produce, and the length of that plant’s life.

Here, for instance, are three seeds of different sizes,
but all belonging to the bean-like or leguminous order
of plants. Supposing that we had never seen them
before, and were told that one would produce a tree,
another a shrub, and the third a dwarf annual, should
we be likely to guess that, from the two smaller seeds,
would grow a laburnum and a broom-plant, while
from the third, which is so many times larger, would
spring only a broad, or Windsor, bean ?

Some of the orchids bear large blossoms, and others

Chances of Life 281

large masses of blossom; yet their seed is almost dust-
like. The seed of the lobelia and of the scented
tobacco is about equally minute; but from the one
springs a plant only a few inches high, with quite small
blossoms; and from the other, one which grows to a
height of two or three feet, and has blossoms at least
four inches long.

Then, again, size of seed has nothing at all to do
with length of life. The large broad bean has life only
for a single season; the small laburnum-seed has life
which lasts for years. The lupin, another leguminous
plant, is both an annual and a perennial; but, strange
to say, the perennial lupin bears the smaller seed,
though it not only lives longer but is also the taller
plant, and produces more blossom of the two.

An oak may live as many centuries as a bean does
months, or more; but who can say why ?

The famous chestnut-tree on Mount Etna is said to
be 1,000 years old ; and among other ancient trees,
whose age is more or less well attested, there is an
oak reputed to be 1,600 years old and a walnut of goo;
there are olives which are believed to be 2,000 years
old; and there is at least one tree in the East which
tradition affirms to be even 6,000 years old! But,
again, why an olive should outlive an oak, who
can say?

There is a great difference, also, as to the length
of time during which the seeds themselves retain their
vitality or power of germinating. Most of them look
equally lifeless ; but in some this mysterious power
lasts much longer than in others, and this, too, with
very little reference to their size, though large seeds,
especially oily seeds, have some advantage. The seed

282 Chances of Life

of the coffee-berry, for instance, is worthless unless
planted without delay directly it is ripe; and willow-
seed is said to live only a fortnight after ripening, or
less, if it is allowed to become dry. Seeds of melon
and geranium, on the other hand, have been known to
germinate after being kept, merely wrapped in paper,
for thirty years. It is believed that, if melon-seeds
produce plants at all, after being kept for some time,
their crop of fruit will be all the larger; but they are
commonly supposed net to live longer than seven
years, and even within this period the longer they are
kept the smaller is their chance of germinating con-
sidered to be.

Cases, however, have been known in which certain
seeds. quite small seeds, too, have kept the life in them
not only for years but for centuries, and evet: millen-
niums. We are not alluding to the famous mummy
wheat; for the grain of wheat, being quite unprotected
except by a thin husk, loses all power of germinating
in a few years at most; and none of the interesting
stories told of wheat raised from grain found in
Egyptian tombs have ever yet been satisfactorily
proved.

Grain taken from mummies has germinated sure
enough, but it has been grain recently introduced by
the Arabs! In one instance the plant raised bore
oats ; but this was unlucky, for oats were not known to
ancient Egypt ; and in no single case has any success
attended the innumerable attempts made to raise
plants from genuine mummy wheat. But seeds found
in Roman tombs have not only germinated, but pro-
duced plants.

Of all weli-authenticated cases, however, the most

Chances of Life 283

remarkable is that of the seedlings raised by Dr.
Lindley, in Chiswick Gardens, from raspberry-seeds
found in Celtic tumuli perhaps some two thousand
years old. Raspberry-seeds have very hard coats, it is
true, and these seeds were safely buried from the air,
and beyond the reach of any great changes of temper-
ature; but yet that things so small should have been
able to preserve living germs within them for so long a
time is a wonderful proof of their great tenacity of
life.

Generally speaking, it seems that the seus of wild
plants have the advantage over the cultivated in this
respect. They retain their vitality longer; but then,
on the other hand, there are not so many of them.
Cultivated plants usually produce most seed—except,
of course, where blossoms have been doubled or fruit
improved at its expense.

When one considers the vast quantity of seed pro-
duced, and the ample contrivances for scattering it, it
is surprising to find that, after all, many plants do not
increase their numbers at all. There are just about the
same number of them now that there were years ago—
neither more nor fewer.

Take, for example, the common wild spotted orchis,
a single plant of which often bears as many as thirty
seed-vessels, each containing 6,200 seeds. Suppose that
there were 400 bad seeds to each capsule, 12,000 in all,
which is a fair allowance, one plant might still be the
parent of 174,000 others—enough to cover nearly an
acre of ground if the plants grew just far enough apart
to allow a proper amount of space to each. The de-
scendants of these, again, might more than cover the

284 Chances of Life

Isle of Anglesey, and the great-grandchildren of the
one original plant would more than clothe the entire
land-surface of the globe !

This calculation was made by Mr. Darwin ; and yet,
as he goes on to observe, the plant is actually not in-
creasing at all in most places, although it is a perennial,
and although its seeds are so minute as to be easily
wafted to a great distance by the wind. So, then, only
one seed out of the thousands borne by a single plant
can come to anything, and even that not every year,
but only once in several years; for, as each plant lives
some years, there must be an increase in its numbers
if but one new plant grew up every year.

That the seeds are scattered, and widely scattered, is
unquestionable, for seedlings have been found eight or
ten miles away from where any plants grew; but it is
equally certain that there is some effectual check to
the plant’s increase, though what that check is remains
unknown.

It is plain, therefore, that the mere scattering of the
seed, however necessary as a first step, is far from
being enough to secure that the plant shall be able to
establish itself in a fresh locality; and the farther the
seed is carried the greater the risk it often runs. Some
plants are much better able than others to adapt them- .
selves to altered circumstances, and these, of course,
make the better colonists; but even they may be quite
unable to effect a settlement simply for lack of space.
Others find that soil, or climate, or situation do not
suit them, and soon die out for that reason. Others,
again, though they may find ample room, and all
things else to their liking, are quite unable to become
permanent colonists because they cannot fertilize them-

Chances of Life 285

selves, and, if there are not the right insects to do it
for them, they cannot produce any seed. Such plants
as have more than one ‘ form ’ (see p. 222), and such as
bear pollen and ovules on separate individuals, run, of
course, especial risks when they migrate, as one is
generally helpless without the other.

In the matter of soil, too, a very short distance often
makes a great difference. The bee-orchis. for example,
grows plentifully on the chalk in Surrey, and one year
it suddenly made its appearance in a clayey field near
Thames Ditton, where it had never been seen before.
About a hundred plants blossomed in this one field,
and nowhere else in the neighbourhood. But they
gradually dwindled away, and in the course of six or
eight years all had entirely disappeared. The seeds
had probably travelled to the clay-field in some chalk
which had been brought from another part of the
county, but the colony could not be a lasting one for
some reason—most likely owing to the change of soil,
and perhaps also of situation.

Then, again, there is the milk-thistle, which has run
riot in Australia, but has utterly failed to make a settle-
ment in New Zealand. Single specimens have been
grown im the latter country, and have seeded freely.
The seeds, too, after the manner of their kind, must
have been carried hither and thither by the wind in
multitudes ; but still the plant has not spread, and is a
failure—a fortunate failure—as an emigrant.

Other European plants, to the number of more than
a hundred and fifty, have been quite successful in New
Zealand, and are thoroughly established ; but, it is re-
markable that, while so many European plants have
made themselves at home there, only two or three

286 Chances of Life

Australians have managed to do so. Yet Australia is
nearer than Europe, and the intercourse between the
two countries is much more close and frequent than it
is with Europe. Moreover, Australian seeds have been
purposely and extensively scattered in New Zealand,
among them being, we may be sure, the seeds of such
common kinds as those of the acacia and eucalyptus ;
yet none of these trees are to be seen growing wild.

It is the same with our own garden-plants. How
many there are which, though they grow in the garden
without any special care, and bring abundance of seed.
to perfection, yet never run wild, even to the extent of
appearing on just the other side of the wall or hedge!
Yet it is impossible to suppose but that the seed is
often carried beyond these limits; and weeds make
their way i without difficulty.

In considering what becomes of the vast amount of
seed which is annually ripened, we must, of course,
bear in mind that a great deal is consumed as food—
luckily for us; for if there were no seed-eating birds,
we should be overrun with thistles and other weeds.
Some seed also falls upon soil which does not suit it;
some requires burying, and gets killed by remaining
exposed; some cannot germinate without special pre-
paration of itself or the soil, or both; still more, if
transported to a distance, will find the climate unsuit-
able.

But in many cases want of space is the only obstacle,
and a very serious one it is. There is generally plenty
of room for weeds in a garden, and they are not slow
to take advantage of it; for there is a good deal of
crowding on the other side of the wall, where, in fact,
a constant struggle for existence is going on, and only

Chances of Life 287

the stronger survive. Seeds falling upon ground already
covered, and thickly covered, with vegetation, as a
hedge-bank generally is, have but little chance. In fact,
they hardly reach the soil at all, the great zaajority of
them.

Look among the long meadow-grass, and you may
often see hundreds and thousands of downy seeds
caught among the stems and suspended, each with its
seed pointing downwards, ready to take advantage of
any crack in the soil in which to insert itself, but quite
unable and unlikely to reach it. And even of the seeds
which do reach it, how many must find that the first-
comers are stronger and better fitted for the situation
than themselves ! and so, even if they spring up, they
are speedily overpowered and crowded out.

This, of course, is especially the case with such seeds
as are transported long distances and to other quarters
of the world, where the chances are that they will find
the soil already occupied by natives, among whom they
will be choked. Should they find a bare spot, however,
and soil and climate suitable, they will still be unable
to do more than effect a temporary settlement—will
not, in fact, become really naturalized—unless the
plants can either fertilize themselves or find insects
able to do the work for them. In the matter of space,
those, of course, have a great advantage which grow
upon others, as fresh surfaces are being constantlv pre-
pared for them.

The number of seeds produced varies enormously in
different plants. Orchids produce them at the rate of
thousands to each blossom; and some of the foreign
species go far beyond this, a single seed-vessel con-
taining more than a million and three-quarters of seeds.

288 Chances of Life

The blossom of an oak, on the other hand, produces
but one seed. But the advantage is not all on the side
of numbers; for the greater the number, the smaller
the size; and the smaller the seed, the smaller the
germ, and also the smaller the supply of ready-made
food with which it begins life. A large seed, such asa
bean, has a large, strong germ; and its two thick seed-
leaves, which are really store-cupboards, can supply
the seedling with plenty of food, so that it starts with
much in its favour. And so ten large seeds will often,
it is said, yield more plants than some thousands of
small ones. One may also conjecture that, when an
ovary contains ovules by the thousand, or million, each
requiring the contents of two or three grains of pollen
at least, and some as many as twenty, it is not unlikely
that some will be left out, and, failing to get what they
want, will not succeed in becoming true seeds at all.

One perfect seed to each plant in the course of its
life is enough to ensure that, at all events, it shall
neither die out nor suffer any decrease in its numbers;
but while the oak will be able to hold its own if it have
but one sound acorn in the course of a few hundred
years, the chickweed must have one good seed every
year, if it is to keep up its numbers. This, of course,
is supposing that the one seed is allowed to produce a
seedling, and the seedling to grow up into a plant;
but, as much seed and many seedlings are devoured,
many more are actually required.

Neither the acorn, nor the chestnut when it has left
its shell, has anything to protect it, except its colour,
which being like that of the earth, or of dead leaves,
may sometimes enable it to escape notice as it
lies on the ground; and if but one escapes now

Chances of Life 289

and then, at long ifitervals, once in a few centuries, the
stock will be kept up, though not increased.

Small seeds have a better chance in some ways, as
they are more easily sheltered, and hidden from the
bright keen eyes of the birds. A bed of damp moss is
a capital hiding-place; and so are the cracks which
open in the soil when the earth is dry; for these close
up again when the wet comes, and the seeds are safely
buried out of harm’s way. Cracks may often be seen
full of seeds. :

Still, ‘if you want a thing done, do it yourself, is an
excellent motto even for seeds, and it is an advantage
to be independent even of cracks! This is what some
seeds are, especially a good many grass-seeds; for
instead of waiting to be buried, they set to work and
bury themselves.

The seed of the grass Aristida, for instance, is
enclosed in a couple of husks tipped with bristles, each
divided into three fine tails, six or eight inches long,
which stand out in different directions more or less at
right angles to the seed. When the seed falls to the
ground the tails keep it upright, and as they dry and
twist, they make it turn round and round on its point,
which is barbed with flint; and so it bores its way
into the earth, the barb holding it fast, so that it cannot
be blown away by wind. .

Another self-burying seed is that of one of the
Cranesbills, which is nearly related to the geranium.
The fruit of this little plant consists of four or five
miniature arrows, which are the hardened and much
lengthened carpels, each having its ovary (containing a
single seed) at the lower end. At first they are fitted
closely together round a central spike, and form the

19

290 Chances of Life

‘beak’ with which we are all familiar in the geranium.
But when they are ripe, they separate at the lower end,
and begin to twist like a corkscrew, still holding together
at the tip, however, for a time. Each arrow is fringed
on the inner side with short stiff hairs, and the ovary
is pointed and barbed in a special manner. They are
readily carried by the wind therefore, besides also
clinging easily to the coats of animals; and when at
last they drop singly to the ground, the barbs catch in
the soil and hold them fast. The shafts of the arrows
twist more and more the drier they grow, and as they
twist, they turn the seed deeper and deeper into the
ground.

Some seeds have many more difficulties in the way
of their growing than others. For with some, it is
absolutely necessary that they should be buried before
they can even begin to germinate; while others, though
they may be able to germinate without help or pre-
paration of any kind, find it by no means easy to do
more than make the first start.

With some, germination is an easy matter enough,
all that they need being a little moisture. Such is the
mustard-seed, which will sprout, and even grow for a
time, on any damp surface; a piece of flannel, or even
the outside of a porous earthenware jar will do, if only
this is kept filled with water. Other seeds begin to
shoot even before they leave the parent-plant. The
seeds of a species of convolvulus put forth quite large-
leaves before they burst the pod; and in hot climates,
the seed of the water-melon sometimes grows in like
manner, within the fruit.

Brazil nuts also begin sprouting before the hard
outer case in which they are enclosed shows any sign

Chances of Life 291

of decay; but though they may all sprout, only one of
the whole number seems to have a chance of doing
more under ordinary circumstances. There are from
twelve to fifteen nuts—or, strictly speaking, seeds—in
each ovary or case, which is filled with the matted
roots sent out by one and all. At the lower end, where
the fruit was attached to the stalk, there is a small
opening, and the fortunate individual which gains pos-
session of this exit may eventually burst the case with
its roots, and so make its way into the soil. But the
shell of the case is extremely hard, and, so far as has
been observed, it is not often that even one single
plant succeeds in freeing itself. But then, on the other
hand, if the shell were less hard, none would probably
ever escape the hosts of animals ready to devour them;
for sprouted nuts, taken out of the case and planted,
have been found to be all dug up and eaten by rats.

Such are the difficulties of the Brazil nuts; but other
seeds have equal, if different, obstacles to contend with.
Many, if they escape being devoured, are still quite
unable to grow as long as they are left lying on the
surface of the ground, especially when that surface is
covered with the leaves of the parent tree.

With the exception of the sugar-maple, none of the
forest-trees or the evergreens seem to have children
growing up round them in Indiana. Seeds of white
pines, firs, American poplars, etc., when they fall upon
the scattered leaves of the parent tree, simply lie there
and die; and their almost only chance of life seems to
be when they fall upon some little bed of earth made
by the hogs, which root about among the leaves and
turn up mould while they are searching for worms.

One would not suspect hogs of doing any useful

292 Chances of Life

work of this sort; but these animals, which have been
turned loose in the woods, do seem to have planted
many clusters of young poplars, for the age of the
trees just corresponds with the date when the pigs
were first brought into the settlement.

Other animals, such as squirrels, also give similar
help by digging through the leaves; and the hoofs of
bullocks make deep tracks in the ground, in which any
falling seeds have a fair prospect of rooting them-
selves.

A change deserving of notice has been wrought in
some parts of the Riverina, New South Wales, solely,
as it would seem, by the introduction of cattle. In the

‘old times there were not animals enough to eat the
_grass down ; and so, when it became ripe and dry, it
was easily set alight by a chance spark from the fire of
a native. The natives were, indeed, suspected of firing
it on purpose, to ensure a fresh crop to tempt the
kangaroos within their reach. Any seeds of eucalyptus
or other trees were either killed in the conflagration or
by exposure __ the weather, for they lay on the surface
of the ground, with no animal sufficiently heavy of foot
to tread them in; and it would seem that their only
hope could be in chance cracks. Trees were accord-
ingly scarce in these parts; but the scarcity evidently
arose, not from want of seed, but from want of oppor-
tunity for its growth. For all now is altered: the
cattle tread the seeds in, and don’t, apparently, eat
the young plants which spring from them ; for dense
forests and scrubs have arisen—not to the satisfaction
of the graziers, who would prefer grass alone.

Some seeds appear to have only an occasional chance
of germinating in a state of nature; for they must

Chances of Life 293

either be scalded, or scorched, or very hard frozen
before they can sprout at all, and even then they
cannot prosper unless they have a clear field, with no
other plants to interfere with them. This is the case
with the seeds of the black locust-tree, which are easily
carried by the wind, and are so very hard that they
may lie exposed for years without being any the worse
for it, it is true, but also without being able to ger-
minate. If they were less long-lived, they would
probably die before their opportunity came. But if,
when a clearing is made in the forest, the trees should
be fired and the ground burnt bare, as it is sometimes,
then comes their long-waited-for opportunity, and up
they spring in numbers wherever the fire has passed.

The same thing is true in some degree of the Tas-
manian ‘fire-weed,’ a thick crop of which springs up
like magic wherever even a camp-fire is made, but
never except where fire has passed over the ground.
The plant, which is nearly related to the groundsel and
cineraria, has downy seeds, which would not, of course,
stand the fire; but the wind is constantly carrying
them to and fro, and wherever there is a spot properly
prepared for them they take immediate advantage of
it. Numbers must perish while they are waiting for an
opportunity which never comes; but still there are
always enorgh left to take possession of any bare,
burnt ‘space.

The seeds of a certain species of cedar could not be
got to grow at all at the Cape until they had been
thoroughly loiled. Such very hard-coated seeds are
well protected against injury, but in a state of nature
they must be dependent upon fires, frost, or perhaps
on being swallowed, for the opportunity of growing.

294 Chances of Life

Other seeds, again, though they require no special
preparation of themselves or the soil, are quite unable
to germinate unless they get rain immediately after
they have fallen, and that, too, continued for some
little time.

Thus the ‘soft maples’ planted in the streets of
Rockville, Indiana, though they have borne seed, have
never succeeded in sowing themselves till within the
last few years, as a single day’s exposure to the hot sun
is fatal both to seeds and seedlings, and even daily
watering often proves insufficient to keep the latter
alive. In the wild state they spring up only in very
moist or watery places, though later on they will bear
transplanting to dry soil.

One year, however, there was a storm which shook
down such a quantity of seed that the streets of Rock-
ville were yellow with it. Then followed several days’
rain, with sunny intervals, and the seeds sprouted
everywhere, all over the streets, in the yards and the
gardens, as thick as weeds — a sight never seen
before.

But the cows ate those in the streets, human beings
weeded out those in the gardens, and.the summer
drought killed the rest; so that, of all the millions
which started into life, only one clump remains, and
these owe their survival to the fact that they are not
only out of the reach of animals, but in a damp spot
near a drain.

To be beyond the reach of animals makes, as Mr.
Darwin has pointed out, an all-important difference in
the seedling’s chance of life; and he mentions the case
of an extensive heath near Farnham, in Surrey, part of
which was enclosed, and part not. Within the enclo-

Chances of Life 295

sure multitudes of seedling trees were to be seen;
outside, none. Yet they were there, plenty of them,
striving, but failing, to get their heads above the
heather, because perpetually browsed down by the
cattle. One aged seedling, three inches high, had been
making persevering but fruitless efforts for six-and-
twenty years, so it seemed, from the number of its
annual rings; and, but for the cattle, the heath would
quickly have become a wood.

Space, as we have said, is a matter of prime import-
ance, and the reason why tropical ferns and orchids
have been so successful in establishing themselves in
the islands of the Southern Ocean is not only because
their seeds are plentiful and easily carried, but because,
as they can grow upon other plants, they are never at a
loss for vacant spots.

Bare spaces are otherwise not of frequent occurrence
in nature, except on mountains, where landslips on a
large or small scale are often taking place and exposing
fresh surfaces. These are quickly sown with seeds
either by the winds or by the birds, and hence moun-
tain chains are very common routes by which plants
travel, gradually making their way along them by easy
stages. Railway embankments, too, are turned to
similar account; and people are sometimes surprised
to see these occupied for a time by plants which are
quite strangers to the neighbourhood, the fact being
that the seeds, though scattered, have never before had
the luck to fall on a free space. Plants which thus
gain a footing may or may not be able to keep it; they
may be overpowered by the natives of the locality, but
even so, if they blossom and bear fruit but once, they
have gained an onward step, a fresh centre from which

296 Chances of Ltfe

to disperse themselves, and so they may make a gradual
advance.

How is it that European weeds have spread so ex-
tensively in the United States, while Australian seeds,
widely and purposely scattered in New Zealand, have
gained no footing ?

First and chiefly because in tne one case there was
a vacancy, and in the other there was none. The
vacancy in America was not natural, but caused by the
cutting down of forests and the dying off of the under-
growth, which was killed by sudden exposure. Of
course, there were plenty of plants in America which
would have stepped in and taken possession in time,
but they were too far off, on the plains and prairies of
the great Mississippi Valley, to do it quickly enough,
and meantime the foreigners arrived. Weeds from
Europe were introduced with grass seed and corn
seed, and in other ways, and when the forest lands
were turned into pastures and fields, these weeds had
as good a chance of thriving as they had at home.

It would be a different matter if they were to arrive
now, for meantime other changes have taken place
which have made it easier for plants to come from the
west, and they do come. New western plants migrate,
it is said, almost every year into the eastern states.

And how do these new plants travel? By rail, to
be sure, in accordance with the spirit of the age. They
come in the coats or in the food of cattle going to
market, and they take advantage of the bared railway
borders, which are such excellent nursery-grounds.
The great railroads run east and west, and as the pre-
vailing winds are westerly and very strong, the plants
of the west are now amply provided with the means of

Chances of Life 207

transport. The seeds also find vacant spots on which
to alight, and by which they may break the journey,
and’ finally they are transported into a climate not
greatly unlike their own, so that they have much in
their favour.

Plants travelling east and west have a much better
chance of finding a climate to suit them than those
which travel north and south, except, of course, such
as cannot thrive without sea air, like the holly, which
cannot live at all more than a hundred miles from the
coast. But of the plants which travel north and south,
those generally have the better chance which travel
from a cold climate to a warmer one. Increased
warmth is better borne than increased cold, and the
plants of temperate latitudes have stronger and more
vigorous constitutions, such as give them great ad-
vantages.

See, for instance, how they have thriven in the
Pampas district of South America, in some parts of
which there is hardly a native plant to be seen for
miles, so completely have the new-comers ousted them.
For the giant ‘thistles’ and the luxuriant clover already
described, are not natives, but colonists. The father-
land of the artichoke family, to which this ‘thistle’
belongs, is on the shores of the Mediterranean, and
from thence ‘thistles’ and clover were probably intro-
duced by the Spaniards. And they not only found the
soil and climate suitable, but, a still greater point in
their favour, they found the ground very scantily
occupied by native vegetation.

There had not been time to plant this corner of the
world’s farm thoroughly, for it had been under water
until comparatively recent times—recent, geologically

298 Chances of Life

speaking, that is. And when it became dry land there
were few plants and no trees at hand to colonize it.

There was abundant vegetation to the north, however,
and that of the most luxuriant kind, and most of the
early colonists came from there. But they were too
delicate to bear well the change to such much cooler
regions, and only a few managed to settle down and
really flourish; so that when the Europeans came,
strong and vigorous, they soon overpowered these
previous colonists, which-had but scantily occupied the
ground, and themselves grew in a rampant manner.
Any delicate new-comers arriving after such sturdy
emigrants as these would naturally have no chance
at all.

The air of Europe seems, indeed, to give its natives,
both men and plants, a wonderful power of pushing their
way and standing almost any climate, and they are to
be found in almost all parts of the world.

The greater the distance to which seeds are trans-
ported, the greater usually the risk they run of meeting
with some difficulty in the way of their permanent
settlement.

They may find a vacant, or almost vacant, spot,
and they may like the soil and even the climate, but
if they are dependent upon any particular insect for
fertilization they will not be able to perfect their seed
without it; and if they cannot do this they can never
become naturalized, and must needs in most cases
die out. -

The vanilla plant, introduced into the East Indies
from tropical America, thrives perfectly up to a certain
point, but cannot at present run wild; for being unable
to fertilize itself, and finding no insects to do the work,

Chances of Life 299

it depends entirely upon man’s artificial aid. In time,
_itis true, the difficulty might, and may, be overcome,
as it has been in the case of some other plants, either
by their becoming self-fertilizing, or by the insects of
their adopted country becoming accustomed to them;
but, in the meantime, without man it would die out.

Of plants which require help, those are most likely
to prosper whose blossoms are least peculiar in shape
and most easily got at. Tubular blossoms, such even
as the common clovers, require insects with trunks of
some length, because their nectar is so deeply hidden
that none but these can reach it. And insects do not
visit flowers where there is nothing to be gained.

Composite flowers, such as the daisy, dandelion,
camomile, groundsel, and many others whose blossoms
grow together in flat heads, are easily fertilized by
almost any insects; and what with this advantage and
the further one, that so many of the family have downy
seeds easily carried by the wind, composites are among
the most thriving and successful emigrants.

XX.
FRIENDS AND FOES

FRom one point of view all animals, with the exception
of a few insects, may be looked upon as enemies of the
plant-world, since they either themselves feed upon
plants, or live on others who do. But this would be a
very partial view of the matter, even where the de-
struction is complete; for it is a positive benefit to the
race that the greater number of seedlings, as well as
‘seeds, should be devoured, or otherwise removed, since
without this thinning of their numbers none could
come to perfection.

Linnzus calculated that any one annual which pro-
duced but two perfect seeds—its descendants doing
the same every year—would have increased to a million
in the course of twenty years. Now all annuals do
considerably more than this as a rule; and as they do
not increase at an alarming rate, it is evident that their
existence must in many instances be cut short, at one
time or other of their career.

Plants have many and various enemies which attack
them at different stages of their lives, but it is chiefly
while they are seedlings that they are altogether ex-
terminated, and this they are wholesale. Out of 357
seedling-weeds growing together without any crowding

Friends and Foes 301

in a small plot of ground, Mr. Darwin found that 295
were destroyed, mainly by slugs and insects.

From the point of view of the destroyed—the victims
—these creatures were undoubtedly foes ; but from that
of the survivors they were as certainly friends, for the
latter would grow up all the more vigorous for having
plenty of space.

But if slugs and insects were allowed to multiply
without check, they would become foes and nothing
else, and would end by eating up every green thing.
There ave checks upon their increase, however; and
besides this, many plants are to some extent protected
against them, as otherwise certain species might be
exterminated altogether.

Plants like the grasses, which bear vast quantities of
seed, are protected by their very numbers, and can
well afford to be eaten, if but a small proportion be
allowed to perfect and disperse their seed; but others,
less prolific, are guarded in various ways, being made
either disagreeable or difficult of approach.

The whole of the Gentian order, for example, are so
extremely bitter, that they are seldom touched even
by caterpillars; and the Eschscholtzia, which is of
another order, is also so intensely bitter as to be more
avoided by slugs and the like than any other plant, it
is said. Even Eschscholtzias are, however, a good
deal bitten at times, probably by earwigs, but this may
be owing to drought and consequent scarcity of vege-
table matter, as it is not a common occurrence. It is
at least something to be proof against certain classes
of enemies; and no plants are defended against all,
since they are intended to be eaten, though not
exterminated.

302 Friends and Foes

The bark of oaks, elms and willows, is made suffi-
ciently unpleasant to most animals by the presence of
tannin; and ferns contain so much of this that few
animals care to eat them, though they have their own
particular caterpillars.

Many plants are not merely disagreeable, but even
poisonous to mammals, though birds may eat the seeds,
and insects the leaves, with impunity; and others again
are of such a biting flavour as to raise blisters on the
tongue or skin. Some members of the buttercup
family are of this acrid nature, and the buttercup itself
is said to be avoided by cattle; but on the other hand,
the deadly nightshade, which is fatal to-man, is eaten
with impunity by the rabbit.

The Asclepias gigantea of the desert is so deadly
that the least drop of the poisonous milk contained in
its leaves and stem causes total blindness if it touches
the eye; and even those who cut the plant for fire-
wood must beware of so much as touching their eyes
afterwards, since a merely accidental rub may deprive
them of sight.

One would suppose, therefore, that the asclepias
was so amply protected as to have no enemy at all;
yet there is one upon which its deadliness makes no
impression whatever; and this, the goat, devours it
greedily, though all other animals refuse and avoid it.

Goats are indeed the most omnivorous and most
destructive of animals, and very few plants, or even
trees, are safe from them. Neither the thorns of the
prickly pear, nor the flinty ‘needles’ of young pines
and firs afford any sufficient protection against them;
and yet even the goat has its preferences, and is said
to refuse lettuce, while it will eat cabbage.

he

Friends and Foes 303

Probably each plant has its own appropriate enemy
—really a friend to the race—whose office it is to check
its undue multiplication. And one reason why plants
introduced into other lands sometimés run riot there,
and even extirpate the natives, is just this, that they
are foreigners, and that there is at first no animal to
keep them within bounds. If there had been some
common bird to eat the seeds of the wild artichoke or
‘thistle,’ for instance, when first it reached South
America, it could not have gained the upper hand so
entirely as it has done. At present the plant itself is
eaten to some extent by horses and mules, but only
when other forage is scarce, as its spiny leaves are a
great protection, and make it actually formidable to
most quadrupeds. Goats might manage it, but other-
wise it seems that birds are what are wanted to keep
it in check. Eventually, however, man may prove to
be its ‘appropriate enemy,’ and will cut and stack it,
as he has begun to do with its cousin the Scotch thistle
in Victoria, which proves excellent winter food for
cows, when thus treated, as the spines lose their stiff-
ness when dried.

Foreign plants are, nowever, sometimes at a dis-
advantage when introduced into a new country, as
they may meet with enemies unknown in their native
land; and against which, therefore, they are un-
defended. But generally speaking, foreigners are
much let alone at first, for most animals are sus-
picious of anything new and unfamiliar; and nearly
all, especially of the mammalia, far surpass us in
keenness of scent. They ‘live in a world of odours,’
most of them with their noses near the ground, always
on the qui vive to notice anything strange; and gener-

304 Friends and Foes

ally speaking, what is new and strange that they
mistrust and avoid.

This fact was strikingly illustrated on one occasion
by a bear in the Jardin des Plantes, one of certain
victims whom it was found necessary to despatch. A
bun dipped in prussic acid was offered to this bear,
and was graciously accepted; but Bruin quickly
decided that there was something not quite satis-
factory about it. He was familiar with buns, but this
was not an ordinary bun, and therefore might be mis-
chievous, so he dropped it into the water and prudently
allowed it to soak until the strange smell was
gone.

In a similar way, cattle imported and turned out to
feed in strange pastures are said usually to avoid
poisonous plants, not because they are poisonous, but
because they are strange, and therefore to be doubted.

When they have attained a fair size most plants can
well afford to have some of their leaves eaten; but if
no blossems are left the plant dies without successors,
and this, in many cases at least, is not to be desired.
Accordingly we find that, as a rule, blossoms are
avoided by all animals, including even caterpillars,
which would rather die of hunger than eat the blossom
of the very plant whose leaves are their favourite food.
Earwigs, indeed, are less particular, and are given to
biting dahlias; and whatever wild rabbits may do,
tame ones often begin with the blossom of poppies and
succory, as if it were a choice morsel.

Plants are protected against indiscriminate con-
sumption in a variety of ways: by being unpleasant
in flavour or poisonous, by the toughness and hardness
of their foliage, by prickles and by thorns, sometimes

Friends and Foes 305

of formidable size, and by hairs, whether sticky or
stinging.

Certain caterpillars are proof against the stings of
the nettle ; but as a rule this plant is very carefully let
alone; and such grasses and sedgesas are unpleasantly
wiry are also avoided by cattle, unless they are driven
to eat them by hunger. The Alpine fescue-grass is so
extremely stiff that its needle-like points prick the
noses of unwary animals, and no doubt in this way it
escapes being eaten; but, on the other hand, it is ex-
terminated wholesale by the herdsmen of the Alps,
who burn it where it occurs in large quantities. In
the ordinary course of nature, however, where man
does not interfere, it is no doubt very effectually pro-
tected.

Prickles and thorns are among the most efficient
guards a plant can have, and are often positively for-
midable weapons of defence. One has only to think
of the strong, stout thorns of the rose, and the long,
sharp ones of the gooseberry-bush to realize that it
would be dangerous for any animal to attempt to make
amealofthem. The sharp little prickles of the rasp-
berry, too, must make it, one would think, anything
but pleasant eating to most creatures, though donkeys
will munch raspberry-canes as well as thistles.

But all these small thorns, sharply as they can
wound, are a mere trifle compared with those which
protect many foreign plants and trees until they have
grown beyond the reach of cattle. There is a palm,
for instance, in Ceylon, whose trunk is covered for the
first six or eight feet with a coating of thorns so closely
set together that the bark is hardly visible; and there
is also a climbing plant, very common in the jungles,

20

306 Friends and Foes

which is thickly studded with knobs, each ending ina
thorn as large and sharp as the bill of a sparrow-hawk.
Even the tough hide of the elephant is not proof
against the ‘jungle nail,’ or ‘ elephant thorn,’ an acacia,
whose lancet-like spines—which frequently grow, not
singly, but in branching clusters—make any forest
where it abounds absolutely impassable.

The buffalo thorn, or bull’s horn acacia, is interest-
ing in another way. Its trunk and branches are beset
by strong thorns two or three inches long and as sharp
as needles, which grow in pairs, and are shaped just
like horns. But, as if this were not enough to ensure
its safety, the tree maintains as well a standing army,
which keeps off all aggressors, large and small, at
least during the wet season, for then every thorn is
tenanted by ants, which rush out and sting severely
any animal venturing to touch the tree.

Caterpillars, which might make their way between
the thorns without injury, have no chance against the
ants, and even their own rapacious relations, the leaf-
cutting ants, are completely battled.

The ants of the buffalo thorn are not to be found
in the forest, or, indeed, anywhere except on this par-
ticular acacia, which belongs especially to the dry
plains or savannahs of Central America. When the
‘horns’ are first put forth they are filled with a soft,
sweetish pulp, which the ants hollow out, burrowing
between the partition which separates them, and thus
making a single dwelling of each pair. The thorns do
not suffer in any way from this treatment, and continue
to grow until they have reached their full size.

But the ants do not frequent the trees for the sake
of comfortable lodgings merely. They want, and find,

Friends and Foes 307

food as well. At the base of each pair of young
leaflets there is a gland, which contains a liquid some-
thing like honey; and, besides this, the young leaves
bear what are described as ‘minute golden pears,’
small, sweet protuberances, which ripen in succession
and need constant examination. These two delicacies,
their sole food, the ants are always ready to defend,
and during the wet season hundreds of them may be
seen running about on the young leaves, which are
thus kept clear of all enemies for some time after they
unfold.

Many other plants (among them being many orchids
and passion flowers) are similarly defended in the
tropics of both east and west, the ants rushing out
and biting the finger of anyone touching them; and
though they have their disadvantages, when, as in the
case of the trumpet-tree, they choose to keep ‘ cows’
—scale insects which suck the juices of the hollow
stem within which they live—still, it is evident. that in
other instances their guardianship is not only valuable,
but positively necessary. This was clearly proved in
the -case of some acacias raised in a garden in St.
Domingo, Nicaragua, which were cut to pieces by the
parasol ant simply for lack of their natural defenders.
For St. Domingo is situated in the midst of forests,
and the ants which protect the acacia are never found
within their precincts, or, indeed, anywhere but on the
savannahs.

This parasol, or leaf-cutting ant, is one of the worst

nemies of vegetation in tropical America, where it is
called the curse of the country, owing to the damage
which it inflicts on the crops. It may bea friend in
disguise to the wild crops, by preventing their too

308 Friends and Foes

great increase, and its services in the past in burrow-
ing and tunnelling and in adding to the organic matter
of the soil must not be forgotten; but at the present
day the farmer can hardly look upon it as other than
anenemy. It is the cultivated plants of foreign origin
which it especially attacks, for very many of the natives
are protected against it in one way or other, while the
foreigners are undefended—a good example of the
risks sometimes run in this way by colonists.

The Indians defend their trees by a very simple
device, that of fastening thick wisps of grass with the
sharp points turned downwards round their stems.
The multitude of points quite baffles the ants, and
prevents their climbing further up. Orange-growers
plant their young trees in the centre of ring-shaped
earthen vessels, which are kept filled with water, and
answer one of the purposes of the natural ‘ basins’ of
the teasel and other similar plants.

In some parts of America orange-trees have run
wild, and have formed thickets, in spite of the ants;
but, generally speaking, all the species of the citron
family—the orange, lemon, etc.—except the lime,
would be very quickly destroyed if they were left
without the help and protection of man. The lime
has run wild, and seems to be less liked by the ants
than the orange and lemon, whose leaves they ‘cut up
into sixpences’ when they have the opportunity, leaving
nothing but rags behind them. They are terrible
enemies to young plantations, nurseries, and gardens;
but they greatly fear the small ants which protect
certain plants.

The agricultural ant of Texas occupies a different
position from that of the leaf-cutter, for she is really

Friends and Foes 309

an agriculturist on her own account, and the only one
in the animal world, so far as we know. She is no
more an enemy to vegetation, therefore, than the
farmer who cuts down ‘bush’ that he may grow
wheat, for she does a precisely similar thing.

It is unfortunate for the farmer, of course, when her
‘bush’ chances to be his corn or sweet potatoes,
which she cuts down as ruthlessly as he does scrub;
or when she decides that his young fruit-trees must be
stripped of their leaves because they keep off too much
of the sunshine from her domain. But she does not
plunder his crops for food, and she does grow and tend
and reap crops of her own as regularly and carefully as
he does himself.

For this purpose, at least partly, she makes circular
clearings some ten or twelve feet in diameter, some-
times in rough, wild pasture, sometimes in the middle
of the farmer’s fields; and she clears away his cotton,
or corn, just as impartially as she does. the weeds, for
-to her they ave weeds. Considering her size, her
labours are truly herculean, for she cuts through, with
her teeth, stems as thick as a thumb; and by dint of
sawing, twisting, pulling, biting, she clare everything
away, no matter how rank the growth. And this is
not all, for the space is not only cleared once, but kept
clear till the ‘ant-corn’ has ripened—a matter in-
volving no small labour where it is surrounded bya
dense growth of weeds always ready to encroach.

The crop consists of a tall, yellowish grass, and not
so much as a blade of any other species is allowed
among it. It ripens about the end of June, when the
seed is cut from the stalk and carefully stored. That
which falls of itself to the ground is not harvested, and

310 Friends and Foes

it is probably from this that the next year’s crop
springs, though some have declared that the ants
actually sow as well as reap. Harvest over, the dry
stubble is cut and cleared away, and weeds are left to
grow as they will during winter, the work of cutting
them down beginning vigorously again in spring.

These ants live chiefly on grass seeds, which they
gather from a distance as well as from the home crop;
but though they do not steal food from the farmer,
they inflict much injury on his fields, and destroy many
an acre of produce, no amount of ploughing being suf-
ficient to drive them away.

It is impossible even to enumerate the many animals
which feed upon plants, and, when allowed to increase
unduly, become the enemies instead of the friends of
vegetation, not merely checking overcrowding, but
destroying wholesale.

We cannot attempt any description of the devasta-
tions caused by locusts, one of whom is reported by
Mahomet to have remarked, ‘ We are the army of the
great God; we produce ninety-nine eggs. If the
hundred were complete, we should consume the whole
earth and all that is in it.’ Nor can we tell of the
ravages of the American crickets, which eat up a whole
crop of maize in a night; or of the caterpillars, which
would completely destroy the tobacco plantations if
not constantly picked off leaf by leaf; or of the minute
beetles, whose grubs, penetrating between wood and
bark, destroyed in 1780 and the following years a
million fir-trees in the Harz mountains and Switzer-
land, 50,000 trees, chiefly oaks, more recently in the
Bois de Vincennes, and are causing avenues of fine
elms to disappear in the north of France. Green fly,

Friends and Foes 311

scale insects, slugs, wireworm, grubs, and the various
other plagues known to the gardener and agriculturist
must also be passed over, and we must go on to
consider by what natural means these various creatures
are kept in check and prevented from becoming positive
enemies to all vegetation, instead of merely thinning
the ranks, to the advantage of the survivors. —

For, when one reads of flights of butterflies which
take days and weeks to pass, of armies of caterpillars
which stop the progress of railway trains, and of
dense clouds of locusts several miles long, it is quite
evident that unless their increase were restricted by
some very efficient means they would all more than
justify the locust’s boast, and leave not so much as a
blade. of grass.

Man is utterly unable to cope with them by any
means at his present disposal, and when he interferes
with nature’s way of keeping them within bounds, he
learns by hard experience his own utter helplessness,
and often not till then.

In the Middle Ages people seem to have had the
feeling that they ought to be able to control grubs and
the like, by the mere word of command, and the
chroniclers of the time often give reports of the law-
suits instituted against these creatures. In 1479, for
example, the canton of Berne was troubled with such
an overwhelming plague of grubs that the Council
petitioned the Archbishop of Lausanne to banish them,
and the priests were authorized by him to doso. In
accordance with the usual custom on these occasions,
advocates were appointed for both parties—the grubs
and the people. A written summons was issued ; the
grubs were cited to appear, and some were brought

312 Friends and Foes

into court; but they were not fairly treated, as the
advocate assigned to them was no longer living, and
judgment was given against them in these terms:
‘We, the Archbishop of Lausanne, condemn and ex-
communicate ye obnoxious worms and grubs, that
nothing shall be left of ye except such parts as can be
useful to man.’

No steps seem to have been taken, however, to give
effect to the sentence, and the grubs obstinately
ignored it.

But if the Council could have imported a few
hundreds of small birds, they would most likely have
been quickly rid of the plague; for these, and these
alone, are the natural and most effectual provision for.
keeping the numbers of grubs, caterpillars, and the
like within their proper limits.

XXI.
NATURE’S MILITIA

‘IF nature’s militia, the army of birds, be killed, it will
be impossible to find a substitute for their faithful
guardianship.’

‘Birds are nature’s soldiers, and keep in subjection
the inferior animals. Their other uses are scarcely
worthy of notice compared with their labours in the
destruction of insects.’

Wise words, which cannot be too often insisted on;
for though we are beginning to wake up to the immense
value of the feathered tribes as guardians of our fields,
we are still only beginning; and, unfortunately, farmers
and gardeners, the very persons most interested, are
precisely those whom it is most difficult to arouse.

They know well enough, of course, that insects,
generally speaking, are their enemies; but they do not.
yet recognise, as they ought, that the birds are their
friends, who, if only let alone, would save the crops
from these marauders.

A plague of grubs finds us, in fact, just as helpless as
our forefathers in the Middle Ages, and almost more
hopeless, for we no longer believe in trying to ‘banish’
our enemies, and we have not yet discovered any more

314 Nature's Militia

effectual means of dealing with them. When the in-
fliction comes, we talk mysteriously of ‘blight’ and
‘weather’; and it seldom occurs to us to connect the
increase of grubs with the destruction of birds, even
though we must know, as a matter of fact, that the
latter live mainly upon the former, and that therefore
for every bird killed, so many grubs must be left
alive.

However, as before said, we are beginning to wake
up, and in some cases the awakening has been so rude
that further slumbers are almost impossible.

It is now some thirty years since piteous complaints
were rife in Germany and Switzerland of the alarming
increase in the number of destructive insects, which
made their appearance in overwhelming swarms, and
inflicted the greatest injury on the fields. And at last
it occurred to the authorities that insects had multiplied
because birds had to so large an extent vanished. The
‘militia’ had, in fact, been either killed off or driven
away; they had been destroyed in the most insane
manner, in ignorance and sheer wantonness; and also
they had been ‘improved ’ away by the spread of agri-
culture. In whatsoever way it had come to pass, the
result was the same—there were fewer birds, there
were more grubs; and as the latter increase much
more rapidly than the former, the prospect was a
dismal one. The land was being devoured.

And it was devoured, partly at least, because more
had been taken into cultivation. For woods and
thickets and groups of trees had been cut down to
make way for fields; and land being precious, hedges
were considered an unnecessary extravagance. There
are, of course, still extensive woods and forests in

Natures Militia 315

Germany, but one may travel many a long mile without
seeing any of the hedgerows with which he is familiar
in England. The fields are for the most part one large
expanse, without any bordering of trees or bushes.

But it is quite possible to be too thrifty. If every
foot of land is occupied by crops, where are the birds
to build their nests? Most of them need more shelter
than is to be found upon the ground, and if they cannot
find it in one place they are obliged to look for it in
another. Ifthe farmer will not spare them a few trees
and bushes, they are compelled to desert his fields and
leave them unprotected.

But this is not all. Grubs, as well as birds, find
shelter in the hedges; and not only shelter, but food.
When the birds are driven away, therefore, the grubs
are driven away, too; but, alas! while the birds
migrate to a distance, the grubs are only driven out of
the bushes and hedge-plants, where they are compara-
tively harmless, into fields, orchards, and gardens,
where, in the absence of the ‘ militia,’ they run riot as
they will.

We see, indeed, the

s. . hedges all alive

With birds and gnats, and large white butterflies,
Which look as if the May-flower had caught life,”
And palpitated forth upon the wind.

We sce; but perhaps we hardly realize that if the
hedge be cut down its population will find quarters
elsewhere ; and that while the birds betake themselves
to the nearest thicket, perhaps some distance off, the
butterflies and moths will simply flit a few yards, many
of them being quite content to supply their offspring
with cultivated plants when they cannot get wild ones.
Somewhere or other they must and will lay their eggs

316 Nature's Militia

—if not in the hedgerow, then in the garden; and the
grub of the white butterfly is, as we all know, able to
make quite a decent living upon cabbage-leaves.

That there should be trees and bushes, with their
usual undergrowth of wild plants, in the neighbourhood
of cultivated land is therefore a double advantage: the
grubs are supplied with food, and kept away from the
crops; and the birds, the grubs’ natural enemies, are
attracted, and keep down their numbers.

But the larger the area of land cultivated, the smaller
the space left to nature; the more fields, the fewer
thickets ; the fewer wild crops to feed the grubs, the
fewer nesting-places for the birds. And thus the mere
fact that more land had been taken into cultivation
would alone be enough to account, in some dégree, for
the marked increase in the numbers of Germany’s
insect enemies.

But this was not all, or nearly all. Not only had the
grubs been driven into the fields, and the birds driven
out of them, but the latter had been killed wholesale.
Government keepers were actually under orders to
destroy the woodpeckers, whose special office it is to
rid the trees of beetle-grubs, and the cuckoos, which
devour the hairy caterpillars which no other birds will
touch, and so on.

And the Germans have not been the only, or even
the chief, offenders. They have killed their own birds,
and have suffered for it. But the Italians have done
worse ; for they have waged deadly war upon the birds
which are the common property of Europe. They have
a perfect mania for slaughtering small, insect-eating
birds, and unhappily they have special opportunities of
gratifying it, as large flocks of migrants pass through

Nature's Militea 317

this, to them inhospitable land, every year on their
way to and from the south. Considering the way in
which they were received, one wonders why they did
not choose some other route; but the force of habit
seems to be too strong for them, and their ranks have
been thinned year after year in the most fatal manner.
Not even the swallows were allowed to pass un-
molested ; for to catch them, by floating hooks baited
with flies in the air, seems to have been considered a
particularly fascinating pastime.

For months the chief delight of the population was
in catching birds, and several million were killed regu-
larly each autumn in the neighbourhood of Verona
alone. Larks are among the most useful of the
insect-eating birds, and so entirely harmless that
even the farmer has no fault to find with them. Yet
neither their usefulness nor their harmlessness were
sufficient to save them from persecution. Unluckily
for themselves, and we may add, for Europe, they had
‘chosen Sicily as one of the places at which to break
their journey, and they could hardly have done worse.
The Sicilians knew when to expect them, for they
came regularly every autumn, nearly a million arriving
daily for ten days, and they gave them a warm recep-
tion. Hundreds of the population went out to meet
them, armed with guns, and there was a regular
battue. How many were slain history does not say,
but the numbers must have been very great. They
did not die unavenged, however ; for every lark killed.
left so many more insects to ravage the crops; and
when people woke up enough-to put two and two
together, and to connect the plagues of insects with
the destruction of the ‘militia’ which should have

318 Nature's Militia

kept them under, measures were taken to check the
persecution.

To some extent birds are now protected in Europe ;
but we do not seem to have learnt our lesson even yet,
for a cry that the birds are being exterminated is now
making itself heard in Asia, Africa, and America. The
war carried on against them in India, is already having
very serious results; the swamps and marshes of
Florida are being depopulated ; Guinea is being de-
spoiled of its birds of paradise, and birds of bright
plumage are becoming more and more rare everywhere
all over the world.

And why all this slaughter? Not because there is a
famine in the land, and the birds are needed for food ;
not even for the sake of ‘sport’; but because the
fashionable ladies of Paris, London, and Vienna re-
quire the sacrifice of at least thirty million birds every
year, that they may decorate themselves with feathers.

In India, which furnishes hundreds of thousands of
skins every year, insect life is rampant beyond any-
thing that we have experience of, and is ‘only kept
within bounds by the utmost effort of all the checks
provided by nature.’ The ‘ patient, unpaid labour of
the useful small birds’ is the one only remedy for the
insect epidemics to which the empire is liable, and it
is sheer madness to allow them to be killed off.

We must hope that the ‘Indian Wild Birds’ Protec-
tion Act’ will at least check the slaughter, for, if it be
allowed to go on, it can have but one result, and the
birds will be avenged here, as they have already been
in Europe. When once they are gone, no artificial
substitutes can by any possibility make up for them.
One may syringe the fruit-trees, cover the gooseberry-

Nature's Militia 319

bushes with road-dust, pay regiments of school-children
to gather grubs by the quart, try in fact all the various
expedients which have ever been resorted to, and yet
find in the end that it is simply impossible to overtake
the damage caused by the absence of the birds, with
their marvellously keen sight and extraordinary appe-
tites.

Let us consider for a moment one single fact. Mr.
Darwin found that scarcely more than a sixth part of
his seedlings survived the attacks of slugs, snails, and
insects. But what does this mean? Only this, that
if the numbers of the enemy had been increased by so
much as a sixth, there would have been no seedlings
left alive at all.

One additional slug or caterpillar to every five would
positively have destroyed the whole crop, even in
England, where there are many hedgerows and many
birds, and where insect life is not anything like as
abundant as it is in warmer latitudes, such, for instance,
as certain parts of the United States, where railway-
trains are from time to time brought to a standstill
by armies of caterpillars or grasshoppers a foot
deep. ;

It is difficult to realize, or even to form a faint idea
of, the numbers of insects, or the extraordinary rapidity
with which they multiply; for the figures which are so
easily quoted are ‘like the distances of the heavenly
bodies, too great for comprehension: nothing equals
them except the incredible appetites of the insect-
eating birds.’

Take, for example, the common house-fly, one of
which is said to have 21,000,000 descendants in the »
sourse of a single summer, or would have, if all

320 Nature's Militia

were allowed to live. That we do not have a yearly
plague of flies is due solely to the vigilance of the
birds.

Look, again, at the country about Torgau on the
Elbe, where, a few years ago, birds were so scarce that
a large sum was spent yearly on the destruction of
grubs and caterpillars, to save the forest from utter
ruin; yet all that human ingenuity could devise was
quite inadequate; 800 acres of fir were entirely
stripped one year, and at the same time so much
grass was devoured that it was necessary to import
hay. In Hesse, too, all efforts to deal with a similar
plague of caterpillars were equally vain; and it was
noticed that they were especially destructive where
there were few trees. to divert their attention and
to attract the birds.

The shrew-mouse, hedgehog, mole, lizard, frog, toad,
bat, and some of the beetles, are all excellent insect-
hunters, and the wasp and ichneumon-fly do good
work against caterpillars. But though their services
are valuable, the birds do more than all besides, each
kind in its own especial department. Some pick
insects, or their eggs, from the leaves, others from the
bark; some dig them and their chrysalids from the
earth, others catch them as they fly.

And what quantities they devour! for their digestion
is very rapid, and whereas human beings require only
a few ounces of dry food a day, they swallow a quan-
tity which is equal to their own weight. Think of it!
—the weight of a bird in insects; green flies, for
instance.

One redstart, kept in a room, has been known to
eat 600 flies in an hour; and one blackcap has cleared

Nature's Militia 321

about 2,000 green-fly from the rose-trees in a green-
house in the course of a few hours.

The titmouse is another most active little bird,
constantly engaged in the hunt for food, creeping into
rolled-up leaves, and devouring by the thousand eggs
which would produce many more hairy caterpillars
than the cuckoos could dispose of. As an example of
the invaluable services which it renders in effecting a
clearance of these, we may mention a garden whose
trees one year were entirely stripped by caterpillars.
In the autumn millions of eggs were seen on the
trunks and branches, and an attempt was made to
clear them off at considerable expense, but was soon
given up as hopeless. It seems strange that: man
should have to acknowledge himself defeated by any-
thing so fragile as a butterfly, but so it was. How-
ever, the birds came to the rescue. Twenty pair of
titmice, as well as some wrens, came and built in the
garden the following spring, and that summer the
trees suffered much less. By the year after, the plague
was so thoroughly under control that they remained
in full leaf the whole season.

The wren, like the titmouse, is perpetually eating,
and feeds her young thirty-six times in an hour; the
cuckoo, too, eats all day long, every five minutes or so,
and devours about 170 good-sized caterpillars in the
day; and as each of these caterpillars, if allowed to
reach the butterfly state, might lay some 500 eggs,
every cuckoo rids us of a possible 85,000 odd cater-
pillars daily !

And the work goes on vigorously in winter, as well
as in spring and in summer, for, with all the vigilance
of the birds, caterpillars and grubs innumerable escape

az.

322 Nature's Militia

and pass into the chrysalis state, which they spend
—as much of it as they are allowed—in cracks
and crannies, in sheltered nooks, on twigs and trunks
of trees, on palings and walls, and in the ground.
These supply food to the many insect-eating birds
which do not migrate; and but for the unceasing
labours of these stay-at-homes we should be over-
run with insects in the spring, in spite of all that is
done in the summer; for each chrysalis devoured
saves us from some hundreds of grubs or caterpillars
later on.

From all this it must be sufficiently plain that with-
out the birds every green thing would be devoured.
Yet to talk of the ‘ patient, unpaid labour’ of the birds
is a trifle absurd, for their ‘labour’ is its own reward,
and consists in picking up food for themselves and their
families; and it is incéssant merely because they and
their nestlings are always hungry—a most fortunate
provision of nature ; for does even the most ardent of
bird-lovers flatter himself that they would devote them-
selves to clearing his trees of grubs if they lost their
appetites ?

If anyone needs proof of what would certainly follow
the extermination of the birds, he need only look at the
island of Jamaica, where they are at present very scarce,
having been killed off, chiefly to adorn ladies’ bonnets.
It must be remembered, too, that while birds multiply
only by tens, insects increase by hundreds, by thousands,
and by tens of thousands, in a single season, so that
although the birds are now protected in Jamaica it will
be long before the loss is made good. Meantime they
are terribly avenged; for the island suffers from a
disgusting and grievous plague of ticks imported with

Natures Militia 493

cattle, which swarm upon every leaf and blade of grass,
except on the higher hills.

To make matters worse, too, the mongoose was
imported a few years ago, and, like sundry other
importations, has proved a dismal failure. The idea
was that it would kill off the rats which so swarmed in
the sugar-plantations as to be a great nuisance to the
planters. And the mongoose began well; but when
its numbers had increased, as they did enormously, it
‘began to vary its diet of rats by eating the eggs of such
birds as build on the ground, and then it went on to
eat the birds themselves, and even poultry, besides
killing off all the lizards and snakes, which were not
only quite harmless but most useful as insect-eaters.
In one way and another, the ticks were thus delivered
from their natural enemies, and now have things pretty
much their own way, and seem likely to have for some
time to come.

Jamaica has given birds for ticks, and the Isle of
Bourbon made an almost worse exchange, for it gave
birds for grasshoppers. A price was put upon the heads
of the swallows, and they disappeared; but in their
stead came grasshoppers in such overwhelming swarms
that they took entire possession of the fields and
devoured everything. And the mischief did not stop
here—there was worse to follow; for when the green
things were destroyed, the island became a prey to
scorching, biting drought. So dangerous is it to inter-
fere with the wise arrangements of nature, so utterly
impossible for any human contrivances to take their
place.

In sandy deserts, birds are naturally almost wanting,
for there are few trees or bushes, and little vegetation,

324 Nature's Militia

of any kind, either to give them shelter or to need their
protection. But itis here that the very worst of insect-
plagues are hatched. Locusts lay their eggs in the hot
sand, and there seems to be no appropriate enemy on
the spot to reduce their numbers. As soon as tuey
take to flight, indeed, which they are compelled
to do for the sake of food, they are followed and set
upon by flocks of birds, but their numbers are
then so large that they are masters of the situa-
tion, and devastate any district upon which they
settle.

It is, nowever, only when they come down upon
cultivated lands that we hear of their ravages, and
since, as before said, cultivation in most cases diminishes '
the number of the trees and with them of the birds, it
is perhaps a question whether, in a state of nature, the
birds might not even then be fairly a match for them.
They seem to be so, at all events, in the Khivan oasis
of Turkestan; for though the locusts arrive there in
clouds, often several miles long, they are at once set
upon by multitudes of small birds. But then Khiva
abounds both in birds and in planted groves, and its
inhabitants apparently know better than some Euro-
peans the value of their defenders.

However, there are probably few people in the present
day who would seriously dispute the value of such birds
as live upon insects only. It is when we come to mixed
feeders, such as the sparrow and the rook, that opinions
are divided.

A fierce battle rages round the sparrow. He is
accused of stealing corn and fruit, and of. heartlessly
destroying crocuses for the sake of the unformed
seeds. In some districts he is persecuted without

Nature's Militia 325

mercy and leads the life of an outlaw. Sparrow clubs,
encouraged by the farmers, kill him by the thousand
and destroy his nests.

That he is mischievous no one can deny, and that
he sometimes does serious damage must be admitted
even by his warmest admirers. But if we cannot have
our crops without paying toll upon them, it seems
better to share with the sparrow than lose all to the
grub—the only choice, according to some, which lies
before us.

The sparrow’s friends, the naturalists, say that each
sparrow actually saves a bushel of corn, for he himself
lives for nine months of the year almost entirely on
grubs, while his family eat absolutely nothing but
insect food as long as they remain in the nest. One
pair of sparrows, it is said, take 4,300 grubs or other
insects to their young in the course of a week; and that
they are the deadly enemies of the cockchafers, which
have done a million pounds’ worth of damage to the
crops in Normandy, is evident, for the wing-cases of
700 cockchafers have been found under a single nest.

Finally, we are told that caterpillars to the number
of 354,375,000,000 are eaten by sparrows every year,
and that while we see the damage which the sparrow
does during three months of the year, we do not see
how hard he works for us during the other nine, or
what far greater damage heavertsfromus. Wegrudge
his wages, in fact, simply because we do not under-
stand how vast are his services.

But a few facts are worth many arguments. Let us
see what has followed the expulsion of the sparrow in
one or two cases. Frederick the Great of Prussia
waged war against the sparrow, and—he was defeated,

326 Nature's Militia

ignominiously defeated, and he had the good sense to
own it. The king liked cherries, and the birds liked
them too; and he gave orders that the sparrows should
be driven away, exterminated, got rid of. And he was
so well obeyed, that in two years’ time there was not a
sparrow left in the neighbourhood. So far he was the
victor, for he had certainly vanquished the birds; but
he had overreached himself, for instead of having more
cherries he had none !

There were no cherries at all that year; worse still,
there was no fruit of any kind, but in its stead a hideous
crop of caterpillars, which had stripped the trees of ©
their leaves. Other birds besides sparrows, of course,
eat caterpillars, but the means used to get rid of the
sparrows had frightened these others away also. The
orchards had been deprived of their guardians, and the
enemy had taken possession, and before matters could
be set right sparrows had to be imported, at consider-
able expense; for they would never, it is said, have
returned of their own accord, as they are not given to
wandering.

Take another instance. In Hungary, as elsewhere,
sparrows are given to stealing corn, and they were
outlawed in consequence. But in a short time it was
found that the people were in danger of perishing by
famine, owing to the frightful increase of insect-plagues.
The decree against the sparrows was hastily revoked,
for they, and they only, could keep down the beetles,
and the thousand winged insects of the lowlands.

Then again, in the spring and early summer of 1888,
there was an almost unprecedented attack of maggots
in the Kentish orchards, and in many cases the nut
and apple crops were grievously damaged, if not

Nature's Militia 327

destroyed. Vigorous efforts were made to fight the
enemy, but all was in vain, and the terrible and unusual
increase in their numbers was ascribed by some of the
wiser farmers to the wholesale slaughter of sparrows.

Of course sparrows, as well as chaffinches, bullfinches,
linnets and others, eat some amount of grain (though
not necessarily the farmer’s), especially when insects
are scarce; and sometimes, no doubt, they take more
fruit than the owner cares to spare them. Nothing is
perfect ; but without the birds there would be no crops
at all, which would surely be the greater evil; and
besides eating as much insect as vegetable food during
the summer, which even the grain-feeders do, it is also
a fact that the seeds which they chiefly eat are those
of wild plants producing such superabundant crops,
that they would overrun and choke other vegetation, if

‘there were not some check to their increase. No less
than 321 chickweed seeds, for instance, were found in
the crop of one sparrow.

Other birds eat large quantities of burdock, plantain,
groundsel, and thistle-seed ; and without their help we
can see, from the state of things in Australia, how
rampant and unmanageable these plants, with their
easily-dispersed seeds, might become.

Pigeons are the only birds which live on nothing but
vegetable-food ; yet the wood-pigeon is now recognised
as such a valuable servant in Belgium, from its habit
of eating the seeds of the poppy, spurge and others,
which no domestic animal can touch, that it is strictly
preserved. Where such seeds are not to be had in
sufficient quantities, no doubt the pigeon makes up for
it by stealing peas and corn, but the Belgians seem to
have made up their minds that it is better to run the

328 Natures Militra

risk of having to pay occasional toll to the pigeons,
than to have their crops choked with weeds.

In this chapter we a-e necessarily considering
‘nature’s militia’ chiefly as they affect the crops of
farmer and gardener, for it is here that we are best able
to see their work; and from what they do in field and
orchard, we are able to form some idea of what their
work is in the uncultivated fields and woods of the world.

It is only when the birds come into contact with
man that any doubts as to their usefulness can possibly
arise, and even here, in that part of ‘the green world’
which he has taken into his keeping, we are learning
more and more to see that they are not only useful,
but actually indispensable.

With the exception of the flying insects which carry
pollen from flower ‘to flower, there are few insects in
any part of the world which are not the enemies of
those who cultivate the soil, though, like prairie-fires,
they have their uses where nature is sole farmer, and
it would be rash indeed to say that any, even of the
worst, could be entirely dispensed with. But insects
in excess, which we most certainly should have if the
* militia’ were withdrawn, would change the world from
‘green’ to brown, and cause a general famine. And
the question before us is: will we share with the birds,
or have all devoured by insects ?

A few words as to what in temperate latitudes may
be regarded, perhaps, as the farmer’s three worst
enemies — cockchafers, daddy-long-legs, and click-
beetles or skip-jacks. It is in the grub-state that most
insects are chiefly mischievous, for this is their grand
eating-time; eating is then their sole business, and
they eat for their whole lives. For when they get

Nature's Militia 329

their wings they usually want so little food, and that
of such a kind that no one can grudge it them. A
caterpillar eats leaves, for instance, and devours them
greedily, whereas a butterfly takes but a sip of nectar,
the loss of which is no injury to even the most delicate
flower. Yet, as the winged insects lay multitudes of
eggs, they cannot be called harmless, and some few of
them even do a good deal of eating on their own
account. Cockchafers, for example, eat leaves, and
sometimes strip whole woods, while their grubs devour
roots. Daddy-long-leg grubs (turnip-fly) are equally
destructive, and so terribly hardy that they thoroughly
deserve their name of leather-jackets. For they are
very little affected by weather, and may be frozen stiff,
or lie under water for a couple of days, and yet be just
as lively as ever afterwards. Insects, indeed, often
take a great deal of killing, and will live through frosts,
especially in the chrysalis-state, when the poor birds
perish by hundreds.

As for the grub of the click-beetle, its very name is
enough to make a farmer shudder, for, as the wire-
worm, it is only too well known. For five whole years
it remains a grub, eating all the time. And it will eat
almost anything in the way of vegetable-food, turnips
as well as sprouting corn, or hops, and grass-roots as
well as any of these. Where the young corn is strong,
it will sometimes recover from having its first shoot
eaten off just below the ground, and will even send up
two or three shoots instead of one; but when the plants
are weak, as they often are on light, chalky soil, there
the wire-worm destroys sometimes the half, and occa-
sionally the whole, of a crop.

To help him in the perpetual war which has to be

330 Nature's Militia

waged with these three special foes, the farmer has
friends—the sparrow again, and the rook, jackdaw,
magpie, jay, all the smaller birds of prey, in fact, and
many of the larger; and besides these, he has the
stoat, weasel, mole and hedgehog, which last, though
much persecuted, is most useful, and quite inoffensive.

The battle about the rook is only less fierce than
that about the sparrow, but while it is no doubt true
that he does uproot some plants in his search for grubs,
that he does steal a little corn, and that, when inseets
are scarce, or rooks too many, he even attacks the
crops, still, where rooks are poisoned, wire-worm
increases and crops fail. One rook will have as many
as three dozen daddy-grubs or click-beetles in its crop
at once, and the birds go over the ground yard by yard
in the most systematic manner, working from early
dawn till evening, each bird catching, it is said, at least
fifty wire-worms in the day.

In some parts of the country the rooks are often
joined at their work in the furrows by large flocks of
gulls, titmice and others, which appear when ploughing
begins, and go away when the furrows are cleared,
without taking any pay from the farmer, except in the
shape of the insect-food which he is glad to be rid of.

Other very useful binds, which must be passed
over with a mere mention, are the various species of
plover, the partridge, and the pheasant—a couple of
which will eat 1,500 wire-worms at a meal—the thrush
and the landrail, both of which clear the fields of
snails and slugs, and the swallow, martin and swift,
without whom the air would be so choked with flies as
to be simply unbreathable.

So much, then, for the services, the incalculable

Natures Militia 331

and indispensable services, of the ‘ militia.’ We have
seen something of these, and we have seen, too, how
surely punishment has followed where the birds have
been exterminated; but there is a word or two to be
said on the other side of the question.

It is very rash for man to interfere with nature by
exterminating any one class of the labourers employed,
whether in the tilling or in the protection of the fields,
cultivated or uncultivated ; but, at the same time, it is
hardly less rash for him to interfere in the other direc-
tion, and to encourage these same labourers overmuch ;
or even, because they are found useful in one part of
the world, to conclude hastily that they must be equally
useful in another.

Thistles do not overwhelm us, and swamp other
vegetation, in Europe; but he was a very rash man
who imported a sack of thistle-seed into South
America and scattered it broadcast about Valparaiso,
with an idea of providing useful fodder for cattle!
The thistle took to the soil and climate amazingly,
and having nothing to check its increase, as it has at
home, quickly spread over large tracts of country, to
the great inconvenience of the cultivators.

Then, someone may be inclined to say, why not
import birds to eat the seed? But things in nature
are so exactly balanced that even this step would
probably be found to have its disadvantages, and
possibly the birds might turn out to be even worse
than the thistles. The sparrows imported into the
United States, for instance, and at first petted and
made much of, have so thriven and multiplied that
they are now a pest, and generally hated. But the
mischief is done, and is not to be so easily undone.

990 Nature's Militia

They, like the thistles, have had things their own
way, for, as there were no sparrows in these parts
before, naturally no special checks to their undue
multiplication had been provided.

In Europe these checks have been provided; but
here, again, man has too often interfered with the wise
arrangements of nature, and when he has disturbed
the balance and brought upon himself a plague of
sparrows and other small birds, then, instead of
blaming his own want of foresight, he proceeds to
wage a war of extermination on these offenders, only
to find himself eaten up with grubs a little later.

Of course, if sparrows and other small birds are
allowed to increase until there are not grubs enough
to feed them, they will naturally take whatever else
they can find. But it is unfair to blame the sparrow
for what is the farmer’s own fault.

The natural checks provided for keeping the small
birds in their proper place are the birds of prey; and
these—many of the larger, and all the smaller—not
only kill small birds for their own eating, but feed
their young entirely upon beetles, grubs, caterpillars,
flies, slugs, snails, and the various insects which attack
the green things. Many of them, too, hunt by night,
and so destroy the night-flying moths and beetles
which éscape other birds.

Yet birds of prey, especially owls and hawks, are
relentlessly persecuted by farmers and keepers, because
they occasionally steal a young chicken, or—more
heinous offence still—young pheasants and partridges,
and perhaps, yet more often, they are killed because it
is the fashion to kill them.

But even owls and hawks have their avengers.

Nature's Militia 333

Sparrows, multiplied to excess, take to thieving, and
commit great depredations in the fields; and still
worse are the plagues of mice, which mar the
land.

In Scotland and the north of Bngland there has
been a great outcry of late against the swarms of mice
and rats which waste the fields and rob the barns,
doing far more damage than the sparrows. But why
this increase in sparrows and mice? Because the
owls, hawks, stoats and weasels have been killed off.
Just that, and nothing else.

Owls are the very best mousers possible—better than
the best cats. One pair of owls have been seen to
take as many as eleven mice to their nest in the course
of a single evening. Ravens, crows, hawks, magpies
and jays all hunt mice, as well as cockchafers and other
insects, as already said; and the young of the brown
owl are fed with anything, from snails even to kittens
and puppies. But the young of the barn-owl require
a steady supply of fresh mice, and she herself makes
mice almost her sole diet, so that she benefits not only
corn but clover. For if it is true that the crop of
clover-seed depends to a great extent upon the number
of cats in the neighbourhood, surely the presence or
absence of those grand mousers, the owls, must make
at least as much difference to it. For mice are very’
much addicted to eating humble-bees, as well as corn;
and as the common purple clover is fertilized by
humble-bees only, there can be no seed where humble-
bees are wanting, which they certainly would be if
mice were allowed to multiply unchecked.

Whether or no people in this land, other than the
naturalists, are connecting the grievous plague of

334 Nature's Militia

mice in Dumfriesshire and elsewhere with the dis-
appearance of the birds of prey, it is being clearly
recognised in America that without the latter sparrows
are a sad mistake. In the States, birds of prey are
comparatively rare ; not because they have been killed
off, as with us, but because nature had not provided
them—a very different matter. But now that the
English sparrow has made himself unpleasantly
obtrusive, hawks are being imported as the only likely
means of quelling him. Why hawks instead of owls
is not evident, but it will be interesting to watch the
result of this second experiment; for if the hawks in
their turn should increase to excess they might prove
even worse than sparrows.

In some parts of the world the balance of animal
life established by nature is very curious, and any
interference with it is attended by danger. In some
districts in India, for instance, the tiger is as useful
to the farmer as owl and hawk are here. If he kills
off the tigers, as his English brother kills the birds
of prey, then the deer multiply and eat his crops; and
on the other hand, ‘if he kills off the deer, the tigers
kill Aim, for even a tiger must live!’ so that on the
whole he finds it better not to interfere.

' We have already mentioned the stoat and weasel as
most useful in keeping,down the numbers of rats,
mice and rabbits, and the hedgehog as being a
devourer of insects, with absolutely no bad habits
to take from its value. Yet all these are persecuted
without mercy as ‘vermin,’ chiefly from habit, in all
probability ; for the old stories as to the hedgehog’s
milking the cows, and rolling itself on fruit and eggs,

Nature's Militia 335

which it carries off on its prickles (!), can hardly, one
would think, be seriously believed.

Another much-persecuted creature is the mole; and
yet the mole is always eating wire-worm and the like,
doing its very best for ungrateful man; for its appetite
is voracious, and it is quite unable to survive evena
short fast. The mole is not without his admirers,
however, in spite of his certainly trying way of throw-
ing up hillocks, and one of his friends says: ‘ As surely
as the farmer destroys the mole, so will he have in ex-
change wire-worm and turnip-fly.’

Insects are, as a whole, such enemies of vegetation
that we are apt to condemn them in a body. Yet
besides the many which convey pollen there are a few
others which deserve honourable mention, and even
the name of friends. These few are positive bene-
factors, for they leave the green things alone themselves
and prey upon other mischievous insects.

Among these insect-friends is the lady-bird, to whom,
as an American writer says, ‘we should take off our
hats,’ for it destroys those terrible pests, thrips and
green-fly.

Wasps carry off flies and caterpillars to feed their
young grubs; and some species of ichneumon-fly
deposit their eggs in the chrysalids of moths and
butterflies, as well as in grubs and caterpillars, thereby
killing them. But of all insects, perhaps some of the
beetles are the most useful, for, both in the grub and
in the winged state, they catch and devour living prey.

To sum up: without insects many plants would be
unable to produce seed, and so must in time die out;
without. the small birds, insects would increase so

336 Natures Militia

much that all green things would be destroyed; and
without the birds of prey to keep the number of small
birds within bounds, not only would farming be quite
impossible, but wild plants would also suffer; for, wher
the insects were devoured, or even very greatly reduced
in numbers, the plants dependent upon them for help
would be seedless, and the remainder would be so
plundered of their seed by flocks of hungry birds, that
little would be left for sowing.

Both insects and birds, then, are the enemies of
vegetation when their numbers are multiplied to
‘excess; but without them, there would be no vege-
tation at all.

XXII
MAN’S WORK ON THE FARM.

HITHERTO we have been considering how the world’s
fields are cultivated when the work is left entirely to
those who labour without hands—to air, wind, frost,
rain, snow, sun, glacier, river, earthquake, volcano; to
the worms and others which plough the soil; to the
insects which act the part of pollen-carriers between
the flowers, and to the birds which keep the insects in
order, and help the winds and waves to scatter the
seed. These and many other workers not here enu-
merated, are at work constantly in the fields which
man has taken under his own care, as well as in those
still left entirely to nature. Together they keep the
world green, and they would keep it green if there
were not a man in it; for they are quite able to do
without his help in the matter, though he would be
entirely helpless without theirs.

But man has done much to modify the result of their
combined labours, not only in that small proportion of
the earth which he cultivates or occupies, but even
beyond. Where men dwell together in numbers, there
the earth is necessarily less green, for towns, cities,
roads, railways, have invaded the woods and fields, and

22

338 Man's Work on the Farm

have not only turned out their inhabitants, animal and
vegetable, but have made their influence felt over a
much wider space than that which they actually cover.
Even where wild plants have been turned out only to
make way for cultivated ones, the result has been
similar in some degree. The earth bears better crops,
no doubt, at least from man’s point of view, but they
are less crowded, and the fields are bare for some part
of the year.

But besides cutting down woods and forests and
clearing away bush, man has drained fields, as well as
marshes, he has cut canals, and he has taken plants
from one land to another and from one hemisphere to
another, in many cases intentionally, but in many
others quite unintentionally.

Other changes, though man has been the cause of
them, have taken place altogether without design on
his part; and even where he has intended to make
some change, he has not seldom found that he has
done a good deal more than he meant, and has in fact
started a whole series of changes.

Trees, for instance, are cut down for the sake of the
timber they will furnish, and nothing else, perhaps.
But a great deal more is done than merely to take
away so many loads of wood. To begin with, the soil
is exposed and dried, and the plants- which have
flourished in the shade and moisture will die off. The
insects which fed upon the plants will die off too, and
the birds which fed on the insects and found shelter in
the trees will be driven away.

If the trees are simply cut down, and the ground is
left unoccupied, it will be gradually taken possession
of by other plants or trees. In Germany, where the

Man's Work on the Farm 339

ground has been cleared of wood and then left to itself,
it is covered in a few years, first with shrubs, then
with trees, chiefly of the pine tribe. In eight years, it
will become a coppice with saplings five or six feet
high; and all this without any further interference on
the part of man.

Man makes the vacancy, and nature, if only let
alone, fills it again. There are parts of the United
States where pine-woods have been cut down for
railway purposes, and have been at once followed by
oaks, planted by some or other of nature’s many
labourers. ‘Why pines should not have sprung up
again, when their seeds must, one would imagine,
have been present in the soil, seems to be one of
the many questions still waiting to be answered;
but it is a well-known fact that in many places
where forests are cut down, trees of an entirely
different kind do spring up in their place. And of
course different trees mean different insects, and
different birds.

Mr. Darwin mentions some remarkable changes of
this sort brought about simply by the enclosure and
planting with Scotch fir of a very barren heath in
Staffordshire never before touched by man. In five-
and-twenty years, the vegetation of the planted and
unplanted portions had become so different that the
soil might have been supposed to be of quite distinct
kinds. Within the plantation there were fewer heath-
plants, but there were also twelve species of other
plants, not counting grasses and sedges, which were
not to be found on the heath at all. Six species of
insect-eating birds, too, were common in the planta-
tion, but did not stray outside it; while two or three

340 Man's Work on the Farm

others, quite distinct from these, were to be found only
on the heath. For change in the vegetation had been
followed by a corresponding change both in the insect-
life and in the bird-life.

Not a marsh nor a field can be drained, not a canal
can be cut, not a railway or even a road can be made,
nor a house built, without making some change, and in
some cases a very great change, in the vegetation of
the place or immediate neighbourhood. As for the
growth of towns and cities, that affects far more than
the immediate neighbourhood; for not only is many a
field covered with bricks and mortar, but the smoke
from the chimneys and the increased traffic on the
roads have their effect upon vegetation, sometimes for
miles round. :

When to houses are added factories, the evil influ-
ence is felt still more widely, and that even by lichens.
Lichens are such very passive-looking vegetables, so’
little life-like, and so largely composed of mineral
matter, that one is apt to fancy they cannot be
sensitive. And they are in many respects very hardy,
as we have seen. But they, too, have their limits
of endurance. They may stand both biting cold and
parching heat; but smoke kills them, especially the
larger leafy-looking species, such as grow on the
trunks of trees. They flourished formerly in the
woods, seven miles from Newcastle, and might flourish
there still, but for the change in the atmosphere, for
nothing else is altered. But the factories and collieries,
though several miles off, have polluted the air; the
trunks and branches of the trees have acquired the
grimy look which they wear in cities, and all the larger
lichens, and most of the smaller, have been killed by

Man's Work on the Farm 341

the soot. Lichens have also disappeared from Kew
Gardens, and are rare in Epping Forest.

Changes of this sort are, however, very small com-
pared with those which have followed the destruction
of primeval forests, the introduction of agriculture,
the wanderings, and even wars, of the human race,
the voyages of traders, and the discovery of new lands.

Those who are accustomed to cultivate the soil, in
however rude and primitive a fashion, naturally carry
with them on their wanderings the seeds of such
plants as they have found useful. This is true even
of such nomads as the gipsies, whose attempts at
agriculture have been necessarily of a very limited
description, since their crops had to be sown and
reaped during -the short time that they remained
stationary.

But besides carrying some seeds purposely, travellers
of all sorts, whether nomads or not, frequently carry
others by pure accident, and quite unconsciously.
They mean to take with them only cultivated plants,
but somehow or other, in this way and in that, the
weeds contrive to get taken too. It is often quite
impossible to say. how they have been brought, but
there they are. This is especially the case with what
may be called cultivated weeds—those which are found
in cultivated fields and nowhere else; for, unless great
care is taken, their seeds are very apt to be mixed
with those of the crop, and then both are sown to-
gether. Clover and grass seeds are especially liable
to adulteration of this sort; broom-rape and dodder
are conveyed in the one, and worthless grasses, and
many another weed, sneak in with the others.

Many seeds are conveyed, also, in forage; and in

342 Man's Work on the Farm

1870, during the Franco-Prussian war, seeds were thus
brought to France by troops from Algiers, and were
scattered in different places, where they germinated
and grew up, but apparently found soil or climate un-
congenial, and died out in the course of two or three
years. Had they travelled south instead of north, they
might have become permanent colonists.

Again, the ballast of vessels is a very favourite
hiding-place for seeds; and foreign plants often first
spring up in the neighbourhood of sea-ports, being
brought not only in this way but in others less obvious.
Intercourse of any kind with foreign lands is almost
sure to lead to the introduction of foreign plants, not
only without any effort on man’s part, but often quite
against his wishes.

Fleeces from South America, Mexico, and the Cape,
have been the means of bringing seeds to some of the
valleys of Gloucestershire, and to the Pont Juvenal,
near Montpellier, where they were washed and spread
out to dry; and in many cases these seeds have not
only germinated but blossomed, though they have not
lasted more than a season or two.

No one, probably, would wish to assist that trouble-
some weed, the wayside plantain, to migrate, yet, if
the tradition of the American Indians is to be trusted,
it has followed the white man all over the western
continent. The seeds are very minute, though they
are not otherwise specially capable of dispersing them-
selves; and if once they managed to slip in anywhere,
they would be carried unnoticed. Certain it is that
the Indians look upon this plantain as having come
with the white man; for they call it the ‘ White Man’s
Foot.’ Botanists have been rather sceptical on the

Man's Work on the Farm 343

subject, as there is a plantain acknowledged by all to
be a native of America, which is so like the stranger
as to have been confounded with it for some time,
except by the Indians and the cows. The latter will
eat the native plant, but not the other; and as the two
are now distinguished by botanists, it seems likely that
the Indians are after all right in their tradition.

One weed, the Canadian fleabane, made its way to
Europe by very singular means. A single seed came
over accidentally in a stuffed bird. This was purposely
sown, no doubt out of curiosity, and then the deed was
done, and the result was beyond control. For the
fleabane has downy seeds,’and these flew away and
spread themselves all over Europe without any further
assistance.

Few weeds have come, or are ever likely to come,
from China, by all accounts, for the population is so
dense, and labour so abundant and so careful, that
none of the cultivated districts are good hunting-
grounds for the botanist. When one thinks of the
many plants to be found in our fields and meadows,
besides those sown and cultivated by the farmer, it is
strange to learn that, with the exception of some few
water-plants in the rice-fields, the botanist finds
scarcely any plants in the fields of China but such as
are cultivated. That is to say, he may find stray plants
of millet among the beans, or lentils among the corn,
and so on; but of ‘weeds’ pure and simple, unculti-
vated plants, he finds scarcely a specimen, and anything
answering to the gay poppies and rampant bindweed
of our corn-fields is absolutely unknown !

It is a curious fact that almost all the really trouble-
some weeds in the world are emigrants from Europe.

344 Man's Work on the Farm

But before we consider, in their proper order, a few
of the more important changes which have taken place
in the vegetation of different lands, a word or two must
be said about names.

It is necessary to be cautious about accepting
popular names, for these are often given without much
reason.

The Indian fig, or prickly pear, is neither fig nor
pear, but an American cactus. The Jerusalem arti-
choke is an American sunflower, in Italian Girasole
(Turnesol), which was corrupted into ‘ Jerusalem,’ and
it was called an ‘artichoke’ because the tubers some-
what resembled in taste the heads of the real artichoke.

As for the names ‘ apple’ and ‘ pear,’ they have been
used in the most reckless manner both in ancient and
modern times. The Persian ‘apple’ of the Greeks and
Romans was the Chinese peach, and their Punic
‘apple’ was the Persian pomegranate. The ‘golden
apple’ of the Italian is not, as one might suppose, a
pippin,' but the tomato. The ‘alligator pear’ of
Mexico is not a pear, nor has it any connection with
alligators. Its native name is ahuaca, corrupted by the
French into avocat and avocatier, suggestive of some
equally mysterious connection with lawyers, with
whom, however, it has as little to do as the pomme
d’acajou has with mahogany. As to the red and white
‘currants’ of our gardens, what right had they to steal
the names of the small grapes of Corinth, which we
now call grocer’s currants for distinction ?

The potato is too curious an instance of this kind
of thing to be passed over. By French and Germans
it has been called the ‘earth-apple,’ and by the
Hungarians the ‘earth-pear’; but the English name

Man's Work on the Farm 345

cannot be said to be much more felicitous than these.
For the potato, like its cousins the tomato and the
tobacco, is a nightshade; and the batata, after which
it is named, is a convolvulus, a native of Brazil. The
Brazilian batata bears tubers, which were imported
into England from Spain in considerable quantities
before the ‘potato’ was known, or at least before it
came into general use; but the two are much alike in
appearance, and the later comer was so much the
more popular, that the name of the convolvulus was
transferred to it, and the true batatas came to be known
as ‘sweet potatoes. To make the confusion still
worse, the potato has been introduced into Brazil,
where it was formerly unknown, and is there called
the ‘ English batata.’

As we have no means of telling when the first
migrations of man took place, it is quite vain for us to
guess at the date of the earliest migrations of such
plants as he carried with him. The earliest wander-
ings of both are equally involved in obscurity, but we
know that they began long before history has anything
to say about them; and we know, too, that cultivated
plants had been brought from Asia to Europe even in
these far-off, dateless ages.

The lake-dwellers of Switzerland, who built their
habitations on piles, and used none but stone imple-
ments, knew something of agriculture; and, from the
blackened remains of grain found, we know that they
cultivated three kinds of wheat, two of barley, and two
of millet, which are none of them natives of Europe,
and must have been brought at some time or other
from Asia.

346 Man's Work on the Farm

But if we cannot say when the first corn was brought
to Europe, still less can we say when, and by whom,
the various kinds were first cultivated. It was, how-
ever, at such a very remote period, that they are none
of them found in the wild state.

The earliest changes in the vegetation of Europe, of
which we have any historical notice, are those made in
the south of Italy by the Greek colonists (from B.c. 734),
who brought with them the garden-rose and the lily.
On their arrival, they found the country much over-
grown with wood, among which beech-trees were
especially prominent, but there were none of the plants
and shrubs then growing there which we are accus-
tomed to think of as particularly belonging to Italy.

We can hardly imagine Italy without the myrtle,
laurel and olive, to say nothing of the orange and
palm. But oranges were quite unknown both to
Greeks and Romans, and Italy was without myrtles
and laurels until they were introduced by the colonists
and planted round the temples of Aphrodite and
Phoebus, to whom these shrubs were sacred. The
olive was in like manner sacred to Pallas, and was
therefore pretty sure to accompany the wanderers, for
it is one of the trees which has been cultivated from time
immemorial, especially in Syria, from which the culti-
vated olive seems to have come originally. Once
introduced, it would soon spread, for birds are very
fond of the berries, and scatter the seeds far and wide.
A wild variety, from the Punjab and Beloochistan, has
been conveyed by their means to Portugal, Madeira,
Morocco and the Canary Islands.

But near Messa, in Morocco, there is a grove of
olives planted in such a regular, but whimsical fashion,

Man's Work on the Farm 347

that one cannot suppose it to have sprung from the
seeds scattered by birds; and if tradition is to be
believed, the trees grew from the pegs used in picket-
ing the horses of an army proceeding to the Soudan.
Owing perhaps to some sudden alarm, the camp was
hastily broken up, and the pegs, cut from olive-trees in
the neighbourhood, were left behind and took root.

No trees but evergreens—the olive, cypress, and
oleander—are depicted upon the walls of Pompeii;
from which it seems that the beeches, and other trees,
had been either exterminated or driven into the moun-
tains, or at least had ceased to be in any way conspicu-
ous, by the time these works of art were executed.

What plants may have been introduced purposely,
or accidentally, by the Phcenicians, who had trading
stations all about the Mediterranean, in Europe as
well as in Africa, we have no record to tell us; but,
judging by what we have seen in other instances, it is
impossible to suppose but that some plants followed,
or were conveyed by them to the various coasts they
visited. And their voyages extended westwards as far
as Britain, and south as far as Senegal.

Nor do we know much more of the effects produced
by the wars of Greece and Persia, or the expeditions
of Alexander the Great, which took him as far as
India. Rice was certainly made known to the Greeks
by the conquests of the latter; but no attempt seems
to have been made at cultivating it.

It is in the second century (8.c.) that the Chinese
first came into contact with Western Asia, on the
occasion of their helping the Scythians to ravage
the shores of the Caspian Sea. A little later, their
ambassador, Chang-Kien, followed on a peaceful mis-

348 Man's Work on the Farm

sion; and coming as he did from a nation of agricul-
turists, he seized the opportunity to carry back with
him to China various useful plants, such as the bean,
pea, cucumber, water-melon, lucerne, saffron, sesame,
spinach, nut, and others, hitherto unknown in the East.
This is the earliest instance recorded of the migration
of cultivated plants eastwards. Westwards we know
they had travelled long before. :

Whether the ambassador was so thoughtful as to
bring any plants with him, or whether any came acci-
dentally in his train, we do not know; but the peach-
tree is said to be a native of China, where it has been
cultivated for ages; and it was so well established in
Persia, when the country was invaded by the Romans,
that they introduced it to Europe as the ‘ Persian
apple.’ The Romans, too, about B.c. 68, brought
from Pontus or Armenia the first cultivated cherry-
tree ; and it is said that a tree laden with fruit figured
in the triumph of the victorious consul. Cherries
became at once so popular that, as Pliny says, ‘in less
than a hundred and twenty years after, other lands
had cherries, even as far as Britain beyond the ocean.’

As to any other plants which the Romans may have
brought to Britain, we have no certain knowledge; no
doubt they cultivated here all such plants as they
found useful at home, so far as the climate would allow
them; but they have at least the credit of having
brought and left with us two wild plants, the columbine
and the Roman nettle. The nettle is one of several
plants which are, it is said, sure to follow the steps of
the European wherever he goes; the plantain, goose-
foot, and fennel are others.

But, according to the old botanists, the seed of the

Man's Work on the Farm 349

large Roman nettle was purposely brought by the
Roman soldiers, ‘who sowed it for their use, to rub and
chafe their limbs, being told before they came from
home that the climate of Britain was so cold that it
was not to be endured without some friction to warm
their blood.’

However this may be, the Roman nettle, which is
a larger species, and endowed with more venomous
‘stings’ than the common stinging-nettle, is rare in
England. But it formerly abounded in the streets of
Romney, and, though driven out of the town, still
flourishes in the neighbourhood. Now, it was near
Romney that Julius Cesar landed, though the town
does not take its name from the Romans, but from a
Saxon word signifying ‘ marsh.’

It was not until Roman times that the date-palm
-was brought to Italy; and then, as it did not bear
fruit, it could neither run wild nor make itself
thoroughly at home, and was therefore dependent
upon the care of man. But the northern barbarians,
who overran the empire in later times, cared nothing
for a tree which was only beautiful, and therefore
allowed it to die out, and Italy was without palms
again, until the Saracens brought them back.

The coming of the Arabs, or Saracens, made a vast
change in the vegetation of the lands of the Mediter-
ranean; for, destructive as they were in some respects,
they had the Eastern respect for, and love of, trees ;
and though their power did not extend nearly as far to
the east as did that of the Romans, it was they, and
not the Romans, who brought to the Mediterranean
the many Asiatic plants which we are now inclined to
think must always have been there.

350 Man's Work on the Farm

The Romans, though they had colonies all round
the shores of the inland sea, made no such changes
in its vegetation as those which followed the coming
of the Saracens. It is, indeed, curious to reflect
how much Europe owes in the way of beautiful.
trees and flowers, and of useful plants, not only to
the fanatical, blood-thirsty Arab, but also to the ‘un-
speakable’ Turk, who brought us the horse-chestnut,
tulip, and other ornamental plants. The Arab of
to-day carries with him the seeds of his favourite
plants, fruits and vegetables, even when he is on his
slave-making expeditions in the heart of Africa. And
wherever he settles, if it be but for a year or two,
there he makes a garden.

It was so, also, in the eighth and following centuries.
Egypt, North Africa, Spain, the Balearic Islands,
South France, Sardinia, South Italy, Sicily, the Levant
—all felt his influence, for wherever he went he tried
to make the new country as home-like as possible.

The planting of the first date-palm in Spain was
an important ceremony, performed by the first caliph,
Abdurrahman himself, in a garden near Cordova, his
capital; and this tree is said to have been the ancestor
of all the palms of modern Spain, including the forest
of 60,000 fruit-bearing trees in Valencia.

In Calabria and Sicily the palm was allowed almost
to die out again when the Saracens were gone, and for.
the same reason as before—because it did not bear
fruit; and it was not until the ceremony of the blessing
of palms on Palm Sunday was introduced, that people
began to think it worth cultivating for the sake of its
foliage only.

Then, however, the palm began to be made much

Man's Work on the Farm 351

of in Italy, as there was a brisk demand for its ‘leaves’;
and the great grove, which is miles long, was planted
at Bordighera, simply for the supply of these. :

Among the other plants which the Saracens brought
to Europe, were the orange and lemon, the sugar-cane,
rice, cotton, saffron, and the locust-tree. The citron-
family, which includes the lime, orange, and lemon,
seems to be a native of China, where the fruits grow
wild, and many varieties have been in cultivation for
ages past; but how and when they travelled west-
wards, as they must have done before the Arabs could
_ make their acquaintance, we have no means of dis-
covering.

Wherever the Arab went, there fields of saffron
were sure to spring up; for this was a flower he
loved and valued very highly for its perfume,
flavour, dye, and medicinal properties. Greeks and
Romans had known it as the crocus, and prized it
too, but the extreme fondness of the Arabs for it
caused it to be cultivated far more extensively than
it had ever been before; and their name for it,
‘saffron,’ quite took the place of the classical one.

Rice had long been known as an expensive foreign
article; but there had been no attempt at cultivating
it out of Asia, until the Arabs tried it with much
success in the Delta of the Nile, and soon after carried
it further west. It flourished in the marshes of
Valencia, and elsewhere in Spain; but the Italians
were only too successful with it; for finding that it
could be grown without difficulty, they turned their
fields and meadows into swamps, in such a reckless
manner that much illness followed, and the law
stepped in and set strict limits to its cultivation,

352 Man's Work on the Farm

Large crops are, however, still grown in the plains
of Lombardy.

So much was done by the Arabs to make the vege-
tation of the East known in Europe, that the Crusaders
found little to bring home in the way of useful plants;
and the next important addition to the food-plants of
Europe, though that too came from Asia, was a much
more northerly one.

Buckwheat grows wild about the river Amoor, and
in some other parts of Asia, and as it made its first
appearance in Europe at the same time as the gipsies,
early in the fifteenth century, they have generally had
the credit of introducing it, as its many names, such as
‘heathen’ and ‘Saracen’ corn, sufficiently testify, for
these were applied indiscriminately to the gipsies also.
It seems not improbable that they should have carried
it with them, for it grows on poor soil, and takes but a
short time to come to perfection, and would therefore
be well suited to the needs of those who lead a wander-
ing life.

Another plant which is said also to have followed
the gipsies from Asia all across Europe is the deadly
thorn-apple, which is unpleasantly suggestive of some
of their evil practices.

Hitherto the various migrations of plants, of which
we have any certain knowledge, had been, with few
exceptions, from east to west. And now, with the
wonderful discovery of the New World, fresh fields
were opened out to them, still in the same direction.
Europe was, as it were, but a stepping-stone for many,
on their way to the Far West; and in the case of not a
few, it was only when they reached the western hemi-
sphere that they showed what they were capable of.

Man's Work on the Farm 353

and became important crops. Rice, cotton and sugar,
for instance, were all grown in the south of Europe to
some extent, after the Saracens had introduced them
there, but what were the little plantations of Spain
and Italy compared with those of the West Indies and
America ?

However, though the stream continued to flow
westward, and that with such vigour that nearly the
whole of the vegetable world of Europe seemed to be
on the move, no sooner was the New World discovered
than a counter movement set in. The eastern world
certainly gave more than it received; but it also
received much, and American plants are now so well
known throughout Europe and great part of Asia, that
they are hardly any longer looked upon as foreigners;
and it is quite difficult to realize what the lands of the
Mediterranean, and even our own kitchen-gardens,
looked like before the discovery of America, when the
blue-green, sword-leaved agave, commonly called the
‘American aloe, the magnolia and prickly pear, were
unknown in the south of Europe; when Italy-had no
maize, macaroni, or tomatoes, the Irish no potatoes,
and the Turk no tobacco.

When we think of the way in which the prickly pear
has spread over all the coasts of the Mediterranean,
north and south, and of the broad fields now devoted
to the cultivation of maize and potatoes, to say nothing
of the garden-ground occupied by Jerusalem artichokes,
scarlet-runners, haricot-beans, and ornamental plants,
we may form some idea of the alterations produced in
the green world of the east by the discovery of the
other half of the globe. There is indeed hardly a park,
or even a cottage-garden in Europe, where plants from

23

354 Man's Work on the Farm

the west are not now familiar objects; they are plenti-
ful in China and Japan, and throughout the length and
breadth of India. But still, though they have con-
siderably altered the appearance of our gardens, and,
in some districts, of our fields, the change has been
mainly confined to these, the cultivated portions of the
soil. In the north, at all events, American plants have
not run wild in any overwhelming manner, though the
prickly pear has done so in the south, and the pine-
apple has covered some parts of Borneo; and it is true
that the American pond-weed even put us to consider-
able expense, by choking our canals. The general
appearance of our woods, moors, wild hill-sides and
‘wastes,’ at all events, is little, if at all, altered by the
presence of strangers; and though potatoes are an
important crop in the north, while maize and tobacco
occupy a good share of the cultivated ground in the
south, yet, except in some few districts, it is only a
share, and wheat, barley, rye, oats, clover, etc., form
the chief part of the crops of Europe now, as they did
before Columbus crossed the Atlantic.

It is far otherwise, however, with that new world
which he discovered. In many parts, European plants
have almost ousted the natives, and have entirely
altered the character of the vegetation. In the south,
for instance, 180 miles of wild artichokes and clover
have sprung up since first the continent was visited
by Europeans. Growing entirely on their own account,
without any other help from man than that of an
‘assisted passage,’ they have overpowered whatever
native plants occupied the ground before them, and
are now being themselves invaded here and there by
large groves of wild apple-trees, also European, planted

Man's Work on the Farm 355

by pigs and cattle. But in the north, greater changes
than this have taken place; for miles— hundreds,
thousands of square miles—have been brought under
cultivation which were never cultivated before; and
the whole of the crops grown throughout the United
States are foreign, with the trifling exception of
Jerusalem artichokes and pumpkins!

When Louisiana was settled by the French, for
example, less than a couple of hundred years ago, the
uplands were covered with magnificent forests of elm,
ash, oak, cherry, magnolia, mulberry, and wild grape.
Whereas the greater part now, where it has not been
abandoned as exhausted, is covered with cotton—
cotton not of the native species, but that brought to
Europe by the Arabs.

This is only a sample of what has occurred through-
out the United States and in Canada. For it isa
curious fact that, useful as are many of the plants
which America has given to Europe, they amount to
no more than forty-five species—about 250 species are
in common cultivation all over the globe—and of these,
all but the two already mentioned are natives of South
or Central America, for the Indians of North America
were chiefly hunters, not agriculturists.

Potatoes, it is true, were brought to Europe from
Virginia, but they were strangers for all that, and not
known in the State until introduced by Europeans,
who had made their acquaintance in the south; and
to make room for them, as well as for the various kinds
of corn, grasses, clover, cotton, hemp, flax, fruit and
vegetables, which form the main part of the crops of
the United States farmer, native plants have necessarily
been turned out. They have not been exterminated,

356 Man's Work on the Farm

but the space they occupy has been much circum-
scribed, and will be limited more and more, as more
land comes into cultivation.

Coffee from Abyssinia, the sugar-cane, peach, and
orange from Asia, are all extensively cultivated in the
Western world, while the two last have run wild, and
form considerable groves in some parts; and whole
forests of coco-palms waved on the islands near
Panama within a hundred years of their first intro-
duction. All these were valuable additions to the
vegetable wealth of the new world; but the more
foreigners, the fewer natives. The green things were
quite as many, but they were different.

So much, then, for the useful plants. It has been
said that ‘no beautiful or useful organic species,
animal or vegetable, becomes naturalized in any
country without the intervention of man, while the
noisome and ugly succeed in establishing themselves
in spite of him’—a sweeping assertion, which, as re-
gards the former half of it, is hardly borne out by
facts. But the second half is undoubtedly true
enough.

Though we cannot consent to call ‘noisome and
ugly’ the weeds which beautify the fields and meadows
of Europe, we must admit that they have followed
man quite without his invitation, though not without
his unconscious help, and that in many cases he has
to fight a sore battle with them, and does not always
come off conqueror.

Most of our weeds have made their way to the
West by the various ways already mentioned, and
among them, it must be confessed, some which are
not only not ornamental, but most injurious to the

Man's Work on the Farm 357

fields. So extremely troublesome are some of these,
of the thistle tribe, that laws are passed to ensure their
being cut down, and fines are inflicted, in some parts, of
a dollar per plant if they are allowed to ripen their
seed; while so desperate is the battle felt to be, that,
in Manitoba, persons who do not cut them down
within five days, after they have been warned, are
fined {1 a day. Station-masters are held responsible
for the weeds on railway property; and seed-merchants
convicted of selling seed containing any admixture of
wild oats, wild mustard, or ‘Canada-thistle,’ are fined
from {£2 to £20. Nevertheless, in spite of the war
waged against it, the last of these is a ‘ pest’ on all
badly cultivated farms, and renders some of the country
roads of Ontario almost impassable.

But now to consider briefly some of the vegetable
changes which have taken place in other parts of the
globe. The last of these have been due to the
discovery of Australasia, where all the crops now
cultivated, as well as many which are not cultivated,
are foreign importations from Europe, Asia, and
America, for Africa has supplied few emigrants.

None of the plants grown by the natives had peen
sufficiently improved to make them worth cultivating
by Europeans; and the only useful plant which
Australia has given to the rest of the world is the
eucalyptus, which seems already to belong to the
Mediterranean as much as the olive, cactus and aloe.

In Australia, as elsewhere, man has had to find out
by experience how hazardous it is to bring colonists
into a new and comparatively unoccupied land, unless
he is sure he can control them. It is not only in the
matter of rabbits that he has discovered his mistake.

358 Man's Work on the Farm

He had, to be sure, no conscious share in bringing
the Pampas-artichoke to Australia; for the seeds made
use of his cattle and his ships without consulting him ;
but he negligently allowed the plant to establish itself.
He did not eat its heads, or boil its stems, as he might
have done; and it has improved the opportunity to
form an impenetrable belt along the margins of the
creeks in many parts of Victoria and New South
Wales. But in other cases man has directly brought
his troubles upon himself, though it would be hard to
blame him; for who, seeing the sweetbriar for in-
stance at home, could possibly guess that it would
prove a nuisance abroad? Yet this is just what it has
done. It has grown so rampantly as to make whole
regions in Tasmania practically valueless, for the
expense and difficulty of clearing it away are so great
that the land has been abandoned and given over to
the enemy.

The prickly pear has also proved an expensive
emigrant, for it has escaped from the gardens in which
it was to have been confined, and has taken possession
of extensive districts, from which it will not easily be
dislodged. This cactus, as well as the Scottish thistle
—brought over by a patriotic but misguided Scot, who
has mot received the thanks of the community—has
been the subject of special Acts of Parliament, and to
keep the two even in check costs the country many
thousands every year.

These and the Capeweed, which has nearly destroyed
every natural pasture plant for miles round Melbourne,
having sprung from seed thrown out on some waste
land—these are, perhaps, the worst vegetable enemies
of the Australian. But they do not by any means

Man's Work on the Farm 359

exhaust the list; and even the watercress, which is
humble enough at home, has become so wildly luxuriant
in some parts as actually to dry up sluggish streams
and cause much inconvenience to the sheep.

Some of the accidental colonists, on the other hand,
have turned out real blessings—such, for instance, as a
coarse species of grass which somehow found its way
to Australia from India, as is supposed. In Arabia, as
well as in India, this grass supplies food for cattle in
districts which would otherwise be desert and unin-
habitable; and it is of incalculable service in the
warmer parts of Australia, flourishing where other
fodder-plants cannot stand the heat, and keeping
luxuriantly green the district round Sydney, which
before its coming had been withered and desert-like
throughout the summer and autumn.

Such, then, are some of the more striking changes
which man has made, intentionally and unintentionally,
in the appearance of the green world. They began as
soon as he began to cultivate the soil and interfere
with the natural labourers, and they have been going
on ever since more and more rapidly, especially during
the last three hundred years. And what we see now
taking place in America and Australia may serve to
remind us of what has been done in Europe; for here,
too, the space now occupied by fields, orchards, gardens,
as well as by towns and villages, was covered in bygone
times by a dense growth of forest and underwood and
green things, of nature’s planting.

And so, also, with the crops. If those grown in
Australia are all foreigners, so, too, are most of those
grown in Europe; for, though in many cases we’ have

360 Man's Work on the Farm

almost forgotten the fact, it is to Asia that the world is
indebted for the most important of its food-plants.

But with all that man has done, and widely as his
influence is felt beyond his own especial domains, he
has at present taken but a small portion of the soil
actually under his own care; and even in that small
portion he would, as we have seen, be quite helpless—
unable to produce even so much as a single crop—
without the constant help of the many natural labourers
who are always at work, some or other of them, day
and night, summer and winter, in every part of the
* great world’s farm.’

INDEX.

ABYSSINIA, 41, 356
Acacia, 6, 98, 306
Acids, 35, 136
Africa, 1, 6, 98

», South, 66, rr0, 112, 115
Air, 19, 164, 176

»» Moisture in, 19, 125
Agave, 353
Albumin, 158
Aloe, American, 193, 353
America, plants from, 353-4; taken

to, 354-7 :
Ant-eaters, 88
Ants, 82-87, 241, 306-9
Apple, 219-20

» wild, 276, 354
Arabs, 349-50
Arbor-day, r2r
Artichoke, Jerusalem, 344, 355; wild,

3, 146, 297, 358
Ash in plants, 16, 140-4, 145
Asia, plants from, 345-52
Australia, 97, 266, 357

BALANCE OF LIFE, 334-6
Bananas, 162

Beans, 13, 280
Beavers, 45
Bees, 215-22, 227, 220
» colours preferred by, 225
»» flowers shunned by, 224
» humble, 13, 218, 225, 227, 232
»» protection against, 244 i
Beetles, 70, 236, 310, 329, 335
Bindweed, 52, 233
Birds, 313

Birds, destruction of, 314, 316-17
» aS Seed-carriers, 261-73
» fertilization by, 224, 234
Bison hollows, 58
Black cap, 320
Black earth, 61, 62, 134, 146
Blossom, size of, 193-4
» Structure of, 194
\Blossoming, 193
Bourbon, Isle of, 323
Brazil-nuts, 265, 290
Breathing, 174
Buckwheat, 352
Bulbous plants, 173, 192
Burrowing animals, 63
Burs, 265-7 ;
Butterflies, 229, 311

CABBAGE, 96, 103, 159, 279
Cactus, 35, 36, 98-9, 111, 353, 358
Canadian fleabane, 343
Carbon, 160, 162, 167, 173-5
dioxide, 22, 161, 164
Carnivorous plants, 149
Carses, 44
Catkins, 209
Caterpillars, 310-11, 320, 321
Cattle, influence of, 276, 292, 294
Cedar, red,272*
Cells, 167-9
Ceylon, sand-bars of, 53
» cinnamon in, 271
» vine in, 187
Cherry, 348
China, agriculture in, 347
»» Plants from, 348, 351
» weeds in, 343

" Chinese gardeners, 176

362

Cinnamon, 271

Citron, 351

Clover, 142, 146, 218, 333, 341, 354-5
1 Toots, 56

Coco-nut, 54, 257, 356

Cockchafer, 325, 328-9

Colchicum, 192, 206

Colonists, 285, 296-7

Colours, meaning of, 224-5, 228, 274

Composites, 196, 299

Convolvulus, 53, 233, 345

Coral-sand, 53

Cork, 91

Corn, 345

Cotton, 353

Crabs, 69

Cranesbill, 289

Cross-fertilization, 204, 206

Crowding, 250

Crown-imperial, 224

Cuckoo, 316

Cultivation, effects of, 338

i extent of, 3
Currant, 213, 344
Currents, 256-9

Dappy LONGLEGS, 328
Dahlia, 197, 224
Dartmoor, 38
Date-palm, 210, 350
Decay, 154
Defences, 240
Delta, 4
Desert, Kalahari, 110, t12 14, 125, 128
» Nubia, 121, 187
ve Pay 6, 118
Deserts, 2, 5, 6
a vegetation of, 112, 122
Djebel Attakah, 5
Dolomite Mountains, 5
Double flowers, 197
Down, 255
Downs, 39
Drought, causes of, 118-121, 323
Dust, 47
1» meteoric, 7
+ on leaves, 176
x» SITOCCO, 47
» volcanic, 48

EGYPT, 41, 120-21
Enclosure, effect of, 271, 294, 339
Eucalyptus, 97, II2, 357
European plants, 285,.298, 354
Evaporation, 91

prevented, 96

Evergreens, 95, 186

Lndex

FALLOW FIELDS, 156
Farm, mearing of word, 4

Ferments, 1
Fertilization by bees, 215-22
fi by birds, 224, 234
i by butterflies 225, 228
” by flies, 236
< in bud, 205
i by moths, 231-2
ti self, 204-206
i by snails, 239
39 by wasps, 235
on by water, 214
” by wind, 208-12
Fig, 247
Fires, forest, 143, 293
» prairie, 61

Fire-weed, 293
Foliage, 98, 103

<j desert, 97
Food of plants, 15, 139, I
different

158-60
Forms, different, 222
Foxglove, 7, 221, 245
Frost, 25, 156, 293
Fruit, 190, 212

» «eaters, 273

» Tipening of, 179-181, 185
Fuchsia, 195, 198
Fungi, 172

” ”

me lies of,

GASES, 18, 164
», weight of, 164
Germs, 154
Gipsies, 341, 352
Glaciers, 27
Glass road 26
Goats, 7, 119
Goose-wheat, 260
Gourds, 111
Granites, 23 37
Grasses, 4, 102, 142, 209, 30K
Grasshoppers, 319, 323
Growth, rate of, 172, 193
Grubs, 310, 314-15, 319-20
1, _ lawsuits against, 31
Gulf Stream, 184, 259
Gum-tree, 97

HAIRS, 100, 305
Hawks, 270, 334
Hawthorn, 272
Heather, 142
Hedges, 47, 57, 31
Helena, St., 119
Holly, 217, 297

Index

Horse-chestnut, 350
Humming-birds, 234
Hungary, dust-storms, 50
5" floads in, 46
is: saltworts in, 144
* sparrows banished from,
326

ICE-PLANT, 110
Insects, numbers of, 9, 318, 319-22
Todine, 140
Tron, 20, 169
Italy, birds destroyed in, 316
» Plants introduced into, 346

JAMAICA, 267, 271, 323

KALAHARI DESERT, 112, 114, 128
Krakatoa, eruption of, 48

LAKE-DWELLERS, 345
Landes, 57
Larks, 317
Lava, breaking up of, 3
» lichens on, 31
Leaf-green, 169, 172 :
+» Pores 93-5, 171
Leaves, alee 157, 196
‘és number of, 103
»» Office of, 169
» Size of, 103
Lichens, 4, 6, 30, 340-41
Locusts, 275, 310-11, 324
Locust-tree, 293
Lupin, 147

MANGROVES, 54

Manitoba, 61

Manuring, 61, 145

Maple, 109, 294

Melon, 12, 112, 113, 185, 197, 282,
290, 348

Mesquite, 111

Mice, 333

Mineral matter in plants, 17, 61, 140

Mississippi, 44

Mistletoe, 272-3

Mole, 66, 335

Mongoose, 323

Monkeys, 264

Moss, 32, 140

Moths, 231-2

Mud, river, 42, 46, 53

Mummy-wheat, 282

NAMES, CAUTION AS TO, 344
Nettle, 223, 247, 305, 348

363

Nile, 42-44, 134
Nitrates, 151-6
Nitrogen, 148-52
‘a compounds of, 153, 158, 160
North; vegetation of, 188
Nubia, desert of, 121, 187
Nuthatch, 264

OAK-FORESTS, 262

Ohio, crops in, 133

Oleander, 224, 347

Olives, 346

Orange, 220, 308, 351

Orchids, 228, 231, 283-5, 307

Organic matter in soil, 61

43 » Yequired by plants, 148

Ovary, 195
» development of, 213

Ovules, 195, 199, 206, 212-13, 248

Owls, 333

Oxalis, 222

Oxygen, 19

PALMS, 193, 2I0
Pampas, 3, 4, 64, 146
Para, vegetation at, 8
Passion-flower, 204, 224, 307
Peru, rainless zone of, 5
Phoenicians, 347
Pigs as planters, 276, 292, 355
Pimento walks, 271
Pines, 57, 95, 100, 209, 339
Pistil, 195, 212, 255
Pitcher-plants, 151, 235
Plantain, 342
Poisonous plants, 302
Pollen grains, 197, 200

» poisonous, 204, 22T

»» tubes, 200, 205, 213.

» ~~: Masses, 231
Potato, 344, 355
Prickly pear, 35, 36, III, 353, 358
Primrose, 142, 194, 222, 228
Protection against enemies, 240, 243,

300 .
% 1» evaporation, 95-100

RAFFLESIA ARNOLDI, 194
Rainfall, 115-23,
Raspberry, fertilization of, 219
- seeds, 283
Rats, 65, 291
Redstart, 320
Red snow, 7, 185
Rhéne, 45
Ripening of fruit, 179-81, 185
Riverina, 292

364

Rivers, 43, 44, 46, 53
Rooks, 262, 330

Romans, 348 9
Roots, 35. 52, 55, 58, 80, 124

» acid in, 35, 136

» hairs of, 131

» length of, 131

» effect of sun on, 187

»» worm-burrows and, 135
Rose, garden, 346

1» ctrees and snow-drifts, 57
Rushes, 55
Russia, 61, 62, 134, 144, 146
Rust, 19

SAFFRON, 351
Sahara, 119
Salt, 143
»» -Worts, 144
Salts, 137, 153
Sand-drifts, 51, 57
Santo Domingo, garden in, 13
Sap, 92, 107-9
Saracens, 349
Scarlet-runners, 13
Scents, 208, 223, 225, 237-9, 303
Sea-reed, 55
» Sedge, 55
» water, 16, 140
1, -weeds, 15
Sedge, bristles of, 268
Seed, destruction of, 286-7
»» carried by animals, 265, 276, 355

ip » birds, 260-72

és » fish, 275

- » locusts, 275
ie +» Water, 256-9

» Wind, 51, 253
», eaten, 327
» feathered, 255
» hooked, 265
» in mud, 268
» hitrogen in, 160
1 mystery of, 277
Secds, hard coats oi, 272, 283, 293
1, quantity of, 287
», self-burying, 289
» Similarity of, 279
» size of, 281
+ Vitality of, 281
Seedlings, destruction of, 12, 284, 300,

1
Seca veexela, exploding, 252
Smell, sense of, 241, 303-4
Snow drifts, 57
Soil, 10, 61-4

os colour of, x85

Index

Soil, moisture in, 126
» warmth of, 185

Sparrows, 324-7, 331
Species cultivated, number of, 4
Squirrels, gray, 264

Se ground, 64

i red, 263

aA tree, 263

- seeds planted by, 264, 292
Stamens, 195

+ and petals, 196
Starch, 166-7
Steam, 24
Sugma, 199
Strawberry, 218
Suez Canal, 120
Sugar-cane 351
Sundew, 150
Sunflower, 103, 151, 344
Sunlight, 161, 177
Swallows, 317, 323

TEMPERATURE, 177

i changes of, 26, 181

af effect of evaporation
on, 116, 183

i effect of ocean on,
184

a of blossoms, 238

on of fruit, 113

” of plants, 113, 175

of soil, 185

Thistles, 146, 297, 303, 331, 357-8

Vhurns, 305-6

Ticks, 322

Titmouse, 321

Tobacco plants, 126

Tokay, 143

Transpiration, 93, 106

Trees, destruction of, 56, 115, 118
» effect of, on air and soil, 57,

103, 118-21, 338-9, 355

Tulip, 350

Turkeys and hedges, 272

Turkestan, birds in, 324

Turks, 350

VALLISNERIA, 214
Vanilia 298
Venus's fly-trap, 149
Vine, 143, 180, 187
Vineyards, 143, 159
Violet, 205, 206

WARMTH OF BLOSSOMS, 238
“s need of, 217
Wasps, 235-6, 335

Index

Waarer, 6, 16
» absorbed by soil, 125
» given up by plants, 102, 104,
116

»» in plants, go .
» movement of, in plants, 108
» insoil, 125, 128 ‘
Water-lily, 256
» -pink, 256
Wax, 93, 96

365

Weeds, 286, 341-3, 348, 356, 358
Wind, birds caret oer = =
» dust carried by, 46, 51
» fertilization by, 208-12

1 seeds carried by, 253
Wireworm, 329-30
Worms, 73-83, 135°
Wren, 321

YELLOW EARTH, 145

THE END.