E C C K

Y
BRETLAND

FARMER
b-Sc-.FRS

I
s

N

\
\
\

/
y

I

/

\
N
\

\
\

/

/

/

B

DISSECTED MODEL OF A TULIP

A. — TULIP PLANT.
i. Bulb. 2. Flowering stem. 3. Flower. 4. Leaves. 5. Bulb scales. 6. Roots.

B.— TULIP PLANT. 0. — TULIP FLOWER LOOKED AT FROM ABOVE.

D.— TRANSVERSE SECTION OF THE OVARY OF THE FLOWER.

7. Base of old bulb-stem. 8. New bulbs. 9. Perianth leaves (i.e. petals and sepals). 10 and n.
Stamens do, the anther; u, the filament). 12. The Ovary. 13. Stigma. 14. The tissue of
the carpels. 15. Ovule.

\

THE BOOK OF NATURE STUDY

INSECTIVOROUS PLANTS.

I. BUTTERWORT. II. BLADDERWORT.

III. PITCHER PLANT. IV. SUNDEW.

THE BOOK OF

NATURE STUDY

EDITED BY

J. BRETLAND FARMER

M.A., D.Sc.(OxoN.), F.R.S.

PROFESSOR OF BOTANY, ROYAL COLLEGE OF SCIENCE, LONDON

ASSISTED BY

A STAFF OF SPECIALISTS

FULLY ILLUSTRATED

VOL. Ill

LONDON:
THE CAXTON PUBLISHING COMPANY

CLUN HOUSE, SURREY STREET, W.C

•:•:• •/H--U:

' * » • . •

•••\\' • ' • •

CONTENTS OF VOLUME III

CHAPTER I
PLANT LIFE

PAGE

THE LIFE AND GROWTH OF SEEDLINGS ..... i

CHAPTER II

THE GROWTH OF THE SHOOT FROM THE BUD . . . . -33

CHAPTER III

THE GROWTH OF PLANTS INDEPENDENTLY OF SEEDS . . . .60

CHAPTER IV

THE IMPORTANCE OF HAIRS IN PLANT LIFE . . . . * 73

CHAPTER V

SOME COMMON FLOWERING PLANTS
INTRODUCTORY ......... 85

CHAPTER VI
SPRING FLOWERS . . . . . . . -115

CHAPTER VII

EARLY SUMMER FLOWERS 166

357750

LIST OF PLATES— VOLUME III

COLOURED PLATES
DISSECTED MODEL OF TULIP ....

INSECTIVOROUS PLANTS .....

CLIMBING PLANTS .....

DANDELION ......

GREATER BIRD'S-FOOT TREFOIL
RIBWORT PLANTAIN .
YELLOW FLAG

PAGE

. Front Board
Frontispiece
. 72
. So
. 172
. 208
. 224

BLACK AND WHITE PLATES
FOXGLOVE, MULLEIN, NETTLE-LEAVED CAMPANULA .
THE CREEPING BUTTERCUP ....

THE LADY'S SMOCK .....

PRIMROSE ......

DAFFODIL . . .

WILD STRAWBERRY .....

THE GARDEN SAGE .....

LONDON PRIDE ......

THE COMMON AVENS .....

vii

• 32
. 96

I2O
. I30

. 160
. 168
. 184
. 192
216

THE BOOK OF NATURE STUDY

PLANT LIFE

BY Miss CHARLOTTE L. LAURIE,
Assistant Mistress, Cheltenham Ladies' College.

CHAPTER I

THE LIFE AND GROWTH OF SEEDLINGS

IT is strange how little the majority of people realise that plants
are living organisms. They are inclined to think of them as
inanimate, and to wonder what Wordsworth meant by speaking
of every flower enjoying the air it breathes, or the budding twigs
feeling pleasure in spreading out their leaves. Now, although
many scientists would hesitate to personify Nature as Wordsworth
does, the fact of life which the poet is here emphasizing is in-
disputable.

Plants are capable of the same vital functions as animals.
They breathe, they take in food, they respond to their surroundings
in the most marvellous way, they grow, they produce other plants
like themselves ; in fact, they are capable of all the functions
which are characteristic of life. Nothing is more interesting than
to trace the adaptation of structure to environment, of which
plants are capable. This is best studied in the various forms of
leaves, in their arrangement on the stem, their hairiness, texture,
etc. Some of the characteristic plants of the dry and sunny
Australian climate have their leaves attached to the stem in such
a way that they present the margin, not the blade of the leaf,

VOL. III. — I

THE BOOK OF NATURE STUDY

v •*> ^ -

to the light. This is well seen in some of the plants now so
commonly sold by florists. The Eucalyptus is an example of this,
as is also the Acacia, though in the latter plant the "leaves" are
really flattened leaf stalks. On the other hand, the majority of
plants spread out their leaf-blades to the light, which is far less in-
tense in our own climate. Again, Alpine plants like those found on
the tops of the highest Scotch mountains, such as Ben Lawers, are
often of much smaller growth, with small hairy leaves in rosettes,
because in these high altitudes, owing to the special conditions of
temperature and wind, it is important that the plant should give
out as little water as possible, and the leaf surface is therefore
considerably reduced, or very hairy. Plants of this kind are to
be found even on hills not more than 800 feet high. The Stork's
Bill, the Field Alchemil, the Alpine Pennycress may be mentioned.
The leaves of water plants, as every one knows, are very different
from those of land plants. Some have long, ribbon-like leaves,
which can stand floods better than any other shape ; others have
leaves adapted for floating, whilst a third set of water plants
have leaves able to live and do their work entirely under water.
In plant life, too, there are quite as many interesting biological
problems to be solved as in animal life. The phenomena of the
distribution of plants offer a wide field to the speculative botanist.
No satisfactory explanation of the flora of certain areas is as yet
forthcoming. There is a district in Gloucestershire, — which shall
be nameless, as there are some rare plants in it, — where certain
species not present anywhere else in the county are to be found.
How did they get there ? Supposing that the answer is, that
certain seeds are carried long distances by the wind, still the
puzzle remains : Why have these plants established themselves
just in this small area and nowhere else in the county ? What
conditions, or combination of circumstances, obtain there, and just
there alone, that are absent in the immediate neighbourhood ?
Or, to take another biological problem. There is abundant
evidence of a struggle for existence going on between plants. This
is being more and more realised, now that vegetation maps are
being drawn in many parts. On certain Yorkshire moors, the
bilberry is struggling with the cotton-grass. Where the moor is
windswept and drier, the bilberry ousts the cotton-grass and

THE LIFE AND GROWTH OF SEEDLINGS 3

becomes the dominant plant. Trees even supplant each other.
Warming states that in Denmark the oak has been replaced by
the beech, whilst in West Jutland it is able to hold its own.

It will be clear from what has been said that the study of
plant life is abundantly fascinating. Every one with even a
small garden can watch the spread of a given plant, or the adapta-
tion of structure, or the growth of seedlings. Even without a
garden a great deal can be done with window boxes, with seeds in
saucers, or in glass jam jars.

The habit of observing Nature brings with it its own delight,
and, once begun, is not likely to be given up ; but the importance
of a real, first-hand knowledge of Nature cannot be exaggerated
in the case of those engaged in what is popularly called " Nature
Study/' The main object of Nature Study should be to develop
the mental faculties of observation and reasoning. This cannot
be done satisfactorily except by those teachers who are always
finding out things for themselves, and constantly experimenting
in one way or another, either repeating the experiments of others,
or, still better, devising new ones, however small, for themselves.
For this reason, constant reference will be made in this section to
new work both in America and in Europe, and a bibliography
will be given, in which the more recent botanical literature will
be mentioned. Laboratory experiments are valuable, and in
towns may be the only ones possible, but those who live in the
country should be content with nothing less than observing
Nature accurately and, like Gilbert White of Selborne, sympathetic-
ally and reverently.

In planning a course of lessons in Nature Study, it is important
to be systematic. There should be one main thought under-
lying the course, just as there ought to be in a well- written
biography. Nature Study courses not seldom resemble those
biographies which are hastily compounded of newspaper articles,
or letters from friends, strung together without any leading idea,
as far as one can see, to form a bond of union. A course on
Plant Life might have for its basis the adaptation of structure
to function, or the manifestations of vitality common to both
plants and animals. In this section, these are the root-ideas under-
lying the various experiments given and the facts of structure

4 THE BOOK OF NATURE STUDY

that are recorded. It does not very much matter what the leading
idea in the teacher's mind is — that must depend on the individual
teacher — but it is important that the lessons should succeed each
other in the order which best develops the conception that it is
desired to impart of Nature and her ways.

STRUCTURE OF SEEDS. — The study of Plant Life may be begun
with that of seedlings, and in order to understand the germination
of a seed, it is necessary first to know its structure. If the seeds
of various typical plants are examined, it will be found that the
essential part of all seeds is the embryo of the young plant. Now
it is obvious that the young plant must have something within
the seed to feed upon until it is able to obtain food-material for
itself from its surroundings, the air and the soil. This food-
material is sometimes contained within the embryo, sometimes
outside it. It is therefore necessary to examine several seeds,
and the following will be found representative types : — i. Bean,
pea, mustard and cress, cucumber, all of which have food-material
contained in the embryo ; 2. Buckwheat, maize, wheat, barley,
which have food-material outside the embryo.

To begin with the structure of the bean or pea. The mode in
which the seeds are attached in the pod is shown in the folded
diagram, inside the cover of Vol. IV. It will be noticed that the
pod, or seed-vessel, splits into two pieces, an experience familiar
to every one who has shelled peas. The seeds come off alternately
in the two pieces, but are all attached to the same edge of the seed-
vessel, each by a little stalk. It was by means of this stalk that
the bean plant was able to feed the seeds when they were
developing. The dry seeds of the broad bean are brown, convex
on one side, and more or less straight on the other. The
brown structure is the seed-coat ; on one side is a black scar
showing the position of the stalk, attaching the seed to the pod.
In seeds which have been soaked for twenty-four hours, the
seed-coat, which was at first wrinkled, becomes stretched, owing
to the water that has been absorbed. A triangular structure is
seen through the testa, the apex of the triangle pointing towards
the scar. This is the radicle, or first root. If a seed which has
been soaked is dried on the surface and then squeezed, water will

THE LIFE AND GROWTH OF SEEDLINGS 5

be seen oozing out through a little hole, situated between the
apex of the radicle and the black scar. It is through this hole
that the root pushes its way. On removing the seed-coat the
greater part of the seed is found to be occupied by two thick,
fleshy lobes ; these are the cotyledons, or first leaves, of the
young plant. It is these that contain the food for the seedling.
Between the cotyledons a structure continuous with the radicle
is seen, namely, the plumule ; this gives rise to the young shoot.
In the case of the bean, then, the seed consists of —

1. The seed-coat.

2. The embryo or young plant, the parts of the embryo being
the two cotyledons, the radicle and the plumule. Note that the
embryo fills the seed, and that the food for the young plant is
contained in it.

With the bean may be compared the buckwheat. The
seed sold by the seedsman is a fruit, for the outer brown coat
is the wall of the ovary. It is a three-sided nut. On soaking
these nuts for twenty-four hours, they swell owing to the absorp-
tion of water. The outer coat is then softer and can easily be
peeled off, exposing the thin seed-coat, or testa, immediately
underneath it. The whole seed then appears to be filled with a
mealy substance. This is the food-material, called endosperm, or
albumen ; the food is outside the embryo, not contained in it, as in
the bean. On gently scraping away the endosperm, the embryo
is visible. The cotyledons are thin leaves folded in the endo-
sperm, the radicle lies at the apex of the seed and the plumule
lies towards the opposite end. This seed then resembles that
of the bean in having two cotyledons, a radicle and a plumule ;
that is to say the embryos are alike in the two cases. It differs
from the bean in having the food-material outside the embryo.
It is an albuminous seed, whilst the bean is exalbuminous.

GERMINATION OF BUCKWHEAT. — The Buckwheat germinates
quickly in a moist, warm atmosphere. If several nuts are sown
in boxes of soil, one seedling can be taken up every day, in order
to see the stages of development.

i. The nut swells, and the radicle, making its way through
the thin testa, bursts the outer coat of the nut at the apex by

THE BOOK OF NATURE STUDY

splitting it into three pieces. It grows downwards, forming the
primary root and giving off lateral branches.

2. The first thing to be observed above the soil is a structure
in the form of an arch. This is the portion of the skin below
the cotyledons, called the hypocotyledonary stem, or hypocotyl.
During the first stages of germination the cotyledons are busy
absorbing food from the mealy endosperm in which they are

enfolded, and handing it on to
the growing seedling.

3. The hypocotyledonary
stem next straightens itself,
sometimes making a revolution,
as shown in Fig. i, at the bent
portion. The two cotyledons
are still folded in the nut.

4. Then the nut falls off,
and this is the moment to
observe the folding of the
cotyledons before they expand.
As soon as they spread them-
selves out they become green.

FIG. i.— Seedlings of buckwheat. A, Section The plumule situated between
of nut of buckwheat; pr, outer coat; them is at first very minute,

radicle; /, plumule : ; *, b t jt SQOn wg — rige

endosperm. B, Seedling of buckwheat

with outer coat ; pr, with coat still on.
C, Seedling, with outer coat off and coty-
ledons folded. D, Seedling with coty-
ledons, c, spread out.

to the stem and foliage leaves.

STAGES TO BE OBSERVED
IN GERMINATING SEEDS. — In
watching the germination of seeds as just described in the buck-
wheat, the behaviour of the cotyledons, the elongation of the
radicle, and then the development of the plumule should be
noted. Observation of several typical seeds will show —

1. That germination is a much slower process in some than
in others.

2. That the cotyledons behave very differently in different
cases. Sometimes they remain underground, the young plant
living for a time on the food contained in them. In other cases
they soon appear above the ground, and begin to make food for

THE LIFE AND GROWTH OF SEEDLINGS

the plant from the materials derived from the air and the water
taken in by the root. In certain types the cotyledons hardly
develop at all, the seedling deriving its food from the food-material
outside the embryo, as described in the buckwheat.

3. The mode of development of the plumule to some extent
depends on the nature of the cotyledons. If these come above
the ground very soon, they carry the plumule with them ; but
when the cotyledons remain in the ground, the plumule has to
force its way through the soil, and it is very interesting to observe
how it does this. It should be noticed, too, that the growth of
the plumule does not take place until the radicle has reached a
considerable length, for the young plant must have a grip of the
soil before it can support the weight of a stem above the ground.

GROWTH OF SEEDLINGS. — In order to watch the growth of
seeds, plant four or five sets of different seeds in boxes at intervals
of about three days, so as to have seeds in different stages of
development at the same time. Radish, mustard and cress,
buckwheat, pea, bean, wheat,
barley, maize are some of the
best types. The patch where
each set of seeds is sown
should be labelled with the
name of the seed and the date
of sowing. As far as possible
they should be kept in the
same temperature. If the
seeds are sown early in March,

the boxes should not be left FIG. 2.— Seedling of radish, in three stages of
OUt at night On account Of development The horizontal lines mark

- _ 1 r° _ . J . the level of the soil.

probable frosts, but it is as

well to put them out during the day, provided they are not
exposed to too hot sun. A good mixture of soil is two parts
turfy loam, one part leaf-mould, half a part peat, and half a
part sand.

In about ten days' or a fortnight's time from sowing the
seeds the cotyledons will be seen above the surface in the
patch of mustard or radish. Each seedling has two cotyledons.

8 THE BOOK OF NATURE STUDY

When they are first seen above ground they are pressed together
looking like one leaf. Compare with these the seedlings of the
seeds that were sown three days later. They are not yet above
ground, therefore in order to see them the surface soil must be
gently scraped away. The hypocotyl will be seen in the form of
an arch, like the letter U turned upside down ; the cotyledons
may be still within the seed, or possibly they may have just
emerged. If they have come out. of the seed, note that they are
yellow, not green. It is by means of the arch that the hypocotyl is
able to drag the seed-leaves out of the seed. As soon as the arch of
the hypocotyl rises above the soil the two limbs of the arch begin
to separate, this allows the inner surface of the arch to grow more
quickly than the outer. The limb of the arch nearest the seed is
helping to keep the seed fixed in the soil, whilst the other is
tugging away vigorously at the seed-leaves, pulling them out of the
seed. As soon as the cotyledons have been dragged from beneath
the ground the hypocotyl 'straightens itself, the two seed-leaves
which had been pressed together separate, turn green owing to the
influence of light, and begin to make food for the young plant.

SEEDLING OF PEA. — The pea and bean seeds behave differently.
To begin with, they grow rather more slowly than the mustard or
radish. Nothing could be seen above the soil till sixteen days

after the seeds were sown.
The broad bean was slower
than the pea, and the kidney
bean the slowest of the three ;
it was nearly three weeks
before there was any sign of
growth above the soil in the
case of the broad bean. The
cotyledons of these three seeds
remain in the ground, the
_ epicotyl, or plumule — not the

FIG. 3.— Seedling of pea. ,

hypocotyl — making its way
through the soil. Here, again, the arch form may be observed, by
clearing away the upper layer of soil and examining peas or beans
in different stages of development.

THE LIFE AND GROWTH OF SEEDLINGS 9

In his work on the Movements of Plants, Darwin gives some
interesting experiments which he devised in order to form some
idea of the upward growth of the plumule after it had straightened
itself. He found in the case of the common bean, that " the basal
leg grew upwards with a force sufficient to lift a thin plate of zinc
loaded with 12 ounces. Two more ounces were added, and the 14
ounces were lifted up to a very little height, and then the epi-
cotyl yielded and bent to one side " (Movements of Plants, p. 88).

HYPOGEAL COTYLEDONS. — The cotyledons of some plants
never leave the seed, partly because the testa does not readily
split, and it is therefore difficult to extricate the seed-leaves.
Those of the pea, the broad bean, and the kidney bean do not
(although those of the dwarf French Bean and other species do) ;
neither do those of the oak, the horse chestnut, and the walnut.
In the month of May in an oak wood, numbers of acorns will be
seen on the ground sprouting, with the cotyledons inside the nut ;
whilst in the beech, the holly, the gorse, and in the majority of
trees and shrubs, the cotyledons will be found above ground.

As a rule, the cotyledons which do not come above ground are
thick and fleshy, for they have absorbed all the food-material
formed in the ovule after fertilisation. These are exalbuminous
seeds. So too are the seeds of the radish, mustard, cucumber ;
but these have smaller and more delicate seed-leaves, which come
above ground, turn green, and are able to take in food-material
from the air and make food for the young plant.

The wheat, maize, barley form another group. They are
albuminous seeds, i.e. they contain food-material apart from the
embryo, in that part of the seed known as the endosperm.

ALBUMINOUS SEEDS COMPARED WITH EXALBUMINOUS. — To
realise the difference in the structure of a grain of wheat and the
seed of a pea, soak a few peas and grains of wheat for twenty-four
hours and then examine them. The seed-coat of the pea is
tightly stretched, owing to the water absorbed, the outlines of the
triangular radicle can be seen, the apex pointing towards the
scar. On removing the seed-coat, the whole of the seed is seen to
be occupied by the two cotyledons with the plumule between them,

10

THE BOOK OF NATURE STUDY

and the radicle just ready to push its way through the testa. In
fact, the seed of the pea consists practically of the seed-coat and
embryo.

In the grain of wheat, the embryo is very minute and occupies
but a small portion of the whole grain. Its position is indicated
by the pale patch on the convex surface of the grain. The greater
part of the grain consists of a white substance, the endosperm
or albumen, which was formed in the ovule as a result of

FIG. 4.— Seedling of wheat.
/, primary root.

FiG. 5. — Seedling of onion.
The dotted line marks
the level of the soil.

fertilisation. The difference between albuminous and exalbumin-
ous seeds is simply this ; in the former the food-material is not
absorbed by the embryo, in the latter it is. The embryo is in contact
with the endosperm by a shieldlike structure, the scutellum,
which probably represents the cotyledon. The scutellum sucks
food from the endosperm and hands it on to the young plant.
The outer coat of the grain is the wall of the ovary, the seed-coat
adheres to it and can only be detected with the aid of a microscope.
The plumule of the wheat is curved, but does not form as complete

THE LIFE AND GROWTH OF SEEDLINGS

ii

an arch as that of the pea or bean, for as the plumule is not
situated between two cotyledons, there is not the same necessity
for a vigorous pull. On the other hand, the onion does make an
arch. Darwin notes (Movements of Plants, p. 87) that in germina-
ting monocotyledonous seeds, the plumules are straight whilst
breaking through the ground, and that those of the Gramineae are
likewise straight ; their emergence from the soil is facilitated,
he thinks, by the sharp crest in which they terminate. In the
onion, the crown of the arch is developed into a white, conical
protuberance which he considers helps the seedling to break
through the ground.

The growth of the onion seedling is shown in Fig. 5. By
gently scraping away the soil the grain is seen, and the
arch form of the plumule. The
level of the soil is indicated by
the dotted line. As the seedling
grows it frees itself from the
grain, but sometimes this is carried
up above the soil, as in the
illustration. As the plumule
grows, it gives off leaves which
ensheath the stem. The root-
system does not show a tap root,
for in monocotyledons the prim-
ary root does not grow to any FlG- 6. — Seedlings of cucumber; r,
great length; the Other roots radicle; A peg of radicle; ,, cotyle-

dons ; /, seed-coat.

soon equal it. A root-system of

this kind is described as fibrous. The primary root can usually

be detected by the sheath at its base.

The pumpkin and cucumber have a peculiar way of
pulling the cotyledons out of the seed-coat. The general
structure of the seed is similar to that of the bean ; the
radicle pushes its way out first and grows down into the soil.
On its lower side it develops a peg, which holds down the
seed -coat until the cotyledons have burst through the testa.
Cucumber seeds must be grown under glass, and are very
slow in developing, although, of course, much depends on the
temperature.

12 THE BOOK OF NATURE STUDY

The seeds already mentioned may be classified in the following
groups : —

I. SEEDS WITH Two COTYLEDONS. — Epigeal Cotyledons. —
Radish, Mustard and Cress, Dwarf French Bean, Pumpkin and
Gourd, Buckwheat, Horse Chestnut, Beech, Holly, Gorse.

Hypogeal Cotyledons. — Pea, Broad Bean, Kidney Bean, Oak.

II. SEEDS WITH ONE COTYLEDON. — Wheat, Barley, Maize,
and those of all Grasses.

Or they may be grouped, according to the presence of food
in the embryo or outside the embryo.

Albuminous Seeds. — Buckwheat, Maize, Barley, Wheat,
Oats.

Exalbuminous Seeds. — Radish, Mustard and Cress, Beech, Holly,
Gorse, Horse Chestnut, Pumpkin, Pea and Bean, Oak.

GROWTH OF THE RADICLE. — Attention has been drawn to
the growth of the cotyledons and plumule before that of the
radicle, because the growth of a radicle takes place out of sight,
and in order to observe it seeds must be grown in moist air, or
on a sponge or blotting paper, in sawdust or in sand. All
these give good results, provided the seeds have sufficient
moisture, heat, and air. Mustard and cress grow very readily
on a piece of sponge, suspended in a glass bottle with water at
the bottom so as to keep the air moist. The mouth of the bottle
may be covered with a thin strip of cork, leaving an opening on
each side, in order that the air may have easy access to the
seeds. The following is a diary kept of the growth of mustard
seeds on a damp sponge : —

1907.

March 5. Seeds sprinkled on damp sponge.
„ 6-8. Seeds are swelling.
„ 9. The first root (the radicle) bursts its way through

the seed-coat.

,, 10. Root-hairs appear behind the tip of the root.
„ 12. The seed-leaves come out and turn green.

THE LIFE AND GROWTH OF SEEDLINGS 13

1907.
March 15. The first bud (the plumule) can just be seen

between the seed-leaves.

„ 30. The stem of the young shoot has given off two
green leaves which are different in shape from
the seed-leaves.

The bean seed is one of the best to grow in moist air, and
the pea also answers well. The seed may be suspended in a
glass bottle with a wide mouth by means of a blanket pin passing
through the cork of the bottle and one of the cotyledons. There
should be water at the bottom of the bottle. The bottle should
not be tightly corked, for the seed requires air ; at the same time
it must be sufficiently tightly corked to allow of the air inside
the bottle being kept moist, otherwise growth is very slow. It is
best, too, to keep the bottle in the dark, bringing it in to the light
from time to time to examine the growth of the radicle, as most
roots grow best in darkness. As far as possible the temperature
in which the bottle is kept should be even and about the average
heat of the room, say 60° F. If exposed to greater heat, the
radicle will grow faster, but the temperature should as far as
possible be kept the same. Two seeds may be fixed each in a
glass bottle, one with the radicle directed downwards, and another
with the radicle pointing upwards. As would be expected, the
radicle grows downwards in the first case ; in the second, as soon
as it has burst the seed-coat and grown a little, it curves and
then grows downwards. Under normal conditions roots always
grow downwards. Gardeners when sowing seed let it fall as it
comes, for they know that in whatever position it happens to
lie, the radicle will grow downwards.

In growing a pea or a bean in moist air, it is easy to show
that growth is most active at the apex of the root. This is an
experiment that can be set up during a lesson and watched from
day to day in a classroom, if the bottles are kept in a cupboard
in the room ; they may be examined at stated intervals and
a drawing made of the radicle, say every twelve or twenty-four
hours. The experiment is as follows :— Draw lines 2 millimetres
apart in Indian ink across the radicle, an inch and a half in length.

THE BOOK OF NATURE STUDY

The lines should be very carefully drawn to the very tip of the
radicle. At the end of twenty-four hours the distances between
the lines, which at first were equal to each other, are now very
different, the greatest distance occurring
near the tip of the root. This experiment
shows that growth is most active just be-
hind the tip of the root.

Another plan is to grow the bean in
sawdust, then to mark the radicle with
equidistant lines, and to examine the radicle
at the end of every six, twelve, and twenty-
four hours. Pfeffer in his Physiology of
Plants (vol. ii. p. 8) gives a seedling of vetch
(Vicia Faba\ in which the end of the root
had grown 4-6 millimetres in six hours and
20 millimetres in twenty-four hours.

Sometimes seeds do not give the ex-
pected results in moist air ; when this is the
case it is generally due to the air not having

beCn ^P1 m°ist> Water haS been lost b^

marked with trans- evaporation and by absorption into the seed,
verse lines to show and has not been renewed. The advantage
the region of greatest f fet air over sawdust is, that if the

growth. . >

seeds are suspended in moist air to the
cork of a bottle, they can be examined without disturbing
them.

ACTION OF GRAVITY ON ROOTS. — That roots grow downwards
owing to the action of
gravity may be demon-
strated to a class by
means of a simple form
of clinostat. A con-
venient form of this
instrument has been
introduced by taking
a strong eight-day clock
and fastening to the FIG. 8.— Clinostat.

FiG.7.-Radicleofbean,

THE LIFE AND GROWTH OF SEEDLINGS 15

axle of the minute hand a disc of metal or wood, faced with
cork about 3 inches in diameter, so that it will revolve in a
plane parallel to the face of the clock. A moist chamber may be
then made of mica, which can be fitted to the edge of the cork.
Seedlings of bean, etc., can then be pinned to the cork in various
positions in the moist chamber thus constructed. The radicles
of the seedlings will be revolving and will therefore not grow
downwards. With this may be compared seedlings pinned in the
same positions to a cork fixed in a similar moist chamber, but
standing upright, not rotating. The radicles in this case grow
downwards.

THE INFLUENCE OF MOISTURE. — Although roots grow down-
wards in obedience to the stimulus of gravity, they are even more
strongly influenced by moisture. To try this, grow seeds in damp
sawdust in a box the bottom of which consists of wire gauze.
Then suspend the box in dry air, being careful to keep the saw-
dust moist. The radicles grow downwards through the saw-
dust, then they make their way through the wire gauze, and
finding themselves in dry air, curve and grow upwards again,
being attracted by the moisture in the sawdust.

It should be remembered that although roots require moisture,
they do not thrive in stagnant water, for they need air as well as
moisture. Nearly all plants flourish better in drained, than in
undrained, land. Some of the advantages of drainage are, that
the roots can penetrate more deeply, and not only air, but also
water falling on the soil, can get into it. Moreover, this water
often contains nutrient materials derived either from the air
or from manure, which are thus supplied to the plant. Farming
in England has been considerably improved of late years by good
drainage.

THE INFLUENCE OF LIGHT AND DARKNESS. — Seeds grown in
moist air, instead of being kept in a dark cupboard until the roots
are fully grown, may be kept in the light. Then if one bottle is
covered with brown paper, whilst the other remains exposed
to the light, any difference in the growth of the radicle can be
seen by comparing the two. A still better plan is to grow the

i6

THE BOOK OF NATURE STUDY

seeds in glass cylindrical vessels. Cocoanut fibre is wrapped
in some porous paper and placed in the cylinder. The paper
is kept moist. The seeds are sown on the paper next the glass.
If exposed to the light, the radicles may be seen bending in-
wards and growing into the cocoanut fibre ; if the glass cylinder
is covered, then the roots grow straight down between the paper
and the glass.

GROWTH OF THE RADICLE IN SOIL. — When planting seeds in
soil, it is usual to make a drill i or 2 inches deep, then to sow
the seeds and to rake the earth gently over them. The weight

of the soil on the seed helps to press it
down and keep it fixed, whilst the radicle
is making its way out and pushing down
through the soil. When the seed is not
pressed down in this way the root-hairs
which are developed behind the tip of the
radicle become attached to whatever sur-
face they may be growing on, and thus
hold down the upper part of the radicle,
whilst the tip is forcing its way downwards
through the soil, or sponge, or blotting
paper, or whatever the substance on which
the seed is growing. This is very well
seen in barley grown on blotting paper
kept moist in a glass jam jar. In about
three weeks' time the roots will be several
inches long, and if it is attempted to pull the

FIG. SA.— Barley grown on ,»,. ,, -11 ,,• , ••• ,

blotting paper, showing seedling away, the blotting paper to which
root-hairs. the root-hairs have attached themselves

will also be torn away.

It is easy to see how a root penetrates the soil. The apex
is always pointed and protected by a root-cap. The tip of the
root grows rapidly in length and thickens. It is thus able to
push away the earth on all sides. Darwin compares the force
exerted by a growing root with that of a wedge of wood, which
whilst slowly driven into a crevice, is made to expand owing to the
absorption of water, and he remarks that a wedge thus acting

THE LIFE AND GROWTH OF SEEDLINGS

dll split even a mass of rock. It is well known that roots help
>nsiderably in breaking up the subsoil ; they also follow the
-ack of earthworms, which, as it were, prepare a passage for the
'oung plant.

REGIONS OF THE ROOT. — As a root grows, certain regions
may be detected : (i.) The growing-point is just behind the root-
cap.

(ii.) Next comes the elongating region, that is the part growing
rapidly in length.

(iii.) Behind that is the region bearing root-hairs.
(iv.) Behind that again, the region which is growing in thickness
id developing branches, i.e. lateral roots.

In order to see how the branches arise, the outer tissues nearest
te branch should be scraped away, and it will then be seen that
ie branches arise internally ; or sections may be made and
:amined under the microscope.

A transverse section should be made through the main root,
iust where one of the branches is
:oming off. In the accompanying
igure the branch (L) is seen arising
:om the inner tissues from one of
ie bundles of the wood. It then
mshes its way through the outer
issues, and grows out laterally from
ie main root. Although these
lateral roots grow more or less
horizontally, their tips bend down-
wards. This enables the root to
reach those portions of the soil

where nutriment an pi moisture are most abundant. These
lateral roots are of special importance in trees. Both the
birch and the beech are able to thrive in very shallow soil,
on account of their immense system of lateral roots. Even
where trees have a deep root-system, their lateral roots are
of great use to them, for they usually extend horizontally to
the circumference of the tree. Every one knows that it is possible
to shelter under a tree during a slight shower, for until the foliage

FIG. 9. — Transverse section through
a dicotyledonous root. L, lateral
root.

VOL. III. — 2

i8 THE BOOK OF NATURE STUDY

is wet through, the soil underneath remains dry. If the tips
of the lateral roots did not reach the circumference, only soaking
rains would be of any value to the tree. Teachers living in the
country might encourage their pupils to observe the root-systems
of trees as far as possible. They might notice, for instance,
the exposed roots of the beech, supporting itself one hardly
knows how on the deep banks of a country lane. Or the Scotch
Fir (Finns sylvestris) may be examined. This tree lives on dry,
sandy soil, and is not usually easily uprooted, for the main root
is deep and gives off widespreading lateral roots. When one of
these trees is found uprooted, it will probably be seen that it
has been growing in shallow soil, and has therefore only been
able to form a short main root. Sometimes two trees, the one
having a deep-rooted, the other a shallow-rooted, system, are
found growing together. The oak and the beech are examples
of this. The former strikes its roots into the soil sometimes to
a depth of 5 feet, leaving plenty of room for the shallower system
of the beech, and at the same time profiting by its association
with the beech, whose leaves furnish it with humus.

CONDITIONS OF GERMINATION. — So far, the first stages of
germination have been considered, namely —

(a) The protrusion and growth of the radicle.

(6) The emergence of the cotyledons above the soil in many
seeds.

Before going on to describe the development of the shoot
from the plumule, it will be as well to consider more exactly
the conditions necessary for germination, and, in fact, for the
life of the plant. And here the teacher should proceed by means
of experiments, in order to develop the reasoning power. The
experiment should be as simple as possible, should be suggested
by the student, and should be carried out with as simple apparatus
as possible. In some laboratories unnecessarily expensive appar-
atus is sometimes provided. This is a disadvantage, for the
simpler the experiment, the more likely is a student to repeat
it at home.

To proceed from the known to the unknown is a very
sound principle. It will be natural, therefore, to inquire whether

THE LIFE AND GROWTH OF SEEDLINGS 19

the conditions of growth in plants are similar to those under
which animals and human beings thrive.

(i.) Necessity of Air. — It is a matter of common experience
>ven to a child that no human being, no animal, can live without
air. Is this true of plants ? By experiment, it can be shown
that air consists mainly of oxygen and nitrogen, the former
being about one-fifth of its volume, the latter four-fifths. To
exclude oxygen from seeds and to see the effect of doing so is
the object of the following experiments.

1. Germinating seeds are grown on a sponge suspended in
a bottle with some pyrogallic acid, dissolved in a strong solution
of potash, at the bottom. The processes of germination are
stopped and the seeds die, because the oxygen has been absorbed
by the solution, and seeds cannot germinate without oxygen.

2. If germinating seeds are put in a glass bottle, tightly corked
with an indiarubber bung, they will, in about twenty-four hours, or
even less, have absorbed all the oxygen. A lighted taper plunged
into the bottle at once goes out, owing to the absence of oxygen,
and supposing the seedlings were left an indefinite time instead
of twenty-four hours, they would die.

These experiments clearly show that seeds require air, for
they must have oxygen. It is because germinating seeds need
oxygen, if they are to live, that care has to be taken in the pre-
paration of the soil of a seed-bed. It should be well separated
and well drained, in order that air may make its way easily
between the particles, so that the radicle as it grows into the
root may get the oxygen necessary to its life.

The taking in of oxygen from the air is not the only chemical
process going on in germination. It is a matter of everyday
experience that the air of a room in which people are living
requires renewing, otherwise it gets stuffy and gives headache
to those who are obliged to remain in it. If some of the air in
a stuffy room is collected in a glass jar in which some lime-water
has been placed, the lime-water will turn milky, owing to the
presence of carbon dioxide. To show a class the source of the
carbon dioxide, it is merely necessary to breathe into a test-
tube containing lime-water, then pressing the thumb tightly
gainst the mouth of the test-tube to shake it well. The lime-

20 THE BOOK OF NATURE STUDY

water turns milky. As lime-water always turns milky when
carbon dioxide is mixed with it, it is clear that human beings
breathe out carbon dioxide, and thus the air in a room in which
people are sitting for some time gets laden with carbon dioxide.
In order to ascertain whether seeds also breathe out this gas,
the air in a glass bottle in which germinating seeds have been
placed for twenty-four hours may be tested in the same way, by
pouring a little clear lime-water into it and shaking it up. The
lime-water becomes milky. The conclusion, therefore, is that
germinating seeds give out carbon dioxide.

Experiments such as these are very simple, but they serve
to develop the reasoning power, and help children to understand
that respiration goes on in seeds as it does in human beings and
in all animals ; for the taking in of oxygen and the giving out
of carbon dioxide always accompany respiration. What is true
of seeds is also true of the fully grown plant ; all the ordinary
plants, as long as they are alive, are taking in oxygen and giving
out carbon dioxide.

(ii.) Water Essential. — Seeds must have water; as long as
they are in a dry condition they will not germinate. Some
seeds can retain their vitality in a dry condition for years. Just
lately Becquerel has experimented on the seeds of 500 species
of plants belonging to 30 of the most important families of
Monocotyledons and Dicotyledons. The age of the seeds was
known from the records of the Museum of Natural History in
Paris. He found that 18 species, 87 to 28 years old, of Legum-
inosse ; 3 species of Nelumbium, 56 to 18 years ; one Lavatera,
64 years old ; and a Stachys, 77 years of age, germinated.1
Gardeners say that the best seeds to sow, best because most
certain of producing good plants, should be a year old. There
is nothing in the external appearance of a seed to denote whether
it is dead or living, but as soon as it is soaked in water the living
seed will begin to germinate; the dead seed will not. Seeds
may be killed by boiling them, and then they will not germinate.
Both living and dead seeds will take up water, but it is only in
the living seed that the radicle will begin to protrude. It takes

1 This, however, is not universally true ; some seeds very soon lose their power of
germination, and require to be sown the same year in which they are ripened.

THE LIFE AND GROWTH OF SEEDLINGS 21

some time for the seed to absorb as much water as it can take up.
When a broad bean, or a pea, or, in fact, any seed is soaked,
the gradual absorption of the water is evident from the stretching
of the seed-coat. When dry, this is more or less wrinkled, but
after three or four days the seed-coat becomes tense and splits,
allowing the radicle to protrude. As seeds swell, they exert
great force ; it is stated that a large mass of swelling peas may
lift 100 Ib.

(iii.) TEMPERATURE. — Seeds require Warmth. — Seeds do not
germinate without a certain degree of warmth. A convenient
temperature is about that of an ordinary living room ; any-
thing between 21° C. and 35° C. will answer for the majority
of seeds. Above a certain temperature, seeds will not germinate.
Similarly, if exposed to too great cold, as, for instance, freezing-
point, germination does not take place. It is advisable to keep
germinating seeds in an equable temperature and rather moist
air. One reason for planting hedges round fields is to protect
the young crops from the strong, often very cold, March winds,
which might injure the seedlings irreparably.

(iv.) Germinating Seeds require Food. — It is by the absorption
of water and the food-material contained in it that young
seedlings get their food. In the first few days of germination,
seeds, like the bean, with fleshy cotyledons feed on the food
contained in the cotyledons. In the case of seeds of rapid
growth, like the radish and mustard, the radicle very soon
develops root-hairs which absorb food-material from the soil.
This food-material is taken in with the water. Even when the
seeds are grown on damp blotting paper, or on a sponge, a certain
amount of food-material will be absorbed with the water, for
no water is absolutely pure. From ordinary tap water with
mere traces of salts, plants manage to collect large quantities
of mineral constituents, and in the case of water left exposed
in rain-butts, or open cisterns, the impurities are considerable
and furnish food-material for the innumerable algae so com-
monly found in it. Seeds planted in soil get their food-material
from the mineral substances present in the soil, from the leaf-
tould and the manure, all these constituents being dissolved in
tter before the root-hairs can absorb them.

22

THE BOOK OF NATURE STUDY

To show that substances must be in a state of solution, in
order that they may be absorbed, the following experiment
should be tried. Place a white narcissus in a tumbler containing
red ink and water. The solution passes up through the stalk of
the flower and colours its petals pink. Compare with this a
narcissus placed in carmine and water. The dye does not find
its way into the petals, for carmine does not dissolve in water.

It is the root-hairs on the roots that absorb water and the
salts it contains. If seedlings are grown in sand, then taken
up when the roots are some inches in length, that part of the
root which has root-hairs will be covered with particles of sand.
The best way of seeing the root-hairs is to shake the seedling in
water, the sand comes off and the hairs are seen glistening in
the water.

A seedling of wheat grown in soil and uprooted is shown.
The root-hairs are covered with particles of soil. (See Fig. 14.)
It is for this reason that in transplanting, it is most important
not to injure the tips of the roots behind which the root-hairs
are situated. If the soil is in a hard and dry condition, and the
plant is roughly pulled up out of the soil, the roots are almost
sure to be torn off in the operation. In such a case as this the
ground should be thoroughly watered, the soil
loosened with a fork or trowel, before the plant
is taken out to be transplanted. Special care
has to be taken with tap-roots, as it is very
easy to break the tip by rough pulling. For
this reason root crops, such as carrots, turnips,
radishes, are seldom transplanted.

In Fig. 10, root-hairs are seen projecting
from the surface of the primary root of
FIG. io.— Root-hairs of barley. Each consists of one long cell, with
very delicate cell walls. The structure of
the cells can only be seen with the aid of a
microscope.

The work of the root-hair is to absorb food-material. The
water with salts in solution enters through the cell wall, which
is permeable. This is due to the fact that the contents of the
cell are different in density from the water with salts in solution.

barley projecting
from surface of pri-
mary root.

THE LIFE AND GROWTH OF SEEDLINGS 23

The following experiment illustrates this process. If the mouth
of a thistle-funnel be covered with a tightly stretched piece of
pig's bladder, and if the funnel, half -filled with a solution of sugar
and water, be placed in a glass vessel containing water, some of
the sugar and water will pass into the water and vice versa. The
cell-walls of the root-hairs may be compared with the bladder ;
they allow of the passage of water, and substances dissolved in it,
into the cell. Soil water necessarily contains those salts which
are present in any given soil. Now, whilst water can enter and
leave the cell freely, the salts contained in it are more or less
imprisoned in the cell protoplasm, and have the effect of stretching
the cell, producing the turgid condition on which growth depends.

It is clear that soils must have the elements necessary for the
food of plants, if they are to thrive. The essential elements may
be ascertained in one of two ways : either by analysing any given
plant and thus ascertaining its chemical composition ; or by
growing plants in solutions containing certain salts, and seeing
how they thrive. The first method is largely adopted in agri-
culture. The exact chemical composition of the crop to be
planted in a particular field is ascertained, then the soil is analysed,
and any deficiency of an essential element is made good by appro-
priate manure. It is hardly too much to say that right manuring
makes or mars a crop, and may make all the difference to the
profits of the farmer. A good deal may be ascertained by experi-
mental plots. The individual plot should be about 20 square
yards ; the plant in question may be grown in a plot without
manure, then in one with sulphate of potash, in a third with
nitrate of soda, in a fourth with superphosphates, and so on.
The plants obtained from each plot should be weighed under
similar conditions. In this way the most appropriate manure
may be ascertained. The second method of water cultures is
of special value in laboratory work. Great care has to be taken
in preparing the water culture solution ; it is very difficult
to get it absolutely pure, and also to prevent the seedlings
" damping off." Any practical book on the physiology of plants
gives methods of setting up water cultures, and experience soon
shows which are the best seedlings to take.

Wallflowers and buckwheat, also pea, bean, and maize, give

24 THE BOOK OF NATURE STUDY

good results; sunflowers do not. In Fig. n three seedlings are
represented : A was grown in distilled, B in water culture solution
minus calcium nitrate, and C in the pure water culture solution,
which had been carefully sterilised. The drawing was made at
the end of a fortnight, and certainly shows that C was thriving best.
The glass vessels were wrapped in brown paper, in order to protect

ABC

FlG. II. — Seedlings of wallflower. A, in distilled water; B, in
water culture solution minus calcium nitrate ; C, in water
culture solution.

the roots from the light. The effect of leaving out any salt,
necessary for the food of the plant, can be thus demonstrated.

Experiments of this kind show that all plants require certain
elements if they are to thrive well ; but not all the mineral salts
found in the soil are essential to every plant. It is a well-known
fact that a chalky soil has a flora of its own, because certain
plants must have lime. Others again hate lime, and are not
found on either hard limestone or chalk. The preference of

THE LIFE AND GROWTH OF SEEDLINGS 25

certain plants for certain soils is the fact underlying the rotation
of crops. In Norfolk, turnips are followed by barley, barley by
clover, and that by wheat. Clover requires a great deal of potash,
wheat very little ; on the other hand, clover requires a great deal
of lime, wheat hardly any. In some parts of Gloucestershire, the
regular rotation is wheat, oats, seed grass and clover, roots ;
in other parts of the same county it is slightly different, wheat
is followed by roots, these by barley or oats, and lastly comes
clover and seed grass.

It has long been known, in fact since the time of Vergil, that
leguminous crops were good for the ground, but it is only of
late years that the reason of this has been ascertained. Experi-
ments have shown conclusively not only that the soil is richer
in nitrogen after a leguminous crop has been grown on it,
but that the effect is felt even the second year when a cereal is
planted. In his book The Soil, Mr. Hall gives the following
account of some striking results : " A piece of land which had
been cropped for five years by cereals, without any nitrogenous
manure, was divided into two portions in 1872, one being sown
with barley alone and the other with clover in the barley. In
1873, barley was again grown on the one portion, but clover in the
other, three cuttings of clover being obtained. Finally, on 1874,
barley was grown on both portions. The quantities of nitrogen
removed in the crops of 1873 and 1874 are shown in the table :

" Nitrogen in crop — Ibs. per acre.

1873. Barley . . 37-3
„ Clover . . 151-3

1874. Barley . . 39*1
„ Barley . . 69-4

"Thus, the barley which followed the clover obtained 30-3 Ib.
more nitrogen than the barley following barley, though the
previous clover crop had removed 114 Ib. more nitrogen than the
first barley crop. An analysis of the soil was made in 1873, after
the clover and barley had been removed ; this showed down to
the depth of 9 inches an excess of nitrogen in the clover land,
despite the larger amount which had been removed/ '

It is clear from these experiments that leguminous plants
enrich the soil, owing to their being able to use the free nitrogen
of the air. During the last twenty years, this property of

26 THE BOOK OF NATURE STUDY

leguminous plants has been the subject of much investigation in
Germany, in the United States, and in England. The discovery
by Hellriegel in 1886 that the power of using the free nitrogen
depended upon the formation of nodules upon the roots has led
to considerable research work. Pure cultures of the organism
producing the tubercles on the roots have been obtained, and
patient investigation has led to the working out of improved
methods of making the cultures.

ROOT-PRESSURE. — The passage of substances in solution in
the soil into the cells of the root-hair has already been described.
Once absorbed by the root-hairs, the contents pass from cell to
cell of the outer layers of the root until the nbro-vascular tissue is
reached. These outer cells of the root may be said to pump the
water with the salts dissolved in it into the wood, thence it circu-
lates through the plant. This is what is meant by root-pressure.
That roots do pump water into the wood may be demonstrated in
the following way : — Take a small fuchsia or geranium plant in
a pot, cut the stem across about 3 inches above the level of the
soil, and below any of the lateral branches. Attach to the cut end
of the stem by means of indiarubber tubing an empty glass tube
and water will be forced into the tube to a height of 2 or 3 feet, if
root-pressure is very considerable, as it is in the spring.

In order to measure exactly the force of root-pressure,
apparatus such as that drawn in Fig. 12 is used. A T-shaped
glass tube is attached by one end of the cross piece to the plant ;
by means of indiarubber tubing, the other end is tightly corked.
To the centre piece of the tube, a U tube containing mercury is
fitted. When the apparatus is set up, the mercury is at the same
level in the two limbs of the tube. But as the sap rises from the
stem into the T-shaped tube it flows on into the U tube, forcing
the mercury into the right-hand limb of the tube. The difference
in the column of mercury in the two limbs gives the column of
mercury which is supported by the sap, and is a measure of the
force of the root-pressure. Regular observation and accurate
measurement shows that the root-pressure varies not only at
different seasons, but at different times of the same day.

Root-pressure it is that makes plants bleed when pruned.

THE LIFE AND GROWTH OF SEEDLINGS

27

The art of pruning requires great care. It is easy when the shoots
are leafless as in winter, and all that has to be done is to cut out
the thin twigs in the centre. Summer pruning may take place
any time from the end of May. The young vigorous shoots of
the current year have to be
restrained, as they are drain-
ing the sap from the roots.
These shoots when they are
about 6 inches or a foot long
are just pinched at their
tips ; a fair number of leaves
should be left and then the
sap is just drawn past the
buds, which practically remain
dormant until the next year.
The short shoots, with the
leaves in a rosette round the
terminal bud, do not, as a rule,
require pruning, neither do
those bearing blossom. Not
only is the amateur gardener
apt to cut the wrong shoots,
but he is apt to cut in the
wrong way. It is said that
there are about 359 wrong
ways to cut a shoot, but
only one right way. The
cut should be begun on the
opposite side of the stem to
that on which the bud which
is to be left is situated, and
the cut should pass through
an angle of 45°.

Roots themselves are sometimes pruned in mild weather
in the autumn or winter, either to prevent too rampant growth,
or to induce fruitfulness. If roots are growing very rapidly
and spreading through the soil very freely, they take up food
very vigorously, fresh shoots are formed, and the flower

FIG. 12. — Apparatus for measuring root-pres-
sure. /, a T-shaped glass tube ; z, india-
rubber tubing ; s, stem ; m, mercury.

28

THE BOOK OF NATURE STUDY

buds do not ripen. On the other hand, if the roots are not
growing properly the tree is not getting enough food to produce
fruit.

One of the first experimenters on root-pressure was Hales,
who carried out a series of investigations on the force of blood-
pressure in the arteries. The circulation of the sap through a
plant may be compared with the circulation of the blood through
the arterial system of an animal.

ROOT-SYSTEMS. — It is interesting to compare the root-systems

of various plants.
Some have a main
root growing straight
down into the soil, with
lateral roots developed
in vertical rows. This
is the tap-root system.
The number of these
rows varies. The
typical number in
dicotyledons is four ;
the beetroot shows two
sets of rows, and many
plants have five or
more. The older parts
of the root keep the
plant firmly fixed in
the soil ; the extremities
of the roots, where the
root -hairs are, absorb
FIG- '3;-R°;t'System F'V4--P;°ot-systT of the food-material.

of bean. /, primary wheat, with grains of sand T

root;/, lateral roots. attached to roots. ln Some C^SCS, par-

ticularly in plants grow-
ing by the sea, the tap-root is very long, so as to penetrate the
deeper layers of the subsoil and thus get as much water as
possible. In prolonged drought the depth to which the roots
can penetrate may make all the difference to the possibility of
the plant surviving the long spell of dry weather.

THE LIFE AND GROWTH OF SEEDLINGS 29

Some plants have a fibrous instead of a tap-root system.
This is characteristic of grasses. Here there is no main root
seen ; but there are several roots, all of about the same length,
and these give off smaller roots. A root-system of this nature
is not strong enough for a plant that grows very tall, and even
in the case of some grasses, such as maize, which grow very high,
fibrous roots are not sufficient. The maize develops rings of
roots from the stem above ground. These grow downwards, and
when reaching the soil they help to keep the plant fixed firmly.

Besides fixing a plant firmly in the soil and absorbing food-
material, roots are often great storehouses of food. They are
then usually swollen, as in the turnip, carrot, and beet. The two
former contain grape-sugar, whilst the beet has cane-sugar.
Plants which have roots capable of acting as storehouses are often
biennials, the food that is stored up one year being used the next
for the production of flowers and fruit.

DEPTH AT WHICH SEEDS SHOULD BE SOWN. — Seeds should not
be sown too far beneath the surface. Small seeds, those, for
instance, of plants that are going to be pulled up or transplanted,
like lettuce, radish, spinach, are sown broadcast on the surface,
for they require very little covering of soil, and after sowing
it is sufficient to rake the soil lightly. Even these small seeds are
often planted in drills, a more economical method. Drills, as
every amateur gardener knows, are tiny furrows from \ inch
to 2 inches or so in depth, according to the size of the seeds
to be sown. Sweet-peas may be planted i or 2 inches below
the soil. Supposing seeds are sown too deep, the plant may not
be able to reach the surface.

The accompanying illustrations of oats planted at different
depths show that a grain planted too deep forms a few roots, then
when the epicotyl has reached the right level for the plant, a
second root-system is formed. If planted much too deep, the
plant might have such difficulty in reaching the surface that it
might die, or it might be at such a disadvantage, that it could
not develop properly.

In this connection it may be mentioned that the roots of
certain plants as they get older have the power of pulling the

THE BOOK OF NATURE STUDY

plant down deeper into the soil. This may be observed in lords
and ladies, or arum, in the crocus, and in many other plants. It is
due to the fact that the oldest part of the root — that nearest the
stem — at a certain age shortens or contracts, owing to changes
that take place in the outer cells. These grow shorter in the

longitudinal direction, and at
the same time often increase
in width. The apical portion

FIGS. 15 and 16. — Oats sown at
different depths. The dotted
line marks the surface of the
soil.

of the root has reached a good depth in plants of a certain
age, and as the tips of all the branches have become more or
less firmly fixed in the soil, the effect of the shortening of
the older portion of the root is to pull the whole plant down-
wards. A contractile root may be recognised by the trans-
verse ridges and furrows which mark it. In the arum the
contractile roots arise on the tuber in the late autumn. In the
crocus, they are found at the base of the young corn in the spring,
and they sometimes even pass through the old corn, situated
underneath the young one. Those who have gardens and would
like to try experiments on the depth to which bulbs, etc., may be

THE LIFE AND GROWTH OF SEEDLINGS 31

pulled down by contractile roots, should consult Professor Oliver's
paper, " The Depth in the Soil at which Plants occur/' in the April
number of the Royal Horticultural Society Journal, 1898.

AERIAL AND PARASITIC ROOTS. — There are not many plants
with aerial roots in this country, but in the tropics they are very
common. Ivy climbs by means of the roots borne by its stem.
Like all roots, they are very sensitive to light, and like to get away
from it. The overshadowing leaf no doubt protects them from
too strong light, and it is in all probability the influence of light
which makes the roots penetrate every chink and cranny they
can, often to the great destruction of the wall. Many orchids have
aerial roots. In the tropics, orchids often grow on other plants
and climb from one to the other by their roots. This does not
injure the plant, for the food of the orchid is chiefly derived from
the dust which falls on the root, moisture being obtained from
the heavy dew. The orchid is therefore hardly a true parasitic
plant. In this country, there are many semi-parasitic plants, getting
their food partly from the air through the activity of their green
leaves, and also from the plant on which they are living. These
all send processes from their roots into the plant on which they
are living, and thus get part of their food from them. The red
and yellow rattle and the eyebright are semi-parasitic plants.

The mistletoe is a true parasite, very fond of the black poplar
and apple trees. The seeds are dispersed by birds, chiefly thrushes,
which eat the mistletoe berries. The seeds become stuck on the
bark of the trees, and remain there some months before they
germinate. When germination begins, the radicle becomes
attached to the bark and puts out a process called a " sinker/'
which grows into the tree.

The young seedling of the mistletoe is then fed by the food
taken from the tree. If it is growing on the poplar, its growth
is generally luxuriant, but if its " host " is a tree from which only
a limited amount of nourishment is derived, then the growth is
scanty.

SUGGESTIONS FOR PRACTICAL WORK. — The contents of a
greengrocer's shop will afford material for three or four lessons

32 THE BOOK OF NATURE STUDY

on roots. Country walks will give opportunity for observation
of plants and their adaptation to their habitat.

1. The difference in the shape of tap-roots may be illustrated
by a comparison of the carrot, the turnip, and the radish. These
should all be drawn.

2. The fact that roots are storehouses will be evident on
examining the' beetroot, the carrot, the turnip, and the spinach.
The nature of the food-material stored can be tested by rough-
and-ready methods. It is often possible to detect sugar by taste,
as in beetroot and carrot ; starch by iodine.

3. The roots of leguminous plants should be examined for
tubercles. Their presence is a sign that these plants are using
the free nitrogen of the air. This can be done by digging up
clover, which is so often planted for fodder.

4. The root-systems of different typical plants may be observed
by growing germinating seeds of the plants between cocoanut
fibre wrapped in porous paper and the side of a glass cylinder.
Maize, pea, wheat, sunflower are suitable.

5. The difference in root-systems, according to the habitat
of the plant, may be studied in walks planned for the observation
of Nature. Plants growing in dry situations often have long
tap-roots. The difference in the firm attachment of the plant
in the soil when the root-system is deep, and when it is shallow,
is soon seen in the comparative ease with which it is possible to
pull up a shallow-rooted plant.

As far as possible, students should try and make their own
observations, and not be content with seeing an experiment per-
formed in class ; it is only in this way that it is possible to get to
know with first-hand knowledge something of the vital activities
of plants.

CHAPTER II

THE GROWTH OF THE SHOOT FROM THE BUD

AFTER the emergence of the cotyledons above ground, the first
bud or plumule is to be seen between them. This is the germ of
the shoot and it develops into stem and leaves. That the plumule
does give rise to the stem and leaves may be ascertained, first, by
watching the growth of the young seedling ; and secondly, by
examining the structure of the plumule. As soon as it appears
above the cotyledons in a young seedling, it should be cut length-
ways through the middle and examined with a hand lens. It
will be found to consist of a central portion and of lateral out-
growths. This central portion is the stem ; the lateral outgrowths
are the leaves. All buds consist of these two parts, however
variously modified the leaves may be.

INFLUENCE OF LIGHT. — The main function of the stem is to
bear the leaves in such a way that they can obtain light, without
which it is impossible for them to do their work. The first leaves
of the seedling, the cotyledons, if they come above ground, are
also dependent on light for the performance of their functions.
In watching the growth of a seedling, it will be found, if accurate
records are kept, that one of the most important factors in its
development is not the intensity only of the light to which it
is exposed, but even more the duration of the hours of sunshine
each day. The intensity of light can be measured by an ordinary
exposure meter such as photographers use, and the hours of sun-
shine are obtainable from meteorological offices.

The influence of light on colour is a matter of common experi-
ence. Any one who has watched a tree in the spring must have
noticed that the buds as they unfold have yellowish-green
leaves ; the same thing is seen in seedlings. When the cotyle-

VOL. III. — 3

34

THE BOOK OF NATURE STUDY

dons of the Radish first show above the surface they are yellow ;
so too are the plumules of the pea and bean. Then as the bud
unfolds, a tinge of green appears ; still, the prevailing tone is
yellow rather than green for some days. Gradually the green
deepens, and with the soft, tender green of the young stems and
young leaves at the tips of the twigs, forming a refreshing contrast
to the darker stems of the preceding year's growth, spring has
come. It is a matter of experience that in some years spring is
earlier than in others, and in those years there has generally been

FIG. 17. — Bean plant grown
in the dark.

FlG. 1 8.— Bean plant grown in
the light.

more sunlight. Putting these facts together, it seems clear that
light is essential for the development of the green colouring matter
of the leaf. It is easy to verify this by growing some seeds in the
dark, and others of the same species in the light. Those grown in
the dark produce cotyledons and foliage-leaves of very much the
same yellow tint as the leaves of the buds of trees when they first
begin to unfold, or of seedlings when they first come above the soil.
The difference in the colour of the leaf is due to the absence of
light. This affects not only the colour of the leaf, but that of the

THE GROWTH OF THE SHOOT FROM THE BUD 35

flower. If two bulbs of the dark blue Hyacinth are grown in
hyacinth glasses, one in the dark, the other in the light, the follow-
ing differences may be seen : —

1. The leaves of the one are yellow ; those of the other green.

2. The flowers of the one grown in the dark are paler.

3. The stem of the one grown in the light is upright, much
shorter and able to bear the weight of the spike of flowers, whilst
that of the one grown in the dark is straggling, inclined to fall
down, much longer and unable to bear the weight of the inflores-
cence.

Exactly the same differences will be found in Nature. A
Dead-nettle growing in the light has shorter internodes than one
hidden in a hedge and more or less shaded from the light, and
although it may not be easy to find plants with yellow leaves in a
hedge, it is very usual to find them with much paler green leaves.
The leaves of trees in a wood show the same differences. Those
on the fringe of the wood are greener than
those in the depth of the wood, and
flowers carpeting a wood are often paler in
the thickest part of the wood than on its
outskirts. This is well seen in the Herb-
Robert.

COMPARISON OF FOLIAGE-LEAVES WITH
COTYLEDONS. — A little observation of
seedlings soon shows that cotyledons are
very varied. This great variety is due to
several factors : the size of the seed, the
presence or absence of endosperm, the
manner of folding of the cotyledons in the
seed, and, perhaps most of all, the shape
of the seed. It is obvious that narrow
cotyledons will fit best into long narrow
seeds, as in the ash and sycamore, but
there are very many instances of narrow

J1 FIG. 19.— Seedling of Radish.

seeds with broad cotyledons. In the latter,

Lord Avebury points out that the cotyledons lie transversely

to the seed, not lengthways as in the former case.

36 THE BOOK OF NATURE STUDY

Cotyledons are folded very variously in different seeds. The
long, narrow cotyledons of the Sycamore are applied face to face,
rolled up in a ball, then as they emerge from the seed they unroll
and spread out. With the Sycamore may be compared the Beech.
The bracts forming the cup of the Beech-nut generally dehisce
into four pieces, enclosing usually two fruits. In each fruit two
ovules begin to be formed, but generally only one develops. The

FIG. 20. — Seedling of Sycamore and Beech, with cotyledons and foliage-leaves.

seed is not large, and the cotyledons are soon too big for it and
become folded, not rolled up.

With regard to the presence of endosperm, it may be stated that
if the cotyledons remain in the seed and do not come above the
soil, the seed is generally exalbuminous, for the young seedling
gets food from the cotyledons. These fill the whole seed, as in
the Bean and Walnut.

Not only are the cotyledons of plants very different from each
other, but they are very different from the foliage-leaves that
follow. Here again the Beech and Sycamore maybe compared. The

THE GROWTH OF THE SHOOT FROM THE BUD 37

Sycamore has a large palmately lobed leaf, very different in size and
shape from the narrow cotyledons ; whilst the Beech has a simple,

comparatively small undivided
leaf, not very much larger than the
cotyledons, and much less fleshy.
The cotyledons of the Oak may be
compared with its first leaves. The
former are thick and fleshy and
remain in the ground, whereas the
first foliage-leaves are almost scale-
like, particularly in the Evergreen
Oak (Quercus Ilex),
and then follow
the well - known
foliage- leaves with
their sinuate mar-
gins.

Another very
interesting seed-
ling to observe
from this point
of view is the
Gorse, usually
found in May, or
if it is an early
spring in April.

rery often not far from Gorse bushes, young
>uds may be seen on seedlings of Gorse, about
or 5 inches in height. If carefully observed
will be found that the cotyledons are deep
•een, rather fleshy, and about J inch long. As
ie stem develops from the plumule it is suc-
ilent, and the first leaves are either simple or
ifoliate. Then the stem gets hard and woody and the later
leaves become spiny. The branches arising in the axils have
spinous leaves from the first.

Many other instances could be given of the difference in
cotyledons and foliage-leaves of the same plants; it is the

rlG. 21. — Seedling of Oak, two years
old. Cotyledons enclosed in acorn.

FIG. 22. — Seedling
of Gorse. The
foliage-leaves im-
mediately above
cotyledons are
not spinous.

38 THE BOOK OF NATURE STUDY

exception if there is any well-marked resemblance. The diffi-
culty is to account for this very striking dissimilarity. Lord
Avebury considers that the form of leaves depends largely on
the shape of the buds, that of the cotyledons on the shape
of the seed. Let us then examine the bud of
the Sycamore and compare it with that of the
Beech. The bud of a Sycamore is much bigger
than that of a Beech, its leaves are far larger and
more folded. It is covered with scales, and as soon
as the buds begin to open hundreds of scales,
green at the bottom where they were covered by
outer scales, but brownish-red at the tip, will be
seen on the ground underneath the tree. The bud
of the Beech is long and slender, and is covered
with brown stipules, from among which the green
leaves appear. The leaves lie straight, and are less
folded than those of the Sycamore. Certainly in
this case the more slender bud does have the
smaller leaf.

BUDS. — The examination of trees in spring just
as the buds begin to burst is a fascinating study.
The best plan is to pick some buds and keep
them in water in one's room to look at frequently
during the day. The first interesting thing is to
notice the position of buds. The accompanying
figure of a twig of Sycamore shows an apical bud
and axillary ones. It will be seen that the axillary
ones all have the scar denoting the position of the
fallen leaf -stalk under them. In this twig the
FIG. 23.— Twig of internodes are long and the year's growth con-

Suysta^boutbUto siderable; {i is what is called a "long-shoot."

burst hi Spring0 The limit of the year's growth is marked by the

scars left by the scales of last year's bud. Some

twigs have much shorter internodes, then the shoots are " dwarf

shoots," and the leaves are more or less tufted. The Beech

and Ash show this very well. In examining buds, it is important

to notice which bear flowers in addition to leaves, as this to some

THE GROWTH OF THE SHOOT FROM THE BUD

39

extent affects the shape of the tree. In the Horse-chestnut the
apical buds contain flowers, and as the formation of a flower
stops growth in length, the Horse-chestnut is broad rather than
tapering. The apical bud of the Ash, on the other hand, contains
only leaves, the flowers being in the lateral buds. Compared
with the Horse-chestnut, this is a more tapering tree.

In winter, buds are usually covered with bud-
scales; in this way they are protected from cold and
damp. In some cases, as in the Horse-chestnut,
the bud scales are covered with resin, which give' it
a glistening appearance in the hot suns of an early
March. Externally, where exposed to the light,
the scales are brownish-red; where overlapping
each other, they are greenish. After removing
the scales the young green leaves in early spring
are wrapped in down, and if the bud is an apical
bud the floral leaves may be seen in the centre.
All those leaves — scales, foliage, and floral-leaves —
are borne on a stem-like portion. It is clear that
a bud is the germ of a shoot, for it consists of a
stem portion and of leaves.

Trees may often be recognised in the winter
not only by their bark, but by their buds. Those
of the Horse-chestnut are dark brown, very large,
and remarkably sticky from the resin on them.
The Ash, as Tennyson notes, has olive-green, almost
black, buds in spring —

"More black than ash-buds in the month of March."

FIG. 24. — Twig
of Sycamore
in winter.

The long, slender, light brown Beech buds are
characteristic of the tree, and allow it to be distin-
guished at a distance from the Oak, with its stouter,
shorter buds of a rich brown.

The Maple may also be distinguished from the Sycamore,
to which it is closely allied, by the pinkish colour of its
buds, which deepens into a beautiful red as the spring
advances. The Alder is recognised by its purplish - brown
scales.

40 THE BOOK OF NATURE STUDY

STRUCTURE OF WINTER BUDS. — Ash. — Winter buds show a
wonderful adaptation of structure to function. Their outer
scales are developed from very different organs. Some are
formed from the part of the leaf attached to the stem, the
" leaf -base " as it is called ; this is the case in the Ash,
Horse-chestnut, Sycamore, and in most rosaceous trees. Or
bud scales may represent stipules, structures which occur in
pairs, as lateral branches of the leaf-base. The bud scales of
the Oak, Beech, Poplar, Alder are modified stipules. In the
Alder and Poplar the stipules are fewer than in the Oak and
Beech. Again, bud-scales may represent true leaves, as in the
Lilac and Honeysuckle. Some of these winter buds may now
be examined more in detail. The bud of the Ash is covered by two
or four thick, olive-green scales. These overlap and enclose the
young leaves covered with down. In the apical bud, these
young leaves are all foliage-leaves ; in the axillary buds, both
foliage and floral leaves are found. As a rule, one axillary bud
develops into a branch ; the opposite one into a flowering shoot.
All these leaves, bud-scales, foliage, and floral -leaves are borne
by a central structure, the stem. It is by means of the scales
and the down that the young leaves are protected from the
cold and damp of winter. The bud scales are of the nature of
leaf-bases, for they show rudimentary leaves at the tip. The
dark colour is due to a layer of flattened hairs, which secrete
a resinous substance, that helps to protect the leaves from damp.

Horse-Chestnut. — The Horse-chestnut has almost the largest
buds of any tree. Each is protected by eight or ten scales, and
is very sticky owing to the resin secreted. To take off the
scales without breaking them, the bud may first be dipped in
methylated spirits. If all the scales are removed and placed
side by side, the difference in colour and size is striking. The
most external are dark brown and small ; inside these come
structures which are green and herbaceous, and within these are
the true foliage-leaves, covered with down. Inside these foliage-
leaves are the floral-leaves. All these sets of leaves are borne by a
stem. This bud shows a gradual transition from bud scales
on the outside, to true foliage-leaves, something intermediate
between scales and leaves being present between the bud-scales

THE GROWTH OF THE SHOOT FROM THE BUD 41

on the outside and the inner leaves. Such a series serves to
indicate the nature of the bud scales. They are leaf bases, i.e.
the bases of leaves which develop no upper parts or blades, but
become hard and scaly as the buds form.

Sycamore. — The bud scales of the sycamore are tough and
dark coloured, where exposed to the air and light ; the inner
portions are paler. As a rule, the bud of the Sycamore has
fourteen scales, arranged in two opposite rows of four each, and
two intermediate rows of three each, but sometimes there are
only twelve scales. Within the scales are two pairs of folded
foliage-leaves. The structure of the bud-scales is best seen in
spring when the bud is expanding and the scales are falling.
They are long and narrow, and concave on the inner side so as
to wrap round the bud. If the tip of each scale is examined
with a lens, a small three- or five-lobed structure is seen, pro-
tected, almost hidden by a mass of brown hairs. This is a
rudimentary leaf-blade ; the scale itself is there-
fore a leaf-base which has become greatly en-
larged. Those Sycamore buds which contain
flowers as well as foliage-leaves are larger and
open earlier than the ones which have only
foliage-leaves.

Oak. — The scales of the Oak are arranged
in five rows, which are tightly folded over each
other. They are arranged in pairs, as would
be expected, because they are developed from
stipules, which occur in pairs. There are some-
times as many as twenty pairs, each pair vary-
ing in shape and size. The lowest scales are
small, the innermost are the largest. The
edges are fringed with hairs, which drain away
the moisture.

Beech. — The bud of the Beech resembles
that of the Oak in having a large number of
scales formed from stipules, some sixteen pairs altogether. The
lowest pair is triangular, small, and pointed ; the next four or
five pairs gradually increase in size and closely overlap each
other. The part of each scale exposed to the weather is brown,

FIG. 25. — Twig of
Beech in winter.

THE BOOK OF NATURE STUDY

whilst the portion overlapped by the succeeding scale is white
or greenish. The hairs of the scales are not black as in the Ash,

but silvery. The foliage - leaves do not
occur between the lowest stipules, but
begin about the twelfth pair. In a bud
just on the point of opening a folded
foliage-leaf will be seen between each pair
of stipules, from the twelfth upwards.
The number of stipules and foliage-leaves
varies in the different buds ; the larger
ones have more leaves and stipules than
the smaller.

The Black Poplar. — The terminal bud
of the Black Poplar has from nine to ten
pairs of stipules, the two lowest being the
hardest. The foliage-leaves of the bud
are first found between the third pair of
stipules ; in this tree the stipules are
largely developed and gummy, in order to
protect the foliage-leaves inside.

Lilac. — The terminal bud of the Lilac
usually does not develop, its place being
taken by two lateral buds. In this shrub
the bud scales are small leaves, not enlarged
leaf -bases as in the Sycamore. They are
opposite each other, forming four rows,
and are from six to ten in number. The
scales gradually pass into ordinary leaves,
and may be regarded, therefore, as modi-
fied leaf -blades. The bud-scales of Honey-
suckle resemble those of Lilac in this
respect.

The Conifers. --The bud -scales in a
Pine may number one hundred, or even
three hundred, in some species, and are
arranged spirally. They are small and

brown, and bear in their axils a small bud ; each scale repre-
sents a whole leaf and not merely a leaf -base, or a leaf -blade.

^> A>
& &>

FIG. 26. — Bud of Beech

with stipules removed.

THE GROWTH OF THE SHOOT FROM THE BUD 43

The so-called " bud " is therefore not a single bud, containing
either foliage or floral leaves, or both ; it is a bud of buds,
each true bud giving rise to a dwarf shoot, the buds which
will give rise to long shoots being developed only in the axils
of a very few of the numerous leaves. The outside scales
have cork layers and resin is secreted, so that the shoots are
well protected. Among the Coniferae, bud-scales are found in
the Pine, Spruce, and Yew, but the Juniper and Cypress have
none.

NAKED BUDS. — Other examples of trees with " naked buds "
as they are called, are the Wayfaring- tree, and the Alder Buck-
thorn. The evergreens of tropical climates are often destitute
of bud scales. In most herbaceous plants the terminal bud is
merely the end of the growing shoot, its covering is just an
ordinary leaf, similar to any other.

Bud-scales are usually developed in those buds which pass
through a period of resting during the winter. They protect
the delicate leaves from the winter cold and wet, and prevent
loss of water which would take place owing to the dryness of
the air at a time when the tree would not be able to replace it.

The following classification of bud-scales, according to the
organs from which they are formed, may be useful :—

1. Bud scales representing leaf -bases occur in Ash, Horse-
chestnut, Sycamore, and most rosaceous trees.

2. Bud scales developed from stipules are found in Oak,
Beech, Poplar, Alder.

3. Bud scales formed from true leaves in the Lilac and Honey-
suckle.

4. Naked buds occur in the Alder Buckthorn, in some species
of Viburnum (the Wayfaring-tree), in Juniper and Cypress, and
in most evergreens, especially in tropical countries.

The way in which leaves are packed in a bud is a never-ceasing
subject of wonder each year as spring comes round. It seems
incredible that the large leaves, such as Sycamore and Maple ; the
compound leaves, consisting of several pairs of leaflets, of the Ash
can be packed in such small space. The only way of seeing the
relative arrangement of the leaves in a bud is to make a section and

44

THE BOOK OF NATURE STUDY

look at it under the microscope. In the Ash, two compound leaves,
each having seven leaflets, will be seen in the centre opposite
each other. The next two leaves are at right angles to those, the

next two to the second pair,
and so on until the four outer
scales are reached. The
accompanying figure shows
the arrangement in the bud
of the Sycamore.

In spring, as soon as the
scales burst and the foliage
begins to open out, the inter-
nodes of the stem grow
longer and longer, giving
rise to the "long-shoots " at
the apex of the twig. As
the shoot elongates, buds
begin to be formed in the
axil of the leaves. Towards
the end of the summer these

buds may be seen, and when the leaf falls off in the autumn,
leaving its scar behind it, the buds are prominent. In the
following spring the apical or the topmost lateral bud develops
into the new shoot. Meanwhile in the winter it is protected
from wet and cold by the scales, downy hairs, resin, etc., already
mentioned.

FlG. 27. — Bud of Sycamore, transverse section.
Bud scales on the outside, and foliage leaves
in the centre.

ADVENTITIOUS BUDS. — Sometimes buds develop without any
definite relation to the leaves; these are called "adventitious" ;
they are, as it were, accidental or accessory. The buds that appear
on the wounded edges of a begonia leaf when it is sliced and
pinned down on damp sand, is a case in point. Under abnormal
circumstances buds may develop even on roots and give rise
to leafy or even flowering shoots, as in the Hawthorn.

The study of buds affords considerable material for practical
work. About March or April, or even earlier, twigs of different
trees may be examined and the position of the buds noted. Then
the nature of each bud should be determined, whether it will

THE GROWTH OF THE SHOOT FROM THE BUD 45

give rise to a leafy or to a flowering shoot. The character of
the bud scales, the organs from which they are formed, and
the means by which they protect the inside tissues should be
investigated, and sketches made of the different structures, with
the date of observation. Then as the buds begin to burst
and the leaves and flowers come out, the buds should be
examined again, and the later stages of growth compared
with the earlier ones. It is a good plan to watch the gradual
opening of the bud and unfolding of the leaves from day to
day. The way in which the leaves are packed in the bud should
be noticed.

In gardening, the effect of pruning will be found to cause
buds to develop which would not otherwise do so. The structure
of such buds, as those of Cabbage and Brussels Sprouts, may be
compared with the buds of shrubs and trees.

BRANCHING. — The branching of a stem depends on the position
of the buds and on which buds develop. As buds are situated in
the angle which the leaf makes with the stem, the branching of
a tree would normally follow the arrangement of the leaves. All
buds, however, do not develop, for if they did the shoots would
become overcrowded and would not get enough light. In the
elms, lime, and some other dicotyledons, the terminal bud is
suppressed and the axillary bud beneath it then swells and
takes its place. In such stems, the main trunk consists of
a series of branches. In time, the lower ones drop off ; the
bare portion of the trunk is then known as the " bole," while
the mass of boughs, branches, and foliage above it, is called the
crown.

Another factor affecting the development of the branches
is the relative position of the leaf and flower buds. In some
trees, the terminal buds develop into leafy shoots. This is the case
in the Ash. In others, the terminal bud contains the flowers, as
in the Horse-chestnut, and growth is continued by the lateral
buds. This partly accounts for the difference in the shape of
these two trees ; the Ash, as we have seen, is more tapering than
the Horse-chestnut, which has its upward growth stopped, in some
branches at any rate, by the formation of the flower.

46 THE BOOK OF NATURE STUDY

The branching of one or two trees may be noted in detail. In
the Oak, the terminal bud is a leaf bud with lateral ones clustered
round it, just as the leaves are. The branching is tufted or
rosette-like, the branches being apt to turn and zigzag from side
to side. If a Beech is growing in the open, the branching may
begin very low down. Sometimes the bole divides into several
trunks, each giving rise to a full-grown tree. When growing
in a dense forest, the branches may not begin below a height
of 60 feet. They are usually developed from " long-shoots "
and are often horizontal. They afford considerable shade,
and without the beech, it has been said, many timber trees
would have to be given up ; on the other hand, herbaceous
plants do not thrive under it, no doubt from want of sufficient
light. In summer, its undergrowth consists mainly of para-
sitic plants, such as the Bird's-nest Orchis, Toothwort, Broom-
rape, etc.

Some trees and shrubs do not develop terminal buds at all,
as the Elm and the Lilac ; in these growth takes place from
lateral buds. In the Elm the branches are some considerable
height above the ground. It often forms hedges, on account of
its habit of throwing up suckers, and other plants thrive well
under it.

Few objects are better suited for the purpose of cultivating
the power of observation more than trees. To be able to recognise
a tree at a distance and at any season of the year is only possible
to those who have a very real knowledge of its growth. The
branching is best seen in winter, when it lies stripped and bare.
The height from the ground at which the lowest branches are
given off, the angle they form with the main trunk, their general
direction, the downward or upward bend of their twigs must all
be known before the tree can be recognised with any certainty.
Then there is the bark, so characteristic a feature of the tree,
and the shape and colour of its winter buds, and in spring and
summer the endless variety of foliage — all affording material
for the observation of a lifetime.

THE WORK OF LEAVES. — The work of leaves is very varied,
and some of it cannot be carried on without light. The necessity

THE GROWTH OF THE SHOOT FROM THE BUD 47

of light accounts for the great variety in the arrangement of
leaves or stems. In temperate regions, where light is often diffuse
and always less intense than in tropical regions, the blade of the
leaf is usually spread out to the light, and one leaf must not be
exactly above another. The arrangement of leaves on the stem
may easily be observed in some of our common plants. In the
Dead-nettle, the leaves are two opposite each other ; the next pair
of leaves is not on the same sides of the stem as those immediately
below or above them, but on the other two sides, and in this
way the lower ones are not deprived of light by those above. The
best way of obtaining some idea of the very varied arrangement
of leaves is to examine several plants and to notice that those
leaves which may be said to lie almost exactly above each other
are borne by the stem at some distance from each other, and there
may be two, three, six, eight, or even as many as eleven leaves
between those which are situated immediately above each other.
Teachers may suggest, as a lesson in observation, the finding
plants in which the leaves are arranged in at least six different
ways.

(i.) CARBON ASSIMILATION. — Light is essential for the develop-
ment of chlorophyll. That it is the chlorophyll which is
concerned in the work of carbon assimilation may be easily
demonstrated, but even when chlorophyll is present, leaves will
not assimilate carbon except under the influence of light. The
fact that carbon assimilation is going on in a leaf generally
shows itself in the formation of starch. When starch is present
in a leaf, carbon must have been assimilated, for carbon is
one of the constituents of starch. Green leaves are always
making starch in sunlight, and it is easy at any moment to find
out whether starch is present in a leaf. Boil it in a test-tube,
then place it in methylated spirits to get out the green colour, in
order that the starch may be more easily seen. As soon as the
leaf looks colourless, place it in iodine, and if starch is present the
leaf will become dark blue. Instead of taking a green leaf, a
variegated leaf may be chosen and tested with iodine ; the leaf
of the variegated Ivy will do. The green part of the leaf becomes
dark blue, the rest does not. This little experiment shows that

48 THE BOOK OF NATURE STUDY

it is the green colouring matter, the chlorophyll, which makes
starch.

Another experiment that any one can try is to cover up the
leaf of a plant with tinfoil for about twenty-four hours and then
to test for starch with iodine, as just described. Or plants
may be grown in the dark and the iodine test applied. It will
invariably be found that when excluded from light, starch is
not formed, because the chlorophyll has not been able to do its
work.

The chlorophyll is present in the form of small corpuscles in
all the cells of the leaf except in the thin skin or epidermis on each
side. The structure of a leaf is seen in Fig. 28.

FIG. 28. — Transverse section through leaf-blade. <?, epidermis ; p, cells
containing chlorophyll ; pp, cells with chlorophyll and intercellular
spaces ; /!?, lower epidermis ; J, stomate.

This was drawn under a low power of the microscope, and does
not show the grains, but merely the layers of cells, forming the
thickness of the leaf. Near the upper surface, two rows of cells
may be seen without any spaces between them, whilst the other
layers have spaces. It follows that the upper face of the leaf
will be darker in colour than the lower, because the chlorophyll is
greatest in quantity there. The majority of leaves have a darker
upper surface and a lighter under surface owing to this arrange-
ment of the chlorophyll. There are some plants, however, with
leaves of the same colour throughout, owing to the absence of
these two rows of cells without intercellular spaces ; the chloro-
phyll is evenly distributed, and the leaf is yellowish rather than
green, as in the Stonecrop.

THE GROWTH OF THE SHOOT FROM THE BUD 49

In order that the chlorophyll may do its work, the plant must
be supplied with carbon dioxide. This gas is always being breathed
out by plants and animals, so that there is always some in the air.
If it is prevented gaining access to the plant, starch cannot be
made. To demonstrate this, a pot containing a green plant —
clover does very well — should be placed under a bell-jar. By the
side of the plant a small bottle containing a strong solution of
caustic potash should be placed, to absorb the carbon dioxide
given off by the plant.
Through the india-
rubber cork of the
bell-jar a bent glass
tube is passed. The
U -portion of the tube
is filled with soda of
lime, which absorbs
the carbon dioxide
from the air passing
through it into the
bell- jar. Thus no car-
bon dioxide reaches
the plant. After about
twenty-four hours the
leaves of the plant
may be tested, and
will be found not to
turn blue when soaked
in iodine. In trying
experiments connected
with carbon assimila-

FlG. 29. — Apparatus for excluding carbon dioxide.
S, soda of lime. C, caustic potash.

tion it is always best to leave the plant in the dark a day or so
before beginning the experiment, in order that any starch then
the present in the leaf may be withdrawn from the leaves through
stem to the root or the other part of the plant.

The work of the chlorophyll is to separate the carbon from
the carbon dioxide. With the carbon thus obtained and with
water from the roots starch is made. The oxygen of the carbon
dioxide is returned to the air ; for it is the carbon alone that the

VOL. III. — 4

THE BOOK OF NATURE STUDY

chlorophyll " fixes/' as it is said. That oxygen is given off by a
plant engaged in carbon assimilation is easily shown on a bright
sunny day. The experiment is best tried with a water-plant such
as Elodea. The plant should be placed in a glass jar of water
under a funnel. Over the funnel, invert a test-tube full of water,
holding it under the water whilst placing it in position. If the
light is intense enough, in less than an hour bubbles of gas will be
seen passing up from the plant and collecting at the top of the
test-tube. In fact, if the apparatus is placed on a lawn in bright

sunlight, the whole test-tube may become
full of gas in a couple of hours or so.
The rapidity with which carbon assimila-
tion goes on depends on the intensity of
the sunlight. One more thing must be
remembered. The carbon dioxide is taken
into the leaf through the stomata which
are present in numbers on the under sur-
face and sometimes also on the upper
surface. In Fig. 28 they will be seen on
the under surface. If the under surface
of a leaf is smeared with vaseline, the
carbon dioxide cannot enter and the
plant does not make starch. Stomata
may get choked up with dust, and then
FIG. 30.— Apparatus to show the plant does not thrive. This is the
evolution of oxygen during reason that palms kept indoors ought to

have their leaves washed about once a
week.

Starch grains are solid bodies, insoluble in water. These
solid grains cannot pass through the cell walls, therefore the
starch is converted into a soluble substance of the nature of
sugar, and can then pass through the cells of the stem into the
root, or underground stem, where it is stored up. The carrot
and potato are instances of this. The grains of the cereals, wheat,
rice, maize, all have a good deal of starch in them.

By the seaside or in sandy situations, plants will be found
with very much reduced leaves, sometimes with none at all. In
these cases, a couple of rows of cells will be found under the

assimilation. O, bubbles of
oxygen.

THE GROWTH OF THE SHOOT FROM THE BUD 51

epidermis of the stem. These cells closely resemble those of the
leaf, they are full of chlorophyll grains, and carry on the work of
carbon assimilation. The Marsh Samphire or Glass wort has no
leaves, whilst Saltwort has very much reduced leaves.

(ii.) TRANSPIRATION. — Leaves are not only engaged in carbon
assimilation, but also in transpiration. Land plants that live in
the medium of our atmosphere are constantly having water pulled
from them by the atmosphere. This is made good by the power
of absorbing water which the roots possess, as already described
in the last chapter. This water passes off into the atmosphere
from the surface of the leaf. Every one knows by experience that
one of the first signs of withering in a plant is the drooping of the
leaf ; watering the roots, if done in time, allows the plant to
recover.

One of the simplest experiments, showing that water passes
off from the leaf surface is to put some ivy leaves with their long
stalks through a piece of cardboard into a tumbler full of water ;
on the top of the cardboard place a dry tumbler of the same size
over the blades of the leaf. In a few hours, drops of water will
collect on the sides of the tumbler and the water in the lower
tumbler will gradually lessen. This is always happening in a
dry atmosphere. When the air is laden with moisture, the leaves
give off little, if any, water. Yet it is in dry situations that it is
important for the plant to retain as much water as possible. The
leaf has various contrivances for securing this. It may have a
very thick skin, as in the Holly ; it may be very hairy, as in the
Hawkweed, Crepis, and many other Composites growing on hills,
or it may curl up so as to shelter the stomata (see Fig. 28) com-
pletely, and thus prevent the giving off of water from its surface.
There is a certain relation between the shape of leaves and the
dryness of the situation. The Conifers are characteristic of dry
soils ; their leaves are very much reduced and acicular in form ;
the Heaths, the Acacias of Australia, the Gorse, the Cacti are
instances of plants belonging to dry situations and having very
much reduced and often spiny leaves.

Plants living submerged in water hardly transpire at all, and
do not have water conducted through them, as in land plants.

52 THE BOOK OF NATURE STUDY

In order to determine the exact amount of water lost by plants
in transpiration, experiments may be tried with two sets of plants,
one set being allowed to grow under the ordinary conditions in
the greenhouse, whilst the plants of the second set, of the same
species as those in the greenhouse, and as far as possible the same
size and age, are kept in an experimental greenhouse under con-
ditions that can be controlled. In an actual experiment con-
ducted in this way, the amount of water transpired was determined
by weighing, and special precautions were taken to prevent loss
of water through evaporation. The result of the experiments
has been thus recorded : " There are two daily extremes, a
maximum loss around noon when the sunlight is most intense, heat
usually the greatest, moisture least in the atmosphere, but a
good supply of water in the soil around the roots ; the minimum
loss occurs some time during the night when the temperature is
low, the atmospheric pressure approaches saturation, the dark-
ness is complete, and in most plants the stomata are closed."
The figures given showed that the amount of water transpired is
about five times as much on the average per hour per square
metre by day as by night. Another important fact brought out
by such experiments is the extreme sensitiveness of transpiration
to even slight changes in external conditions. The plants which
are well adapted for class experiments are Chrysanthemum
frutescens, Tropceolum majus, and several species of Pelar-
goniums.

It is interesting to inquire by what tissues the water travels
through a plant. If a young twig with the cortex stripped off
between two leaves is fixed in a cork, so that the cut end dips
into a jar containing water, it will be found that the twig does not
wither ; the leaves remain spread out and do not droop, as they
would do if they were not supplied with water. Clearly the water
is not travelling along the cortex of the stem. In order to find
out along which tissue it does travel, red ink may be added to
the water, and after some hours, sections of the stem should be
cut. The woody part of the stem is stained. The water travels
along the wood. This tissue can be recognised with the naked
eye, and looks like white lines. With care it can be traced from
one internode to another, in such plants as the Dead-nettle.

THE GROWTH OF THE SHOOT FROM THE BUD 53

It is because a plant is constantly giving out water that it is
necessary to water it regularly. Young gardeners generally give
too much water. It is important not to over- water, especially in
frosty weather, but in warm weather, when evaporation is going
on rapidly, water is necessary. As a rule, it is best not to
water unless sufficient water can be given; surface watering
does more harm than good. Too much water rots the roots,
for this reason it is bad to leave pot plants standing in water
day after day.

(iii.) RESPIRATION. — Although all the parts of a plant respire,
the leaves are specially concerned in this work. Air enters
through the thin cuticle when the leaf is young, through the
stomata when the cuticle gets thicker, and carbon dioxide is got
rid of by the same channels.

Through their manifold work of carbon assimilation, trans-
spiration, and respiration, leaves profoundly affect the atmosphere
around them. All visitors to the seaside know what a difference
trees make to their enjoyment of the place ; it is the drawback of
some of our resorts that one is exposed to the glare cf a pitiless
sun without the shade of the green foliage so restful to the eye.
Leaves prevent that dryness of the atmosphere which may become
unpleasant, from the fact that water is being given out by them.
Trees, too, attract clouds laden with moisture, and thus may be
the means of securing moisture in a dry region ; it is a well-known
fact that the cutting down of forests, or even the thinning of trees
in a garden, will make a difference to the degree of dampness of
a house. Leaves also help to purify the atmosphere, for they
need the carbon dioxide which is being constantly breathed out
by all living things. When it is remembered that in this country
our parks, meadows, pastures are carpeted with millions of blades
of grass all using carbon dioxide under the influence of sunlight,
and that the leaves of all our herbs, shrubs, and trees are also doing
the same thing, it is hardly possible to overestimate the beneficial
work done by leaves in keeping the atmosphere fit to breathe.
Not only are they using the carbon dioxide of the air, but they
are returning to the atmosphere the oxygen which has been
separated from the carbon.

54 THE BOOK OF NATURE STUDY

(iv.) CLIMBING. — Some plants climb by twisting their leaf-
stalks round any object with which they come in contact. The
Garden Nasturtium (Tropceolum) and the Clematis are the best
known instances of this. It is this power of climbing that helps
the Clematis to reach the luxuriance it does in Gloucestershire
and Somersetshire, although something too depends on the soil.
Many of the Leguminosae develop tendrils in the place of leaflets
for the same purpose, e.g. the Peas, the Vetches.

CLASSIFICATION OF LEAVES. — So far foliage leaves have been
the most fully discussed. In botanical language, however, the
term " leaf " includes not only foliage-leaves but also seed-leaves
or cotyledons ; bud scales and the bracts which protect flowers ;
floral-leaves, namely, sepals, petals, stamens, and carpels. It was
Goethe who first saw the identity of origin amidst this diversity
of structure. In his treatise on The Metamorphosis of Plants,
written in 1790, he shows that all these structures stand in the
same relation to the stem, they are all developed laterally from it.
This generalisation gave the impetus to other similar researches,
hence hairs and prickles being developed from the epidermis are
now regarded as structures analogous to each other. Similarly, in
the animal world, the fur of the rabbit, the scales of fishes, the
feathers of birds, being alike in origin, are equivalent to each other
morphologically, although the function of each is very different.
Enough has already been said about cotyledons and bud scales,
but not about the bracts which form the involucre of flowers, or
of inflorescences. In the Composite, the minute florets are
protected by bracts which overlap each other and are often fringed
with hairs that conduct the water down from the bud. In this
order, some arrangement of the kind is necessary, for the sepals of
the flowers are very much reduced, and instead of protecting the
essential organs of the flower, they become an organ of dispersion.
These flower-heads of the Composite often close at night or in
wet weather, then the bracts are erect, completely enclosing the
florets ; when the flower-heads are open, the bracts are more
spread out, allowing the flowers to expand. Linnaeus observed that
the Dandelion opened from five to six in the morning and closed
some time between eight and ten, that the Goat's Beard or John-

THE GROWTH OF THE SHOOT FROM THE T3TJD 55

go-to-bed-at-noon opened from three to five in the morning and
closed from eight to ten ; the Mouse-ear Hawkweed, he says, is
open in fine weather from seven in the morning until three in the
afternoon.

Another order, in which an involucre of bracts is often though
not always found, is the Umbelliferae. One of the most beautiful
species is Astrantia, in which the bracts are white and shining,
looking silvery in the sunlight ; they are far larger than the
flowers themselves. In the Sea Holly the bracts are also coloured
and conspicuous. When the wild carrot is in bud, the long
green bracts arching over the umbel, form a great protection
for the young flowers. In the Arum (lords and ladies) the
conspicuous bract (Fig. 44) forms a chamber in which the flowers
are situated and to which insects are enticed. Many hothouse
plants, natives of tropical regions, have very conspicuous coloured
bracts. The Poinsettia and the Bougainvillea are plants growing
in the open air in the tropics, they are commonly seen at flower
shows in this country ; the one has a large leaflike scarlet bract,
the other purple bracts forming a cup around the flower.

The observations that may be made on leaves are practically
unending, only a few can be indicated here.

(a) The arrangement of leaves, whether radical or cauline.
If the latter, whether they are spread out to the light, or merely
present their edge to the sun's rays. Again, their relative position
to each other, so as to secure light.

(&) The endless variety of shape, and the connection of this
with the habitat of the plant.

(c) The general structure of the leaf ; note any marked differ-
ence between the two sides, one much darker than the other.
See whether leaves in which the chlorophyll is evenly distributed
are connected with any particular habitat, as Stonecrop with dry
situations. Make notes on the habitat of plants with hairy leaves,
or leaves that roll in to protect the stomata. These will often be
found in grasses growing by the sea.

(d) The difference in bud-scales of different trees and different
herbaceous plants may be noticed. The scales of the winter buds
of trees are particularly interesting.

(e) The sensitiveness of leaves, e.g. Wood-Sorrel, Mimosa.

56 THE BOOK OF NATURE STUDY

The movements of the wood-sorrel leaves have been thoroughly
investigated by Darwin and other botanists. Darwin also describes
in detail the sleep movements common to many Lupines. " The
shorter leaflets/' he says, " which generally face the centre of
the plant, sink at night, whilst the longer ones on the opposite
side rise, the intermediate and lateral ones merely twisting on
their own axis." Other plants with sleep movements are
Melilot, Clover, Lotus, Mimosa. In fact, it may almost be
said that sleep movements are specially characteristic of the
Leguminosae.

Pfeffer has devised methods by which leaves register their
own movements. The records show not only the sleep move-
ments, but the automatic movements which often accompany
them. He found that under constant conditions the sleep
movements disappeared in from three to five days, but automatic
movements of much shorter rhythm continued independently
of the sleep movements.

(/) The difference in cotyledons. To find cotyledons of
shrubs and trees, look in the humus of woods, under and around
the tree or shrub, in the months of April and May. Very often
the cotyledons will be seen pushing their way through the dead
leaves ; it will often be possible to find some when at the first
glance there may appear to be none, by scraping away some of
the upper layers of the leaves.

THE WORK OF THE STEM. — The main work of the stem is to
minister to the leaves.

1. The stem bears the leaves in such a way that they can all
get light which, as we have seen, is necessary for the performance
of some of their functions.

2. It conducts food to the leaves. The woody tissue in the
root is continuous with that of the stem. By root-pressure water
with mineral salts dissolved in it is forced into the wood of the
root, thence it travels the whole length of the stem, to the leaf-
stalk and veins of the leaf.

3. The stem conducts food from the leaves to the root. The
starch made by the leaf is converted into sugar and passes, mostly
by the outside cells of the stem, down to the root, where it is stored

THE GROWTH OF THE SHOOT FROM THE BUD 57

up either in the form of sugar, or it may be reconverted into
starch.

If the stems of plants growing in a hedge are compared with
each other, great variety will be found. Some will be green
and slender, others will be yellowish-brown, and a third set may
have the power of twining. The green stems in all probability
belong to plants that are annuals, i.e. they grow up, bear leaves,
form flowers and fruit, then die down at the end of the season.
Such a plant has no great weight of leaves to bear, and therefore
can manage with a slender stem ; it has to make food as rapidly
as possible, and for this reason chlorophyll, which gives the
green colour, is necessary to it. Further, as the plant dies down
in the autumn the stem will not be exposed to the cold and damp
of winter, and therefore needs no protection. The case is different
with biennials. They do not produce seed until the second
season, and therefore have to face the winter cold. Underneath
the thin skin of the stem, a layer of cork is formed. This protects
the underlying tissues, and may be recognised by its yellowish
colour. Some plants are perennials. Their stems remain above
ground several years, and go on increasing in thickness. These
plants often have branched stems, because it is the only way
in which they can get enough light for their leaves. A branch
always arises, as we have 5

already seen, in the angle
which the leaf makes with
the stem. This is shown
very clearly in the accom-
panying illustration, which
is magnified about fifty
times. It also shows the
layer of cork developed at
the base of the leaf-stalk

in the autumn. As SOOn

. , . . r

as this is formed the cell

sap from the stem cannot get to the leaf, which, deprived of

nourishment, dies.

Plants growing in hedges often have twining stems. The
Black Bryony is one of the commonest. At the bottom of a

c —

FlG> 3 1.— Section through stem and axillary buds.
s. stem ; /, leaf; b, bud ; r, layer of cork.

58 THE BOOK OF NATURE STUDY

hedge it is often found twisting round a grass, then the tip of
the stem may hang in the air for a while, until it catches hold of
some other plant, and both together will climb up the Hawthorn,
of which the hedge is composed, until they reach the top, where
they can get the light. The Black Bryony must not be confused
with the White Bryony, which is also a climbing plant. This
latter has tendrils and very different leaves from the former.
The Hop and the Convolvulus are instances of plants with twining
stems, each in a different direction from the other. Scarlet
Runners or Kidney Beans may be observed in any kitchen garden.
In order to see how stems twine, the following easy experiment
may be tried. Plant some Kidney Beans in a pot, and when
the shoot has grown to about a foot in length, tie the stem
to a stick 8 inches high. This will leave some 4 inches of
the stem hanging over. This will revolve. Place a sheet of
paper underneath the pot, make a dot to represent the tip of
the stem at regular intervals ; in this way a tracing of the move-
ment of the stem will be obtained. That plants climb by their
leaves has already been discussed.

The effect of light on the growth of a stem is varied.

1. If exposed to light on all sides, the internodes are shorter
than they would be if the plant has been deprived of light. A
plant growing in a hedge should be compared with the same
species growing in the open.

2. Stems, not naturally climbing, sometimes are very much bent
and curved in their struggle to reach the light. On 2gth July
a species of Campanula growing in a high hedge on the sheltered
side of the road was gathered. The stem had no less than
four bends and curves, owing to the attempts it had made
to reach the light. It was much entangled with other plants
growing round one, then another, until its purple blossoms stood
out to the light. Ferns kept in a room often bend towards the
window.

CONCLUSION. — The adaptation of structure to function is very
striking in both stem and leaf. The best way of realising this
is to observe plants in their natural habitats as far as possible ;
this can easily be done by those living in the country. They can

THE GROWTH OF THE SHOOT FROM THE BUD 59

observe hedges, noting the difference in annuals and biennials ;
or they can climb some hill and compare the stunted growth of the
herbs at the top of the hill with the more luxuriant vegetation of
the valley below. In winter they can note the manner in which
the buds are protected, and in the spring the folding of leaves
in the bud.

Students that live in towns may do much with a small garden.
Climbing plants may be observed in the Nasturtium, Scarlet
Runner, or Kidney Bean ; buds in such shrubs as the Lilac or the
Laburnum ; the stem of the biennial Wallflower may be compared
with that of a perennial Sunflower. Simple experiments, such
as those indicated, may be tried by any one who has the necessary
patience, and experiments help in the interpretation of Nature.
In teaching, the important thing is to plan the experiments
so that they succeed each other in a right order, the one following
naturally on the other. The best time of year for experiments
on the life and growth of plants is undoubtedly the spring, because
the vital activity of the plant is then specially great ; but even
in the autumn and winter a great deal can be done, provided
care be taken to secure a right temperature.

CHAPTER III
THE GROWTH OF PLANTS INDEPENDENTLY OF SEEDS

MANY plants propagate themselves independently of seeds. This
is especially the case in cultivated plants, like the Sugar-cane,
the Potato, the Begonia, and the Geranium. Plants which are
not indigenous to a country often take a long time to mature
and do not make seed freely ; it is an advantage to such plants
to be able to multiply independently of seed production. At
the same time it must be remembered that a plant propagating
itself independently in this way may in time become worn out . The
most striking instance of this is the sugar-cane, which has been
grown for some two thousand years by- " suckers " springing from
the original stem. In Barbados, where the Bourbon cane was the
species chiefly cultivated, attempts are being made to grow other
species. In this country, the potato is said to be less strong than
it used to be, and new varieties are being introduced, or seedlings
are grown in order to get a stronger plant than is the case where
tubers alone are cultivated. Seeds, too, are used when new varieties
are being sought. Many wild plants are also propagated without
forming seed, as it is an advantage to a plant to have two means
of multiplying itself, for there is great loss of life where seeds are
concerned. They may be eaten, they may fall on hard ground,
they may die through exposure to cold, they may rot from damp.
Even where seedlings are produced, a large number must perish ;
they may choke each other, they are eagerly devoured by grazing
animals, and young seedlings are peculiarly susceptible to changes
in weather and particularly to extremes of heat and cold.

METHODS OF SELF-PROPAGATION. — (i.) By creeping stems. — One
of the most common of our buttercups (Ranunculus repens)

multiplies in this way. The stem creeps along, rooting at the

60

GROWTH OF PLANTS INDEPENDENTLY OF SEEDS 61

nodes, and as the internodes decay, a new plant is formed at
each node that has developed adventitious roots. This is one of
the most prolific of the Meadow Buttercups, and is therefore
easily observed. The Ground Ivy, very common in hedges,
propagates itself in a similar way. Two weeds that are very
troublesome to the farmer, and which would cover large areas of
ground if left alone, spread in this way, namely, the Creeping
Plume Thistle and the Couch-Grass. It is no use cutting off the
heads of the thistle, as the underground stem is perennial and
creeps along underneath the ground. The couch-grass forms
buds in the axils of the leaf-sheaths, the buds burst through the
sheath and run horizontally as underground stems, called stolons.
These root as they creep along, forming new plants at each rooting.
Although some grasses are a nuisance to the farmer, others are
of value, especially on sandy shores. The two most important are
the Sea Mat-Grass (Psamma arenaria) and the Sand Lyme Grass
(Elymus arenarius). Neither of these is of any use as fodder, but
they bind sand together, and help to build up sand-dunes. This
is very well seen at a place like Newbiggin-on-Sea, not far from
Newcastle. The sand on the seashore is blown about by the wind,
and may be described as shifting sand ; here the grasses begin
their work of binding, and a few yards inland the shifting sand
gives place to a region of firmer sand, where sand-dunes are being
formed. In passing, it may be mentioned that the vegetation
of the shifting sand area is far more scanty than that of the firmer
region, for until the grasses have done their work, it is impossible
for many other plants to get a sufficient depth of soil in which
to grow.

The common Cinquefoil (Potentilla reptans\ which is found
in most hedges and on waste ground, has stolons with long inter-
nodes. On examining these stolons, it will be found that each
is made up of a number of branches, for at each node there is a
reduced leaf, in the angle of which a new stolon-branch originates ;
each new branch continues the direction of growth of the pre-
ceding branch, giving the appearance of one long continuous
stolon.

This creeping habit of plants has been made use of in cultiva-
tion. The Solomon's Seal and Iris of our gardens are perpetuated

62

THE BOOK OF NATURE STUDY

by means of creeping underground stems. In Fig. 32 the nodes (11)
of the underground stem of Solomon's Seal from which the roots
are given off are well marked ; the internodes (inf) are very
short, because the nodes are crowded together. The new plant
arises from the bud (&). The leaf -scars, showing the position of

the leaves, are shaded. These leaves
are scale-leaves and protect the tip
of the growing stem. They must not
be confused with the green foliage-
leaves, which are borne on the aerial,
and not on the underground stem.
The underground stem of the Iris
very closely resembles that of Solo-
nion's Seal. It is fleshy, and bears
parallel leaf-scars, but in this plant
the leaf-scars represent the basis of
the foliage-leaves. Both these plants
come up in larger clumps year by
year, and new plants are easily ob-
tained from them by the process of

separation

0 ,* , ,

Strawberries are propagated by
stems creeping along above the ground. These stems are called
runners, and grow out in the axils of the main plant. That
they are stems is clear, because they bear small leaves and end
in buds. From these buds foliage-leaves arise, and at the base
of the bud roots are developed, thus a separate plant is formed.
This plant in its turn may become the parent of others, by
producing runners.

With the Strawberry may be compared the Gooseberry. The
branches of this latter plant bend down, roots are formed at the
end of the branches, which become detached and form independent
plants. The suckers of Raspberries are also of the nature of
stems.

(ii.) By bulbs. — A bulb consists of a short conical stem portion,
and of leaf-structures borne by the stem. These latter occupy
the greater part of the bulb. In some bulbs the leaf-structures
are merely the basal portions of green leaves, the blades of which

FIG. 32.— Underground stem, Solo-

mon's Seal. », node ; «*/, intei-
node ; &, bud.

GROWTH OF PLANTS INDEPENDENTLY OF SEEDS 63

have withered. In the Snowdrop, the bulb consists of a short
stem portion, which bears two scaly leaves. These are the bases
of the two green foliage-leaves of the snowdrop plant. Many
bulbs have scale - leaves on the outside ; foliage - leaves within
these ; floral-leaves in the centre. All these sets of leaves are
borne by the short stem. The accompanying illustration is a
medium vertical section of a Narcissus bulb, showing the scale-
leaves (sc) on the outside, within these the foliage-leaves, and in
the centre the floral-leaves (/).

Onions and Shallots are bulbs commonly grown in kitchen
gardens. Onion seed, sown
the end of February or
early in March, will produce
young onions for salad by
June. If wanted for the winter
they should be disturbed as
little as possible, though care
should be taken to keep the
ground free from weeds. When
the bulbs are fit to gather
they should be laid out on
an open piece of ground,
where they will dry and
harden ; they should be turned
two or three times a week, and when thoroughly dried stored for
the winter.

Bulbils are small buds produced in the axils of foliage leaves,
as in the Lesser Celandine and some lilies. These bulbils contain
stores of reserve material, and dropping off the parent plant form
new plants.

(iii.) By corms. — The Crocus is an example of a plant which
propagates itself by a corm, a structure very closely allied to
a bulb and differing from it mainly in the relative porportion
of stem and leaves. The greater part of the corm consists of
the stem portion, whilst the scale leaves are few ; just the reverse
is the case in the bulb. It follows that in the Crocus the food
is contained in the stem ; in the bulb it is stored in the leaves.
In order to understand the life-history of the Crocus, corms

FIG. 33. — Median vertical section of Narcissus
bulb, sc, scale-leaves ; /, floral-leaves ;
£, bud ; s, stem.

64

THE BOOK OF NATURE STUDY

should be examined at different times of year, about November,
February, March, July. Drawings should be made of each stage
and compared with each other.

In November the plant is in its resting condition and shows
a large corm bearing a bud in the axil of a scale-leaf, with an
old corm underneath it. Roots are given off from the circum-
ference of the corm. (See Fig. 34.)

Early in February a crocus has reached the stage shown in
Fig. 35. The corm marked I in Fig. 35 is gradually shrinking, for

the bud (II) is feed-
ing on it. If this
bud is dissected it
will show a succession
of sheathing leaves,
then a few green
leaves, then the floral-
leaves all borne by
the stem portion of
the corm (II). The
flowers often come
above ground before
the leaves ; buds are
formed in the axil of
one or more leaves at
the end of the season,
when it is preparing
to rest for the winter.
After flowering

the crocus appears as in Fig. 36. The corm has very much
increased in size owing to the deposition of starch made by
the green leaves, which are always tied up by gardeners after
the flower has faded. It is seen in Fig. 36 how very much
corm I has shrunk ; if undisturbed, it would very soon have been
a mere skin under corm II. This figure also shows the development
of a corm from a lateral bud, which was present in the crocus
from which it was drawn. The development of new corms from
lateral buds is an arrangement by which the plant gradually
occupies new ground and thus gets more nourishment. This is

FIGS. 34-36. — Corm of crocus showing three stages of
development. The Roman numerals refer to the
same corm throughout.

GROWTH OF PLANTS INDEPENDENTLY OF SEEDS 65

very well seen in the Autumn Crocus, a plant belonging to the
Lily order and not to the true crocuses. It grows in pastures, and
flowers the end of August. It is very like the Purple Crocus.
The new corms are formed on one side of, and a little below, the
old one. When the corms have reached a certain depth, about
7 or 8 inches, they do not penetrate any deeper, but spread
laterally.

The life-history of a Crocus may be summed up — i. It develops
from a corm, which is a swollen stem with roots on the lower,
and a bud on the upper, surface. In its earliest stage everything
is beneath the ground.

2. The flowers and leaves come above ground ; the corm
shrivels, for it is feeding these organs.

3. Buds are produced in the axil of one or more leaves. The
food made by the blades of the leaves is stored up in these buds,
which develop into corms, having the structure described in i.

With the Crocus may be compared the Montbretia. If Mont-
bretia plants are dug up in
October, old corms will be
found under new ones, as in
the Crocus, but in addition
to this, long runners or
underground stems are also
found at the end of the
summer. These, swelling
up at their ends, form fresh
corms at some distance from
the mother plant, in order
to get food material from
a new area. In this way
the plant is propagated and
spreads rapidly in a garden.

Both corms and bulbs

have the power Of forming FlG- 37-— Corm of Montbretia. st, underground
r stem; r, root.

contractile roots. In cro-
cuses grown in the open these are found in the months of
April or May at the base of the young corms. They grow
rapidly, sometimes through the old corm, and pull down the
VOL. in. — 5

66 THE BOOK OF NATURE STUDY

new plant to the soil best suited to it. Kerner mentions a
species of Garlic (A Ilium paterfamilias}, the old bulb of which
gives rise to a hundred young ones in a year. Naturally they
could not all develop, if they remained crowded together ; by
contractile roots the young bulbs are drawn away from the old
one. Only a few of the roots, he says, strike downwards ; by
far the greater number grow out parallel to the soil. With this
species maybe compared the behaviour of another garlic, A Ilium
ursinum, very common in woods and easily recognised by its
strong smell. In early spring, it forms a circle of fleshy roots,
which grow obliquely downwards. As soon as they are firmly
attached to the soil, they contract to about two-thirds of their
original length, and thus draw the bulb downwards. In the
autumn another set of roots is developed. These grow
outwards, and their work is to get nourishment for the plant.
Then follows the period of winter rest, and the following spring
another circle of contractile roots is developed to drag the bulb
downwards. Other plants which have contractile roots are
the Ranunculus bulbosus and young Raspberry bushes, these
latter in contracting form spiral coils.

The Bluebell is specially interesting. In the month of May
bulbs will be found with large roots, 4 or 5 inches in length,
transversely wrinkled in the upper region. The lower portion of
the root being firmly fixed in the soil, the upper part contracts
and pulls the bulb underground.

Tulip bulbs develop droppers or sinkers. A dropper is a
continuation of the base of the foliage-leaf. It emerges from the
bulb by boring its way through the scale leaves enclosing it. It
is not a solid structure, but a hollow tube containing in its swollen
tip a small knob. Figs. 38 and 39 give drawings of two droppers
very unlike each other externally. The difference in length is
due to the age of the Tulips. Short droppers are characteristic
of older Tulips ; the slender dropper probably belongs to a young
seedling, and would have swollen up a good deal by the end of the
year, if it had not been disturbed. It is by means of droppers
that some bulbous plants, particularly Tulips and Squills, prevent
overcrowding and protect themselves from frost in winter and
drought in summer. The Tulip with the short dropper in Fig. 38,

GROWTH OF PLANTS INDEPENDENTLY OF SEEDS 67

being much older, has probably reached the level best suited to

the plant, whilst the one with the long, slender dropper, being

much younger, was still seeking the right depth.

The price that used to be paid for Tulip bulbs strikes us now

as incredible. The chief trade in the sixteenth

century was carried on by the Netherlands, and

it is said that as much as £500 or more would

be given for an individual bulb. The bulbs of

the Double Hyacinths when first produced at

the beginning of the eighteenth century fetched

£100. The rivalry that sometimes existed be-
tween bulb-growers is well shown by Dumas in

his pathetic story La Tulipe Noire.

(iv.) By tubers. — A tuber (Latin turner e, to

swell) is a swollen underground stem. A Jeru-
salem Artichoke should be
examined first, as it is then
easier to understand the
structure of the Potato.
The leaves in the Artichoke
are long, scaly outgrowths;
in the axil of the leaf will
be seen a bud. Then the
Potato should be ex-
amined. It, too, is a
much swollen structure,
bearing very small scale-
leaves with buds in the
axils. These are called
" eyes" in both the Arti-
choke and Potato ; in the
latter there are from two

to six buds in each " eye/' but they do not usually all develop.

As these underground structures in both plants bear leaves and

buds, they are underground stems, not roots, for stems alone bear

leaves, or structures answering to leaves. As a rule, stems alone

may be said to bear buds, although there are one or two instances

of a root bearing a bud.

d —

FIG. 38. — Dropper of old
Tulip, d, dropper.

FIG. 39.— Dropper of
young Tulip, d,
dropper ; £, swell-
ing at tip.

68 THE BOOK OF NATURE STUDY

If a Potato plant is carefully dug up without breaking the
branches, the relation of the Potatoes to the parent plant can be
seen. The tubers are situated either at the end of shoots which
bear scale-leaves, or on short branches arising in the axils of the
scale-leaves. Both of these are shown in the illustration.

Root-tubers are also swollen, underground structures, but
their origin is different from that of the stem-tuber. They grow
out from the base of the stem, and are therefore of the nature of
roots. The Peony and the Dahlia have root-tubers.

FIG. 40. — Potato plant, showing Potatoes in different stages of growth.

All these tubers are storehouses of food for the plant. If a
drop of iodine is put on a slice of a Potato, a dark blue stain is
at once produced. This indicates the presence of starch. When
good potatoes are properly boiled, they have a floury appearance,
owing to the bursting of the grains containing starch.

In preparing " seed " potatoes, a well-grown potato should be
cut into as many pieces as there are " eyes " at the apex ; each
piece should contain one of the " eyes/' and should not be cut
too close to it, as the bud when growing into the plant requires
to draw nourishment from the tuber. A pound of potatoes will

GROWTH OF PLANTS INDEPENDENTLY OF SEEDS 69

give about a hundred shoots, reckoning three buds to each " eye."
Potatoes do not require as rich soil as many other crops. The
best soil for them is a light open soil, well drained, and of a sandy,
loamy character. It is interesting to read the directions for
planting potatoes which used to be given when they were com-
paratively new in England. Thus Evelyn in his Kalendarium
Plantarum, the first gardener's calendar published in Britain,
writes, " Plant potatoes in your worst ground." In Mortimer's
Gardener's Kalendar for 1708 the Potato is thus described : " The
root is very near the nature of the Jerusalem Artichoke, although
not so good and wholesome but that it may prove good for swine."
Gerarde mentions in his Herbale, published 1597, that he culti-
vated the plant in his garden, where it succeeded as well as in its
native country. This is one of the earliest references to the Potato
in England. That potatoes naturally like a sandy soil was
observed by Darwin, who relates seeing the wild Potato growing
abundantly among the Chomos Islands near the sea beach in
thick beds, on a sandy, shelly soil, wherever the trees are not
too close together.

CLASSIFICATION OF SPECIAL FORMS OF STEMS. — i. Creeping
stems. — These sometimes occur above ground, as in the runners
of the Strawberry. Rhizomes are generally underground, as in
the Bracken, Iris, etc.

2. Bulbs. — These differ from creeping underground stems
or rhizomes in having the nourishment contained in the
leaves.

3. Corms, which have a swollen underground stem and very
few scale-leaves.

4. Tubers, which bear " eyes " and are swollen parts of under-
ground stems.

The plant thus has more than one way of storing up nourish-
ment. When the plant is propagated by seeds, it is necessary
that food for the young seedling should be contained in the seed,
or that the seed leaves should be able to make food for it almost
as soon as germination begins. If the plant, however, multiplies
itself independently of seed, then food must be stored up for it
in some other organ, as the root or underground stem. The

7o THE BOOK OF NATURE STUDY

character of the food stored up varies with the plant. Perhaps
the food most commonly found is starch, which is present in the
underground stem of bracken, the tuber of potatoes, and the corm
of the Crocus ; the leaves of bulbs often contain sugar. Arti-
choke tubers contain another carbonaceous substance, called
inulin, so too do those of the perennial sunflower.

SUGGESTIONS FOR PRACTICAL WORK. — i. Plant bulbs of Onion,
or some other plant, in damp sawdust, noting the position of the
roots, of the buds, and of the new bulbs. Onion is mentioned as
the cheapest bulb procurable.

2. Grow tubers of potatoes in damp soil, some in light and some
in darkness. Compare the growth of the two, and make drawings
at regular intervals.

3. Plant corms of crocus in sawdust, and make observations at
intervals of two or three months. To do this, draw the external
appearance of the corm and then cut a median vertical section
of it.

4. Look for contractile roots of crocus in March or April, and
for droppers in tulips.

5. Compare the underground structures of the Lesser Celandine,
the Parsnip, the Pignut, and the Gladiolus. Decide whether they
are roots or underground stems. The important fact to bear
in mind here is, that stems bear leaves and roots do not.

6. Examine the scales of the Snowdrop, Onion, Tulip, and
Hyacinth. See which are entire scale leaves, and which are
parts of foliage-leaves, the blades of which have withered.

7. Determine the nature of the food stored up, whether starch
or sugar. The former can be tested with iodine, the latter by
tasting.

8. Compare the bulb of a Lily with that of a hyacinth, noting
the difference in the arrangement of the scales. In the former,
the scales simply overlap at their margin, and the bulb is said
to be scaly ; in the latter the outer leaves completely ensheathe
the inner portions of the bulb, which is then described as
tunicated.

9. Count the number of plants produced by a single Strawberry
plant.

GROWTH OF PLANTS INDEPENDENTLY OF SEEDS 71

10. Note the rapidity with which certain weeds, if left to
themselves, spread. See whether this is due to growth by under-
ground stems or to dispersion of seeds.

11. Note the propagation of plants in gardens by methods
such as layering, taking of cuttings, budding, grafting, etc. These
are all means of reproduction independently of seed, either from
the leaf, or the stem, or a bud — the vegetative organs of the
plant, as they are called, for they are the organs engaged in the
normal life of the plant, not usually in the special work of repro-
duction. These modes of propagation have been also developed
in plants, which have been introduced from other countries and
therefore may not readily form seed in England. Carnations and
Strawberries are " layered/' that is young shoots are pegged
down to the ground, in order that they may become rooted before
being severed from the parent stem. Geraniums and many other
plants are propagated by cuttings. These are best made in
August. A cutting should be made straight under the node,
and the sap allowed to ooze out for some twenty-four hours
before it is planted in a pot.

Roses are often propagated by budding. A dormant bud of
the variety of rose tree that is to be perpetuated is inserted on a
stock which is in the right condition. The Dog Rose is often
chosen, and stocks can be obtained from country lanes during
the winter. By the following July, the shoot is ready for the
insertion of the buds. A plump young bud of the Rose with
a little bark attached to it is inserted under the bark of the
stock, and the wound bound up, leaving the bud uncovered.

Corms, it may be noted, sometimes form cormlets or " spawn "
at their bases. The Gladiolus can reproduce itself in this way.
The cormlets are collected and sown in the spring, in beds of
rather sandy soil. They are " lifted " from the soil annually,
just as older plants are, and flower in about three or four
years.

Lastly, it may be mentioned that Begonias are propagated
by their leaves. The principal veins are cut through and the
leaf pegged down with hairpins, or small stones, on to specially
prepared soil placed in a pan or box. The box has to be kept
at a certain temperature, and, if properly treated, plants will be

72 THE BOOK OF NATURE STUDY

produced at almost every cut of the leaf. Begonias are also
propagated by means of cuttings.

Now that school gardens are being established in the majority
of elementary schools, opportunity is aiforded of first-hand
observation of these methods, and the Nature Study lesson may
well be planned so as to lead the student to take an intelligent
interest in gardening, and to know the reason of these common
operations.

CLIMBING PLANTS.

I. BLACK BRYONY, WITH STEM TWINING FROM LEFT TO RIGHT.
II. WHITE BRYONY, CLIMBING BY MEANS OF TENDRILS.

III. SCARLET RUNNER, WITH STEM TWINING FROM RIGHT TO LEFT.

IV. GARDEN NASTURTIUM, CLIMBING BY LEAF STALK.

CHAPTER IV
THE IMPORTANCE OF HAIRS IN PLANT LIFE

THE term " hair " in its widest sense includes all structures
that are developed from the outer skin of any part of the plant ;
root-hairs, the prickles of the rose, the hairs on stems and leaves,
the bristles on many fruits are all " hairs " in the botanical sense
of the word. It is evident at a glance that hairs play an
important part in plant life, and that their functions are very
varied.

ABSORPTION AND DIGESTION. — In germination the root-hairs,
as we have seen, are engaged in drinking in food material for the
young plant. As soon as the lateral roots are formed the root-
hairs behind the tips are engaged in the same work. This has
already been fully described (p. 22), therefore we now pass on to the
share hairs take in digestion under certain circumstances. There
are some plants that feed on insects and obtain their nitrogen
from the dead bodies of the insects they capture. These plants
are usually found, as one might expect, in soil deficient in nitrogen.
The Pitcher-plant, Sundew, Butterwort, and Bladderwort are
instances. If these be examined it will be found that the insect
is often entrapped by means of hairs on the structures concerned,
and in some cases the hairs secrete a fluid which enables the
plant to digest the body of the insect. In the Pitcher-plant
(Plate II.) the leaf -stalk is modified into three distinct parts :
a flattened leaflike lower part; a tendril and a pitcher, the
blade of the leaf forming the lid of the pitcher. The insect,
attracted by the bright colouring, is caught by the bristles of
the rim ; unable to escape owing to the fact that the bristles
point inwards, the insect falls into the pitcher and is drowned
in the liquid which it contains. In the Sundew the leaves are

73

74

THE BOOK OF NATURE STUDY

covered with delicate red hairy-looking filaments, generally
called tentacles. Botanically, they are described as " emergences.'*
One hardly ever gets tired of watching these filaments curl up
when touched ; they serve to entangle the insect. At the ex-
tremity of each there is a gland which secretes a juice containing
an acid that digests the nitrogenous substances present in the
body of the insect. The leaves of butterwort are thickly covered

with glandular hairs ; it is said that
the eight rosette leaves of one
plant have as many as 500,000 of
such hairs. These aid in the cap-
ture of the insect, and the fluid
they secrete, in digesting it. The
bladders situated on the leaves of
Bladderwort are also covered with
hairs.

IN DRAINING OFF WATER. — The
bud-scales of winter buds often
bear delicate hairs at their edges.
These help to direct the current of
water down the bud and thus pre-
vent its reaching the delicate inner
leaves, which would rot unless
they could be protected from the
cold rain of winter. The stipules
of the Oak or of the Beech should
be examined in spring, when the
bud opens and the fringe of hairs
will be easily seen.
A very interesting arrangement of hairs occurs on the stems
of Stellaria media (Common Chickweed). The plant is for the
most part smooth, but there is a line of hairs running down the
side of the stem which is opposite the flower. The leaves
are opposite, and their bases form a cup ; the edges of the
leaf -stalks are also fringed with long hairs. It is thought
that the line of hairs on each internode serves to conduct the
water from the cup above to the one beneath. It should be

FIG. 41.— Chickweed (Stellaria media\
showing hairs which drain off
water.

THE IMPORTANCE OF HAIRS IN PLANT LIFE 75

noted that
internode.

the line of hairs on the stem alternates with each

PROTECTION. — Hairs are often developed on the stom or
leaves, or on both, in order to protect the plant from animals.
Stinging Nettles are let severely alone, and some people have
supposed that the Dead-nettle has gained some advantage to
have leaves which very closely resemble those of the Stinging
Nettle. If a Nettle is grasped from below, the hairs which point
forwards are merely compressed and do not sting.

These hairs contain an acid fluid, which causes the irritation.
The leaves of the common Elm have on
their under surface, especially along the
ribs, hairs which sting, though not so
severely as those of the Nettle. This tree
is often planted in hedgerows, and is no
doubt protected from browsing animals
by these hairs. The teeth of the Holly are
a protection to the tree. Lord Avebury
notices in this connection that the upper
leaves which are out of the reach of animals
tend to lose their spines, and old trees
are often almost entirely without them.
(British Flowering Plants, p. 281.)

Another plant which has stiff, almost
prickly, leaves protecting it from animals
is the Viper's Bugloss.

In some plants prickles are developed instead of hairs. These
are often protective in function; they may be also an aid in
climbing.

Flowers are sometimes protected from creeping insects by
hairs on the involucre, as in Crepis pakidosa. In the Composite
it is very common to find the bracts of the involucre with stiff
hairs, e.g. Knapweed. The stomata of leaves are often pro-
tected from dust by hairs. In London parks the hairs on the
under surface of the leaves of the Wych Elm are often found
covered with soot particles, which are thus prevented entering
the stomata.

FIG. 42. — Under surface of
leaf of Elm, showing hairs
along the ribs.

76

THE BOOK OF NATURE STUDY

To LESSEN TRANSPIRATION. — As a general rule plants that
grow in dry situations are much more hairy than those belonging
to damp places. The different species of a genus illustrate this.
Crepis paludosa grows in damp places and is smooth, whilst
Crepis biennis and Crepis fcetida are hairy. Professor Henslow,
describing the plants of the desert near Cairo, notes the grey colour
of the leaves, and attributes it to the dense coating of hairs, which
conceal the green colouring matter. The effect of hairs is to lessen

the amount of transpiration. This is
a most important function, for plants
that live in dry situations need to
retain as much water as possible, the
supply being very irregular. A cover-
ing of hairs prevents evaporation
from the surface of the leaf into the
air. This may be observed on hills,
which are always drier than the
adjoining valleys and on the seashore.
Many of the Hawkweeds and Hawk-
bits and Crepis have leaves densely
covered with hairs, to protect from
too rapid transpiration. In the
Mouse-ear Hawkweed the under sur-
face of the leaf is covered with
stellate hairs ; in dry weather the
leaf rolls up so that the under surface
is uppermost, and evaporation con-
siderably lessened. This decrease of
transpiration owing to the protection
of hairs is one of the best marked characteristics of alpine
plants. The Edelweiss and Cudweeds are instances that will
occur to every one.

In this connection it is interesting to note the variation in
the degree of hairiness in the same species owing to a difference
in situation. The Restharrow (Ononis arvensis) is very variable.
When growing by the sea it is more hairy than when growing
inland. Similarly, it has been stated that Meadow-sweet, which
is usually smooth, develops hairs when growing in a dry situation.

FlG. 43.— A species of Crepis show-
ing hairiness of leaves.

THE IMPORTANCE OF HAIRS IN PLANT LIFE 77

Not only do hairs protect against too rapid transpiration,
but also against changes of temperature. The young leaves in
buds are often wrapped in white downy hairs which protect
them from the cold of winter, as in the White Beam tree, which
looks in the distance almost white from the thickness of the
cottony filaments on the under surface of its leaves.

CLIMBING. — Hairs, especially if hooked, help a plant to climb.
Hop-pickers dislike having to pick hops in wet weather, not only
because all outdoor work is pleasanter in a bright sunny atmo-
sphere, but on account of the way in which their hands get cut
by the hairs, which are much stiffer in damp weather. The leaves
of the Hop are covered with hairs, some of which are seen under
the microscope to have, as it were, two horned appendages. It
is these that enable the hop in its wild state to cling to any support
it may touch in the course of growth. Many of the genus Galium
are provided with hairs for climbing purposes. The best known
example is the Wild Cleavers, which is covered with small, stiff,
hooked hairs. Not only the stem and leaves are thus provided,
but the burrs are even more difficult to get rid of when once they
have attached themselves to clothing. Another species of Galium ,
the Crosswort, also has closely packed hairs, though not with such
well-developed hooks. Both those plants, especially the Wild
Cleavers, are found abundantly in hedgerows. Without some
means of climbing they would probably be far less luxuriant in
growth, for their stems are weak and the plant would be very
likely to be trodden down. Prickles often have the same function.
Rose and Blackberry stems catch hold of other plants by means
of the prickles developed on them. The Blackberry is often found
entwined with clematis. If the two plants are untwisted it will
be seen that the Clematis has climbed by twisting its leaf-stalk,
the Blackberry by hooking its prickles on to the other plant.

POLLINATION. — Perhaps the most striking use of hairs is
their share in the work of pollination. One naturally dwells on
the part played by insects in the carrying of pollen from one flower
to another, and botanists have always been fascinated by the study
of the relation of plants and insects, but hardly enough emphasis

78

THE BOOK OF NATURE STUDY

has been laid on the use of hairs. It is owing to the stigmatic
surface being covered with hairs that the pollen grains are kept
firmly on the stigma, whilst the pollen tube is being put out. In
fact, there seems to be a definite relation between the length of
the hairs and the size of the pollen grains.

Insects are often entrapped by hairs, in order to ensure cross
pollination. The common plant called " Lords and Ladies "
(Arum maculatum) shows this very well. Small flies are attracted

by the dark red spadix on which the
flowers are borne, by the smell, and
some may fly to the plant for shelter
in the large green bract (spathe). They
creep down until they reach the upper
part of the chamber formed by the
bending round of the edges of the bract.
Just on a level with the upper part of
this chamber the spadix bears hairs
which radiate outwards and allow the
insects to creep down, but not to get
out of the chamber. In reality, they
are imprisoned there until they have
done the work the plant requires from
them. In this plant the stigmas are
mature before the anthers. The flies, if
they have visited other Lords and Ladies,
will pollinate the stigmas with the
Then the stigmas
wither, and the flies get the honey
which is secreted on the tips of the
stigmas. Lastly, the anthers mature, the pollen sacs dehisce,
the pollen falls to the bottom of the chamber where the flies
still are, and they get dusted with it. Then the hairs shrivel
up and allow the insects to escape. These, laden with pollen,
if they fly to another Arum, will cross-pollinate it. One wonders
that any fly, having once tasted of this imprisonment, should
repeat the experiment ; but it seems certain from the large number
of flies found in the chamber of the Arum, that many must visit
one flower after another. Lord Avebury states that often more

FIG. 44. — Inflorescence of Arum

maculatum. b, bract; ss, pollen brought,
spadix ; ^, hairs ; a, anthers ;
c, carpels.

CL

s

THE IMPORTANCE OF HAIRS IN PLANT LIFE 79

than one hundred small flies will be found, and mentions, on the
authority of Knuth, an instance of 4000 being found in a single
Arum. It is possible that the honey is exactly the food this species
of fly (Psychoda) loves best, or the smell may prove an over-
powering attraction. Other very opposite explanations have
been given lately. Father Gerard's opinion, quoted by Lord
Avebury, is that the honey has a stupefying effect on the insects,
which he says are killed and digested in the chamber, for the
dried remains of flies are found on the walls of the cavity. It is
quite probable, however, if flies visit the flower in such numbers,
that some should get killed, owing to the want of oxygen ; the
presence of a large number alive is a fact
largely in favour of the usually received
theory.

Hairs may entangle the desired insects,
but they may also keep away undesirable
guests, thus guarding the nectary and pre-
serving the honey for the insect able to
pollinate the plant. In the Dead-nettle
the honey is secreted by a nectary just
below the ovary, and it collects at the
bottom of the corolla. Here there is a ring
of hairs which effectually prevent small FIG. 45.— Median vertical
insects getting the honey, for the Humble-
bee is the species best adapted to the
structure of the flower.

Sometimes flowers have no honey, and

insects visit them in order to get pollen with which to feed their
young. Under these circumstances some flowers have special
staminal hairs to which the insect clings. The mulleins are
good examples of this. The Black Mullein, in particular, has
on its stamens a row of rich violet-coloured hairs. In all these
ways hairs are of use in pollination.

DISPERSION OF FRUITS AND SEEDS. — Many fruits are dispersed
by hairs or bristles. It is well known that in many of the Com-
positae the sepals are represented by hairs. After the formation
of the fruit those develop into organs of dispersion. The

section of flower of
Dead-nettle, a, an-
thers ; s, stigma ; h,
hairs.

8o

THE BOOK OF NATURE STUDY

" pappus " of the Dandelion is a case in point. The wind wafts

the fruits long distances, and this largely accounts for the wide-

spread habit of the plant, and
indeed of many Composites,
e.g. Thistle, Groundsel, Knap-
weed, Burdock.

Sometimes the styles become
the organ of dispersion through
the long hairs developed on
them. The Water Avens (Geum
rivale) has very hairy styles,
which no doubt serve to dis-
perse the fruits. Another
species of Geum growing at
high altitudes, as for instance
on Swiss mountains, also has
very long hairy almost silky,
styles. The most common
species in England, Geum
«*™»*. * hedgerow plant,
develops styles each of which

ends in a hook, and this serves the same purpose of dispersion.
The fruits of the Clematis are too well known to need

description, but that of the Anemone pulsatilla is much less

common, and shows styles even more

hairy than the Clematis. In this plant

the flower-stalks lengthen after flowering,

perhaps also to help in dispersion. In the

common Wild Anemone the fruits are downy,

but have not got the long feathery awns of

the Anemone pulsatilla. In this connection

the " awns " of the grasses may be men-

tioned. The most remarkable instance of

this is Stipa pennata, a species much used in

decoration. The Cotton-Grass, really a sedge,

has a perianth of long cotton-like hairs which aid in the dis-

persion of the fruit.

In many cases the hairs forming the organ of dispersion are

°f Water

DANDELION (Taraxacum ojficinale, Web.).
R. Root. L. Leaf. Infl. Inflorescence. Br. Bracts.

THE IMPORTANCE OF HAIRS IN PLANT LIFE 81

attached not to the fruit, but to the seed. The cotton that is
imported from Africa and America, and manufactured into calico,
consists of the fine hairs in which the seeds are wrapped. One
of the factors affecting the price of this raw cotton is the way
in which it is picked. It should be absolutely clean, free from
every bit of the husk or particle of dirt of any kind.

The Willow-Herbs have seeds wafted by the wind long distances
owing to the hairs with which they are
provided. So too have the seeds of
the Willow, which belongs to a very
different group of plants. In the
months of May or June the fruits of
the willow catkins begin to dehisce.
Then the seeds are exposed, and are
seen to be covered with delicate silky
hairs by which they can be blown long
distances. The same thing occurs in
the Black Poplar, which is particularly
beautiful. The fruits dehisce into
two valves, each containing many
seeds ; the whole catkin seems to be
enveloped in snowy white fluff.

STRUCTURE OF HAIRS. — Hairs may
consist of a single cell. This is almost
invariably the case in root -hairs,
which, as a rule, do not branch.

Unicellular hairs are generally de- FIG. 48.— Fruits of willow,
scribed as simple. Multicellular hairs,
as the name implies, consist of more
than one cell ; these may be branched

or unbranched; they may be filamentous or scaly. Thus the
Stock has simple, branched hairs, the Mullein branched com-
pound hairs, whilst the stinging hair of the Nettle is simple
and unbranched. This plant has three kinds of hairs ; those
that sting are the largest. The point of the stinging hair breaks
off in the skin, leaving a tiny wound into which the acid juice
>ntained in the swollen base can enter.

VOL. III. — 6

single fruit is shown on right,
dehiscing and exposing seeds
covered with hairs.

82 THE BOOK OF NATURE STUDY

The prickles of the Rose are of the nature of hairs, because
they are developed from the epidermis. These are often popularly
called thorns, but the term " thorn " in botanical language
generally represents a modified branch, as in the spines of the
Blackthorn and Hawthorn. Sometimes thorns represent modi-
fied leaflets, not branches. The leaves of the Barberry plant
show an interesting transition from foliage - leaves to spines.
The lowest are foliage-like, the uppermost spiny ; the intermediate
ones are smaller than the lowest, and end in a spiny process,
so that they are something between the foliaceous and spiny
forms. The thorns or spines of the Gorse are either modified
branches or modified leaves : those that arise in the angle which

FIG. 49. — Different forms of hairs : Stock, simple, and branched ;
Stinging Nettle and Mullein.

the leaf makes with the stem are from their position branches ;
whilst those that are borne laterally by the main stem or branch
are modified leaves. The young seedling of the Gorse has tri-
foliate, ordinary foliage-leaves (Fig. 22), but as the plant grows
older these are replaced by spines. It seems likely that these
spines have gradually been developed, possibly in the first instance
to prevent too rapid transpiration in dry seasons, the Gorse
liking a sandy soil ; now the thorns also serve to protect the
plant from herbivorous animals.

The spines of the Garden Acacia (Robinia) may also be men-
tioned. These arise at the base of the leaf-stalk, and are modified
stipules.

THE IMPORTANCE OF HAIRS IN PLANT LIFE 83

It is interesting to compare the structure of the same plant
growing in different situations. The Rest-Harrow is more thorny
in dry situations than in moist valleys, the Meadow-Sweet appears
to have almost entirely smooth leaves, when growing in damp
places, and to develop hairs on the leaves in drier soil.

Much more accurate observation needs to be made on this
subject of the hairiness of plants. Although it may be stated
generally that plants belonging to dry situations are hairy, there
are many exceptions of which as yet no explanation is forth-
coming. Why are those Forget-me-nots which grow in damp
places hairy ? The reason may possibly be that they belong
to an order of plants which is conspicuously hairy. The Viper's
Bugloss, Borage, Alkanet are all strikingly so. Then the Water
Forget-me-nots and Comfrey, which also belong to damp situa-
tions, and might be expected to be smooth, are also hairy.
As a rule, structures of this kind are not necessarily affected
by facts of relationship. There are numerous instances of very
closely allied species, which differ in this character of hairiness
according to the situation in which they live. Another explana-
tion that is sometimes suggested is, that these hairy plants now
found in wet ground, as by streams, etc., at one time grew in
drier situations, and that they have not yet lost the hairy char-
acter which then was of use to them. It is impossible in the present
state of our knowledge to account for these differences. More
accurate observation of the same species under different con-
ditions is necessary, and one or two suggestions are now offered.

Examine the leaves of plants growing by streams, or in marshy
places, such as the Meadow-Sweet, Ragged Robin, Cuckoo Flower,
Water Avens, Figwort, etc., and note whether they are hairy
or not. Compare them with other plants of the same species
growing in drier situations, as for instance in land which was
marshy but has been drained.

Compare plants of the same species growing on hills and by
the seashore ; the common Erodium will be found in both these
habitats. Note the degree of hairiness. As a rule, plants growing
in both these localities are hairy, on account of the dryness of
the situation. Not only are plants by the seashore inclined to
be hairy, but they often have their leaves reduced to spines.

84 THE BOOK OF NATURE STUDY

The Saltwort is a typical instance of this. The Salt Spurrey,
though it has fleshy leaves, develops scaly stipules ; the apparent
leaves of the Glasswort are branches, which are jointed, and the
true leaves are represented by the small teeth at these joints. In
fact, there is no organ of the plant which adapts itself to its
environment more readily than the leaf ; by becoming hairy, or
thorny, or very much reduced.

BIBLIOGRAPHY (Chapters I. to IV.). — Lord Avebury, A Contribution to our
Knowledge of Seedlings ; Buds and Stipules ; Flowering Plants ; Pfeffer, A Text-book
on Physiology of Plants, 3 vols. ; Darwin, The Power of Movement in Plants ;
Hall, The Soil ; Kerner and Oliver, Natural History of Plants ; Ganong, The
Teaching Botanist.

SOME COMMON FLOWERING PLANTS

BY WILLIAM H. LANG, M.B., D.Sc.,

Lecturer on Botany in Glasgow University

CHAPTER V
INTRODUCTORY

FOR the student of nature knowledge, and especially for the
teacher, the study of the flowering plants of our fields and gardens
is of especial importance. They are of great interest, but so are
all other living beings and natural objects. It is their familiarity
and the ease with which they can be obtained that gives them a
place before many other things in Nature Study, and the teacher
is sure to draw largely upon them in his efforts to interest his
scholars. One great advantage is that they can not only be
easily obtained, but obtained in quantity, and no lesson
need, or ever should, be given from a single specimen. The
scholars may sometimes be able to collect the plants required
for themselves, and, if common kinds are chosen, each child
can have his own specimen to study. Another advantage is
that the flowering plants are easily grown and watched through
the various stages of their life, and at the different seasons of
the year.

Every flowering plant has its own interest and, in the hands of
a teacher who has himself studied it properly, will serve* as the
basis for interesting lessons. The commonest and most familiar
plants are, however, in many ways the best to use. Familiar wild
flowers of the meadows and roadsides, common trees and plants
grown in gardens, as vegetables, fruit trees, or for the sake of
their flowers, afford excellent objects of study. That the common

'85

86 THE BOOK OF NATURE STUDY

plants are the most suitable to begin with is the principle under-
lying this section of the Nature Study Book.

The study of flowering plants may be begun in several ways,
and the difficulties for the unassisted student lie in great part in
making a proper start. One very common method is to start by
trying to name all the plants met with in a district by the help of
a book of descriptions, or what is known as a Flora. This is an
excellent thing to do later on, but has disadvantages as a way of
beginning. The student is liable to be bewildered by the number
of plants, and the descriptions are necessarily brief and concerned
with the features that serve to distinguish one plant from another
rather than with their uses to the living plant. An opposite
course, the thorough study of the life history, form, and minute
structure of one plant, requires the assistance of a teacher and
more complicated apparatus than the plan which is here suggested.

We shall start from the fact that, however slight his real know-
ledge of plants may be, every one knows a number of wild and
cultivated plants by name, and can recognise them when in flower.
The Buttercup, the Daisy, the Dandelion, the Tulip, the Potato,
and the Oak, for example, may be assumed to be either known to
the reader, or at least to be so commonly known that he will have
no difficulty in getting them pointed out to him, and in obtaining
specimens for study. In the following pages a number of plants,
which may thus be assumed to be familiar, have been selected,
and a description given of what can be seen when they are care-
fully examined with the assistance of only simple apparatus.
This description is meant to help the teacher in his own study of
the plant. His teaching should be based upon his own observa-
tions, not upon this or any other written description.

It was mentioned as one of the drawbacks of commencing
by naming the plants of a district, that it concentrated atten-
tion on the differences between plants without considering the
relation of these differences to the life of the plants. In studying
the plants described below, the use to the plant of the various parts
is always to be borne in mind. It will be found that the general
features in which flowering plants resemble one another are related
to processes of life common to all these plants. Special features
of the roots, stems, leaves, and especially of the flowers, require

FLOWERING PLANTS— INTRODUCTORY 87

careful study in the light of the particular uses these parts serve,
and the way in which these uses are carried out. The study of
even a small number of plants from this point of view will enable
the student to examine with interest and profit other plants than
those described here. It will also suggest further work in various
directions, some of which are treated of in other sections of this
book.

It cannot be too strongly impressed upon any one commencing
the study of plants that reading about plants is by itself of little
use, and may even be worse than useless if it leads to the neglect
of observation. What should be aimed at by teachers as well as
scholars is first-hand information based upon the student's own
observation. He should know a thing, not because he has been
told it, but because he has seen it for himself and understood it.
This is a truism, but one of the most difficult things to cultivate
is the frame of mind which is not content until the knowledge
acquired is based on personal observation and not on hearsay. It
is most important that right methods of work should be followed
from the outset, and it should be expressly stated that the de-
scriptions below are intended to be used along with specimens of
the plants to assist in their detailed study. The order in which
the plants are examined is of little or no importance. Plants
which are known to be in flower at the particular season should
be selected. Evidently the spring and summer months will be
the most suitable season for this branch of Nature Study, though
observations on the plants should be continued throughout the
year. Advice as to collecting and examining plants and as to the
apparatus needed will be given below.

All the plants to be described here are what is known as
Flowering Plants, and all except the Pine belong to the great group
of the Angiosperms. This is the highest group of the vegetable
kingdom, and includes the plants which appeared last on the
surface of the earth, where they now form the dominant and
most conspicuous part of the vegetation. The Pine, which will
also be described, belongs to a more ancient group, the Gymno-
sperms, and will be found to differ more profoundly from the
others than they do among themselves. All the plants we are
concerned with are composed of similar parts, and have much in

88 THE BOOK OF NATURE STUDY

common, but each has its own peculiarities and differs not merely
in appearance but in mode of life from the others. The common
features are so many, however, that a certain amount of repetition
is unavoidable in descriptions which are to be used independently
of one another.

To avoid this as far as possible it seems advisable to give at
the outset some general ideas as to the parts of which all flower-
ing plants consist, and of their uses. The student must refer to
ordinary botanical text-books for further details, for only the
main facts necessary for our special purpose will be briefly stated
here. In doing this it will be convenient to introduce some
necessary names or terms, which will be used in describing most
of the plants.

A word may be said as to the use and abuse of technical terms
in the study of plants. Far more terms are employed in the
concise describing and cataloguing of the many different kinds of
plants than are of any use in studies such as this. To avoid the
use of technical terms altogether would not, however, be an
advantage. In studying plants, and the parts of which they
consist, we are in much the same position as when we consider
any class of machines and their way of working. It is obviously
inconvenient, for instance, to speak about bicycles and avoid
technical terms. In addition to such terms as saddle or wheel,
which exist in everyday language and only find special applica-
tion, handle-bar, hub, and tyre are all technical terms which are
found useful. There is no more justification for taking unnatural
trouble to avoid the use of a convenient term in botany than for
talking of " the cross piece by the ends of which the rider holds
on/' instead of calling it the handle-bar. A certain number of
technical names for parts of the plant that we have to distinguish
repeatedly will be found of use, and be freely employed in the
descriptions. These will be found to present no real difficulty, but
it is of course quite justifiable to still further reduce the number
of such terms, or even to avoid them altogether in teaching
children.

In looking at the parts of which an ordinary flowering plant
consists, and the chief modifications they present, it is useful to
have a particular example to refer to. For this purpose we shall

FLOWERING PLANTS— INTRODUCTORY

89

take the Buttercup, not for straightforward description, as in the
succeeding examples, but as a text from which " digressions "
can be made, to consider a number of necessary preliminaries.

The selection of the Buttercup at once leads to the considera-
tion of the naming of plants. Each kind of plant requires to be
given a distinct name, by which it can be referred to without
risk of confusion with other kinds. Since only the more prominent
and distinct kinds of plants have
been noticed and given local or
English names, difficulties arise in
the use of these. Whenever possible
it is well to refer to common plants by
their English names, and these only
should be used in teaching children.
The English name, however, often
applies to two or three plants, and
even when it is clearly applied to
one kind only, different names may
be given to this plant in different
localities. In other countries different
popular names will apply to the same
plant. For these and other reasons
it has been found of the greatest use
to give a definite scientific name to
each kind of plant. This name is
the same in all countries, and a
knowledge of it, even when for
ordinary use the English name is
sufficient, makes it easy to consult
books giving information about the plant. Since the time of
Linnaeus, who laid the foundation of the modern methods of
naming and describing plants and animals, the scientific name
has consisted of two Latin words. Thus three kinds of yellow-
flowered Buttercups are found commonly in our fields and hedge-
rows, and these, together with some rarer kinds, are all usually
called Buttercup. Distinctive English names are hardly in
common use since the ordinary observer does not distinguish
between these plants. The three kinds are the Upright Buttercup

FIG. 50.— Plant of Upright Butter-
cup (Ranunculus acris). (After
Farmer.)

go THE BOOK OF NATURE STUDY

(Ranunculus acris, L., Fig. 50), the Creeping Buttercup (Ranun-
culus repens, L., see Plate), and the Bulbous Buttercup (Ranunculus
bulbosus, L.). Without entering into other details, it may be said
that the two latter kinds may be distinguished from Ranunculus
acris by having creeping branches by which the plant spreads in
Ranunculus repens, and by having a globular, swollen base to
the stem in Ranunculus bulbosus.

The scientific name in each case consists of two Latin words,
and all three kinds of Buttercup have the first name, Ranunculus ,
in common. This may be compared to a family name or sur-
name. The group of closely related and similar plants to which
it is given is called a genus, and this name is spoken of as the
generic name. The second name, on the other hand, is different
in each case, and applies, when joined to the generic name, to one
particular kind of plant only ; it is the name of the kind of plant
or species, the specific name. Thus the scientific name not only
serves as a definite label for the kind of plant, but gives a clue
to the plants to which it is most nearly related. An example
will make this clearer. Among the descriptions will be found
one of the Lesser Celandine (Ranunculus Ficaria). The English
name gives no clue to the real relationship of the plant, but the
scientific name at once indicates that it belongs to the same genus
as the Buttercups. The scientific name of each plant described
will be given at least once, even when the English name is used
throughout the description.

Any flowering plant appears, even on the most superficial
observation, to be composed of a number of distinct parts. So
obvious is this that ordinary language has names, which on the
whole are correctly applied, for all the principal parts. We
distinguish in any entire plant such as the Buttercup, when dug
up carefully, the roots, the shoots composed of stems bearing
leaves, and the flowers. It is characteristic of all living beings,
both animals and plants, that their bodies are differentiated into
distinct parts, each with its own duties to perform in the life of
the whole. These parts are called organs, and living beings are
on this account often spoken of as organisms. Just as the eye,
the ear, or the hand have their special duties or functions to
perform in seeing, hearing, and grasping, and are suitably formed

FLOWERING PLANTS— INTRODUCTORY 91

to exercise these functions, the construction of the various organs
of the flowering plant can only be understood in the light of a
knowledge of their main functions.

The whole root-system of many flowering plants is developed
from the main-root of the seedling. This grows down into the
soil, and gives off branches similar to itself. These branches
arise at some depth in the main root, and burst through the surface
layers of this. They grow obliquely downwards on all sides, and
in turn bear finer branch roots. The mass of soil around the base
of the plant is thus thoroughly penetrated by the roots of the
latter. In the Buttercup no main root can be distinguished.
The plant is fixed in the ground by numerous, rather stout,
whitish roots springing from the base of the stem. These bear
the finer branches. The characteristic features of most roots
can be well studied in the root system of a Bean seedling. They
need only be briefly mentioned here. The cylindrical shape,
the absence of the green colour found in the parts of the plant
exposed to the light, and the deep origin of the branches are
common to nearly all roots. All the branches are essentially
similar, and the root never bears leaves. The roots have to make
their way between the particles of soil, and the growing tip of
every branch is protected by a little sheath of firmer tissue called
the root-cap. The root enters into very close contact with the
mineral particles making up the soil, by means of delicate hairs,
which grow out in large numbers from the surface. These are
called root-hairs, and are found a short distance behind the tip of
the root, dying off on the older parts behind.

All these features are related to the uses or functions of the
root. In the first place, the root-system serves to fix the plant
firmly in the soil. The growth of the roots in all directions through
the soil round the base of the plant, and the close connection
between the roots and the particles of soil, fit it admirably for
this. The same relations between the root and the soil also
enable the root to obtain from the soil a part of the food which
the plant requires. A plant takes up no solid food ; all the food
materials which it absorbs are taken up in a state of solution
or in the gaseous form. By means of the root, water, in which
are dissolved small quantities of certain substances of relatively

92 THE BOOK OF NATURE STUDY

simple chemical composition, is obtained. The close connection
between the root-hairs and the particles of soil enables the plant
to withdraw water from soils that appear almost dry. The water
with its dissolved salts is passed up into the stem and reaches
the leaves.

The shoot differs greatly in appearance from the root. It
is composed of two distinct parts, the stem bearing the leaves.
The leaves are usually flat and green and of limited growth, and
thus differ from the stem, which bears them, both in form and
in construction. At the tip of the shoot we find the young leaves
closely crowded and folded over the summit of the stem. The
actual growing point of the shoot and the youngest developing
leaves are thus protected by the older leaves. The whole structure
is known as a bud. As the bud unfolds, the regions of stem
between the attachments of the leaves lengthen as a rule more
or less. The fully grown shoot has thus the leaves attached at
certain parts, called nodes, which are separated by intervening
regions known as internodes. The shoot branches, that is new
lateral shoots like the main shoot, are developed on the latter.
In their young condition these are found as lateral buds occupying
a constant position with regard to the leaves. Usually a single
bud is developed in the angle between each leaf and the stem.
This angle is known as the axil of the leaf. Many of these buds
may remain of small size, but some grow on into branches.

The stems of plants are usually more or less cylindrical. The
leaves are characteristically thin and flat, with a clear distinction
between the upper and lower surface. A number of parts can
usually be distinguished in the leaf. The thin flat portion, or
leaf-blade, is the most important, and may form the whole of the
leaf. Usually the region by which the leaf joins the stem is
more or less widened out. This is the leaf -base, which may form
a definite sheath encircling the stem. Between the leaf base
and leaf-blade there is often a narrower stalk-like region bearing
the leaf -blade at a distance from the stem. This is the leaf-
stalk. In many but not all leaves there are two outgrowths,
one on either side of the leaf -base, known as the stipules. In
examining a leaf it is well to bear in mind the possibility of its
being differentiated into leaf-base with stipules, leaf-stalk, and

FLOWERING PLANTS— INTRODUCTORY 93

leaf -blade. The leaf -blade may be unbranched, although its
margin is more or less deeply indented, and is then described as
simple. In other cases the leaf-blade is branched, and appears
to be made up of a number of smaller leaf -blades or leaflets.
Such leaves are described as compound. The leaflets are most
commonly arranged on either side of a stalk which continues
the leaf-stalk (pinnate leaves), but they may diverge from the
end of the leaf -stalk like the fingers of a hand (palmate leaves).

The blade of the leaf or of the separate leaflets is traversed by
a branched system of conducting and supporting strands which
form the veins of the leaf, and persist as leaf skeletons when the
softer parts have rotted away. There is often a central vein or
midrib running from the base of the blade to its tip and giving
off lateral branches, while the fine network extends in the intervals
between these. In other cases no midrib is distinguishable,
but numerous parallel veins run in the leaf, connected at intervals
by finer veins, and so forming a network in a different way.
The stronger veins often project on the lower surface of the
leaf, and the whole system serves to support the thin expanded
blade. The veins are the ultimate branchings of a system of
conducting strands which run continuously from the root to
the stem and out into the leaves. It is by means of them that
the water taken up by the root is brought to the leaf-blade.

In the special case of the Buttercup the base of the stem is
relatively stout, and bears a number of long-stalked leaves which
are closely crowded together at their insertion and thus appear
to spring from the level of the ground. Above this the inter-
nodes of the stem lengthen, but only small leaves are borne at
the nodes. The branches in the axils of these bear the flowers.
In the axils of some of the lower leaves, in the case of Ranunculus
repens, long creeping branches arise, to the consideration of
which we shall return. The stem is cylindrical, green or reddish,
and hairy. Each foliage-leaf has a wide sheathing base, but
no stipules. The leaf -base becomes more strongly concave on
passing towards the leaf-stalk, on reaching which the thin ex-
panded margin stops. The long firm leaf-stalk is green, and
sparsely covered with hairs. It is strongly convex below, but
has a narrow, shallow groove on the upper side, i.e. the side

94 THE BOOK OF NATURE STUDY

facing the stem. The leaf blade consists of three lobes, two
attached opposite to one another by very short stalks, and the
third borne on a continuation of the leaf -stalk. Each leaflet
has a triangular outline widening out from the base, and is in
turn divided by deep indentations into three lobes, the margins
of which are toothed. The lower surface and margins of the
blade bear long and fairly stiff, white hairs. The branching of
the shoot proceeds from buds in the axils of the leaves, but as
it is seen only in the region bearing the flowers, or in the pro-
duction of creeping branches, its consideration may be deferred.

The almost universal differentiation of the shoot in the higher
plants into a stem bearing thin flat leaves points to these parts
performing important functions different from those of the root
system. The leaves especially are constructed to play an im-
portant part in obtaining and preparing the food materials, at
the expense of which the plant grows. We have seen that the
roots absorb water, in which salts are dissolved, from the soil.
This passes up the stem, which thus serves to support and display
the leaves, and as the path by which the water reaches them.
The water passes up the leaf-stalk and is distributed by the
veins through the leaf -blade. The ordinary leaf -blade is charac-
teristically thin, and exposes a large surface to the air. One
use of this is to enable the plant to get rid of a great part of the
water absorbed by the roots ; this water escapes in the form
of vapour. The salts dissolved in it are left behind and accumulate
in the leaf, where they form part of the food material needed by
the plant.

The expanded shape of the leaf, together with the green
colour found in most parts of the plant exposed to the light,
but especially in the leaf-blade, fits the leaves for their other
great use in the life of the plant. The plant takes up, mainly
by its leaves, a gas called carbonic acid gas, which exists in small
quantity in the air. From this gas, and not from the soil, the
carbon, which is one of the most important food materials of
the plant, is obtained. From the carbonic acid gas, the water
and the salts, which we have now followed to the leaf-blade, a
green plant can build up more complex substances and continue
to live and grow. The process of construction of these complex

FLOWERING PLANTS— INTRODUCTORY 95

materials requires the assistance of energy, and this is derived
from the rays of the sun. The leaf displays its broad flat surface
to the sunlight, the blade being usually expanded at right angles
to the rays of light. The green colour serves to catch certain
rays of light that are required in this important process of food
manufacture. The characteristic green colour of vegetation
thus indicates a widespread similarity in the mode of feeding
of plants.

Even this very brief outline of the uses of the root, stem,
and leaf will show how they co-operate in the nutrition of the
individual plant. The manufactured materials may either be
at once used for the growth of the plant (at their expense new
roots and shoots are developed), or they are carried away from
the leaf and stored up for the subsequent use of the plant or
its progeny. Many individual plants live and grow for years
without bearing flowers or giving rise to new individuals. They
require for this only the organs which have been described, the
roots, stems, and leaves, and these are often spoken of on account
of this relation to the growth of the individual as the vegetative
organs, and contrasted with the reproductive organs by means
of which new individuals are produced. The similarity in general
features of the roots and shoots throughout the Flowering Plants
shows that the mode of nutrition is similar. When we meet
with modifications affecting the whole plant or particular organs,
we have to study them in the light of the altered functions of
the organs, or of the more profound change in the nutrition of
the plant.

However long the life of a plant may be, it is limited. Some
Flowering Plants live for many years (perennial plants), others
live for two seasons and die after they have flowered in the
second year (biennial plants), while others are annual plants only,
living for a single season. Like all other living beings, flowering
plants have therefore to provide for the formation and establish-
ment of new individuals, i.e. for reproduction. This is always
effected by the separation from the parent plant of a larger or
smaller part, which is capable of continuing to grow and of
becoming an individual like the parent. Sometimes the part
which is separated is a bud or a more or less modified shoot,

96 THE BOOK OF NATURE STUDY

and when the multiplication in number of individuals is thus
carried on by the vegetative organs we speak of vegetative or
asexual reproduction. The special organ of reproduction of the
flowering plants is, however, the flower, from which, as a result
of complicated processes, into which we shall not enter in detail,
the seeds are formed and separated as the reproductive bodies
from which new plants arise. Since two minute parts or cells
of the plant have to unite to give rise to the new individual in
the seed, the reproduction effected by the flower is distinguished
as sexual reproduction. Both vegetative and sexual reproduction
are found in the Creeping Buttercup (Ranunculus rep ens).

This plant spreads vegetatively by means of the creeping
branches already mentioned as arising in the axils of some of the
lower leaves. These branches, which are called runners, have

elongated inter-
nodes, and do not
stand erect but lie
along the surface
of the soil. At
each node is a
single foliage-leaf,

FIG. 51.— Runner of Creeping Buttercup. (After Baillon.) m tne axl1 of which

is a bud. This

bud grows rapidly, and sends down a number of roots into
the soil; it thus comes to possess all the vegetative organs
of a complete plant. At first the new plants that are
established in this way all around the parent are connected
to the latter by the runners, but in time the internodes of
these decay and the new plants become independent. It is
most instructive to select a strong plant of the Creeping Butter-
cup growing in open ground, and to trace the spread of new
plants around it. Many of the runners are a yard or more in
length, and may give rise to a number of plants. Probably most
of the plants of this kind of Buttercup that are met with have
arisen vegetatively. It is much more difficult to be sure that
a plant of Ranunculus repens has come from a seed than it is in
the case of either of the other two common species which have
no runners. In considering the success and the means of

FLOWERING PLANTS— INTRODUCTORY 97

spreading of a plant, any arrangements to ensure its vegetative
reproduction should always be looked into carefully.

The flower of the Buttercup is a very suitable one to examine
in the first place, and in the light of its study we shall be able to
consider some general features of flowers which will prepare the
way for the special descriptions of plants which follow. We have
seen that the flower is the part of the Flowering Plant by which
the seeds are formed, as a result of a complicated process of sexual
reproduction. The flower can thus be recognised as the organ
of sexual reproduction of the Flowering Plant. In its construction
the flower is a shoot specially modified for this purpose. It
consists, as we shall see, of a stem bearing lateral organs, which
correspond to leaves, though very unlike the foliage leaves in
appearance. Further, the flowers are always borne on the shoot,
never on the root, and in their position correspond to branches.
As a rule each flower will be found to stand in the axil of a
leaf, which is often much smaller than the foliage-leaves of
the plant, and is called a bract. The flowers are often grouped
together on special regions of the shoot, the whole association of
flowers forming what is known as an inflorescence.

In a strong plant of the Buttercup the main shoots, after bearing
the crowded foliage-leaves described above, lengthen and become
branched. If carefully looked at it will be found that the main
shoot ends in a flower, and similarly the summit of each branch
bears a flower. This whole region of the shoot may be called the
inflorescence, and, in contrast to the vegetative region below, it
has elongated internodes, while the leaves borne singly at its
nodes are reduced in size and differ in form from the foliage-
leaves. The uppermost of these reduced leaves (bracts) may
consist only of a sheath and a small green blade. Branching
takes place from the buds in the axils of the bracts. The flower
at the end of the main shoot is the first to open, and is followed
by those terminating the branches. From the axils of the small
bracts on the latter further branching proceeds. The whole of
this region of the shoot, with its reduced leaves and numerous
flowers, has evidently the display of the flowers rather than of the
leaves as its function (Fig. 50).

Many other inflorescences are constructed on the same general

VOL. III. — 7

98

THE BOOK OF NATURE STUDY

plan as that of the Buttercup, the essential feature of the branch-
ing being that the main shoot ends in a flower, and that further
flowers are borne terminally on lateral branches. Such in-
florescences are called cymose. In contrast to such an arrange-
ment of the flowers we shall meet with many inflorescences in
which the main shoot does not end in a flower, but continues
its growth while the flowers are produced in regular succession
as lateral branches. These are called racemose. The two modes
of branching will be evident from the diagram (Fig. 52), and a

FlG. 52. — Diagrams of (A) cymose inflorescence, and (B) racemose inflorescence.
The numbers indicate the order in which the flowers open.

recognition of the distinction between them will be of use in
dealing with special examples.

The flower of the Buttercup is borne on a slender, green flower-
stalk. This in R. repens is marked by slight longitudinal grooves,
and, like the stem, bears whitish hairs. At the upper end of the
flower-stalk a number of floral leaves of different kinds and very
different appearance are crowded together, forming the flower.
These parts are of four kinds. On the outside are five green
leaves, within which come five larger and more conspicuous
yellow leaves. Still further in are a large number of narrow
stalked yellow structures, and in the centre are a number of small
green bodies closely crowded together. The relative positions of
these parts will be best understood if a flower is cut in half with

FLOWERING PLANTS— INTRODUCTORY 99

a sharp knife and examined through a lens (Fig. 53, B). It will then
be clear that all these parts are borne laterally on the flower-
stalk, i.e. that they stand in the same relation to this as leaves
to the stem. The slightly widened, conical end of the flower-
stalk to which the floral leaves are attached is known as the
receptacle of the flower. As contrasted with the ordinary vegeta-
tive shoot, growth usually stops with the production of the
floral leaves, and the latter are not separated by internodes.

The outermost series of floral leaves consists of five narrow
green structures, the inner face of which is concave and smooth,
while the outer surface is clothed with long whitish hairs. These
parts are more obviously leaf-like than the other parts of the
flower. They are called the sepals, and together form the region
of the flower known as the calyx. When the flower is young,
in the condition of
a bud, the sepals are
closely overlapped,
and completely en-
close and protect
the more delicate
parts within. Those A B

edges Of the Sepals FlG> 53>_Fiower Of Buttercup. A, whole flower ; B, flower
Which were thus cut in half. (After Baillon.)

covered over can be

distinguished by their thinner texture and yellow colour. When,

as is the case with the sepals of the Buttercup, a number of leaves

are borne at the same level on the stem they are said to form a

whorl.

The five conspicuous yellow leaves, which come next within
the calyx, are called petals, and together make up what is known
as the corolla. The petals also form a whorl, and stand higher
on the floral receptacle than the calyx. As is usually the case,
where the number of parts in the succeeding whorls is the same,
the five petals do not stand immediately above the five sepals,
but above the intervals separating the latter. The petals are
said to alternate in position with the sepals. The petals are the
parts which give the flower its prominent and attractive appear-
ance. Though flat and leaf -like in shape, they are very unlike

TOO THE BOOK OF NATURE STUDY

the foliage-leaves or the sepals in texture and colour. Each is
attached by a narrow base to the receptacle, and widens out
gradually from this to the rounded margin. Except for a region
of the upper surface close to the attachment where the colour
is paler, the petal has a bright yellow colour ; the surface is
dull below, but smooth and shining above. Everything about
the petals shows that they are of use in making the flower con-
spicuous. The reason for this we shall see later.

If a petal be carefully pulled off and looked at from the inner
or upper side another feature of interest will be noticed. Close
to the base of the petal is a small yellow scale ; this is short, and
is almost as broad as the narrow part of the petal against which
it lies. The free edge of the scale can easily be raised with the
point of a knife, and a little recess or pocket will be found to
exist between the scale and the petal. In this pocket a sweet
sugary juice called nectar is formed and held, and the structure
secreting it is called the nectary. The use of the nectar will also
be seen shortly.

The parts of the flower within the corolla are less leaf-like
than the petals and sepals, and require careful study with the
help of the pocket lens. Immediately above the petals on the
receptacle come a large number of stamens. They do not form
whorls, but are spirally arranged. Each stamen is composed
of a cylindrical stalk, bearing a widened, flattened portion ;
the stalk is called the filament, the upper part the anther. The
whole stamen has a more or less intense yellow colour. The
filament calls for no further description, except to say that it
continues directly into the middle portion of the anther, between
the two halves of which it can be traced as the connective. This
is most easily seen on the side of the anther turned towards the
centre of the flower, since the two halves or lobes of the anther
face outwards and conceal the continuation of the stalk on this
side. Each lobe of the anther contains two cavities called pollen-
sacs, within which the pollen is formed. When the stamen is
mature a longitudinal slit forms on either side of the anther,
opening the pollen-sacs, and the pollen is shed as a somewhat
adhesive, yellow, powdery mass. The formation of the pollen,
which consists of isolated cells, is the function of the stamen.

FLOWERING PLANTS— INTRODUCTORY ,,,

In the centre of the flower a group of small green bodies will
be seen. These are the carpels, and together they make up the
region of the flower called the pistil. The numerous carpels are
inserted separately on the upper part of the floral receptacle,
and are much less leaf-like than the other parts of the flower.
They are best seen on removing the sepals, petals, and stamens
from a flower, or on cutting a flower in half. A single carpel
can also be removed from the receptacle with the point of the
knife, and will be found to have been attached by a narrow
base, above which it suddenly widens out to narrow again
to a fine tip, which curves outwards. The whole carpel is
flattened laterally ; the lower part has a pale green colour, while
the narrower upper portion is yellowish. Each carpel is really
a hollow body, and corresponds to a leaf bent round so as to
enclose a cavity. Within this cavity is a small stalked body,
which is destined later to develop into a seed. This little
body is the ovule, and can be seen with the lens through the
translucent wall of the lower part of the carpel. With care it
is possible to open the latter, and remove the ovule on the
tip of the knife. The wider lower part of the carpel, within
which the ovule is contained, is called the ovary, the narrower
part above is the style, while the small rough tip to this is
the stigma. The pistil of the Buttercup is thus seen to consist
of a number of separate carpels, each of which encloses a single
ovule.

Before the ovule can develop into the seed some of the pollen,
which we have seen to be formed in the stamen, must be brought to
the stigma. The pollen may be derived from the stamens of the
same, or of another flower, and the process of transferring it
from the anther to the stigma is known as pollination. Pollina-
tion is followed by other changes, into which it is unnecessary to
enter here, but it must be understood that one of the two cells,
which unite to give rise to the new plant in the seed, comes from
the pollen grain, while the other is contained in the ovule. It
is because these two cells must be brought together by the transfer
of pollen to the stigma, and the processes that follow on this,
that the reproduction effected by the flower is spoken of as
sexual, and contrasted with vegetative reproduction. The

102

THE BOOK OF NATURE STUDY

flower, as was stated above, is a shoot specially modified for the
purpose of sexual reproduction.

Once the need of pollination has been recognised we are in
a position to consider the use of the brightly coloured petals and
the nectar in the flower. The uses of the other parts will have
been already realised ; the sepals serve to enclose and protect
the other parts of the flower in the bud, while the stamens form
the pollen, and the carpels enclose and protect the ovules. Why
has the Buttercup, like so many other flowers, an apparently
useless display of brightly coloured petals ?

Since the stamens and carpels are close together in the same
flower it might have been expected that the pollen would fall
directly on the stigmas. This is, however, comparatively rarely
the case, and many of the features of flowers are to be explained
as rendering likely the carriage of pollen from the stamens of
one flower to the stigma of another. Sometimes this cross-
pollination is effected by the wind, but in the case of most con-
spicuous flowers the pollen is carried from flower to flower by
the insects visiting them in search of food. Everyone knows the
way in which bees, butterflies, flies, and other insects visit flowers,
and has probably realised that they get honey and pollen from
them. The insects may feed off the nectar or pollen, or they
may in the case of bees carry it home to be stored, or to feed
their young. In visiting the flower the insect gets some part
of its body dusted with pollen, and on going to another flower
of the same kind may rub this on the stigma, and so pollinate
the flower. The variety in form and colour of flowers finds its
explanation in the complicated and beautiful adaptations which
exist between the flower and its insect visitors. These will be
pointed out in each example described.

The Buttercup has a relatively simple method of pollination.
Many insects, especially flies, visit the flower, the bright colour
of which makes it conspicuous from a distance. They may
either feed off the pollen, of which a large quantity is formed in
the numerous stamens, or may suck the nectar from the little
pocket-like nectaries at the base of each petal. The provision
of this food is not an indiscriminate charity to the insects on
the part of the plant. While feeding, the insect visitors get

FLOWERING PLANTS— INTRODUCTORY 103

dusted with pollen, and, while they may rub some of this on the
stigmas of the same flower, they are more likely, on going to
another flower, to effect cross-pollination. Cross-pollination is
often more advantageous, and many of the arrangements found
in flowers appear to render it likely or to prevent self-pollination.

After pollination has been effected the sepals, petals, and
stamens of the Buttercup wither and fall off, but the group of
carpels remains on the receptacle, and enlarges to form the
fruit. Before considering this, however, it will be useful, as a
preliminary to the study of particular examples, to form some
idea of the chief modifications which are found in flowers.

The Buttercup is a particularly good flower to start with, for
all its floral -leaves are inserted distinct ^ -^ ^
from one another on the receptacle. In (._\(\f\(\
most flowers, however, the distinctness of
the parts is modified by their union in
various ways and degrees. Examples will ^^ ^^^ ^.^ ^^^
be met with in the plants described later. ( \( ]( ](
Here it is only necessary to make clear
the nature of the modifications to be ex-
pected. In the first place, parts of the
same kind inserted at the same level on
the receptacle, i.e. belonging to the same
whorl, may be more or less completely FIG. 54.— Diagram to iiius-
united together. When the sepals are trate the mode of union of

..,.,,. , parts of the same whorl.

joined in this way the calyx appears as

a tubular or bell-shaped structure. This has usually a number
of free teeth or lobes projecting from the margin and indicating
the number of the united sepals. The petals are even more
commonly united to form a tubular corolla, and the stamens
are sometimes joined together in the same way. The union in
all these cases is not to be looked upon as a joining together of
distinct and separate, fully grown parts. It results from a modi-
fication in the development of the flower, which the diagram
in Fig. 54 will make clear. The petals, for example, arise as little
outgrowths of the receptacle. When they are distinct the further
growth is limited to the base of the outgrowth. But when growth
spreads to the region of the receptacle between the petals these

104

THE BOOK OF NATURE STUDY

are raised upon a tubular growth, and thus appear to be united.
The parts developed from the original outgrowths give rise to
the free lobes on the margin of the tubular part of the corolla.

It is comparatively rare to find the carpels distinct from one
another as in the Buttercup. They are usually less numerous
than in that flower, and form a single whorl, the number of carpels
being the same or smaller than that of the petals or sepals. They
may be more or less completely united to form a single pistil.
Sometimes only the lower parts are joined, the upper portion of
the ovaries as well as the styles and stigmas being separate.
Often there is a single ovary from which the free styles project,
their number indicating the number of carpels making up the

ovary. When the union is
most complete the styles and
stigmas are also joined, and
the number of carpels is not
distinguishable, or is only indi-
cated by the lobing of the
stigma (Fig. 55).

While considering the union
of the carpels, attention must
be directed to the construction
of the ovary and the different
positions in which the ovules
are borne. When the carpels
are separate and distinct, as in the Pea or the Marsh Marigold, it is
often easy to see that each corresponds to a leaf bent round so that
the margins meet, and thus enclosing a cavity. In such cases
the ovules are borne along the united margins, and thus stand in
a row along the junction which faces the centre of the flower
(Fig. 56, A). The Buttercup has a carpel of this kind, but this con-
tains a single ovule only. When joined together to form a single
ovary, the latter has often as many chambers as there are carpels,
and the position of the ovules in them corresponds to their position
in the single carpel. Examples of this are the Tulip or Wild
Hyacinth, where the pistil is formed of three carpels (Fig. 56, B).
In other cases the carpels are joined edge to edge to enclose the
single cavity, and then the ovules usually spring from the wall of

FIG. 55.— The pistil of— A, Monkshood ;
B, Flax ; C, Tobacco Plant. / ovary ;
g, style ; «, stigma. (From Strasburger's
Lehrbuch der Botanik.}

FLOWERING PLANTS— INTRODUCTORY

105

B

FIG. 56.— Diagrams of arrangements of ovules in the
ovary. A, Marsh Marigold ; B, Wild Hyacinth ;
C, Violet ; D, Primrose.

the ovary along the lines of junction of the carpels. The pistil

of the Violet is an example of this (Fig. 56, c). Another important

type of attachment of

the ovules is when, as in x-rr-^ c

the Primrose, the ovary

has only one cavity, but

the ovules are borne on

a projection from the

base of this and do not

spring from the walls

(Fig. 56, D). These ex-
amples do not in any

way exhaust the variety

in the construction of

the ovary, but will serve

to indicate the import-
ance of examining it very

carefully in studying any

flower. This is also

important as enabling the construction of the fruit to be

understood.

In the same way, as parts of the same whorl may become united,

parts of two succeeding whorls
may be joined by being lifted
up on a common zone of growth.
The most common case of this
is when the stamens appear to
be attached to the inner face of
the petals, or to spring from the
inside of the tube of the corolla.
The diagram (Fig. 57) will make
this clear, and examples will be
met with below, in the Primrose,
the Periwinkle, and many other
flowers.

Another important series of
differences in the construction

pet, petal ; st, stamen ; c, carpel. of flowers depends Upon the

io6 THE BOOK OF NATURE STUDY

unequal growth of the floral receptacle. The receptacle in
the Buttercup is conical, and the sepals, petals, stamens, and
carpels stand in the order named from below upwards upon it
(Fig. 53, B). The relation of the various parts is that shown
in the diagram (Fig. 58, A). In many flowers, however, the region
of the receptacle that bears the sepals, petals, and stamens grows
more actively, and widens out into a plate-like (Fig. 58, B) or cup-like
(Fig. 58, B') structure bearing these parts on its edge around the
pistil, which remains on the true summit of the receptacle. A
still further modification is reached when the hollow receptacle is
joined to the wall of the ovary (Fig. 58, c). The sepals, petals, and
stamens now appear to spring from the upper surface of the
ovary, while the styles stand up in the centre of the flower. In

A B 3'

FIG. 58. — Forms of receptacle of the flower. (From Strasburger's
Lehrbuch der Botantk.}

this case the ovary is spoken of as inferior, while in the two former
cases (A and B) it is termed superior.

Flowers also differ in their general symmetry. In the Buttercup
and many other flowers the floral leaves are disposed symmetrically
around the centre of the flower, which could be divided into equal
and similar halves by a number of planes passing through the
centre. Such flowers are called regular. In many other flowers,
however, we can recognise an upper and lower side, and right
and left halves. The parts are no longer placed symmetrically
around the centre, but differences in either their number or in their
size and shape lead to the flower being symmetrical with respect
to one plane of division only. Such flowers are termed irregular,
and many of the flowers most highly specialised in relation to
their insect visitors will be found to be of this kind. The Violet,
the Dead-Nettie, and the Orchid are good examples from among

FLOWERING PLANTS— INTRODUCTORY

107

those described below. The plane of division separating the
flower into similar halves usually runs from front to back of the
flower ; in a few cases it lies at right angles to this. Insects visiting
irregular flowers are usually induced to approach the flower
from one particular direction. On taking up their position in
the flower they touch the stamens and stigmas with particular
parts of their body, and the arrangements for cross-pollination
can thus be made more precise. Details will be found under
the examples described.

We may now return to the consideration of the fruit of the
Buttercup (Fig. 59), which was seen to be derived from the group
of carpels after the other parts
of the flower have fallen. The
carpels enlarge, as do the young
seeds within them, and the seed
practically fills the whole space
within the carpel. When ripe
the seed is protected by the
firm dry carpel. The product
of development of the whole
pistil may here be called the
fruit, and that of the separate
carpels fruitlets. The latter at
maturity become detached from
the receptacle and are shed
singly. Since each fruitlet has
only one seed within it, the wall does not burst open to liberate
the seed, which remains, until germination, protected by the
carpel.

The seed of the Buttercup (Fig. 59) consists of a covering
called the seed coat, a mass of food material and a very small
embryo plant. Under suitable conditions of moisture and warmth
the little plant commences to grow ; the seed is said to germinate.
Growth is at first at the expense of the food material stored
beside the embryo in the seed. When the first roots have pene-
trated the soil, and the first leaves are exposed to the light, the
little plant can obtain and manufacture food for itself.

From what was said above, as to the differences between the

FIG. 59.— A, Fruit of Buttercup ; B, single
fruitlet cut in half, showing the seed in
which the embryo plant and the mass
of food material can be distinguished.
(After Baillon.)

loS THE BOOK OF NATURE STUDY

pistils of various plants, it will be evident that great differences
will be found in the construction of the fruits derived from them.
Details will be found under the plants described. A word must,
however, be said introductory to their study. The fruit, like the
flower, must be studied from two points of view. Its structure
must be examined in the light of that of the pistil and the other
parts of the flower taking part in its formation, and the way in
which the fruit is of use in the life of the plant must also be con-
sidered. Put broadly, the fruit has to protect the developing
seeds and to ensure their distribution, so that they will have a
chance of lodging in suitable situations and grow into new plants.
Fruits are either dry or succulent. In the latter case, when parts
of the fruit are attractive as food to birds or other animals, these
effect the dispersal of the seeds. When the dry fruits or the
fruitlets contain only one seed, as in the Buttercup, they do not
as a rule open to set the seed free. When, however, the seeds
are more numerous they are usually shed from the fruit, which
opens to allow of this. Dry fruits or seeds are adapted to be
dispersed in a variety of ways, very often by means of the wind.
These remarks will serve to show that the study of fruits must
be carried out in the light of their uses, as the structure of the
flower had to be studied in the light of the method of pollination.

The seeds of plants and their germination are treated of in
another section of this work, and may be dismissed with brief
reference here. The seed, which varies greatly in size, is always
enclosed in a seed-coat, which may be thick or thin and variously
sculptured. Within the seed-coat is a small plant which often
shows the young root, shoot, and the one or two seedling leaves.
This embryo plant may entirely fill the seed-coat, as in the Pea,
or along with it may be found a tissue containing food material,
as in the Buttercup. In the former case food is usually stored
in some parts of the embryo, usually the seedling leaves, which
are enlarged for the purpose. The start in life of the plant can
sometimes be followed in seedlings collected in the wild state in
the neighbourhood of the parent, but usually it is necessary to
collect and sow the seeds.

We have now passed in brief review the main features that
can be observed without special apparatus in any Flowering

FLOWERING PLANTS— INTRODUCTORY 109

Plant. It will be of use to summarise the points regarding which
information should be sought in studying any plant. A scheme
such as the following will assist, though it should not limit, our
observation, and will ensure its being carried out methodically.

1. The general appearance of the plant ; the situation in
which it grows ; its duration of life.

2. Root-system : existence or not of a tap-root ; branching ;
origin of additional roots from the stem ; whether the root
extends deeply or spreads out in the superficial layers of soil.

3. The vegetative shoots : underground shoots must be
carefully distinguished from roots, and studied ; the features of
the stem ; the arrangement of the leaves ; branching of the
shoot ; the form of the leaves.

4. Means of vegetative reproduction, if any.

5. The inflorescence : its branching ; presence and form of
the bracts.

6. The flower : calyx, corolla, stamens, pistil ; shape of floral
axis or receptacle ; symmetry of flower, regular or irregular ; pre-
sence of nectaries and their position ; method of pollination.

7. The fruit : construction ; mode of dispersal of the seeds.

8. The seed : germination ; the seedling.

ADVICE AS TO PRACTICAL WORK

The importance of practical work has been emphasised above.
Observations on Flowering Plants of the kind described here
can be carried out with the help of very simple apparatus, and
in any dwelling-room or even in the open beside the plant. The
simplicity of the work is one of its great advantages in the teaching
of Nature Study. Interest in the life of the plant and patient
observation are of more importance than any apparatus, and
the great aim of the teacher should be to awaken and sustain
the interest of his scholars. Given this interest, the thorough
study of one or two plants will lead to observations being made
on others. The descriptions of common plants given below are
not exhaustive, but will direct the attention of the student to
the main features of the plant. They should be used as a help
in the practical study of the plant.

no THE BOOK OF NATURE STUDY

The first methodical examination of a plant is best made
in a room, and it is advisable to have a bare unpolished table,
or to protect the surface or table-cloth so that the necessary
mess can be made. The first study of the plant will probably
disclose some difficulties which can only be cleared up by ex-
amining further specimens or plants at another stage of their
growth. Many points also regarding the mode of growth, the
method of pollination, the dispersal of the seeds, etc., will have to
be inquired into by studying the plants as they grow in nature.
It is well to start, however, with specimens of the plants collected
and brought home, so that they can be examined with comfort
and the results methodically recorded.

A word must be said as to collecting material. If possible
this should be done by the student himself, since this ensures
a general knowledge of the situation and mode of growth of
the plant. Small plants should be carefully dug up so as to
obtain the root system uninjured. This may be done with a
stout knife, but a trowel or digger is better for the purpose. A
number of specimens should always be collected, and should,
if possible, show flower-buds, flowers, and fruits. When flowers
and fruits cannot be obtained at the same time, and indeed
in every case, the plant should be studied at different seasons.
In the case of larger plants, such as shrubs and trees, it is obvi-
ously impossible to collect the whole plant. Shoots showing
as much as possible of the mode of growth and bearing flowers
or fruit should be taken. The branching and the general form
of the plant should be studied in living specimens in position,
and advantage should be taken in the case of trees of any up-
rooted specimens to make notes on the root system. To carry
the specimens home and to keep them fresh, they are best kept
in a tin box, and the collecting-tin or vasculum of the shape
which tradition has sanctioned will be found the most convenient
thing for the purpose. The vasculum should be of good size, large
enough to take in complete specimens of any moderate-sized
herbaceous plant, and should be fitted with a strap by which it
can be slung over the shoulder, leaving the hands free. Many
plants keep better for a day or two in the vasculum than when
removed and put in water.

FLOWERING PLANTS— INTRODUCTORY in

The apparatus needed for the dissection and examination of
the plant is very simple. A sharp penknife, kept for the purpose,
or one or two scalpels with straight blades, are needed to dissect
flowers, buds, etc. Another essential both for examining plants
at home and in the field is a magnifying-glass or pocket-lens.
This need not be of an expensive type ; for all ordinary purposes
the single or triple lenses in vulcanite mounts, sold for the purpose
for half a crown or less, will do admirably. A pair of forceps
for holding small parts of the plant when examining them, and
one or two needles mounted in wooden handles, are useful additions
to the furniture of the working table.

To record what has been seen and to assist accurate observa-
tion, it is necessary to make notes, and especially to draw the
parts of the plant. For this purpose the student should be
provided with a note-book of good paper without lines, with
pencils of various degrees of hardness, including a hard one
for making definite outlines, and with indiarubber. The
drawings that should be made are not pretty pictures of the
whole plant, but detailed outline drawings of the separate parts.
Accuracy rather than beauty is the object of drawings for this
purpose. All the drawings should be on a good scale, small
parts being drawn several times their actual size to allow of
the details made out by the lens being recorded. Clear outline
drawings are the most useful, and shading should only be employed
when it is really necessary to make the form clear. Drawings
of this kind are of special value for the teacher, since they are
an excellent preparation for illustrating the subject on the black-
board. Besides the value of these drawings, as a record of what
the student has seen for himself, the attention to details which
is necessitated by making a good drawing leads to features being
noticed that would otherwise be passed over. Thus even when
the drawing is not preserved the making of it is a valuable assist-
ance in accurate observation. The drawings should not be crowded
in the drawing-book. A brief statement of what is represented
should be written beneath each, and all the parts represented
in the drawing should be carefully labelled. If this labelling
is done fully it almost does away with the need of making detailed
descriptive notes, though, when the plant has been fully studied,

H2 THE BOOK OF NATURE STUDY

a full description of what has been observed and of the chief
features of interest will be of use to bring the facts together and
for future reference in teaching.

When the form of parts of the plant is complicated it may
be found helpful not merely to draw the object from several
points of view, but to model it. The preparation of modelling
clay known as plasticine is readily obtained and serves admirably
for this.

Although the making of a collection of dried plants is not in
any way a chief end or object in such studies as these, some well
chosen specimens will be found of great use along with drawings
and notes for future reference. While drawings must be depended
on for details of the flower and fruit, such features as the general
appearance or habit of the plant, the arrangement and shape of
the leaves, the branching and the structure of the inflorescence may
all be shown in a well-arranged dried specimen. It will be found
useful if, without making any haste to amass a collection, specimens
are carefully selected and preserved of each plant that is studied.
To assist the student in doing this, a brief account of how to dry
plants may be given !

Careful selection should be exercised to obtain an individual
plant which shows as many as possible of the characteristic
features clearly. It should be brought home without crushing or
injury, and arranged so as to display the parts naturally on a
sheet of drying paper. There is a special kind of absorbent paper
sold for this purpose, but sheets of thick blotting-paper do ad-
mirably, and ordinary newspaper may be made to serve. The
sheets should be of good size ; 17 inches by n inches is ample.
It is essential that the paper should be thoroughly dry, since the
object is to absorb the juices of the plant quickly. Having ar-
ranged the specimen on the sheet, beneath which should come
half a dozen similar sheets, it is to be carefully covered with
another sheet of paper. Upon this come several other sheets, and
then, if desired, another specimen, and so on. When the pile is
complete it should be subjected to light but steady pressure.
This is best done by enclosing the papers between two boards or
wire frames, placed above and below the bundle and held in position
by a strap. Books or bricks can be piled upon the upper board,

FLOWERING PLANTS— INTRODUCTORY 113

and the whole left for twenty-four hours. The papers should
then be changed for the first time, each specimen being lifted and
carefully arranged again on a new and dry sheet. In its limp
condition this is more easily done than when the plant was
fresh, and great care should be taken to place the parts of the
plant in the positions they are to permanently occupy. A longer
interval, depending on the succulence of the plants, may elapse
before the next change of papers, and after two or three changes
the plants may be left for a week or two until thoroughly dry.

They should then be mounted on sheets of stiff white paper a
little smaller than the drying sheets ; 16 inches by 10 inches is a
convenient size. After laying the plant in the right position on
the sheet it can be fastened down with strips of gummed paper,
crossing the stems and leaf-stalks at intervals. If necessary a
touch of strong gum will serve to fasten down any slacker portions.
The sheet should then be labelled with the scientific name of the
plant, its English name, the situation and locality in which it was
found, and the date at which it was collected. This is all that is
done with ordinary specimens for a collection, but in the case
of plants which have been carefully studied, the specimen, as it
lies on the sheet, may be treated like a drawing, and all the chief
parts labelled. Notes and sketches of details of the flower or
other features not shown in a dried specimen may, if it is desired,
be added, and the specimen will thus serve as a fairly complete
record of the observations made. Such specimens are not only
useful for reference, but may be of great value in teaching. Thus
when a plant is being studied in its winter condition the specimen
will show what it was like when in flower in the summer.

While thorough dissection and study of specimens of a plant
are necessary, and dried specimens are useful for future reference,
it must never be forgotten that these are merely aids to the under-
standing of the plant as a living being growing in its own place
in nature and having a definite life-history. Every opportunity
should be taken of observing the plant growing in natural sur-
roundings, and at various times of the year. This applies also
to cultivated plants, though in them the competition with other
plants cannot be directly studied. Every plant in a wild state is
in competition with its neighbours, and should be regarded from

VOL. III. — 8

H4 THE BOOK OF NATURE STUDY

this point of view. Sometimes the causes of success can be
traced in the vegetative growth of the plant, or in its means of
vegetative reproduction. The success and spread of the Daisy
in a lawn, for example, or of the Creeping Buttercup on
waste ground, are illustrations of this. The use of the tubers of
the Potato to the plant can only be realised when growing plants
are examined, and the value of this mode of reproduction to the
plant when growing wild can be inferred. Another important set
of observations that must be made in the open are those on the way
in which flowers are pollinated, and on the relations between
flowers and insects. While the probable effect of insects visiting
a flower can be made out by dissecting the flower at home, only
patient observation can show whether insects visit it, what insects
come, and how they behave when feeding. This work demands
time, but is of the greatest interest. The dispersal of seeds and
fruits also affords many opportunities for open-air observations.

Another direction which practical work should take is the
cultivation of selected plants, and the study of their whole life-
history. Easily grown plants should be chosen, and should be
planted either in a small school garden or, if no ground is available,
in pots or boxes. The Pea grown from seed, the Potato grown from
the tuber, the Crocus from its corm, and the Tulip or Narcissus
from the bulbs, are examples of very easily cultivated plants from
among those described below. A sufficient number of plants
should always be started to allow of specimens being dug up at
intervals and examined at various ages. The study of one or two
plants in this way will indicate the sort of observations which
can be made on the life-history or annual history of others in the
wild state, if they are examined periodically throughout the year.

The study of single plants on the lines that have been indicated
will lead, on the one hand, to the recognition and collection of the
flowering plants of the locality, and to their identification with the
help of a flora, — that is, to the study of the classification of plants.
On the other hand, it will form a valuable preliminary to the study
of plant communities, which is treated of in another volume of
this work.

CHAPTER VI

SPRING FLOWERS

The Lesser Celandine — The Lady's Smock — The Sweet Violet — The Primrose —
The Lesser Periwinkle— The White Dead-nettle— The Dandelion— The
Tulip— The Field Wood-rush— The Daffodil— The Crocus.

THE LESSER CELANDINE (Ranunculus Ficaria, L.).

THE Lesser Celandine, as its scientific name indicates, is a close
relation of the yellow Buttercups which flower later in the season.
One of the Buttercups has already been described, and a compari-
son of the Lesser Celandine with this will show admirably in what
different ways closely related plants are fitted to meet the needs of
their life, and of competition with other plants. That the Lesser
Celandine is well adapted to the conditions under which it grows
is shown by its abundance, especially in shady and marshy spots,
under trees and by streams. Considerable tracts of soil may be
covered by it, and be bright with its yellow flowers, which appear
in March and April and are over early in the summer.

The Lesser Celandine is a perennial plant, and, like many other
spring flowers, grows rapidly early in the year at the expense of
food materials manufactured by the leaves of the preceding season,
and stored in the subterranean parts for this purpose. The
underground parts will be found to be specially modified for the
storage of food material, so that the specimens to be examined
should be carefully dug up and their roots washed free from soil.
A superficial inspection of a whole plant at the time of flowering
(Fig. 60) will show that in addition to a number of thin branched
roots of ordinary appearance there are a number of club-shaped
tuberous roots clustered at the base of the stem. The shoot has a
number of foliage leaves crowded together at the lower part, while
above this the internodes are elongated and the shoots branched.

«s

n6

THE BOOK OF NATURE STUDY

As in the Buttercup, the main stem and each branch ends in a
flower. All these parts require to be examined in detail.

The root system consists of a number of roots springing,
not from a main root, but from the base of the stem. The slender
branched roots that extend into the soil around, and obtain from
it the water and salts needed by the plant, call for no special
description. The storage roots, which form a cluster diverging
from the base of the plant, are more or less numerous, according
to the size and strength of the latter. They are unbranched,

club-shaped bodies, widening
gradually from the point of
attachment to the stem. In a
plant examined in May two sets
of these tuberous roots can be
distinguished. One group con-
sists of fully grown roots of a
brown colour. Many of these
have a wrinkled or shrivelled
appearance. The roots of the
other set, which appear to
spring from a slightly higher
level of the stem, are plump
and firm, often whitish, and
not fully grown. The older
roots are those in which the food, which has been used up in the
growth of the shoot and flowers of the plant, was stored. Their
use is now over, since, as the wrinkled appearance indicates, they
have been depleted of the substances stored in them and they will
perish and decay as the season advances. The new series of
tuberous roots will be stored with food material during the early
part of the summer, and when the shoots die down will remain
in the soil until growth again starts at the expense of the food
they contain.

In most cases a single bud develops into the leafy shoot of
the plant. In specimens examined very early in the year this
will be found in an unexpanded condition. As it unfolds it is
seen that on the outside are several whitish scale leaves and
following them come a number of foliage-leaves, which are borne

FIG. 60.— Whole plant of the Lesser Celan-
dine, in flower. (After Farmer.)

SPRING FLOWERS 117

close together on the stem, the internodes not elongating in this
basal region. These foliage leaves thus form a cluster springing
from just above the root. Above their insertion, in plants which
are large enough to flower, the shoot continues its growth, and
here the internodes are more or less elongated. Usually there is
an internode above the basal leaves, and then come two leaves
inserted one above the other but close together. The stem
may bear two more leaves, but above them continues as a long,
leafless flower-stalk supporting the first flower, which thus ter-
minates the main axis of the shoot. The plant usually bears
more than one flower, and the later flowers terminate lateral
branches, which spring from the axils of the leaves on the main
shoot. In the axils of the leaves borne by the branches shoots
of a third order stand, and also end in flowers.

The foliage-leaves of the Lesser Celandine have a wide sheath-
ing base, a long leaf -stalk, and a heart-shaped leaf -blade. This
is of a rather dark green colour above ; in some varieties it has
paler blotches. Like the rest of the plant, the leaves are hairless.
The leaves borne on the flowering shoots are similar, but have
shorter stalks. The scale leaves correspond to the enlarged
sheaths of leaves, the upper portion of which is not developed.

In the axils of the scale leaves at the base of the shoot a number
of small buds are developed. There are several of these minute
buds in the axil of each scale, so that a considerable number
surround the base of the shoot. The buds remain very small,
but from each a single tuberous root develops. These do not
therefore, like the ordinary absorbent roots, spring directly
from the main stem, though, since the buds are not easily seen,
they appear to do so. In a flowering plant in April or May the
scale leaves have perished, and the tuberous roots in connection
with their axillary buds have attained a considerable size. The
relation of the root tubers of the Lesser Celandine to the shoot
is thus more complicated than appears on first sight.

Buds are also formed in the axils of the basal foliage leaves
which succeed the scale leaves. Usually only one of these, that
in the axil of the uppermost leaf, attains any size, but sometimes
more than one develops. The enlarged bud is destined to form
next year's shoot, and has the structure described above. At

n8 THE BOOK OF NATURE STUDY

the end of the season, when the flowering shoots die down, there
is left in the soil the group of tuberous roots in relation to the buds
at the base of the stem, and above them this bud or buds. Nor-
mally the whole group of storage roots is subordinated to the
requirements of the single bud growing into the new shoot, and
the small bud at the base of each root-tuber does not develop.

Should, however, a root-tuber become detached from the plant,
it carries with it the small bud from the base of which it sprang.
Under these conditions, which must often happen in nature,
the root-tuber serves as a means of giving rise to a new individual,
and thus reproducing the plant vegetatively. The plant is of
course small, and usually only puts up a single foliage-leaf and
forms one new tuber, but in the course of years grows larger,
forms more numerous tubers, and then sends up a flowering
shoot. Young plants developed from separated root -tubers are
constantly found in the neighbourhood of the larger plants.

On plants growing in shady situations tuberous storage roots
are often developed in connection with buds in the axils of the
leaves higher up on the flowering shoot. In these cases the
relation of the storage root to the bud is readily made out, and
since the buds, each attached to a root filled with food material,
are necessarily isolated by the decay of the shoot and scattered on
the surface of the soil, the plant may be largely spread in this
way.

The construction of the underground parts of the Lesser
Celandine thus stands in relation, in the first place, to the con-
tinuance of the individual plant from year to year, and secondly,
to the vegetative reproduction of the plant. Apart from the
growth of new plants from seeds, this can take place : (i) by the
production from a plant of more than one flowering shoot each of
which will form its own group of tubers at the base ; (ii) by the
detachment of root-tubers from the base of a plant ; (iii) by the
natural isolation of the root-tubers formed higher up on the
shoot. While the increase in size of the areas occupied by the
plant may be assisted in all three ways, the spread of the plant
to any distance is most likely to be effected vegetatively by the
tubers formed on the aerial shoots.

The position of the flowers at the end of the main stem and

SPRING FLOWERS 119

its branches, and the branching of the flowering shoot or in-
florescence having been mentioned above, it remains to describe
the flower itself (Fig. 61). It will be found to be constructed
on an essentially similar plan to that of the Buttercup. On
the outside are three greenish-yellow sepals, which enclose the
flower-bud when small. Within the calyx come eight to twelve
narrow strap-shaped petals, greenish below but bright shining
yellow on the upper surface. Each petal has a small scale on
its upper surface close to the attachment, and nectar is secreted
in the little pocket formed by this. Within the petals come a large
number of stamens, each with a yellow stalk supporting a relat-
ively broad anther. The carpels
are inserted separately, though
closely crowded, on the summit
of the conical floral receptacle.
Each consists of a flattened green
ovary bearing at its summit the

L •••--• r -IT FIG. 6 1. —Flower of Lesser Celandine,

rough stlgmatlC Surface. If a cut in half. (After Baillon.)

carpel is carefully opened with the

tip of a sharp knife or scalpel it will be found to contain a single

ovule attached close to the base of the cavity of the ovary.

As in the Buttercup, all the parts of this flower are inserted
separately on the enlarged conical end of the flower stalk or floral
receptacle, and stand in undisturbed succession on this. The
calyx is lowest, while the pistil, composed of the group of separate
carpels, occupies the summit of the receptacle.

The flowers close at night or in bad weather, but when widely
open in the sunshine are very conspicuous, and are visited by many
insects, chiefly small flies and bees. These may come in search
either of the pollen, of which there is abundance formed in the
numerous stamens, or of the nectar, which is hidden in the
nectaries but easily reached. Since the stamens and stigmas
are usually mature at the same time, there is every possibility
that the flower may be pollinated with its own pollen, though
in passing from flower to flower an insect may effect cross-
fertilisation.

Many of the flowers do not develop fruits, though these can
usually be found on careful search. The fruit is composed of

120 THE BOOK OF NATURE STUDY

the enlarged group of carpels borne on the receptacle, from which
the sepals, petals, and stamens have fallen. Each separate carpel
develops into a fruitlet containing a single seed. When ripe
the fruitlets, which do not open to liberate the seeds, become
detached from the receptacle and scattered. The seeds do not
germinate till the following spring, and the seedling is peculiar in
having only a single cotyledon, although the plant belongs to the
Dicotyledons which, almost without exception, have a pair of
seed leaves.

THE LADY'S SMOCK, OR CUCKOO FLOWER (Cardamine
pratensis, L.).

This is a very common and abundant plant in damp meadows,
to which its flowers sometimes give an almost continuous lilac
tint in the later months of spring. It is one of a number of
plants which bear the English name of Cuckoo Flower, doubtless
because they are in flower at the season when the note of the
Cuckoo is heard. The case may be mentioned as an illustration
of the disadvantage of only knowing the English name of a plant.
There is only one plant to which the scientific name Cardamine
pratensis applies, and this makes reference easy and certain. Of
the two English names of this plant, Lady's Smock is to be
preferred as avoiding the risk of confusion with other Cuckoo
Flowers.

The plant is a perennial, growing up season after season,
and a well-grown plant has a thick underground stem upon which
the scars of the leaves of former years can be distinguished.
In the axils of some of them are buds, which are often developed
as lateral shoots. Numbers of fine white roots spring from the
stem. At the base of each shoot are a number of closely crowded
leaves, the stalks of which are longer than those of the leaves
higher up on the stem. In the case of shoots which are not
going to flower, and remain short, these are the only leaves present.
One or more shoots, however, elongate, and after bearing a number
of scattered leaves end in an inflorescence of lilac-coloured flowers.

If the underground stem is more carefully examined it will
be found to bear the marks of the flowering stems of former

A

THE LADY'S SMOCK (Cardamine pratensis, L.]

SPRING FLOWERS 121

years, and a little consideration will show that it does not repre-
sent a shoot which has grown continuously from year to year
giving off lateral flowering branches. It is rather made up,
as is the case with the underground stems of many herbaceous
perennial plants, of the basal region, of each annual growth. The
growth is always continued by a lateral shoot, since the main
shoot has continued into the flowering stem.

'The long-stalked leaves at the base of the shoot have wide
sheathing bases, and in the axil of each is a bud. The leaf-stalk
is slightly channelled above and convex below. It bears a
number of pairs of small stalked leaflets, and ends in a
similar but larger leaflet. The leaf-blade is thus not a simple
or unbranched one, but is compound or branched. Since the
leaflets stand on either side of a main stalk, they are called pinnae,
and the whole leaf is described as pinnate from the general re-
semblance to a feather. This is a very common arrangement of
the leaflets in compound leaves, and may be compared with
the similar disposition of the main lateral veins in many simple
leaves.

The cylindrical flowering stem has distinct internodes separ-
ating the leaves borne upon it. These have practically no leaf-
stalk, the lowest pair of pinnae standing close to the leaf-base. The
leaflets are long and narrow as compared with those of the lower
leaves. In the axils of these leaves are buds, which may remain
undeveloped, or in stronger plants grow out into branches ending
like the main shoot in an inflorescence.

Above the uppermost leaf comes a bare region of stem, and
toward the end of this the flowers are crowded together. Their
association on a special region of the shoot renders the
group of flowers more conspicuous than the flowers would be
singly. The inflorescence here consists of a number of flowers
borne laterally on the main stem. This does not itself end on a
flower, but grows on, producing flowers in regular succession.
The youngest buds are thus found at the top of the inflorescence,
the lowest flowers being the oldest and the first to open. Though
the flowers correspond to lateral branches of the main stem, no
trace of the leaf which we might expect to find beneath each is left.

An inflorescence such as this, in which the growth of the main

122

THE BOOK OF NATURE STUDY

axis, which does not end in a flower, is unlimited, may be contrasted
with that of the Buttercup or Lesser Celandine (cf. Fig. 52).

Each flower consists of a flower-stalk bearing, in order from
below upwards, the calyx, corolla, stamens, and pistil, which are
crowded together on the end of the stalk or the floral receptacle.
In the bud only the calyx, the sepals of which completely cover
in and protect the other parts of the flower, is visible. The four
sepals do not stand at the same level on the receptacle, but are
arranged in two pairs. The sepals of one pair, those standing

front and back in the flower, are
narrower than those of the other
pair, and the latter are also bulged
out at the base. A little careful
observation is needed to make out
which pair is outermost, but if it is
noticed which pair overlaps the
other it will be clear that the
narrower sepals are the lower ones,
although the bulging downwards of
the bases of the other pair suggests
at first glance an opposite interpreta-
tion. The corolla is composed of four
showing the six stamens around petals, which, unlike the sepals, all

the pistil and the nectaries at the j ,, i i ' T» i_

bases of the two short stamens. stand at the Same leveL Each Petal

stands above the interspace between
two sepals. As will be seen if the
sepals are removed from a flower, the
petals are all quite distinct or free
from one another. Each consists of an erect stalk-like portion
of a greenish-yellow colour, and of a wider oval portion which
is bent so as to stand almost at right angles to the lower part.
The end portions are coloured lilac, the colour being more
strongly marked in the veins, and the four petals diverge like
the arms of a cross, forming the most conspicuous part of the
flower. The lower portions of the petals are enclosed and held
together by the erect sepals, so that a sort of tube which
surrounds the other parts of the flower is formed by -the calyx
and corolla.

A B

FIG. 62.— Lady's Smock. A, flower
with sepals and petals removed,

B, the same cut in half to show
the construction of the ovary
and the position of the ovules.
(After Baillon.)

SPRING FLOWERS 123

The parts within are best seen on stripping both the sepals
and petals from a flower. This leaves the stamens standing on
the floral receptacle around the pistil (Fig. 62). There are six
stamens, two of which are shorter and stand farther away from
the pistil, while the other four are longer and are grouped in
two pairs. The two shorter ones stand lower on the receptacle,
and are placed on either side of the flower immediately within
the bulged-out sepals of the inner pair. Each stamen consists of
a stout greenish stalk supporting the anther, the pollen sacs of
which at first face inwards towards the centre of the flower.
When examining the stamens the nectaries will be seen. The
green rim around the base of each short stamen is a nectar-
secreting gland, and a smaller nectary is present just below each
pair of long stamens. The nectar secreted by these glands
accumulates in the bag-like bases of the two inner sepals.

The pistil, which is borne on the summit of the receptacle
and stands in the centre of the flower, presents difficulties to
the observer on account of the small size of the parts. It is
differentiated into a green ovary surmounted by a stigma which
is slightly two-lobed. It is composed of two carpels joined
together edge to edge, and the cavity of the ovary is divided
into two by a longitudinal partition. In each half there are
two rows of ovules lying against the partition (Fig. 62, B). [The
structure of the pistil in the Charlock, where it can be more
easily studied, should be compared.]

The flowers are visited by numerous insects, which come
in search of the nectar concealed at the base of the flower. In
sucking this they will place their heads between the stamens
and the stigma, and on going to another flower may touch its
stigma with the pollen-covered surface of their heads and so
effect cross-pollination. The risk of direct self-pollination by
the pollen from the anthers of the longer stamens falling on
the stigma is lessened by the anthers making a half -turn outwards
when the flower opens.

For some reason or another the flowers often do not set fruit.
The construction of the fruit and its mode of opening, should
specimens be found, will be understood from the description
given in the following chapter of the fruit of the Charlock.

124

THE BOOK OF NATURE STUDY

The plant is vegetatively reproduced by bulbils, i.e. small
buds which develop at the base of some of the pinnae of the lower
leaves and grow up into new plants. These bulbils, while they
spread the plant in its immediate neighbourhood, are not suited
to disperse the plant widely, and this must result from seed-
production.

THE SWEET VIOLET (Viola odorata, L.).

A number of different species of Viola grow wild in Britain,
while others with more showy flowers are in cultivation. The

Dog Violet (Viola canind) and
the Wild Pansy (Viola tricolor)
are, together with the Sweet Violet,
the most familiar of our wild
species. The numerous garden
varieties of the cultivated Pansy
have sprung from a foreign species,
Viola altaicay and other cultivated
forms have been derived from
Viola tricolor. All these plants,
while differing in details, are suffi-
ciently alike in their vegetative
organs, in the construction of the
flower, and in the mode of polli-
nation for the description of the
Sweet Violet that follows to be
of some assistance in their study. The description will, of
course, only apply in detail to the Sweet Violet.

This species grows wild on grassy banks in the southern
counties of England, and is found less commonly farther north.
It is also extensively cultivated for the sake of its scented flowers,
which are on sale throughout the winter months and can thus
be easily obtained for study. The plant is a perennial, and has
a short, stout, woody stem which grows on at the summit year
after year, producing each spring a rosette of leaves inserted
close together on the stem (Fig. 63). A plant derived from
seed has a main root, but in those which have been produced
vegetatively in the manner described below the roots spring

FIG. 63.— Plant of the Sweet Violet.
(After Baillon.)

SPRING FLOWERS 125

from the stem. This also bears the withered bases of leaves
of former years.

The leaves have long slender stalks, grooved on the upper
face, which lift the heart-shaped leaf -blade well above the soil.
The leaf-blade is simple, its margin being cut into small rounded
teeth. The blade and stalk bear numerous short hairs. At
the base of each leaf we find a pair of pointed stipules, which
assist in the protection of the young parts in the bud.

In the axils of most of the leaves flower-buds are found, but
in some vegetative buds develop. These grow into long creeping
branches, which resemble the runners of the Strawberry. The
internodes of these branches are long, and a small scale-leaf is
borne at each node. Roots also spring from the stem. The
end of the creeping shoot ultimately turns up and bears a rosette
of foliage-leaves like those of the main plant. The runners thus
serve to spread the plant vegetatively, and when they decay
the new plants become independent at some little distance from
the parent.

The flowers are borne singly in the axils of the leaves of the
main shoot, and also in those of the creeping branches. Flower
buds are already well developed in the axils of the foliage leaves
in the autumn, but do not unfold till March or April. By this
time the foliage-leaves of the preceding year are more or less
withered, and the brightly coloured flowers borne on long stalks
are conspicuous. The new foliage leaves are at this time beginning
to expand. About half-way up the slender flower-stalk two
small leaves or bracteoles will be found. Just below the flower
the stalk is sharply curved, so that the flower stands horizontally
or is directed obliquely downwards. The curvature takes place
before the flower opens, and is always directed so as to cause the
flower to face the strongest light. The flower itself (Figs. 63, 64)
is an irregular one, so that, as borne on the flower stalk, we can
distinguish an upper and lower side and right and left halves.
The very complex and beautiful arrangements to favour cross-
pollination by insects can only be understood after specimens
of the flower have been carefully dissected.

The sepals are five in number, and as usual are of a green
colour. One of them stands in the middle line at the back of

126 THE BOOK OF NATURE STUDY

the flower. The bases of the sepals are prolonged backwards
as short flaps. The five petals alternate in position with the
sepals, so that one stands in the middle line in front, while a petal
stands to either side and two form the back of the flower (Fig. 63).
The petal in front is the largest. It is produced backwards as
a hollow sac or spur, which projects between the two anterior
sepals, and lies beneath the flower-stalk (Fig. 64, A). The spur
is slightly flattened from side to side. This petal, the free margin
of which is slightly notched, forms a lower lip to the flower. The
lateral petals widen out from the narrow stalk-like basal part
and form the sides of the flower. Each has a small tuft of white
hairs about half-way up on its inner face ; the use of these will
be apparent later. The two petals at the back of the flower

are narrower, and
bend backwards when
the flower has opened.
All the petals are
coloured a beautiful
violet blue, which is
paler near the base
A and deeper in the

FlG. 64. — Sweet Violet. A, flower cut in half ; B, stamens expanded portions
and pistil after removal of the sepals and petals. _«* -

(After Baillon.) The VemS °f the

petals, especially of

the one in front, are more deeply coloured, and form a system
of lines converging into the opening of the flower.

There are five stamens alternating in position with the petals.
The form of the stamens will be best studied if the sepals and
petals are carefully removed from a flower (Fig. 64, B), but their
relation to the corolla must be studied in an uninjured flower.
The stamens have extremely short stalks, and their anthers are
very broad and flat. Above the anther, which has a pale yellow
colour, the connective is continued as a triangular orange flap.
The anthers stand close around the pistil, and touch by their
edges, as do the triangular connective flaps, the tips of which
bend in round the style. The stamens thus form a little box
around the style, and the pollen is shed into this. The two
lowest stamens have flat green processes springing from below

SPRING FLOWERS 127

the anther (Fig. 64, B). These extend back into the spur of the
anterior petal, which is adapted to contain them (Fig. 64, A) and
are the structures which secrete the nectar. This accumulates in
the spur.

The pistil is seen if the stamens are carefully removed. It
consists of a small three-sided conical ovary continuing into a
slender style, the tip of which bends down in front of the tips
of the stamens. This bent tip is the stigma. The ovary is formed
of three carpels, but has only a single cavity. The ovules are
borne on the inner surface of the wall of the ovary in three rows,
which correspond to the lines of union of the carpels (cf. Fig. 56, c).

If, having studied the form of all the parts of the flower,
we take another specimen, and look at it from in front, the
relative positions of the parts will be appreciated. The stamens
and pistil will be seen to be enclosed by the basal portions of the
petals, the tip of the cone formed by the stamens projecting in
the opening of the flower. In front of this the style bearing the
hooked stigma projects. Entrance to the spur, within which
the nectar is contained, might be by the sides or beneath the
staminal cone. The passage by the side of this is, however, filled
up and blocked by the tufts of hairs projecting inwards from
the two lateral petals. It is thus clear that the only easy way
into the spur will be beneath the cone of stamens.

The flowers of the Sweet Violet are visited by a number of
different kinds of insects, especially by bees, which come in search
of the nectar secreted by the appendages of the two anterior
stamens. Pollination is most satisfactorily effected when the
insect alights on the anterior petal, and passes its proboscis be-
neath the stamens into the spur. In doing this it will touch
the stigma first, and will then have pollen deposited on its pro-
boscis, either by disturbing the stamens, when pollen will fall
out of the box formed by the anthers, or from the groove in the
petal, where pollen will have fallen. On the insect going to another
flower the pollen on its proboscis will be deposited on the stigma,
and the flower will be cross-pollinated. Pollination does not
appear to result if the visits of insects are prevented, and the
whole construction of the flower indicates its high specialisation
for insect pollination. The shape of the irregular flower leading

128 THE BOOK OF NATURE STUDY

to its being approached by the insect in a particular way, the
converging lines on the petals pointing to the entrance to the
nectary, the hairs on the lateral petals limiting the entrance to
below the stamens, and the deeply seated nectar all find their
explanation in the light of a knowledge of the pollination of the
flower. The arrangement of the stamens and stigma deter-
mine the special mechanism for shedding and receiving the pollen.
Only the first developed flowers of the Sweet Violet have the
structure described above. A little later in the season, when the
new rosette of leaves is unfolding on the plant, the flower buds
give rise to small and inconspicuous flowers, which remain hidden
among the leaves and do not open. These flowers are self-polli-
nated, the pollen from the stamens reaching the stigma, around
which the anthers are placed. These flowers
are thus always fertilised and set fruit, while
the conspicuous flowers must be cross-pollinated
by means of insects for this to take place.

The fruit of the Violet, whether developed
from the large or the inconspicuous flowers, is
formed from the pistil. The sepals persist
FIG 6; —Wild Pans around the base of the fruit, but the petals
(Viola tricolor), and stamens wither and fall off (as does the
Fruit opening by style) as the ovary enlarges. The fruit contains

vaivel^ int° threC a number of smooth round seeds attached in
three rows to the inside of the wall of the
developed ovary. As the fruit ripens its wall becomes dry, and
ultimately splits into three valves along lines midway between
the rows of seeds. As the valves of the fruit dry their edges curl
inwards. In the Sweet Violet this serves merely to loosen the
attachment of the seeds, which fall off ; but in other species, such
as the Wild Pansy (Fig. 65), the seeds are thrown to some distance
from the fruit. The smooth seeds are nipped by the infolding
edges of the valve, and are jerked away, just as a smooth marble
might be if nipped by the finger and thumb.

The Dog Violet will be found to resemble the Sweet Violet
in many respects, and, like it, has both conspicuous and self-
pollinated flowers which do not open. The Wild Pansy, on the
other hand, has only conspicuous, insect-pollinated flowers. The

SPRING FLOWERS 129

general mechanism is similar in all three flowers, though differ-
ences will be found in the shape and exact relations of some
of the parts.

THE PRIMROSE (Primula vulgaris, Huds.).

In April and May the rosettes of large leaves, and the pale
yellow flowers of the Primrose, are conspicuous on grassy banks
and in copses, where the plants often occur in such numbers
as to lend a definite character to the landscape. The Primrose
is a perennial plant, so that the individuals persist in the same
spot year after year, and by branching may form a small cluster
of shoots. This branching, which may lead to an increase in
number of individuals if the branches become isolated, is more
marked in Primroses and their relations grown in rich garden soil.
Such cultivated plants will serve for study, but it will be found
better to use the smaller plants of the wild Primrose if these
can be procured.

In a plant at the time of flowering (Plate), which has been care-
fully dug up and its underground parts washed free from the soil,
the rosette of leaves, which was alone apparent above ground, will
be found to be borne on a fairly thick underground stem. Further
back this bears a number of pink swellings, which comparison with
the leaves of the rosette will show to be the bases of the leaves
of former seasons. These persistent leaf -bases closely cover the
whole stem, and add to the bulk of the plant available for the
storage of reserve food material. Numerous thick white roots
also arise from the underground stem, and give off finer lateral
roots, which extend on all sides through the soil.

The leaves forming the rosette have persisted since just after
the preceding flowering period, when they expanded ; they are
now about to wither and to be replaced by a new set. Each
leaf has a broad, thick leaf-base, a wide, ill-defined leaf -stalk, which
is somewhat concave above and strongly convex below, and a
large, oval leaf-blade. The leaf-stalk is continued as the well-
marked midrib, which projects on the lower side of the blade and
tapers towards the tip of the latter. Lateral veins spring alter-
nately to right and left of the midrib, and they and also the finer

VOL. III. — 0

130 THE BOOK OF NATURE STUDY

veins project on the lower surface. The surface of the leaf -blade
thus appears wrinkled ; it is deep green above and paler beneath,
where the veins bear numerous short hairs.

Within the circle of foliage leaves, that is, higher up on the
stem, we come to a number of small pointed leaves which require
to be carefully looked for. These are the bracts, and in the
axil of each is a single flower. After the foliage leaves have
been formed the stem bears the bracts, and with the production
of the flowers that particular shoot ceases to grow. Provision is,
however, made for the further growth of the plant. This is
carried on by a lateral bud standing in the axil of one of the
uppermost foliage leaves. This bud is now expanding, and the
leaves, the blades of which are rolled backwards towards the
midrib in the bud, contrast with the withered ones of the old
rosette. The old leaves will shortly perish, and the bud will
give rise to the rosette of leaves. These will remain until after
the next flowering season, to be in turn replaced by a lateral
bud. The underground stem is thus seen to be made up of
the shoots of each year, and careful search among the leaf-
bases will reveal the scars left by the group of flowers of
each season, and enable the amount grown in each year to be
determined.

The flowers in the Primrose are borne on long stalks which
carry them clear of the leaves. In some close relations of the
Primrose, such as the Cowslip, the whole group of flowers is carried
up on a bare cylindrical region of the stem. This does not develop
in the Primrose. The flower stalks are thin and cylindrical, and
clothed with soft hairs. The flowers themselves are of two types
which are borne on distinct plants, so that any individual bears
flowers of one type only throughout its life. In general features
the two kinds of flower correspond ; they differ in the length of
the style and the position of the stamens. The two kinds are
familiar to gardeners, who call them "pin-eyed" and "thrum-eyed"
flowers, and can readily be distinguished by looking at the face of
the flower. In the pin-eyed or long-styled flowers the entrance to
the tube of the corolla is occupied by a greenish globular stigma.
The stamens are out of sight lower down. In the thrum-eyed or
short-styled flowers the five anthers are seen at the entrance to

SPRING FLOWERS

the corolla tube, while the stigma borne on a shorter style is out of
sight (Fig. 66).

Taking a long-styled flower (Fig. 66, B) for description we find
it to consist of calyx, corolla, stamens, and pistil. The arrange-
ment of these parts is, however, greatly modified by the union
which has taken place between them, and the flower should be
contrasted in these respects with such a flower as the Buttercup
described above. The calyx is a pale green, tubular structure
with its margin prolonged into five pointed teeth. These are the
free tips of the five
sepals, which are
united together.
The calyx has five
ridges which con-
tinue down from
the free teeth. The
petals are also
united together to
form a tubular
corolla. Their ex-
panded tips are,
however, separate,
and bend almost at
right angles to the
tubular portion.
The five lobes thus
form the conspicu-
ous face of the flower. They will be found to alternate with
the teeth of the calyx. The greater part of the exposed por-
tion of the corolla has a pale sulphur-yellow colour, but around
the narrow entrance to the tube and on the base of the free lobes
the tint is deeper, and this makes the entrance to the tube more
prominent. The tubular portion is not the same width throughout,
but suddenly widens about half way.

When the corolla is split open the widening is found to corres-
pond to the place of insertion of the stamens, which are not borne
on the receptacle of the flower, but are attached to the inner surface
of the corolla. There are five stamens, which have very short

FlG. 66. — Primrose. Diagrams of relative positions of the
parts in the thrum-eyed (A) and pin-eyed (B) flowers, cal,
calyx ; cor, corolla ; stam, stamens ; stig> stigma ; sty^
style ; ov, ovary.

132 THE BOOK OF NATURE STUDY

stalks. Each stamen stands opposite the middle line of a petal.
The anthers open inwards, and expose the sticky yellow pollen.

In the centre of the flower, occupying the summit of the floral
receptacle, is the pistil. This consists of a pale green, globular
ovary, a long slender style like the shaft of a pin, and a small ex-
panded stigma like the head of a pin. In the long-styled flowers
the style is about the length of the tubular part of the corolla,
and the stigma stands at the entrance to the tube. The surface
of the stigma will be seen with a lens to be distinctly papillate and
rough. When the ovary is carefully opened or cut through longi-
tudinally, the numerous, small, greenish white ovules will be
found to be borne on a globular projection from the base of the
cavity. There is no trace of partitions dividing the latter, and
only comparison with the other parts of the flower shows us that
the pistil is composed of five carpels very completely united
together.

The short-styled or thrum-eyed flowers are composed of the
same parts as the long-styled, but the widening of the corolla tube
will be found not about the middle but close to the upper end.
The stamens are attached here so that their anthers project in the
entrance to the corolla. The style, on the other hand, is much
shorter in these flowers, and the stigma stands about half-way
up the tube, i.e. at about the same level as the anthers in the
long-styled flowers. The stigma is smoother and the pollen
grains are larger in the short-styled flowers.

This remarkable development of two types of flower, both con-
taining stamens and pistil but the position of the stamens in the
one flower corresponding to that of the stigma in the other, occurs
in a number of plants, the Primrose and its relations being the
most familiar examples. In the Primrose it has been found that
the best production of seed results when pollen is carried from
stamens standing at the same level as the stigma receiving the
pollen. This can only be brought about by a transfer of pollen
from one type of flower to the other, that is, by cross-pollination.

While flowers may sometimes be self-fertilised, it has been
found, by carefully watching the plants when in flower, that on
favourable days a number of insects of different kinds visit the
flowers in search of the nectar secreted at the base of the ovary.

SPRING FLOWERS 133

Owing to the length of the corolla tube, only long-tongued insects
can reach the nectar, and the visitors observed are long-tongued
flies and occasionally humble-bees. When an insect visits a short-
styled flower its head will be dusted with pollen. Should it now
pass to a long-styled flower this pollen will be deposited on the
stigma. At the same time, pollen will be deposited from the
stamens of this form about half-way up the proboscis of the insect.
When the latter visits a short-styled flower this region of the tongue
will touch the stigma, which will thus receive pollen from stamens
of the corresponding height.

The ovary of a flower that has been fertilised enlarges and
develops into the fruit, which is surrounded by the calyx, while
the corolla disappears The fruit contains a number of seeds, and
opens, by splitting at the summit into ten short teeth. These roll
back so that the seeds, as they become detached from the pro-
jection from the base of the seed - capsule, can fall out of the
fruit.

THE LESSER PERIWINKLE (Vinca minor, L.).

Two kinds of Periwinkle can be found wild throughout Britain,
growing usually in the shade of trees in open woods or on hedge-
banks. The Greater Periwinkle (Vinca major) is less common,
but is commonly grown in gardens. The Lesser Periwinkle is
well established in many places, and often covers the soil of open
woods to the exclusion of most other plants. Neither of the
species is probably a true native of this country, and there is
reason to believe that the introduction of both the larger and
smaller kind took place at the time of the Roman occupation
of Britain. The plants flower in April and May, though occa-
sional flowers can be met with in the autumn. Either will serve
for study, the description being based on the commoner Lesser
Periwinkle (Fig. 67).

This is a small perennial plant with dark green, glossy,
evergreen leaves. It spreads largely by vegetative growth. At
the level of the soil prostrate creeping shoots will be found. From
some of the nodes of these shoots, which persist for years and
become tough and woody, the buds grow up as more slender

134

THE BOOK OF NATURE STUDY

erect shoots. These have elongated internodes, and at each
node a pair of small, oval, foliage leaves with short stalks. The
pairs of leaves alternate at successive nodes. On the horizontal
shoots the leaves become twisted round so as to spread out in
one plane, and appear as if they formed only two rows. From

the persistent lower
portions of the erect
shoots lateral branches
arise in succeeding
years, giving rise to
the clusters of erect
shoots which spring
at intervals from the
creeping stems (Fig.
67). From these
nodes numerous roots
grow down into the
soil. This mode of
growth enables the
plant to spread, and
is largely responsible
for its abundance and
success in favourable
situations.

The flowers are
borne singly in the
axils of one or more
of the upper leaves of
the erect shoots. The

FIG. 67.— The Lesser Periwinkle. (After Baillon.)

shoot in the Lesser
Periwinkle often has
only one flower. This is borne on a slender green stalk, and
consists of sepals, petals, and stamens in regularly alternating
whorls of five, and of a pistil composed of two carpels. The
construction of the flower is a complicated one, and should
be carefully studied in several examples, since even the most
minute features will be found to have their use in the pollination
of the flower by means of insects.

SPRING FLOWERS 135

The calyx is short as compared with the corolla. The sepals
are united for a short distance at the base, but above this project
as pointed green teeth. In the growing flower-bud the corolla
in its closed condition projects far beyond the sepals, and shows
clearly the twisted arrangement of the petals characteristic of
this plant and its relations. When expanded it is seen to be
composed of a tubular or funnel-shaped region, and of five lobes,
which alternate in position with the sepals and correspond to the
free ends of the petals. These lobes are peculiarly shaped, having
one edge longer than the other. They diverge almost at right
angles to the tubular portion of the corolla, and since they, as well
as the tube, are of a bright violet-blue colour, render the flower
conspicuous as it projects from the dark glossy foliage. The
entrance to the corolla-tube is strengthened by a slight ridge of
a paler tint, which gives the opening a pentagonal outline, each
side of the pentagon stretching from the middle line of one petal
to that of the next. Corresponding to the interspaces between
the petals a white streak extends down the inside of the tube,
and is indicated on the outside of the latter by a slight groove.
The upper portion of the corolla tube is thus fluted (Fig. 68).

On looking into the tube the more internal organs of the
flower are seen blocking the cavity about one-third way down.
They form a whitish, ridged dome-shaped mass, which does not
itself fill the cavity, but the space between it and the wall of
the tube is occupied by downwardly directed white hairs springing
from the latter.

To see the exact relation of the stamens and pistil to one
another and to the corolla- tube, a flower must be carefully split
in two (Fig. 68), or the corolla split up along one side and flattened
out. The stamens will be found to be five in number, and to be
attached to the inner surface of the corolla-tube opposite to the
intervals between the petals, i.e. on the line of the white streaks
mentioned above. The shape of the individual stamens is peculiar.
The stalk springs from the inner wall of the tube a short distance
below the widened upper end of the style, and slopes upwards
and inwards beneath this. The stalk then bends sharply out-
wards until it touches the corolla tube, and then, bending inwards
again, ends in the anther. Each of these has a wide flattened

i36

THE BOOK OF NATURE STUDY

connective, bearing the pollen sacs on the inner face and con-
tinuing above them as a flap-like appendage. These appendages
roof over and conceal the pistil.

The shape of the stamens is only to be understood in relation
to that of the pistil (Fig. 69). This consists of two carpels forming

FIG. 68. — Flower of the Greater Periwinkle cut in half. (After Baillon.)

the green ovary ; from this springs a cylindrical style which
gradually widens till the level of the inwardly projecting filaments
is reached. Above this the style suddenly widens out into a
disc at the level of the concave portions of the filaments, which
arch round it. The expanded disc is surmounted by a narrower
portion. The summit bears a plume of white hairs, which slope
downwards on all sides between the tip of the style and the upper

SPRING FLOWERS

137

surface of the cylindrical expansion of the style. The sloping
surface formed by these hairs lies immediately within the circle
of anthers. The actual receptive surface or stigma is not at the
tip of the style, but is the vertical edge or outer surface of the
disc-like widening of the latter. The relative positions of the
regions of the stamens and style are constant, and will be better
understood from a study of the flower with
the help of Fig. 68 than by any further descrip-
tion. The lower portions of the filaments bear
downwardly directed hairs, and, as was seen
on looking into the flower, the space between
the stamens and the corolla - tube is filled up
with similar hairs springing from the corolla.
The latter hairs are omitted in Fig. 68.

The ovary consists of two carpels, which
are separate from one another in the lower
region of the pistil but joined to form the
style. Each carpel in the ovary encloses a
cavity which has two rows of ovules springing
from the infolded inner margin. Seen from
the outside, the ovary has the appearance
of a deeply two-lobed, flattened, green body.
Alternating with the lobes are two yellowish
green glands, not much behind the carpels in
size. These are the nectaries, and the nectar
formed by them accumulates around the ovary
in the lower part of the corolla tube.

If this very complex inter-relation of the
parts enclosed by the corolla is considered with
regard to the action of the insects visiting the
flower it will be found to be intelligible as a
very beautiful adaptation for cross-pollination,
in search of the honey, and only those with long tongues can reach
this. Humble-bees and some smaller bees are the chief visitors
to the Lesser Periwinkle, while only bees with still longer tongues
and moths can obtain the honey from the larger flowers of Vinca
major. The insects alight on the flat, target-like expansion of
the corolla, and will pass their tongues down to the nectar. Owing

FIG. 69.— Pistil of the
Greater Periwinkle.
The nectaries are
seen to either side
of the ovary. (After
Baillon.)

The insects come

138

THE BOOK OF NATURE STUDY

to the curving of the stamens and the attachment of their stalks
to the corolla, the insect* s tongue must be passed down one of
the five intervals between the stamens. The hairy ridges on the
upper part of the corolla- tube further direct the insect to the narrow
passages, which lie opposite the middle lines of the petals.

As soon as the flower opens the whole mass of pollen from
each anther-lobe is shed and deposited in a mass on the sloping
crown of hairs at the summit of the style. The pollen thus lies in
a chamber roofed in by the flat tips of the stamens. It does not

get upon the stigmatic surface,
which is enclosed in a lower
chamber formed by the five
curved filaments. The stigmatic
surface is very sticlsy and viscid.
If no insects visit the flower the
pollen remains undisturbed, and
the stigma is not pollinated.

When, however, the slender
proboscis of an insect is passed
down between two of the stamens
to the nectar, it will evidently
come in contact both with the
pollen lying on the top of the
pistil and with the stigmatic rim.
The pollen is not as a rule
moved downwards on the inser-
tion of the insect's tongue, but
when this is withdrawn the
region which has rested against the stigma is sticky from the
abundant stigmatic secretion, and a quantity of pollen adheres
to the sticky surface and is carried away on the proboscis.
This is not likely to be deposited on the stigma of the same
flower, since the insect has exhausted its nectar and will pass to
another flower. In this the pollen-covered region of the insect's
tongue will rest against the stigma, which will thus be cross-
pollinated receiving pollen from the first flower.

The whole construction of the flower becomes comprehensible
when the way in which pollination is effected is understood.

FIG. 70.— Fruit of the Greater Periwinkle
opening to liberate the seeds. (After
Baillon.)

SPRING FLOWERS 139

The action of the insect can be imitated by passing a fine bristle
down one of the openings between the stamens, and on then
inserting the bristle into a second flower this will be pollinated
and will develop a fruit.

In the wild state in this country many of the flowers do not
form fruits, though these can be found on careful search. The
corolla, with the stamens and the style, drops off, while the two
halves of the ovary separate and increase in size. When ripe,
these open along the line of union and liberate the seeds (Fig. 21).
Many of the flowers drop off without forming fruits, even when
pollination has taken place.

THE WHITE DEAD-NETTLE (Lamium album, L.).

The White Dead-nettle grows in social groups, often on grassy
banks or beneath hedges ; and can be found in flower from about
May until late in the year. It is a perennial plant, and, though
the leafy shoots die down for a short time in the winter, can be
found year after year on the same spot. Although the arrange-
ment and shape of the leaves resemble the Stinging Nettle, the
two plants are not related, and the hairs on the shoots of the
Dead-nettle have not the special complicated structure of those
of the Stinging Nettle, nor do they sting.

To understand the growth of the plant, the leafy shoots must
not be merely picked off, but the underground parts bearing them
must be carefully dug up (Fig. 71). The green, leafy shoots will be
found to be the ends of longer or shorter underground branches.
These are whitish, and have a four-sided stem with distinct inter-
nodes. At each node is a pair of small scale-leaves. The cross
section of the stem is square, and the internodes are not hollow
as they are in the aerial stems. Numerous roots spring from the
nodes and extend into the soil, giving off lateral roots. In the
axils of the whitish scale-leaves are buds. These grow out into
branches, which may have a longer or shorter underground portion
and then grow into an erect shoot. The crop of new shoots grow-
ing up in the spring comes from such buds.

The stem of the aerial shoots is also quadrangular, but it is
only solid at the nodes. The internodes are hollow, and this

140

THE BOOK OF NATURE STUDY

tubular construction, while quite rigid, economises the material
needed in the growth of the shoot. Two leaves are borne at
each node, and stand immediately opposite to one another. The
pair of leaves alternates in position with the pairs immediately
above or below. This arrangement avoids the shadowing of
the leaves of one pair by those borne at the succeeding node.
The stem is green or purplish in colour, and is sparsely covered

with white hairs. Each foliage-leaf con-
sists of a slightly widened leaf-base,
a well-marked leaf-stalk, and a simple
leaf-blade ; there are no stipules. The
leaf-stalk is grooved above and rounded
below, and its margins bear long soft
hairs. The blade widens out suddenly
at the upper end of the leaf-stalk, and
just above this attains its greatest
breadth, from which it gradually narrows
to the tip. Its margin is cut into
teeth, which point like the teeth of a
saw to the tip. The blade is traversed
by a midrib, and it, as well as the main
branches which form a beautiful net-
work, project on the paler lower surface.
While buds which may give rise to
small lateral shoots are found in the
axils of some of the lower leaves, all the

FIG. 71.— Plant of the white upper pairs of leaves have clusters of

flowers in their axils. The flowers are
so closely crowded that they appear to
completely surround the stem at the

node. They are, however, in two groups in relation to the two
leaves. The cluster of flowers lowest on the shoot begins to
open first, and is succeeded by the group at the next node,
and so on. The flowers of any one axillary group also do not
open simultaneously. The first to open is the flower standing
immediately over the leaf-base ; this is followed by one to either
side, and these by buds standing laterally to them. All these
flowers after the first one stand in the axils of minute, pointed

R

Dead-nettle. R, roots ; I,
internode ; N, node ; F,
flower. (After Farmer.)

SPRING FLOWERS 141

bracts, which can be easily made out, but the whole inflorescence
is so condensed and shortened that it is difficult to follow the
branching in detail.

The flower (Fig. 72) is an interesting one, and deserves careful
and repeated study. All the flowers stand in a definite position
with regard to the shoot, so that a front and back and two sides
can be distinguished. Unlike such flowers as the Buttercup and
Primrose, which are symmetrical about the central point, that
of the Dead-nettle can only be divided into similar halves by one
plane. This passes through the flower from front to back. Such
a flower is described as irregular, in contrast to the regular flowers
mentioned above, and it will be found that this feature leads to

FIG. 72.— White Dead-nettle. A, flower from the side ; B, flower cut
in half ; C, lower part of a flower cut in half more highly magnified.
(After Baillon.)

a greater precision in the relation between the parts of the flower
and visiting insects than is usual in regular flowers.

The five sepals are united to form a tubular calyx, from the
margin of which the pointed tips of the sepals project. One sepal
stands in the middle line of the flower behind. The calyx is green
with purplish markings, and the tubular part is ridged. The
petals are also joined together to form the corolla, which is tubular
below but divided into two well-marked lips at the upper part.
The lower lip, which widens out and has an indentation in front,
is composed of one petal. The sides of the entrance to the tube
are bounded by pointed lobes, which mark the position of lateral
petals ; while the upper lip, though undivided, is made up of two
petals. This can be shown by comparison with related plants,

142 THE BOOK OF NATURE STUDY

but can also be inferred from the presence of a sepal in the middle
line behind since the petals alternate with the sepals. The
corolla is easily removed, and, looked at from the side, shows a
narrow tubular portion at the base. Above this it widens out
suddenly into a sort of pouch in front, and continues to widen
slightly until it divides into the two lips described above. When
split open, or in a flower cut in half, a number of white hairs will
be found blocking the corolla tube just where the narrow part
at the base ends (Fig. 23, c). The whole corolla is of a yellowish
white tint.

There are four stamens, not five as might have been expected.
The stamen which should stand in the middle line behind is absent.
The stamens are joined on to the corolla, and their attachment
will be seen on slitting up a corolla in the middle line behind and
spreading it out. The two stamens, which are attached farther
forward in the flower, have longer stalks than the other two, and
their anthers stand in front of those of the other pair. All four
anthers lie beneath the upper lip of the corolla, which protects
them from wet, and they face downwards. The pollen does not
drop out of the open anthers.

The style is also bent backwards, and lies between the stamens
beneath the upper lip of the flower. It ends in a two-lobed
stigma, one branch of which is directed forwards and the other
backwards. The inner surface of these lobes is the receptive
one for the pollen. Usually the style, being entangled among
the stamens, is pulled off when the corolla is removed, but some-
times it can be left in position. It is then seen to spring from
the centre of four green lobes, which are visible on looking into
the cup-like calyx. These are the four lobes of the ovary, which
is not, however, composed of four carpels but, as the two-lobed
stigma indicates, of two. Each of these is subdivided into two
chambers, and in each of the four cavities thus formed is a single
ovule. If the calyx is carefully split open with the point of the
knife, and peeled away from the ovary, two delicate whitish
yellow scales will be seen lying against the front of the latter,
and springing from beneath it. These are the nectaries, and
the nectar accumulates in the narrow lower part of the corolla
tube protected by the ring of hairs.

SPRING FLOWERS 143

When the structure of the flower has been made out by dis-
secting several examples an intact flower should be considered
in relation to the insects which visit the flowers in search of
the nectar. This can only be reached by insects with a fairly
long proboscis, and the flowers are in fact visited by humble-
bees and other large bees and adapted for pollination by
them. The way in which this comes about can be inferred
by a study of. the flower, but whenever possible growing
plants in flower should be watched on fine days, and the
insects which come to seek the honey noted and their behaviour
observed.

The bee alights on the lower lip of the corolla, and thrusts
its head as far down the wider portion as possible. Its proboscis
thus reaches the nectar, and it remains sucking this. The body
of the bee fills up the space between the under and upper lips,
so that its back presses against the latter. The stigma and
anthers are placed beneath this, the front lobe of the stigma
projecting farther forward than the other parts. The bee will
first come in contact with this, and pollen brought on its
back from another flower may be deposited on the stigma. A
further supply of pollen from the anthers, which have been seen
to open downwards, will be deposited on the corresponding
portion of the insect's body, and will be deposited on the stigma
of the next flower visited. Since the stigma is receptive when the
stamens are shedding their pollen, the flower may readily be
self-pollinated by the insect. But since the flowers are largely
visited, and insects pass rapidly from flower to flower in search
of the honey, the chance of cross-pollination is very great. All
the features in the construction of the flower are to be understood
as rendering this probable.

After pollination the corolla falls off, carrying with it the
stamens and the style, and the ovary enlarges and becomes the
fruit. The lobes develop into four nutlets, each containing a
single seed. When mature the nutlets split apart and are shed
separately, but show no special arrangements to facilitate dis-
persal. Since each contains only one seed, there is no need for
the nutlet to open, and its wall protects the seed until this ger-
minates and gives rise to a new plant.

i44 THE BOOK OF NATURE STUDY

THE DANDELION (Taraxacum officinale, Web.).

The Dandelion can be found in flower from early spring to
late in the autumn. It grows in grassy ground and in waste
places, its excellent method of fruit dispersal enabling it to become
established in every suitable spot, where, being a perennial, it
persists for years if undisturbed. In studying this plant it is
well to bear in mind that we are dealing with a thoroughly
successful plant, and to try to trace the reasons for this success.

A well grown plant in flower should be dug up. It needs
care to obtain a complete specimen, for the root extends to a
considerable depth, and is easily broken across in removing
the plant. This consists (Plate) of a short, brown, tap-root
from which finer lateral branches extend into the surrounding
soil. At the upper end of the root we pass to the short, thick
stem, which bears a rosette of green foliage leaves. Sometimes
the shoot has branched, and several rosettes of leaves are related
to the one root. The shoots do not rise above the level of the
soil, being pulled down against this by the contraction of the
main root. The wrinkling of the surface of the upper part of
the root is an indication of this contraction having taken place.
The inflorescences, which are commonly but inaccurately known
as the " flowers " of the Dandelion, spring from the axils of the
leaves.

The stem is only indistinctly marked by the scars of the
foliage-leaves of former years. The present leaves arise close
together from a short region of the stem, and spread out on all
sides. Sometimes they are more or less pressed against the
surface of the ground. The summit of the shoot is a bud composed
of immature leaves. The foliage leaves consist of an expanded
whitish base, narrowing into a short leaf-stalk, which passes
as gradually into the leaf -blade. This has a well-marked midrib,
from which the thin flat blade extends on either side. Near
the tip the margin is entire, but lower down it is cut into lobes
by indentations which extend almost to the midrib. The lobes
are pointed, their points being directed backwards towards the
base of the leaf. The sloping margin of each tooth is cut into
smaller pointed projections.

SPRING FLOWERS 145

The stalked heads that are usually known as the " flowers "
of the Dandelion are really the inflorescences, each of which
bears a large number of small flowers. Each inflorescence or
flower-head stands in the axil of one of the leaves of the rosette.
Since the main shoot does not grow into an inflorescence, it con-
tinues to produce new rosettes of foliage-leaves year after year
as the older leaves decay.

The flower-head is borne on a cylindrical greenish stalk, which
is at first short and only reaches its full length shortly before
the flowers are ready to open. When the stalk is short it will
be found to be covered with long cottony hairs, which doubtless
assist in protecting it. The remains of these can be seen at
intervals on the fully grown stalk, being most numerous just
below the head where growth has been less rapid. The flower-
head is surrounded by a large number of narrow green leaves or
bracts, which at first fit closely together and completely enclose
the little flower buds within. When the head opens the outer
bracts bend back, but the inner longer ones stand up around
the flowers. The relative positions of the bracts and florets,
as the little flowers are called, will be best seen on splitting a
flower-head in half. The hollow stalk of the inflorescence will
be found to widen out into a hollow expansion which is slightly
concave on the upper surface. The bracts are borne around
the edge of this, while the little flowers are closely crowded
together in the centre.

The flowers can be readily pulled off singly, and their struc-
ture should be carefully made out with the assistance of the
pocket-lens. This will be most easily done if fresh inflores-
cences with expanded florets are taken on a fine sunny day.
All the florets in a flower-head are alike.

At the base of the floret is an elongated, oval, whitish swelling.
This is the ovary, which is here inferior, all the other parts of the
flower springing from above it. Immediately above the ovary
we come to a very short greenish stalk, narrower than the ovary
itself, and at the upper limit of this the structure which takes
the place of the calyx is borne. This is a circle of long, fine,
white hairs, which stand up around the lower part of the corolla.
The use of this peculiarly developed calyx will be seen when we

VOL. III. 10

146

THE BOOK OF NATURE STUDY

consider the fruit of the Dandelion. It may be noted, however,
that, since all the little flowers are protected by the bracts around
the inflorescence, there is no need for the calyx of each flower
protecting the parts within.

The corolla is composed of five petals united together to form
a tube, which continues on the side away from the centre of the
inflorescence as a long, flat, strap-shaped extension (Fig. 73). If
the edge of this is looked at with a lens it will be found to be
divided into five minute teeth. This is the
only indication in the mature flower of the
five petals, which are joined together to form
the corolla.

Considerable care and patience will be
needed to make out the other parts of the
flower. If a well opened floret be chosen
from near the outside of a fully expanded
head and examined with the lens, there will
be seen projecting from the tube of the
corolla a yellow column, and from the top
of this a more slender stalk divided above
into two lobes (Fig. 73, A). The yellow column
is composed of the anthers of the five stamens,
single floret; B, the These are joined edge to edge and form a
five stamens showing tube jf^ however, the lower parts of the

the free filaments and i i i r , i

the anthers united stamens are looked for, the five separate
edge to edge to form stalks will be seen. These bend from the
a tube, which is here bases of their respective anthers to the

shown slit open. . r r ., . , , ,, « • <

(After Warming.) inner surface of the tubular corolla to which
they are attached. The way in which the
stamens are joined will be understood from Fig. 73, B. The
thin structure projecting from the anther tube is the style,
dividing at the top into the two lobes of the stigma. With
a little care the tube formed by the anthers can be slit along
one side with the tip of a sharp knife, and the style pulled
away and traced down into the tube, where it springs from
the summit of the inferior ovary. The pistil is really composed
of two carpels, but the only indication of this is afforded by the
two lobes of the stigma, which correspond to their free tips. Within

FlG. 73. — Dandelion. A,

SPRING FLOWERS 147

the ovary, if it is carefully opened, a single ovule, attached to the
base of the little cavity, will be found.

The description above refers to a fully mature floret. In
order to understand the mode of pollination it is necessary to
follow the changes in the flower from its opening until it is fully
grown. If an inflorescence be selected in which some of the
florets in the centre are still unopened, the florets immediately
outside these will be a little older and have just opened, while the
outermost florets will be the oldest. In the florets which have
newly opened the yellow anther tube will be visible, but no trace
of the style or stigma. The stamens have shed their pollen into
the hollow cylinder formed by the anthers. As the style, ending
in the stigma, the two lobes of which have not yet separated,
grows in length it pushes its way up this cylinder and sweeps out
the pollen ; this accumulates as a little yellow mass at the summit
of the tube. When the stigma has reached the top of the anther
tube the pollen is all swept out, and as the growth of the style
continues the two lobes of the stigma separate and expose the
receptive inner surface, which has till now been safe from contact
with the pollen.

Flowers in the first or pollen-shedding stage, and the second
or pollen-receiving stage, occur in the same inflorescence. The
whole expanse of one to two hundred florets contained in the
inflorescence makes a conspicuous and brightly coloured object
in the sunshine. It is visited by many insects, by small flies
which come to eat the pollen, and by longer tongued insects in
search of the nectar secreted at the bottom of the corolla tube.
The insects coming in contact with florets in the first stage will
be dusted with pollen, and in passing from flower to flower may
deposit this on the open stigmas of older flowers in the same
or in another inflorescence.

Should the florets not be cross-pollinated in this way the lobes
of the stigma, as they continue to curve back, will bring the re-
ceptive surface in contact with some of the pollen still adhering
to the hairy outer surface of the style, and so the floret will in
any case be self -pollinated.

There are other complications in the reproduction of the
Dandelion into which we cannot enter here. A careful study of

148 THE BOOK OF NATURE STUDY

the construction of its flowers and of the way in which they are
suited to pollination by insects will prepare the student to under-
stand the pollination arrangements in other members of the
great family of plants to which the Dandelion belongs.

Practically every floret produces a fruit. The heads bearing
the ripe fruits are familiar to all children as " clocks/' After
flowering the head closes up while the fruits are developing, but
when the latter are ripe the bracts are bent back and the fruits
stand on the convex upper end of the inflorescence. Each fruit
has come from a single little flower. The corolla and stamens
of this have withered and fallen off, and the ovary has enlarged
into the fruit itself. The short stem-like region, which intervened
between the ovary and the hairy pappus, has lengthened and
carried the latter up on a long stalk. The hairs of the pappus
are bent back, and stand at right angles to this stalk, forming a
parachute-like expansion. The fruits are very easily detached
from the head, and are carried by the wind with the help of the
expanded pappus. When they settle down in a crevice of the
soil they will tend to remain owing to the presence of small up-
wardly directed teeth on the surface of the upper part of the
ovary.

The success of the Dandelion and of many of its relations,
such as the Groundsel and Thistles, depends largely on the
certainty of each flower producing a fruit, and on the excellent
adaptation these show for wind dispersal.

THE TULIP.

The many cultivated forms of the Tulip are for the most
part varieties of a wild species, Tulipa gesneriana, which was
introduced from the Levant. In Britain one species with yellow
flowers, Tulipa sylvestris, is found growing wild. Any of the
single varieties of cultivated Tulips will serve for study with the
help of the following description. The examination of the plant
may perhaps be best commenced at its flowering season in the
spring, when it will have the appearance represented in the figure
(Frontispiece), but its life-history should be carefully followed
through the year. A plant in flower will be found to consist of

SPRING FLOWERS 149

the bulb, from which roots extend down into the soil, while the
unbranched stem grows upwards, bears a few foliage-leaves, and
ends in the single large flower.

Such a plant has been grown from a bulb, which is usually
planted in the autumn to flower in the following spring. We
may commence by considering the construction of such a bulb,
and follow its development into the full-grown plant. A bulb
is a specially modified shoot, and consists of a small stem bearing
a number of leaves. This is best seen if a bulb is split in half,
when the small flattened stem will be found to bear a series of
closely crowded, white, fleshy scales. These overlap one another and
fit closely together. The outermost leaf is developed as a brown
protective scale, completely enveloping the rest of the bulb. The
inner surface of this thin scale is clothed with fine hairs, all pointing
towards the tip of the bulb. The thick, white scale-leaves within
contain a store of reserve food material, which was manufactured
by the leaves of the parent plant in the preceding season. In
the centre of the bulb is a yellowish shoot, a continuation of the
stem which bears the scales of the bulb. This shoot already
consists of the foliage-leaves which will expand next season.
These closely surround the single flower, with which the stem
ends. In the flower all the parts are already developed and,
like the leaves, only need to grow to their full size.

When placed in the soil the short stem produces numerous
roots, which spring from the region between the protecting scale
and the lowest storage scale and so form a fringe around the
base of the bulb. The shoot in the centre of the bulb commences
to grow at the expense of the material stored up in the scales of
the bulb, and appears above ground as a cylindrical stem bearing
three or four foliage-leaves. Each of these consists of a broad
sheathing base, which extends completely round the stem ; this
passes without any leaf -stalk into the leaf -blade, which has a
simple oval outline. This leaf -blade is rather thick and fleshy,
and the veins in it can be seen to run parallel to one another.
No buds are evident in the axils of the foliage-leaves, and the
shoot remains unbranched. A longer or shorter region of bare
stem, the flower-stalk, separates the highest foliage-leaf from the
flower.

150 THE BOOK OF NATURE STUDY

When the bulb of a plant from which the shoot has grown
up is compared with the bulb at the time of planting, great
changes are apparent. It is rooted in the soil and partly by the
escape of the roots, partly by the increase in size of the enclosed
parts, the brown protective scale is more or less ruptured. The
storage scales within, which were plump and white, are now
shrivelled and drying up. The food material stored in them
has been removed and utilised in the growth of the shoot and
flower. The use of these storage scales is over, and they will
now gradually decay.

The development of the bulb or bulbs, which will remain in
the ground after the rest of the plant has decayed, is already
far advanced. These new bulbs arise from buds situated in the
axils of the inner storage scales of the parent bulb. The bud
enlarges and develops into a bulb like that with which we started.
As the new bulbs grow they force apart and rupture the withered
scales of the old bulb. On dissecting one of the developing bulbs
the protective outer scale, which is still soft, and the series of
storage scales can be distinguished. In some cases the protective
scale will be found to bear a small green leaf-blade, and this shows
that the overlapping bulb-scales correspond to the transformed
bases of leaves which completely surround the stem. The food
material, which is being stored in the growing bulb or bulbs, is
formed by the activity of the green foliage-leaves exposed to the
light, and is conveyed downwards through the stem into the
bulb-scales, where it accumulates as starch. Since the growth of
the shoot took place at the expense of the material stored in the
old bulb, practically the whole of the substance manufactured
by the foliage can be saved and stored up in new bulbs. The
Tulip, like many plants which flower early in the season, depends
for its growth on material manufactured in the preceding season.

In some cases only a single new bulb is formed, but usually,
under favourable conditions of nourishment, two or three bulbs
of considerable size develop, and sometimes other smaller ones.
When the old bulb decays these become isolated from one another
in the soil, and so form independent plants in the next season.
The formation of the new bulbs thus serves to increase the number
of individuals, and is a most efficient means of vegetative repro-

SPRING FLOWERS 151

duction. In multiplying the number of individuals of any
particular variety of Tulip, horticulturists rely entirely on this
vegetative mode of reproduction. Each new individual produced
in this way represents a detached lateral bud of the parent.

The flower, with all its parts developed, has been seen to be
already present in the bulb at the time of planting. The outer-
most leaves of the flower are at first closely folded over the more
delicate inner structures, and are firm and green. As the flower
becomes ready to open the outer leaves become brightly coloured,
and there is often little difference to be made out between the
two series of floral leaves, both being delicate in texture and
coloured. Each flower has thus two whorls of three perianth
leaves, between which no distinction of calyx and corolla can be
made. The leaves of the inner whorl alternate with the three
outer perianth leaves. The other parts of the flower follow
in regularly alternating whorls of three. There are two whorls
of stamens and three carpels united together to form the pistil.
The latter stands in the centre of the flower and occupies the
summit of the floral receptacle.

The perianth leaves are brightly coloured, red and yellow in
various shades and combinations being the prevailing colours.
White varieties are also common. The stamens have short,
thick stalks and large erect anthers, which shed their pollen in-
wards towards the centre of the flower. The pollen is somewhat
sticky, and does not fall out of the open anthers. Each stamen
is joined to the base of the perianth segment opposite which it
stands, and when this is removed the stamen comes also.

The pistil is a green three-sided column surmounted by three
diverging, rough, yellowish surfaces. The lower portion is the
ovary, the three-lobed summit the stigma. The number of
lobes of the latter indicates that the pistil is composed of
three carpels united together, and further evidence of this is
obtained by cutting the ovary across. On examining the cut
surface with a lens three cavities will be seen, separated by parti-
tions that run inwards from the flat sides. The three projecting
angles of the ovary correspond to the midribs of the three carpels.
The ovules are borne on the margins of the carpels, which
meet in the centre. The two rows of ovules present in each

152 THE BOOK OF NATURE STUDY

chamber appear to be borne on a central column traversing the
pistil.

No nectar is secreted in the flower of the Tulip, which is, how-
ever, conspicuous, and is visited by insects. These feed on the
pollen, and in doing so may carry some of it from the stamens of
one flower to the stigma of another, and so effect cross-pollina-
tion. After being pollinated the pistil develops into a capsule
containing numerous seeds, but in cultivation the Tulip is
rarely reproduced in this way except for the production of new
varieties.

The germination of the seeds is, however, very interesting.
This takes place at no great distance below the surface of the soil,
and not at the depth usually occupied by the bulb. The necessary
depth is reached by the formation of what are known as "droppers.'*
The seedling sends a root into the soil, and the cotyledon appears
above ground, its tip remaining for a time in the seed-coat to
absorb the nourishment stored there. The growing point of the
shoot becomes carried down in a tubular prolongation of the
sheathing base of the cotyledon. By means of this " dropper "
the bud, which forms the small bulb of the plant in its second
year, is placed deeper than the original seedling. This may
happen for several years. Ultimately the bulb becomes strong
enough to produce a flower. The first flowers produced are as a
rule self-coloured, and after two or three years or longer " break "
into coloured blossoms. It is not possible to enter farther into
the production of new varieties of the Tulip, which once established
usually come true when reproduced vegetatively. Enough has
been said to indicate the interest attaching to the whole life-
history as well as to the regular annual development from the
bulb, which can be more easily followed.

THE FIELD WOODRUSH (Luzula campestris, Willd.).

More or less extensive patches of this little plant may be
found in almost any piece of grassy ground. Though the indi-
vidual plants are inconspicuous, the colonies formed by them
can be readily distinguished when in flower even from a distance.
The plant is a perennial, and not only appears year after year in

SPRING FLOWERS 153

the same spot, but spreads on all sides in a most successful fashion.
In spite of its grass-like appearance the Woodrush is not a true
Grass, and will be found to resemble in the construction of the
flower such plants as the Tulip and Lily rather than the
Grasses.

The firm underground stem, from which the leafy shoots spring,
is covered with the brown and withered bases of the leaves of
former seasons. Fine roots also spring from it, and grow down
into the soil. When the end of a shoot grows on into an inflores-
cence, the further growth of the plant continues from lateral buds.
The leaves at the base of such a shoot are small and scale-like.
Above them come the long, narrow, grass-like foliage-leaves.
These have a long sheathing base which surrounds the stem, and
a narrow flat leaf -blade with parallel veins. Fine silky hairs are
conspicuous at the margin of the blade, and where the latter joins
the sheath. The stalk of the inflorescence has elongated inter-
nodes, and the leaves borne at the nodes are smaller than the
foliage-leaves. Still smaller leaves or bracts are present below
the branches of the inflorescence, while the closely crowded
flowers stand in the axils of scale-leaves.

The appearance of the inflorescence differs according to the
stage of opening which the flowers composing it have reached. In
the first stage the flowers are still closed as in the bud, the brown
perianth leaves not having expanded. From the tip of the closed
perianth of each flower the style projects just far enough to allow
the three whitish stigmas to expand. These are of relatively large
size, and when looked at with a lens show a rough or feathery
surface. In flowers at this stage the stigma is ready to receive
pollen, which evidently cannot come from the same flower/since
this has not opened to expose the stamens. It is even unlikely
that the pollen will come from a flower on the same inflorescence,
since all the flowers are often at the same stage. If the flower be
watched, or if a series of inflorescences in successively later stages
be collected and compared, the stigmas will be found to wither
and turn brown before the perianth expands. When this takes
place the stamens are ready to open, and the flower is in the second
stage.

The structure of the flower will be most readily made out from

154 THE BOOK OF NATURE STUDY

such a fully opened specimen (Fig. 74). The perianth will be
found to consist of six small brown pointed leaves, which form two
series of three, the inner whorl alternating with the outer whorl.
The perianth leaves are very unlike the delicate coloured petals
of most other flowers. They are dry and scale-like, with a, thicker
brown midrib and a thin greenish or brown margin. While they
protect the parts within in the bud, they do not, even when fully
expanded, render the flower conspicuous, as do the petals of many
equally small flowers.

Within the perianth come six stamens, also in two whorls of
three. Each stamen has a short stalk, which continues into a
relatively large anther. In the unopened anthers the four pollen-
sacs can be distinguished as four
ridges, but on the opening of the
anther the loose powdery pollen is
exposed. In the centre of the
flower is the pistil, consisting of the
small green triangular ovary, a
slender style, and the three long
branches of the stigma. The pistil
is composed of three carpels, as is

FIG. 74-Fiower of the Field Wood- indicated by the number of stig-
rush fully opened. (After Baiiion.) matic lobes, which are by now

withered and no longer capable of

receiving pollen. The ovary contains three ovules in its single
cavity, and at this stage has commenced to develop into the
fruit.

The features of this flower can only be understood in the light
of the method of pollination. The flowers are inconspicuous and
secrete no nectar. They thus offer no inducements to insects to
visit them. They are, in fact, pollinated by the help of the wind,
and not by insects, and all the characters in which they differ
from brightly coloured and conspicuous flowers fit them for this.
The pollen, in contrast to that of most of the other plants described
here, is loose and powdery, and the stamens are freely exposed
in the open flower. If on a fine warm day one of the inflorescences
be gently tapped or shaken, a cloud of dusty pollen will be found
to escape into the air. Evidently thousands of pollen grains will

SPRING FLOWERS 155

be floating in the air around a colony of the plants. Some of these
may come in contact with the stigmas of other flowers, and we can
now appreciate the use of the large rough stigmas, which are well
fitted to catch and retain the pollen grains borne against them.

The likelihood of pollination being effected in this way is in-
creased by the social mode of growth of the Woodrush, which
leads to many inflorescences being present within a limited radius.
Some of these inflorescences will bear flowers in the earlier, some
in the later stage. This is important, since, as has been seen, the
stigma alone is exposed in the earlier stage, and withers before the
stamens of the same flower shed their pollen. Self-pollination is
thus impossible, and pollen must always be brought from a dis-
tinct flower in the second stage, and probably from another plant.

The Woodrush is an instructive example of a wind-pollinated
flower, and its features should be contrasted with those of the
insect-pollinated Tulip, in which the general
plan of construction of the flower is almost
the same. The Woodrush is peculiar both
in the absence of conspicuousness and other
attractions, which are present in order to
attract insect visitors in other flowers, and FlG- 75-— Fruit of the
in such features as the large stigma and the
powdery pollen which directly assist in wind- the seeds.
pollination. These general characters are
found in the flowers of many other wind-pollinated plants, and
associated with them we often find arrangements to prevent self-
pollination. This is sometimes effected by the stamens being in
one kind of flower and the pistil in another, but in the Woodrush the
flower contains both stamens and pistil. We have seen, however,
that the sharply marked stages of flowering result in each flower
being at first in a pollen-receiving and later in a pollen-shedding
condition. It is instructive to compare, in this respect, the Wood-
rush with the Ribwort Plantain, which is described below.

That the mode of pollination is thoroughly effective is shown
by the way in which practically every flower gives rise to a fruit.
This is formed from the ovary, and when ripe its dry wall splits
into three valves which bend apart and allow the three, relatively
large, seeds to escape (Fig. 75).

156 THE BOOK OF NATURE STUDY

THE DAFFODIL (Narcissus pseudo-narcissus, L.).

The Daffodil or Lent Lily is found growing wild in many
parts of England, and is cultivated everywhere for the sake of
its flowers. Whether it is a truly native plant or one of those
we owe to the Roman occupation of Britain is uncertain. In
any case the plant grows successfully in pastures, copses, and
by the banks of streams, sending up its long green leaves and
single flower each spring, while the bulb is hidden and protected
beneath the ground. The appearance of the plant is well shown
in the photographs in the accompanying Plate.

The general course of the annual history of the Daffodil re-
sembles that of the Tulip and many other bulbous plants. The
bulb, hidden in the ground, already contains in the autumn
the leaves and flower, which will appear and grow to their full
size in the spring. The foliage-leaves remain exposed to the
light and air throughout the early summer, after the flower
has given rise to a fruit or has withered, and then in turn die
down. The food material manufactured by the foliage-leaves
is carried down and stored in their basal parts, and in the bases
of some outer leaves which do not bear leaf -blades. These
leaf -bases form the bulb of the next season. It is at the expense
of the material stored in this bulb that the growth of the shoot
and flower of the following spring will take place.

The bulb of the Daffodil is best examined in a specimen in
which the shoot is commencing to grow in the winter or in a
flowering specimen in spring. A number of long, unbranched,
white roots will be found, growing down from the base of the
stem. The construction of the bulb will be best appreciated if
two specimens are taken, one of which is split in half lengthways
while the other is cut across with a sharp knife. On the outside
are some thin withered brownish scales ; these are the remains
of the leaf -bases of the season before last. Within these come
the sheathing white bases of the leaves of last season ; these
constitute the bulb-scales. They are arranged in two rows,
each leaf standing a little higher on the short stem, and opposite
to the preceding one. The outermost three of these scales were
the bases of scale-leaves, while the inner two or three belonged

SPRING FLOWERS 157

to last year's green foliage-leaves. In the axils of one or two
of the outer scales buds may be developing, while the base of last
year's flower stalk, which, like the scales, has served for storage
of food material, stands in the axil of the uppermost scale.
Within these scales, which constitute the bulb formed last year,
the shoot continues for the present season. The short region of
stem bears similarly three scale-leaves and a few foliage-leaves.
In the axil of the uppermost of these is the single flower, while
the tip of the shoot is commencing to grow into the shoot of
next year. The arrangement of the leaves will be understood
from the diagram in Fig. 76.

The bulb of the Narcissus thus differs from that of the Tulip
in that the flower is lateral and does not terminate the shoot.
This is therefore capable of giving rise to the shoot of the next
season. Another difference lies in the fact that the bulb-scales are
here the thickened bases of the leaves of the preceding season.
While the main shoot continues, if undisturbed, to grow on
year after year, the lateral shoots developed from the bulbs
referred to above give rise to small bulbs. As these become
free from the main shoot by the decay of its older scales they
serve as a means of multiplying the plant vegetatively. Thus
from a single bulb a small colony of plants may be derived by
vegetative reproduction in the course of a few years.

The foliage-leaves have, above the sheathing and thickened
leaf -base, a long narrow leaf -blade of a bluish-green tint. The
midrib is convex below, while the upper surface is concave.
The veins, as in the Tulip, run parallel in the blade, and do not
form a network.

The flower, the position of which in the axil of the uppermost
foliage-leaf has already been noted, is borne on a long, ribbed,
green stalk. A short distance beneath the flower itself is a
brownish membranous sheath, which serves to enclose and protect
the flower when in bud, and later remains around the base of
the flower. This sheath is made up of two bracts, borne on
the stalk, joined together. Above the sheath is a very short
region of flower-stalk continuing into the flower. This region
of the flower-stalk is straight in the bud and until shortly before
the flower opens. It then undergoes a bend or curvature, which

158

THE BOOK OF NATURE STUDY

is always so directed that the flower faces the strongest source
of light. In the Daffodil there is always a single flower, but
in related species of Narcissus additional flowers develop in the
axils of the bracts which form the sheath.

At the base of the flower is the inferior ovary, which appears

FIG. 76. — Daffodil. To the left a diagram of the arrangement of the leaves on the stem
of a flowering specimen. To the right a flower cut in half. (After Church.)

SPRING FLOWERS 159

as an enlargement of the flower stalk. It is somewhat triangular
when cut across, and shows three cavities. In each cavity, spring-
ing from the inner angle, are two rows of ovules. All the other
parts of the flower appear to spring from the summit of the
inferior ovary. The perianth is composed of two whorls of
three leaves each ; there are two whorls of three stamens, and
in the centre is the style, ending in a three-lobed stigma, which
indicates that the pistil is composed of three carpels. The
modifications due to the unequal growth and the union of the
parts of the flower will be best understood from Fig. 76, which
represents a flower cut in half.

In the centre of the flower is the cylindrical style, which
springs from the summit of the ovary and is formed of the upper
portions of the three united carpels. It bears the three lobes
of the stigma at its upper end. The other parts of the flower
form by their union a tubular or bell-shaped structure of
rather complex construction. Above the ovary comes a short,
tubular region. Just where this widens out into the next region,
which extends to the place of divergence of the free parts of the
perianth leaves, the six stamens are borne on the inner surface
of the tube. Three of the stamens are inserted at a lower
level than the other three. The stamens have short yellow
stalks, and the large anthers stand close around the style. The
second or middle region of the perianth tube is wider than the
lowest region. At its upper limit the two series of free pointed
perianth segments diverge almost at right angles to the tube.
The outer three segments are broader than the inner three.

Above the divergence of the perianth segments the tube
of the flower is continued as a cylindrical tube of a deeper yellow
colour. The inner surface of this is wrinkled, and the edge is
slightly frilled. This structure, which is peculiar to the Daffodil
and its near relations, is called the corona. In the Daffodil
itself it makes up the largest part of the tube. The corona is
a new formation in the flower and appears late in its develop-
ment, after all the other parts have been formed. It extends
forward beyond the style and stamens, which are completely
protected by it.

As compared with the Tulip or the Woodrush, we find the

i6o

THE BOOK OF NATURE STUDY

flower of the Daffodil to have the same number of parts but to
have an inferior ovary (cf. p. 106), and to have the other parts
peculiarly developed and united. The use of the arrangement
of the parts will be appreciated when the method of pollination
is considered. This is effected by insects, which visit the flower
for pollen or nectar. The nectar is secreted by three slit-like
glands which extend for some distance into the three partitions
of the ovary, and it accumulates in the basal region of the tube.
It is thus a long way from the opening of the corona. In the
middle of this the stigma stands ready to receive pollen, while

the stamens around the style a
little farther back have opened
and are shedding their sticky
yellow pollen. An insect such
as the humble-bee coming in
search of nectar creeps into the
tube of the corona, rubbing its
back against the stigma and then
against the stamens. It will thus
be able to reach the nectar. On
going to another flower the pollen
on its back will be brought in
contact with the stigma.

It is interesting to compare
the flower of the Pheasant's Eye
Narcissus (Narcissus poeticus) with
that of the Daffodil as regards

its construction and mode of pollination. The parts of the
flower (Fig. 77) are as in the Daffodil, but the lowest region of
the tube is much longer and narrower, while the corona is short
and wide. The margin of the corona is reddish, while the
perianth segments diverge at right angles to the tube. The
flower has thus the appearance of a white target with a coloured
centre. It is probably pollinated by moths, and not by bees creep-
ing into the tube. These will be attracted as they fly in the
dusk, and with their long tongues will be able to reach the
nectar. In doing this they may convey pollen from the stamens
of one flower to the stigma of the next. Self-pollination may,

FlG. 77.— Flower of Pheasant's Eye Nar-
cissus cut in half. (After Baillon.)

Photo by Henry Irving, Horley

DAFFODIL (Narcissus Psendo- Narcissus, L.)

SPRING FLOWERS 161

however, be effected here even more readily than in the case of
the Daffodil. The interest of the comparison of the two flowers
lies in the fact that with very similar structure one is adapted
to pollination by moths, and the other to pollination by large-
bodied bees. Their study from this point of view is most in-
structive.

When a flower is fertilised the corolla withers and falls off,
leaving the ovary, which enlarges and becomes the fruit. This
is a dry capsule with three chambers, in each of which are two
rows of smooth, black seeds. When ripe the fruit opens by
splitting into three valves, with the seeds attached to their inner
faces. The seeds fall off, but show no special arrangements for
conveyance to a distance.

The Daffodil is well suited for thorough study, since it can
readily be grown from the bulbs either in bowls or pots or in the
garden, and the whole course of its annual history followed.
One plant thoroughly studied in this way will be found of more
value in awakening an interest in nature knowledge than a
number hastily looked at.

THE BLUE GARDEN CROCUS (Crocus vernus, AIL).

The structure of the Crocus may be studied either in the
Blue Garden Crocus (Crocus vernus) or the Yellow Garden Crocus
(C. aureus), both of which are grown in every garden for the sake
of their flowers. These appear in February and March. If plants
of the Saffron Crocus (C. sativus) are cultivated in the neighbour-
hood its flowers may be studied in the autumn months. This
plant is cultivated for the sake of saffron, which is obtained from
the lobes of the stigmas, and was formerly grown on a large scale
at Saffron Walden. The mode of growth of the Crocus is shown
by all these plants, which differ in such details as number of
leaves, colour of flowers, etc., but are constructed on the same plan.
The description will be based especially upon the Blue Garden
Crocus, which is grown in many varieties, some of which have the
perianth violet-blue with deeper veins, others have only the veins
coloured, while other varieties are white.

The underground part of the Crocus, which is situated some

VOL. III. — II

162

THE BOOK OF NATURE STUDY

four or five inches below the level of the soil, might at first sight
be mistaken for a bulb. It is really, as is best seen on splitting
it lengthways in half (Figs. 78, 79), a flat cake-like stem, bearing
the remains of a number of thin brown scale-leaves. The food
material is here stored in the stem, not in the thickened scale-
leaves as in a bulb. The swollen underground stem is called a

corm. The summit of the corm bears
one or several buds, which stand in the
axils of leaves borne upon it. Each of
these buds grows into a flowering shoot,
the growth taking place in the autumn
and being completed in the spring, when
the leaves and flower appear above
ground.

The plant is fastened in the soil by
numerous unbranched roots, which
spring from the base of the corm,
and serve to obtain the water and
food salts required for growth. The
material for the growth of the shoot
and flower is obtained from that stored
up in the corm, which has served its
use as soon as the flowering is over
and decays later in the year. A new
corm is formed by the enlargement
of the base of the flowering shoot,
and this gets stored with the material
manufactured by the foliage-leaves, and
remains to carry on the growth of the plant next season.

When more than one shoot is present as many new corms
will form (Fig. 78), and then on the decay of the old corm will
become isolated from one another. In this way the plant is
multiplied vegetatively, and does not merely persist year after
year.

The shoot of the Crocus consists of a short stem bearing a
number of closely crowded, thin, scale-leaves which enclose the
parts within. These scales persist on the base of the stem when
it enlarges to form the new corm. Above them come three to

FlG. 78.— Yellow Garden Crocus.
Corm, with the flowering
shoots beginning to grow,
cut in half. (After Baillon.)

SPRING FLOWERS

163

five long, narrow foliage-leaves. These are dark green with a
whitish stripe along the midrib. Above the foliage-leaves the
shoot continues as a long slender flower stalk. This bears two
scale-like sheaths, one near the base and
the other at the upper end just beneath
the ovary of the flower. This long inter-
node of the flower-stalk carries the base of
the flower nearer to the surface of the soil,
but it is still situated some distance below
the level of the latter. Usually the shoot
only bears the single flower, but some-
times a second flower is produced in the
axil of the scale at the base of the flower-
stalk of the first flower.

The general relations of the parts of
a plant in flower are shown in Fig. 79,
which represents a plant of the Saffron
Crocus cut accurately in half. The old
corm rooted in the soil, the new corm
in process of formation, the scale-leaves
and the foliage-leaves are all seen. The
long flower stalk is also clearly visible
within the leaves of the shoot.

The flower is also shown cut in half
in this figure. The ovary is inferior, and
comes at the end of the flower stalk. It
consists of three chambers, in each of
which are two rows of ovules. Above
the ovary comes a long slender tubular
region. This extends to well above the
level of the soil, and must not be mis-
taken for the flower-stalk. This tube
widens out above, and divides into the
six large coloured leaves of the perianth.
These are in two whorls of three, an outer
and an inner, and form the expanded, bell-shaped, upper region
of the flower.

Just where the narrow tube widens into this region three

FIG. 79.— Plant of the Saffron
Crocus in flower cut
through longitudinally.
(After Baillon.)

164 THE BOOK OF NATURE STUDY

stamens are attached to it opposite to the three outer perianth
leaves. These have short, rather stout stalks, and large anthers,
which open outwards to shed the abundant yellow pollen. The
slender style springs from the summit of the ovary, and extends
upwards through the narrow part of the tube and between the
stamens for some distance above the latter. It then divides
into the three orange-coloured stigmas, each of which is rolled
inwards to form a tube, while the edge is fringed.

It is further to be noted, in considering the structure of this
flower, that nectar is secreted by three glands which extend as
slits into the partitions of the ovary. The nectar accumulates in
the narrow region of the tube, which is usually completely filled by
it. A fringe of hairs at the level of the attachment of the stamens
serves to cover in the nectar.

The flowers are very sensitive to changes of temperature,
warmth causing the perianth leaves to bend apart and disclose
the stigma and stamens, while the flower remains closed in
cold and damp weather. They are visited by numbers of the
insects found in early spring, especially by bees which may
come in search of either nectar or pollen. Since the stigma
projects well beyond the anthers, an insect already dusted with
pollen from another flower will be likely to rub some of this
on the stigma as it enters. Whether it feeds on the pollen or
creeps past the stamens to get at the nectar, the insect is sure
to get covered with pollen. The warmth which causes the
flowers to open will be likely to induce insects to visit flowers in
search of food.

When the flower is fertilised the perianth droops and withers
and ultimately falls off. The ovary develops into the fruit, which
is raised to the surface of the soil by further growth of the flower-
stalk. Later, as the fruit ripens it is raised still higher, quite clear
of the soil. The fruit ripens about June and is a somewhat three-
angled capsule, which opens by splitting into three valves to
liberate the numerous rather large seeds.

The foliage dies down shortly after this, and the later stages
of the development of the new corm, and the preparation of the
shoots for next season, are carried out below the surface of the soil,
all trace of the plant above ground having disappeared. It will be

SPRING FLOWERS 165

clear to the reader that the proper study of this plant requires
the cultivation of specimens throughout the year, and their
examination at various seasons. If this is done systematically,
and records and drawings kept, the description given above,
which only deals with the main points, may be greatly amplified,
and material for an interesting course of Nature Study lessons
accumulated.

CHAPTER VII

EARLY SUMMER FLOWERS

The Wild Strawberry— The Bird's-Foot Trefoil— The Daisy and the Feverfew
— The Perennial Rye-Grass — The Garden Sage — The Cuckoo Flower and
the Red Campion — The White Meadow Saxifrage and the London Pride —
Herb-Robert— The Spotted Orchis— The Greater Plantain and the Ribwort
Plantain — The Charlock — The Shepherd's Purse — The Common Avens—
— The Bugle — The Yellow Iris — The Germander Speedwell

THE WILD STRAWBERRY (Fragaria vesca, L.).

THE structure and the mode of reproduction of the Straw-
berry may be studied in any of the numerous species or varieties
which are in cultivation, but perhaps better in the common Wild
Strawberry of our woods and hedge-banks. The conspicuous
white flowers of this plant are to be seen everywhere in April
and May, while the fruits, which ripen in succession as the flowers
fade, have the same construction as those of the cultivated
Strawberry, though they are much smaller.

If a plant in flower be dug up and examined it will be found to
possess a firm, woody, underground stem, covered with brown
scales. This stem may be simple or branched. From it spring
roots which grow down into the soil. At the end of the stem
we find a rosette of foliage leaves and a single inflorescence.
The inflorescence does not spring, as might perhaps have been
expected, from the centre of the group of leaves, but stands to
one side of this. It does not, in fact, belong to the same branch
as that bearing the foliage leaves, but was formed in the centre
of the rosette of leaves of the preceding season. These have now
withered, and the inflorescence marks the end of the shoot on
which they were borne. A bud in the axil of one of the leaves
of last year has continued the growth of the plant in the present

166

EARLY SUMMER FLOWERS 167

season, and has produced the rosette of leaves we see. This
shoot will end in the inflorescence of next year, which will be
already formed before autumn although it will only grow to its
full size after the leaves have withered and decayed. The under-
ground stem of the Wild Strawberry is thus really made up of a
succession of lateral shoots, and the mode of growth of the plant
may be instructively compared with that of the Primrose.

The foliage-leaves are attached to the stem by a wide, sheath-
ing base, to either side of which is joined a pointed, membranous
stipule. These stipules never become leaf -like in appearance, but
turn brown and, together with the leaf bases, remain after the
leaf has fallen. It is the persistent stipules of the leaves of former
years that give the scaly covering to the underground stem.
Above the leaf-base comes a long and almost cylindrical leaf-stalk,
which is often reddish and is covered with soft whitish hairs
standing out from the surface. The leaf-stalk continues into the
midrib of a leaflet, and to either side below this is a lateral leaflet.
The leaf-blade is thus branched, consisting of three oval green
leaflets with toothed edges.

As usual a bud is formed in the axil of each leaf. Those in the
axils of some of the lower leaves straightway develop, not into
leafy branches but into special shoots which are familiar as the
" runners " of the Strawberry. The runner has greatly extended
internodes, which are more or less red in colour and are hairy. It
bears reduced scale-leaves at the nodes. Usually the bud in the
axil of the first scale-leaf does not develop, but that in the axil of
the second leaf grows into a leafy shoot, while from the node
and the base of the shoot roots spring which attach the latter
to the soil and ensure a direct supply of water and food-salts.
The runner may continue its growth and start new shoots similar
to the first. Owing to the length of the thin regions of the runner
between them and the parent plant the new shoots are rooted
at a distance from the latter and from one another. When
they become separated from the parent by the decay of the
runner they are already fixed in the soil, and established as
independent plants. A little study of the growth of a strong
Wild Strawberry plant on a bank which is not too thickly popul-
ated by other plants will show what an efficient method of

i68

THE BOOK OF NATURE STUDY

vegetative propagation the plant has in these specially modified
branches.

The origin of the inflorescence and the explanation of its
apparently lateral position has been already considered above.
It is an erect cylindrical, hairy stem, bearing small and reduced
leaves. The internodes are long. The leaf borne at the first node
has the form of a small foliage-leaf, while that at the second node
consists of the leaf-base with the stipules and a single small green
leaflet. The main stem of the inflorescence continues above this
second leaf, and ends in the flower which is the first to open.
Branches are, however, formed in the axils of both the leaves
and end in flowers, while further branching proceeds from the
axils of the reduced leaves they in turn bear.

Each flower (Fig. 80) has a calyx of five pointed sepals,

between and below
which are five
smaller green
leaves. These are
not a second series
cf sepals, but are
probably derived
from the stipules
belonging to the
five sepals. Since we might have expected to find a stipule to
either side of each sepal instead of one pointed leaf between
every two sepals, this explanation is not quite clear. The
fact that flowers are often found in which a more or less com-
plete division into two affects one or more of the outer segments
supports the suggestion that each of them corresponds to two
stipules belonging to adjacent sepals fused together. We shall
meet with a similar state of affairs in the Common Avens, which
is a not very distant relation of the Wild Strawberry.

The five white petals, which form the conspicuous corolla,
alternate with the sepals. They widen out rapidly from the
narrow base by which they are attached to the receptacle. The
petals, unlike the other parts of the flower, are very readily shed,
so that uninjured and fresh flowers should be chosen for study.
Within the corolla come the numerous stamens, the yellow anthers

FlG. 80. — Wild Strawberry. A, entire flower ; B, flower
cut in half. (After Baillon.)

Photo h' Henry Innng% Hortey.

WILD STRAWBERRY (Fragaria vesca, L.)

EARLY SUMMER FLOWERS 169

of which contribute to the colour of the flower, while in the centre
we find the hemispherical group of carpels. The carpels, like
those of the Buttercup, are quite separate from one another.
They are inserted on the globular end of the receptacle, and can be
removed singly from this. If this is done and a carpel is examined
with the lens, the small oval ovary will be seen. Springing not
from the summit but from the side of this is the slender style
which ends in the small stigma. The ovary contains a single
ovule.

If another flower is cut in half with a sharp knife (Fig. 80, B)
the sepals, petals, stamens, and carpels will be seen in their relative
positions on the receptacle of the flower. In this a difference
will be found from the Buttercup, with the flower of which that
of the Strawberry may in many respects be compared. In the
Strawberry the receptacle is widened just below the hemispherical
end which bears the carpels, and the sepals, petals, and stamens
all stand on this expansion.

The flowers of the Wild Strawberry, though not of large size, are
conspicuous by reason of the expanded white corolla and the
yellow centre formed by the stamens and carpels. They are
visited by flies and bees in search of the nectar that is secreted by
a region of the receptacle between the lowest carpels and the
innermost stamens. The shallow, expanded shape of the flower
allows the honey to be obtained by quite short-tongued insects.
These alight on the petals, and on bending their heads inwards
to reach the nectary will bring them in contact with the pollen
shed from the open anthers and with the stigmas. On an insect,
thus dusted with pollen, visiting a second flower it may carry
pollen to the stigmas of the latter and so cross-pollinate it. This
is a more likely result than self-pollination, for the stigmas ripen
before the pollen of the flower is shed and are usually pollinated
or have ceased to be receptive before the anthers open.

The fruit (Fig. 81) develops from the flower as a result of
pollination. The petals fall off early, but the calyx and the
withered remains of the stamens can be found at the base even
of the ripe fruit. The fruit itself is almost entirely developed
from the receptacle upon which the carpels were closely crowded.
This enlarges and ultimately becomes succulent, while the colour

170 THE BOOK OF NATURE STUDY

changes from green to yellowish white and then to red. As the
receptacle increases in size the carpels become more separated
from one another, and the true fruitlets, which are the result of
the further development of the carpels, are distributed over the
surface of the succulent receptacle. Each
fruitlet is seated in a small depression of the
latter, and consists of a firm yellow coat de-
veloped from the wall of the ovary and the
single seed protected by this. The fruitlets
do not fall off, but should an animal eat
the succulent fruit their hard wall will pro-
tect the seeds against the action of the digestive
FIG. 81.— Fruit of the juices. The structure of the strawberry, like
that of other succulent fruits, is to be looked
at in the light of this.
Both in the wild state and under cultivation the increase in
number of individuals of the Strawberry plants is mainly effected
by means of the runners. The spread of the plant to a distant
spot must, however, be by seed, and in cultivation seedlings are
raised in the search for new varieties.

THE BIRD'S-FOOT TREFOIL (Lotus corniculatus, L.).

The Common Bird's-Foot Trefoil is to be found in exposed
and sunny grassy situations, where it forms extended patches
conspicuous in May and June on account of the golden yellow
flowers. The Greater Bird's-Foot Trefoil (Lotus uliginosus, Schk.)
(Plate), while differing in some minor points, will serve equally
for study. These plants get their name from the groups of pods
which, borne on the slender stalk of the inflorescence, have some
resemblance to the claw of a bird.

To understand the mode of growth of the plant, specimens
should be carefully dug up, when the student will be surprised
to find that what appeared to be a considerable colony of the
plant is really a group of radiating branches attached to the
one root. This is a long and stout tap-root, from which finer
branches pass off into the soil around. On some of these branches
little swellings, called root - tubercles, will be found (Plate).

EARLY SUMMER FLOWERS 171

These tubercles on the roots of this plant and its relatives are
inhabited by Bacteria, which assist the plant to obtain the
nitrogen it requires as food. At the upper end of the root we
find a number of short, stout branches, from which thinner pro-
strate shoots in turn arise. It is the latter only that are obtained
when a plant is pulled and not dug up, and, since they extend
horizontally for some distance before they appear above the
soil, it is easy to be misled into thinking that the whole plant
has been obtained.

The underground parts of these shoots are whitish, and bear
only small scale leaves at the nodes. On passing farther up
the shoot the leaves gradually increase in size until the ordinary
foliage-leaves are reached. The foliage-shoots are more or less
erect. On them the leaves, which are exposed to the light, are
larger. The stem is green, sometimes with a more or less intense
red tint on the side exposed to the light. The terminal bud
continues to grow and unfold new leaves, while in the axils of
the uppermost foliage leaves the inflorescences occur as lateral
branches.

The foliage leaves are pinnate and have no true stalks. The
lowest pair of leaflets stands close to the insertion of the leaf on
the stem. Separated from them by a short stalk come the other
pair of leaflets and the single terminal leaflet. The leaflets of
the lower pair are readily mistaken for stipules, but minute
pointed stipules can sometimes be made out in addition to them.

The inflorescence has a long, thin, leafless stalk, at the upper
end of which is a small green bract with three leaflets and a group
of flowers. The short stalks of the flowers all spring from the
same point, and the flowers bend over so as to face in the one
direction. A single flower requires to be examined in great
detail if the method of pollination is to be appreciated. What
might appear to be trifling details of structure have their signi-
ficance and use.

The flowers (Fig. 82, i, 2) are irregular and stand in a definite
position, so that an upper and a lower side can be distinguished.
The calyx is composed of five sepals. These are united together
to form a tubular structure, surrounding and holding in place the
bases of the petals. As the free projecting tips of the sepals show,

172

THE BOOK OF NATURE STUDY

one sepal stands in the middle line of the flower in front. The
corolla consists of five petals, which alternate in position with
the sepals, so that one stands in the middle line behind. This
petal, which is larger than the others, is called the standard.
Below this to either side stand two other petals called the

FlG. 82. — The Bird's-Foot Trefoil, i, flower from in front ; 2, flower
from the side ; 3, side view, the standard :being removed ; 4, the
same, seen from above ; 5, side view, the standard and wings being
removed ; 7, the same, seen from above ; 6, one-half of the keel
removed to show the position of the parts within ; 8, front portion
of 6, more highly magnified ; 9, the stamens and style from the
side; 10, the same from above; n, the nine united stamens spread
out. a, entrances to the honey ; b, free stamen ; c, depression in
keel into which the bulge of the wing (c'} fits ; */, the five short
stamens ; £, the five longer and club-shaped stamens ; f, stigma ;
g, open tip of keel. (From Miiller, Befruchtung der Blumen.}

wings, and overlapped by them and still lower are two more
petals, which together form a boat-shaped structure known as
the keel. The petals are of a bright golden-yellow colour. The
standard, which wraps over the others in the opening bud, is
more or less crimson on the outer side, and this gives the buds
a vivid crimson colour. On the inner face the standard has a

*•"'•'

GREATER BIRD'S-FOOT TREFOIL (Lotus uliginosus, Schk.).

I. ROOT SHOWING THE ROOT TUBERCLES. II. FLOWERING SHOOT.

III. FLOWER, SEEN FROM IN FRONT. IV. FLOWER, SEEN FROM THE SIDE.

EARLY SUMMER FLOWERS 173

number of narrow red lines converging to the centre of the
flower.

If the calyx is carefully slit up and bent back the insertion
of the petals will be visible. The narrow horizontal base of the
standard is concave and overlaps the wings to some extent.
Each wing is inserted by a very narrow stalk-like part ; parallel
to this on the upper side is an extension backwards of the
broader portion. The base of this extension appears from the
outside as a depression. From the inside it appears as a
projecting bulge, which fits into a corresponding depression on
the outside of the petal forming one-half of the keel (Fig. 82, 3, 4).
The wings and keel are thus locked together, and the edges of
the wings are also joined for a short distance above the keel.
The two petals forming the keel are inserted separately by
narrow stalks on the receptacle. The edges of the wider portions
are joined both above and below (Fig. 82, 5, 7), so that the keel
forms a flattened tubular structure tapering to the point, where
the tube is open.

The stamens are completely enclosed in the keel, which must
be slit up to show them. One stamen standing in the middle
line behind is free from the other nine, the stalks of which are
joined together to form a trough-like structure. The free portions
of the filaments bearing the anthers spring from the margin
of this ; they occupy the up-turned tip of the keel. Five of the
stamens are longer than the other five, and their filaments are
swollen below the attachment of the anthers. As Fig. 82, 8
shows, these club-shaped ends of the filaments together fill up
the narrowing tube formed by the keel. The anthers open
early, so that the pollen is shed in the tip of the keel in front
of this.

The green pod-like ovary is enclosed by the trough formed
by the united filaments. The ovary stands almost horizontally,
while the slender style is almost at right angles to it, and lies
between the free portion of the stamens and extends beyond
them (Fig. 82, 8). The style ends in the small stigma, which is
thus surrounded by pollen near the tip of the keel. The ovary
contains a number of ovules attached to the upper margin where
the edges of the single carpel join together.

174 THE BOOK OF NATURE STUDY

To complete the description of the flower it must be pointed
out that the receptacle is widened out to form a shallow cup
(cf. p. 106). Nectar is secreted around the base of the ovary, and
is concealed within the tube formed by the stamens. Entrance
to the nectary can only be obtained to either side of the base
of the free stamen.

It might at first appear as if self-pollination were a necessary
result of the stigma being surrounded by pollen in the tip of the
keel. The stigma is not receptive, however, until it is rubbed, so
that it remains unfertilised while the flower is opening and
becoming ready for the visits of insects. The flower is visited
especially by bees. These come in search of the nectar, to which
they are guided by the converging red lines on the standard.
The bee alights on the wings, and the weight of its body is trans-
mitted to the keel owing to the interlocking of the petals. The
keel will thus be depressed, its open tip resting against the under
side of the body of the visiting insect. This depression does not
extend to the stamens, so that the keel is forced down over the
group of filaments, which fill its cavity as the piston of a syringe
fills the cylinder. The effect of this is to force some of the
pollen from the tip of the keel, and this pollen will be deposited
on the region of the under surface of the insect. When
the weight of the insect is removed the keel rises up and
the mechanism is ready to work in the same way on another
insect coming to the flower. When the keel is sufficiently
depressed the stigma emerges and will rub against the same
spot on the insect where pollen may have been deposited
from a flower previously visited. The whole arrangement, in
the study of which Fig. 82 will be found of great assistance,
is beautifully adapted to render cross-pollination likely if the
flowers are visited by insects. There is some reason to think
that in the absence of the latter the flower's own pollen is
effective.

The fruit of the Bird's-Foot Trefoil is, when ripe, a straight
brown pod. This has the calyx at the base, but the other parts
of the flower have fallen away. The pod contains a number of
smooth round seeds like small peas, and opens by the two valves
splitting completely apart.

EARLY SUMMER FLOWERS

175

THE DAISY (Bellis perennis, L.) AND THE FEVERFEW
(Matricaria inodora, L.).

The Daisy is such a common and successful plant that it
must be referred to. Owing to the small size of its flowers
many of their features are
difficult to make out in
the Daisy itself, and their
study may be supple-
mented by that of the
Feverfew, in which the
flowers are similarly con-
structed but somewhat
larger.

The Daisy occurs
everywhere in waste and
grassy ground, and is a
successful weed in lawns.
Its mode of growth will
be best shown in speci-
mens not from a well-
mown lawn, but from
some spot on which the
plants have grown for
some years undisturbed
(Fig. 83). In such a
plant of medium size the
root-system will be found
to consist of a number
of stout, cylindrical roots

, . ' _ , FIG. — 83. — Daisy bearing inflorescences.

bearing finer branches. (After Baiiion.)

These roots spring from

the lower end of a short, stout stem. The latter may form a
single leafy shoot, but more commonly the shoot is branched
and a number of leafy shoots extend on all sides from the main
stem, in connection with the root-system. These branches lie
along the soil, and their older parts, like the surface of the main
stem, are marked by the scars of fallen leaves. Nearer the tip of

176 THE BOOK OF NATURE STUDY

each shoot comes the rosette of foliage-leaves, which are closely
crowded on the stem. Each foliage-leaf is simple, the leaf-stalk
narrowing slightly from the leaf -base and then widening out into
the dark green leaf-blade, the edge of which has a few teeth.
The surface of the leaves and stem is sparsely covered with
short, coarse hairs.

The plant, according to its size, bears one or many inflorescences
or flower-heads, the so-called " flowers " of the Daisy. Each of
these stands at the end of a long, bare, green stalk, and some little
care will be needed to make out the way in which the shoot
bearing a number of flower-heads is constructed. It will be found
that the shoot always ends in a flower-head. Its further growth
is continued by a lateral bud, which forms a shoot bearing two or
three leaves and in turn ends in an inflorescence. These therefore
are only apparently lateral.

When growing on a lawn the Daisy plants spread vegetatively
by the production of short prostrate branches. In this way the
patches extend, and the growth of the plant is further favoured
by the rosettes of leaves pressed close to the ground escaping
destruction by the mower.

Each flower-head has a long, cylindrical, leafless stalk, which
expands into a conical upper end. This is best shown on splitting
a flower-head in half, when the little flowers will be seen closely
crowded together upon the surface of the expanded stem of the
inflorescence. On the outside of the inflorescence we find a
series of small green leaves. These are the bracts, and covered
in all the developing flowers when the inflorescence was in bud.
The flowers or florets are of two kinds. Little yellow tubular
florets are crowded together, forming the centre or disc of the
flower-head. Around them comes a circle of florets of the ray,
the white corollas of which are drawn out into strap-shaped
structures ; this renders the flower-head as a whole more con-
spicuous.

If the general mode of growth of the plant and the nature of
the so-called flowers are appreciated, the details of the flower and
fruit, though they can be made out in the Daisy, will be more easily
studied in a plant with similar inflorescences but larger florets.
For this purpose we shall take

EARLY SUMMER FLOWERS

177

THE FEVERFEW (Matricaria inodora). — This plant is a common
weed in waste places, especially in cornfields throughout the
country. Another species of the genus, M. chamomilla, is closely

8

FlG. 84. — 1-8, Matricaria chamomilla ; 9, Matricaria inodora ; 10, Anthemis
arvensis. i, shoot with two inflorescences ; 2, 9, 10, flower-heads cut in
half ; 3, ray-floret ; 4, disc-floret cut in half ; 5, pollen grains, highly
magnified ; 6, fruit ; 7, fruit, cut across ; 8, fruit cut in half, lengthwise.
(After Schumann.)

similar and will do equally well for the study of the flowers.
Both are represented in Fig. 84. The Feverfew is an annual, and
the plants attain a smaller or larger size, with a less or more
branched shoot. It flowers in July and onwards until autumn.

VOL. III. 12

178 THE BOOK OF NATURE STUDY

The vegetative organs may be very briefly described. The
plant has a stout tap-root, and at the base of the shoot are a number
of leaves closely crowded together. These have usually withered
at the time of flowering. Above this region the shoot has elongated
internodes, with the finely divided pinnate leaves borne singly
at the nodes. A bud is present in the axil of each leaf, but it
depends on the strength of the plant how many of these buds
develop into shoots. In smaller and weaker plants the main
axis may end in the single inflorescence and no lateral branches
form. In strong plants a number of branches may form, and the
lower and longer ones be in turn branched. Here also the main
axis and each lateral axis ends in an inflorescence.

The inflorescence, as in the Daisy, consists of a large number
of small flowers crowded together on the enlarged end of the stem
of the inflorescence, and surrounded by a number of bracts. The
yellow disc-florets are to be distinguished from the white ray-
florets. The relative positions of the bracts, the ray-florets and
the florets of the disc, will be best appreciated if a flower-head is
cut in half (Fig. 84, 2, 9, 10).

The disc-floret is best studied first, and for this purpose single
fully open florets (Fig. 84, 4) should be detached from the flower-
head. These florets are tubular and regular. At the base is a
relatively large, whitish structure, the inferior ovary, upon which
all the other parts of the flower stand. Within the ovary is a
single ovule, which can be seen if the ovary is held against the light.
The calyx is practically absent, consisting merely of a slight rim
or fringe below the corolla. The protection of the whole group of
florets when young is given by the bracts of the inflorescence.
The corolla is composed of five united petals and is tubular.
It is narrower below but widens out above and its edge bears
five yellow teeth, which are the free tips of the petals. On looking
into the corolla a yellow body composed of the five anthers will
be seen, and in old flowers the two lobes of the stigma will be
found projecting above this. The determination of the relative
positions of these parts requires delicate manipulation and the
assistance of a good lens. It will be understood from Fig. 84, 4,
which represents a mature floret cut through longitudinally.
The five stamens, which alternate in position with the teeth of

EARLY SUMMER FLOWERS 179

the corolla, spring on slender stalks from the inner surface of the
latter just where it widens out. The filaments are separate and
distinct, but the anthers are joined together edge to edge and
shed their pollen into the tube thus formed. The two lobes
of the bifid stigma are at first closed together, and are gradually
pushed up the anther tube by the growth of the style, only
unfolding when the pollen has all been swept out.

The florets of the ray (Fig. 84, 3) have also an inferior ovary
and practically no calyx. The lower part of the corolla is tubular,
but the upper portion is prolonged on the side away from the
centre of the inflorescence into a white strap-shaped structure.
The free edge of this shows three minute teeth, which indicates
that three only of the five petals are concerned in the outgrowth.
A style and bifid stigma stand in the centre of the ray-floret, but
no stamens are present.

The disc-florets are thus regular and have both stamens and
pistil, while the florets of the ray are irregular and are purely female.

Insects visit the flower-heads, which are conspicuous objects,
in search of pollen and of the nectar secreted at the base of the
tubular corolla. In doing this they will come in contact with
florets of various ages. In those in an earlier stage pollen will
be swept out of the anther tube and the stigma will not have
appeared. In those at a later stage the pollen will have been
removed, and the receptive stigma will be exposed. The proba-
bility is therefore that the stigma will be pollinated from another
floret, and possibly from another plant. Cross-pollination must
take place in the case of the ray-florets, but the florets of the disc
may be self -pollinated if cross-pollination fails. This comes
about by the curving backwards of the lobes of the stigma in
old flowers, as was described for the Dandelion.

The ovary develops into a one-seeded fruit (Fig. 84, 6, 7, 8),
which ultimately becomes detached from the flower-head but
has no special means of dispersal.

The study of the Dandelion, Daisy, and Feverfew will enable
the student to understand the construction and mode of pollina-
tion of the flower-heads and flowers of a large family of plants,
to which belong, for example, the Thistles, the Hawk-weeds, and
the Ragworts.

i8o THE BOOK OF NATURE STUDY

THE PERENNIAL RYE-GRASS (Lolium perenne, L.).

This common Grass can be found in abundance in any piece of
grass land, as well as on waste ground and by roadsides. Its study
will prepare the student for the examination of other grasses. The
Perennial Rye-grass can be recognised among most common grasses
by the long flattened inflorescence. The main stem of this bears
some eight to twenty flat " spikelets," which are placed edgewise
on the stem and alternate on the two sides of this. Plants with
inflorescences should be dug up and their roots washed. If, as may
happen in cold, wet weather, no open flowers are found a number
of inflorescences can be placed in water and kept in the house,
when the flowers will open.

The plant consists of a group of stems attached to the soil by
numerous, fine, branched roots springing from the bases of the
various stems ; no main root can be distinguished. Each shoot
bears at the base two or three leaves separated by short inter-
nodes. In the axils of these leaves are buds, and the further
development of the latter increases the number of shoots of the
plant. The formation of new shoots, and in consequence the
local spreading of the plant, is increased by cutting back the
flowering shoots. This is the explanation of the advantage of
regularly mowing any lawn or piece of turf. The general appear-
ance and mode of growth of the plant is so characteristic of all
common grasses that plants with slender stems springing in a
group from the base and bearing long narrow leaves are often
spoken of as grass-like.

The shoot has long cylindrical internodes, and at each node a
single leaf is borne. The leaves alternate on opposite sides of the
stem. The nodes are marked by swellings of the base of the leaf-
sheath (Fig. 85, 2). This is of considerable length and surrounds
the stem closely, though the sheath is not joined to form a tubular
structure. Owing to the length of the sheath the leaf -blade
stands out from the stem some distance above the nodes. Just
where the blade joins the sheath a delicate semi-transparent
fringe, which fits closely against the stem, will be found. This
is characteristic of the leaves of most grasses, and is called the
ligule. The leaf-blade is long and narrow, and tapers to a point.

EARLY SUMMER FLOWERS

181

FlG. 85. — Perennial Rye-Grass. 2, node ; 3, node cut through, length-
wise ; 4, spikelet ; 5, flower between the upper and lower pales, the
latter bent away to show the lodicules, stamens, and pistil ; 7, parts
of the flower removed from the spikelet. (After Schumann.)

182 THE BOOK OF NATURE STUDY

The veins run parallel in it. We thus find the leaves to consist
of a large sheath and a blade, without any intervening leaf-stalk.

If the stem be cut in half through a node (Fig. 85, 3) it will be
seen that the long internodes are hollow, while the nodes are solid.
It will also be clear that the swelling at the node is due to the
leaf-sheath and not to the stem. The lower region of the inter-
node is very delicate, and continues in a growing condition for a
long time. The swelling of the leaf-sheath at the node explains a
familiar power of many grasses. Everyone has noticed that when
a part of a field of hay has been laid flat by heavy rain a certain
amount of recovery is possible. The lower parts of the shoots
may remain flat on the ground, but the ends turn up and become
erect. This sharp curvature of the stem is due to the swollen base
of the leaf-sheath starting to grow on the lower side when dis-
placed from the vertical position.

Above the uppermost foliage-leaf comes a long bare region of
stem which is slightly flattened. This ends in the inflorescence,
small groups of flowers or spikelets being attached alternately on
opposite sides of the main stem. The side of the latter against
which the edge of one of the flattened spikelets lies is somewhat
grooved, so that when the spikelet is young it is protected by the
main stem on this side. A single spikelet must be very carefully
examined in order to make out the position and structure of the
flowers. For this purpose one with open flowers should be
selected ; this will be recognised by the anthers of the stamens
hanging out from it. In such a spikelet the various parts can be
seen with little difficulty and hardly any dissection.

Each spikelet (Fig. 85, 4) evidently represents a lateral branch
of the main stalk, and bears a number of green leaves or bracts of
peculiar shape. These enclose and protect the flowers. Lowest
of all, on the outer side of the spikelet, so that this appears to
stand in its axil, is a bract between which and the main stem the
young spikelet was enclosed. This is called the glume. In the
lateral spikelets there is no corresponding bract on the opposite
side, for here the spikelet was protected by the stem. But in the
spikelet which terminates the inflorescence two glumes will be
found enclosing the rest of the spikelet between them. This
is the condition most commonly met with in the spikelets of

EARLY SUMMER FLOWERS 183

grasses. No flowers stand in the axils of the glumes, but on the
slender stem of the spikelet above them they will be found placed
alternately on the side turned towards the main axis of the in-
florescence, and on the side away from this.

Each of the little flowers is a side branch of the thin stem of
the spikelet itself, and appears to be enclosed between two narrow
concave bracts. The short stem of the flower stands in the axil
of the lower bract, which is called the inferior pale, and the other
bract, the superior pale, is placed a little higher on the axis of the
flower facing the inferior pale. The inferior pale is concave, and
overlaps the margins of the superior pale. The latter is thin and
translucent at either edge, and in the middle line ; the middle
portion that fits against the flower immediately above is not only
flattened but concave. These two protecting bracts completely
enclose the structures forming the flower itself until the moment
of flowering.

When this takes place, the pales diverge like the two valves
of a shell, and by pulling them farther apart we can see all
the parts of the very simple flower (Fig. 85, 5). There are three
stamens and a pistil. The stamens have large yellow anthers,
which hang freely from the spikelet on delicate filaments. The
pistil, which stands in the centre of the flower, consists of a small
greenish, pear-shaped ovary bearing at its upper end to either side
a feathery stigma. The stigmas are delicate, white, plume-like
structures exposing a relatively large surface.

There is no trace of either calyx or corolla of the usual kind
surrounding the pistil and stamens. Two little structures have,
however, yet to be recognised. At the lower side of the flower,
i.e. at the base of the inferior pale, are two pale translucent
bodies, swollen below and pointed above (Figs. 85, 5, 7). These
delicate structures are called the lodicules, and perform an im-
portant function. At the time of flowering they swell, and it is
their enlargement that forces the two pales apart, and thus ex-
poses the parts of the flower. It is possible that the lodicules
represent the perianth of the grass flower.

There are some eight or ten flowers in each spikelet. In
comparing various grasses, the flowers of which are very similar,
it is important to ascertain exactly the construction of the spike-

184 THE BOOK OF NATURE STUDY

let, and the student will do well to thoroughly master that of the
Rye-grass by examining and drawing a number of specimens.

We can now consider how the flowers are pollinated. As seen
above, all the parts remain enclosed by the pales till the moment
of flowering. This usually takes place on a bright warm day,
and the anthers are quickly carried clear of the spikelet by the
growth of their filaments, and open, thus liberating the pollen.
This is shed as a dusty substance, the separate grains floating freely
in the air. Some of these pollen-grains may come against the
stigma of a flower on the same or more probably another in-
florescence. The plume-like stigmas are well fitted to catch the
pollen grains. The flowers are thus pollinated by help of the wind,
and this explains their inconspicuousness, the absence of nectar,
and the fact that they are not visited by insects.

The result of pollination is that the ovary, which has one
cavity and contains a single ovule, develops into the fruit. The
seed-coat of the one seed is so closely united with the wall of the
fruit that they together form a single brown layer around the seed-
like fruit. This contains an embryo lying against one side of the
fruit near the lower end, and a relatively large mass of tissue
containing food material. The fruits of most grasses are very
similar, and a grain of Wheat will afford an interesting example for
study.

THE GARDEN SAGE (Salvia officinalis).

The Garden Sage is commonly grown in the vegetable garden
as a pot-herb, and other species, which well serve for study, are
cultivated for the beauty of their flowers. The plant is a small
perennial shrub, never attaining a large size, since the smaller
branches die back each winter leaving the main stem and
branches, the buds of which unfold in the next season. Owing
to the presence of glandular hairs on the leaves the plant has
a strong aromatic scent.

The stem is square and covered with short hairs. The leaves
are borne in pairs at the nodes, the successive pairs alternating.
Each leaf has a grooved leaf-stalk extending from the widened
leaf-base to the leaf-blade, into which it continues as the midrib.
The elongated, oval blade gradually widens out at the base, and

THE GARDEN SAGE (Salvia officinalis).

EARLY SUMMER FLOWERS 185

contracts at the tip to a more or less sharp point. The upper
surface, deeper in tint than the lower which bears the glandular
hairs, is thrown into small folds, and the margin is bordered by
small rounded teeth.

It is in the flowers of the Sage, however, that the chief interest
of its study lies, and these should be carefully compared with the
flowers of the Dead-nettle described above, which is a related
plant. The inflorescences are borne at the ends of some of the
vegetative shoots (Plate). The bracts are small and incon-
spicuous, but are arranged like the leaves in alternating pairs.
In the axil of each bract stands a group of stalked, blue flowers.
The middle flower of the group is the first to open, then one stand-

FlG. 86. — Garden Sage. A, flower seen from the side ; B, flower cut in half.

(After Baillon.)

ing on either side, and then a bud between this and the central
flower.

Each of the irregular flowers (Fig. 86) has a short stalk, and
can be divided into similar halves by a plane passing from front to
back. The calyx is composed of five united petals, and is distinctly
two-lipped. As shown by the pointed free tips, three sepals go to
make up the posterior lip and two the anterior lip. Its colour
is green, the ribs being purplish. The corolla is of a bright blue
colour, and is also two-lipped. It is made up of five united
petals, which alternate in position with the sepals. The posterior
lip forms a hood protecting the anthers and stigma ; it is com-
posed of two petals. The anterior lip is broad and is formed of
three petals. The middle one forms a broad two-lobed pro-
jection, which serves as a landing-place for insects.

186 THE BOOK OF NATURE STUDY

So far the flower resembles in general construction that of
the Dead-nettle. If the corolla is removed and slit up along
the middle line in front the stamens will be seen attached to its
inner surface. The two well-developed stamens join the corolla
opposite the lines of junction of the anterior and lateral petals,
which form the lower lip, and have a very peculiar shape. Each
has a stout, white, cylindrical filament, the shape of which is shown
in Fig. 86, B. A curved portion is fixed at right angles to the free
end of the filament, like the cross-piece of a T. At the forwardly
directed end of this is a yellow anther-lobe and at the other a
small knob. Comparison of this peculiar stamen with that of
the Dead-nettle will show that the cross-piece corresponds to
the connective between the two lobes of the anther. This in the
Sage is greatly extended, and separates the two anther-lobes
widely. Only one of the lobes of the anther forms abundant
pollen ; the knob-like one forms little or none. The Dead-nettle
had four stamens, and careful examination of the flower of the
Sage will reveal traces of the second pair as two small, white,
bodies, no longer bearing anthers, inserted opposite the junction
of the petals of the posterior lip with the lateral petals (Fig. 86, B) .
As compared with the Dead-nettle, then, the stamens are reduced
in number to two, and these are peculiarly developed so that only
one-half of the anther forms pollen. Another feature to be noted
in the corolla-tube when slit open is a ring of white hairs which
stand at the junction of the lower colourless portion of the tube
with the upper coloured part. These hairs serve to protect the
nectar, which is secreted by the large purple-coloured nectary at
the base of the ovary, and accumulates in the lower portion of
the corolla- tube.

If the corolla is carefully removed from a flower the style
and stigma, which lay beneath its posterior lip, will remain pro-
jecting from the calyx. The tip of the style bears a two-lobed
or forked stigma, the lobes of which diverge only in the later
stage of flowering. On splitting the calyx open the style will
be found to spring from the centre of the ovary, which is com-
posed of four, rounded, green lobes. In each of these is a single
ovule.

Having dissected one or two flowers and studied the form

EARLY SUMMER FLOWERS 187

and relative positions of all the parts, an intact flower should
be taken and the relation of the parts when undisturbed
carefully considered. We have seen that the nectar is to be
found at the base of the corolla-tube, protected by a ring of hairs.
The curved style lies against the posterior lip, and the stigma,
which at first is closed, projects beyond the anthers. The elon-
gated connective is balanced on the end of the filament, so that
the two fertile anthers lie side by side beneath the posterior lip,
while the sterile knobs stand right in the path leading to the
nectar. Each connective thus forms a lever balanced on the
filament, the shorter arm of the lever bearing the sterile knob.
If now an insect such as a bee alights on the lower lip and, insert-
ing its head, passes its proboscis down to the nectar, it is easy
to understand what will happen. The downwardly directed
halves of the anther will be pressed upwards out of the way, and
this will cause the other arms of the levers to descend. This
movement will bring the pollen-containing half of the anther in
contact with the insect's back, and pollen will thus be deposited
on the latter. The action of the insect can be imitated by passing
a needle or bristle into the corolla.

In older flowers, that will have already shed their pollen,
we find that the style has grown longer and its tip has curved
down. The two lobes of the stigma now gape apart, and are
ready to receive pollen on their inner faces. If a bee, which has
had pollen deposited on its back in visiting another flower, comes
to a flower in this later stage, the stigma will brush against the
region of its back on which the pollen was placed. The flower
will thus be cross-pollinated.

The flower of the Sage is a highly specialised arrangement
for ensuring cross-pollination by the agency of bees visiting the
flower for nectar. In correspondence with the precision of the
mechanism, we find that the amount of pollen needed is reduced.
As compared with the Dead-nettle, two stamens have become
functionless, and only one half of the anther in each of the other
two forms pollen. Other species of Salvia cultivated in the
flower garden will show even more specialised arrangements for
pollination on the same principle.

The fruit consists of four nutlets, each developed from one

i88 THE BOOK OF NATURE STUDY

lobe of the ovary and containing a single seed. The developing
fruit can be seen at the bottom of the calyx, all the other parts of
the flower having fallen off after pollination.

CUCKOO FLOWER (Lychnis flos-cuculi, L.) AND THE RED
CAMPION (L. diurna, Sibth.).

The Cuckoo flower or Ragged Robin and the Red Campion
are closely related. It is of interest to study them together and
compare their flowers. The Ragged Robin is usually found in
damp grassy ground, flowering from June onwards ; it is often
found along with the Lady's Smock (Cardamine pratensis), which
is also often called Cuckoo flower, and has been described above.
The plant is perennial, fixed in the ground by a strong main
root, and also producing roots from the bases of the branches.
The latter develop from the axils of the lower leaves, and in this
way the number of stems produced yearly by a plant increases.

The leaves at the base of each shoot are closely crowded, but
resemble the leaves borne higher on the shoot where the inter-
nodes are well developed. The stem between the pairs of leaves is
marked by six longitudinal ridges, and bears whitish hairs pressed
closely against the surface. The nodes are swollen and have a
reddish tint, which also extends over the lower internodes. Two
leaves are borne at each node, placed opposite to one another ;
their sheathing bases unite around the stem. There is no leaf-stalk,
and the blade is of a simple elongated form with a well-marked
midrib, and stands almost erect beside the stem. The pairs of
leaves inserted at successive nodes alternate in position.

As we pass upwards to the region of the inflorescence we find
that the bracts resemble the leaves, but are smaller, more pointed,
and of a brownish red colour. The branching of the inflorescence
is very characteristic. The main stem ends in a flower which is the
first to open, and growth is continued by two branches which
spring from the axils of the uppermost pair of bracts. Each of
these branches ends in a flower, and below this bears a pair of
bracts. Branching similarly proceeds from the buds in the axils
of these bracts.

The flower itself consists of calyx, corolla, stamens, and pistil.

EARLY SUMMER FLOWERS 189

The slender flower-stalk has a brownish red colour. The five
sepals, the free tips of which project as pointed teeth, are united
to form a wide tubular calyx. The midrib of each sepal appears
as a brownish red ridge on the outside of the pinkish calyx, and
a similar rib runs down midway .between each of the first set, so
that ten ridges are present. The tubular calyx holds together
the five free petals, the insertion of which is seen on splitting
open the calyx to be separated by a distinct internode from that
of the sepals. In each petal we distinguish a narrow stalk-like
part from the pink-coloured portion, which expands above the
mouth of the calyx. The wider terminal portion is deeply notched,
and each half is in turn divided. Just where the stalk passes into
the expanded part two upgrowths, pink at the base, whitish above,
spring from the upper surface of each petal. These upgrowths
stand edge to edge, and may be compared with the corona of the
Daffodil.

There are two whorls of five stamens, the outer standing
between the petals and the inner ones opposite to the petals.
In the centre of the flower is the green ovary bearing five long
whitish stigmas. If the ovary is carefully opened the numerous
ovules will be found to be borne on a central plug projecting into
the cavity, and not connected with the wall except at the base of
the ovary (cf. Fig. 56, D).

Nectar is secreted at the base of the stamens, and the flowers
are visited by a number of insects, especially by butterflies and
moths, in search of it. To understand the effect of the insects
passing from flower to flower it is necessary to follow the order of
maturing of the stamens and stigmas. The five outer stamens
ripen first, and while the pollen is being shed their anthers occupy
the entrance to the tube of the flower. As the other five stamens
in turn mature, their anthers take the same position, and when
they have withered the five stigmas, which till now have been
small and undeveloped, grow up and fill the entrance to the
flower. When an insect visits a flower in the earlier pollen-
shedding stage it will carry away pollen on its proboscis or head ;
on going to a flower in the later stage, in which the stigmas are
mature, it will deposit pollen on these but will not receive pollen
from the flower. Cross-pollination is therefore likely to take

igo THE BOOK OF NATURE STUDY

place, but in default of this the stigmas as they develop may come
in contact with pollen grains remaining adherent to the withered
anthers of the same flower, and so be self-pollinated.

After pollination the ovary enlarges and becomes the fruit.
This is surrounded by the calyx, while the other parts of the
flower wither and fall away. The fruit, when mature, opens by its
dry wall splitting at the tip into five teeth, which curve backwards
and leave a wide opening into the single cavity. From this the
little seeds developed from the ovules can readily be shaken.

The Red Campion (Lychnis diurna) occurs, often in large num-
bers, on sunny banks or in partially cleared woods. The mode of
growth of the plant is very similar to that of the Ragged Robin, and
the branching of the inflorescence is the same. The stem is round
and hairy, and the leaves are larger and softer and bear short
hairs on both surfaces.

In collecting material for study two kinds of plants will be
recognised. These are best distinguished by looking at the flowers.
In the opening of the corolla of all the flowers on some plants the
anthers shedding the pollen will be seen, while in the same position
in other specimens are the five whitish stigmas. Several whole
plants of each kind should be collected, when it will be seen that,
though alike in mode of growth, arrangement of leaves, and branch-
ing, the plants bearing flowers with stamens are less robust and
have thinner stems and smaller leaves than those bearing pistillate
flowers.

The two kinds of flowers (Fig. 87) require separate examination.
In the staminate flowers we find a somewhat distended calyx
bearing at the margin five pointed teeth. The corolla consists
of five rose-pink petals resembling in shape those of the Ragged
Robin, but not fringed in the same way. Within the petals are
ten stamens, but there is no pistil in the centre. Sometimes
five little projections are present within the ring of stamens, and
occasionally a flower is found with a rudimentary ovary in this
position. The nectar is secreted on the inner side of the bases of
the filaments; it is protected by the hairs growing from the
lower parts of the latter.

The other type of flower (Fig. 87, B) is similar as regards the
calyx and corolla, but there are no obvious stamens. Within

EARLY SUMMER FLOWERS

191

the corolla is the large pistil. This consists of the green ovary sur-
mounted by five white stigmas, which are receptive to pollen on
their inner faces. The ovary, as in the Ragged Robin, has a single
cavity, and the ovules are borne on a central projection from the
base. The position of the partitions, which are not developed,
is indicated by ridges projecting from the inner surface of the wall
of the ovary. At the base of the ovary are ten little pointed
bodies. There are the rudiments of the stamens, which are here
arrested at an early stage of their development. The nectar in
this flower is secreted around the base of the ovary.

In contrast to the Ragged Robin, the Red Campion has flowers
of two kinds, pis-
tillate and stamin-
ate, on distinct
individual plants.
Comparison with
related plants leaves
no doubt that this
has come about by
the arrest of the
stamens in the
flowers of some
plants and of the
pistil in those of
other individuals,
though we know nothing of the cause of this difference between
the individual plants. Evidently self-pollination is impossible in
the Red Campion, but the long-tongued insects, especially butter-
flies, which come to the flowers in search of the deeply placed
nectar, will carry pollen from the male or staminate flowers to
the stigmas of the female or pistillate flowers. The fruit which
develops from the ovary of the pistillate flower is of similar con-
struction to that of the Ragged Robin.

While in the Ragged Robin we have flowers with both stamens
and pistil, the development of the stamens before the stigmas
were mature almost prevented self-pollination. The separation of
the two sexes on distinct plants, as in the Red Campion, renders
self-pollination impossible.

A B

FIG. 87. — Flowers of the Red Campion cut through length-

wise. A, staminate flower ; B, pistillate flower.
Baillon.)

(After

192 THE BOOK OF NATURE STUDY

THE WHITE MEADOW SAXIFRAGE (Saxifraga granulata, L.)
AND THE LONDON PRIDE (Saxifraga umbrosa, L.).

In damp grassy land and on banks in May and June the
White Meadow Saxifrage may be met with. It is not quite so
common as most of the plants described here, but is of interest
in a number of ways, and should be carefully studied if it is
found. Specimens should be dug up with care, since the parts
in the soil will be found as interesting as those above it.

The short underground stem bears some brown roots, and has
clustered around it a number of pink spherical bodies, to the
study of which we shall return. If the plant is examined early
in the season a number of leaves will be found springing close
beside one another and forming a rosette at the base of the shoot,
which continues its growth and bears the flowers. These leaves
have a well-marked sheathing base, which narrows gradually
into the leaf -stalk. This again widens out into the kidney-
shaped leaf-blade ; the margin of the blade is cut into rounded
lobes. The surface of the leaf is hairy both above and below,
while the margin is fringed with a row of longer hairs. Short
hairs are also found on the leaf-stalk.

The cylindrical stem above the rosette of leaves bears a few
leaves separated by long internodes. The leaves become suc-
cessively simpler in form, and have shorter stalks, till we come
to the reduced leaves or bracts on the inflorescence. The sur-
face of the stem is sticky, owing to the secretion formed in the
small globular heads of the numerous short hairs covering it.
A little careful observation will show that the main stem of
the inflorescence ends in the flower which is the first to open.
From the axils of the two highest bracts branches arise that
also end in flowers, and each branch in turn bears another flower
in the axil of its uppermost bract.

The flowers themselves are fairly large, and when fully open
are conspicuous. The flower-stalk widens into a green hemi-
spherical region, which will be found to enclose the base of the
ovary. On the margin of this dilated portion the five sepals are
situated. These are rather large, and green ; they are covered on
the outer surface with glandular hairs similar to those borne on

Photo by Henry Irving, Horley.

LONDON PRIDE (Saxifraga urnbrosa, L.)

EARLY SUMMER FLOWERS 193

the stem. Alternating with the sepals are five white petals, the
main veins of which, converging towards the base, are of a
greenish yellow tint. When the sepals and petals are removed
ten stamens will be visible, five of which stand slightly farther
out than the other five. It is remarkable that the five outer
ones are those standing opposite to the petals. The anthers
on opening expose the yellow pollen. In the centre of the
flower are two styles, which join together lower down. On
cutting a flower in half, so as to cut through both the
carpels, it will be found (Fig. 88) that the greater part of
the ovary, formed of the two united carpels, is enclosed within
the expansion of the floral receptacle noticed from the outside
of the flower. The upper parts of the two carpels separate
and form the styles, which taper some-
what till they end in the enlarged
stigmas.

If a number of flowers of different
ages are examined the order in which
the stamens and stigmas mature will be
ascertained and the way in which the
flower is pollinated can be understood. Fia gs.— Flower of the White

When a flower Opens none of the Meadow Saxifrage cut in half

stamens have shed their pollen, and the m the plane of the two car-

pels. (After Baillon.)

styles are short and stand close together

in the centre of the flower ; their stigmas are still immature.
The stamens of the inner whorl mature first, and as they open
their anthers bend inwards and stand immediately above the
pistil. As the pollen is shed these stamens gradually bend away
from the centre of the flower. The anthers of the outer whorl
of stamens next take up this position and open. The opening
of the anthers and shedding of the pollen takes two or three days,
and during this period the styles with the undeveloped stigmas
remain close together. Then the styles elongate and diverge
from one another, and the expanded stigmas develop. The flower
thus passes through a stage in which it is shedding pollen, but
has immature stigmas, to a stage in which the pollen is all shed,
but the stigmas are mature and ready to receive pollen.

The conspicuous flowers are visited by flies and small bees,

VOL. III. — 13

I94 THE BOOK OF NATURE STUDY

which come in search of the nectar, secreted by the upper surface
of the ovary and protected in the centre of the flower. The
insect visitors on passing from flower to flower will tend to effect
cross-pollination, carrying pollen from flowers in the earlier
stage to flowers in which the stigmas are receptive. Should
cross-pollination fail, the stigmas, as the styles bend apart, may
come in contact with the stamens and so receive some pollen
from their own flower.

The half-inferior ovary has two chambers, and in each a
large number of ovules are contained, borne on a swelling of
the partition. The pistil develops into a dry fruit, which splits
in the plane of the partition and liberates the small sculptured
seeds.

The reproduction of Saxifraga granulata is not, however,
wholly dependent on the seeds. A number of individual plants
are usually found growing close together, and their origin will
be understood if we return to the small pink bodies at the base
of the main stem. Each of these is a small shoot, doubtless
formed in the axil of one of the lower leaves, and is specially
modified for reproducing the plant. It consists of a short stem
bearing closely crowded pink scales ; these are leaves modified
for the storage of food material. The little shoot thus resembles
a small bulb, and is called a bulbil (Fig. 89). When isolated
in the ground the bulbils grow further at the expense of the food
material stored in them. Each forms a stem bearing foliage-
leaves and flowers. At the base of a plant which has originated
in this way the remains of the bulbil will be found, and, as has
been seen, new bulbils will be developed on the lower part of the
shoot. The plant is probably reproduced in the same spot year
after year by means of the bulbils, though its spread to new
positions must be effected by means of the seeds.

The London Pride (Saxifraga umbrosa) is familiar in all
gardens in town or country. It belongs to the same genus as
the White Meadow Saxifrage, and is found wild on the mountains
of the west of Ireland, where it flowers in June and July. Since
it is more easily obtained than Saxifraga granulata, attention will
be briefly directed to its chief features.

The general appearance of the plant when in flower is repre-

EARLY SUMMER FLOWERS 195

sented in the plate, which shows that the foliage-leaves form a
close rosette at the base. The fairly long leaf-stalk widens out
into a leaf-blade, the margin of which is cut into rounded lobes.
The margin of the leaf-stalk bears hairs, and glandular hairs are
scattered over the surface of the cylindrical stalk of the
inflorescence and more closely on the finer branches bearing
the flowers. Small bracts are borne at intervals on the stem
of the inflorescence. In the axils of the upper bracts are
branches, which in turn branch. If carefully looked into, the
main and lateral branches will be found to end in flowers,
the inflorescence being, as in the White Meadow Saxifrage, a
cymose one.

The small flowers consist of the same parts as do those of

2

FIG. 89.— Bulbils of the White Meadow Saxifrage. (After Schumann.)

5. granulata described above, and the parts are arranged in
the same way. The petals are, however, small and of a pinkish
white colour, marked with a number of pink spots ; each has a
larger yellow spot near the base. The pistil, which is not so
deeply sunk in the- floral receptacle, has a pink colour and
it and the anthers add to the colour of the little flower.
This is visited by small flies and, since the stamens have
shed their pollen before the stigmas mature, cross-pollination
is readily effected. The branches of the London Pride form
short runners and readily take root, so that the plant extends
by vegetative means and forms large patches. It is of
interest to compare this less specialised means of vegetative
reproduction with the formation of bulbils in the White Meadow
Saxifrage.

196

THE BOOK OF NATURE STUDY

HERB-ROBERT (Geranium Robertianum, L.).

There are many points of interest in the Common Wild
Geranium or Herb-Robert that will repay careful study. This
plant can be found in any hedgerow, and flowers throughout
the whole summer. It is an annual, and grows rather loosely
attached to the soil by a main root bearing lateral branches.
At the base of the main stem are a number of closely crowded

foliage-leaves with long
stalks, and from the
axils of some of these,
branches resembling
the main shoot may
spring. The internodes
of the upper portion of
the shoot become longer,
while at each of the
rather swollen nodes a
pair of leaves is borne.
The stem and leaf-stalks
at the base of the plant
have a bright red colour,
and this is also found
at the nodes and the
bases of the leaf-stalks
in the upper part of the
shoot. The surface of
these parts is clothed
with projecting whitish hairs. The plant has a peculiar and
rather unpleasant odour, and is noticeably brittle, the leaves
and stems separating readily at the nodes. The general appear-
ance of a shoot bearing leaves, flowers, and fruits is represented
in Fig. 90.

Each leaf has a pair of small stipules, which remain on the stem
when the leaf breaks away. These are green and pointed, and
hairy on their lower surface and edges. The almost cylindrical
leaf -stalk shows hardly any distinction of upper and lower surface.
It tapers gradually till the compound blade, consisting of three

FIG. 90. — Flowering shoot of the Herb-Robert.
(After Baillon.)

EARLY SUMMER FLOWERS 197

main leaflets each of which is deeply divided, is reached. The
leaf -blade is softly hairy, especially above where it is of a deeper
green tint. The leaves are all similar, though in the flowering
region the blades are smaller and the stalks are very short.

The main branch terminates in an inflorescence, and lateral
branches from the axils of its leaves end similarly and continue
the branching of the plant. The ultimate region of each shoot
bearing the flowers always consists of a thin cylindrical stem
bearing a pair of leaves reduced to their minute stipules. This
ends in the first flower, and in the axil of one of the reduced bracts
is a second flower opening later than the first one. The small
inflorescences have thus regularly two flowers (Fig. 90).

The calyx of the flower consists of five sepals, which are not
joined together but stand so close and erect as to practically form
a tube enclosing the base of the flower. Each sepal has well
marked green veins bearing glandular hairs, and ends in a green
point tipped with red. Within the sepals, and alternating with
them, are the five petals forming the corolla. These are also free
from one another, and each consists of a stalk-like portion stand-
ing erect within the calyx, and a wider pink and red-coloured part,
which spreads out almost at right angles to the lower portion
and forms the conspicuous corolla. Each petal shows three
whitish streaks converging towards the centre of the flower.

Projecting from this we find the stamens and stigma. The
stamens are ten in number, and form two whorls of five. Each has
a colourless stalk, which is flattened out at the base, but is slender
and cylindrical above, where it bears a reddish anther. This on
opening liberates the bright yellow pollen. The pistil, which is
clearly seen on removing the stamens, consists of the pale green,
five-lobed ovary, the style, which tapers upwards, and the reddish
stigma consisting of five diverging lobes. There are five carpels
composing the pistil, and in each of the five chambers of the ovary
is a single ovule.

The flowers of the Herb-Robert are visited by insects, and are
usually cross-pollinated by their assistance. Nectar is secreted
by the outer sides of five of the stamens close to their attachment,
and accumulates in the bases of the sepals. The five outer stamens
open first, and when they are shedding their pollen the style is still

198

THE BOOK OF NATURE STUDY

short, and the lobes of the stigma closed together. By the time the
five inner stamens are shedding their pollen the style has lengthened
and the stigmatic lobes are expanded at a somewhat higher level
than the anthers. The flower has thus an earlier stage in which
pollen is being shed, but fertilisation is impossible, and a later stage
in which it is capable both of giving and receiving pollen. Even
in this stage, cross-pollination is, however,
more likely to occur than self-pollination,
owing to the position of the stigmas above
the anthers.

The fruit is of interest on account of the
way in which the seeds are scattered to a
distance from the plant. After pollination
the ovary with its five lobes enlarges, and the
lower portion of the style also increases in
length, and thickens. At the upper end it
bears the remainder of the style and the
withered stigma. The base of the fruit is
surrounded by the sepals, but the stamens and
petals have fallen off. The fruit is dry when

< J

ripe, and opens by the five outer portions
of the carpels separating from below upwards from a central
column (Fig. 91), and forcibly scattering the seed to some little
distance. In the Herb-Robert the seed, when detached, is
enclosed by the lower part of the wall of the ovary, while
in some other species of Geranium the seeds are ejected
separately, and the wall of the fruit remains attached to the
central column.

FIG. 91.— Fruit of the
Herb-Robert, open-

jn/f to 2e* th<r seed

(After Baillon.)

THE SPOTTED ORCHIS (Orchis maculata, L.).

The Early Spotted Orchis is one of the commonest of our British
Orchids, and can be found in flower, often in large numbers, in
damp grassy spots and on heaths and moors, in May and June.
Its study will serve admirably as an introduction to the wonderful
adaptations which the Orchids show both in their vegetative
organs and their flowers. It must be remembered, however, that
these adaptations are very various, and require special study in

EARLY SUMMER FLOWERS 199

each case. The description of Orchis maculata applies in general
to a number of our native Orchids.

For the study of the Spotted Orchis care must be
taken to obtain complete specimens. The plant must be very
carefully dug up, and the underground parts freed from the
surrounding soil. When this is done the plant will be seen to
consist of two swollen, tuberous structures and a number of
ordinary roots below ground, and of a single erect stem bearing
foliage-leaves below and ending in the inflorescence of crowded,
whitish-lilac flowers. Smaller specimens which do not flower
should be studied as well as the larger plants, and observation
should be carried on throughout the season, so that the annual
history can be followed.

The two tubers at the base of the plant present important
points of difference (Fig. 92, i). They are thick swollen struc-
tures divided at the free end in a palmate fashion ; each lobe con-
tinues as a cylindrical root. The tuber is evidently a peculiarly
modified root or group of roots. It is modified for the storage of
reserve food material. One of the two tubers stands immediately
at the base of the leafy shoot of the plant, while the other appears
to be attached to the side of the lowest part of the shoot. The
latter tuber is plump, firm, and of a white colour. Above it is a
bud to which the tuber is related. The bud which once stood above
the other tuber, which is now brownish and soft, has grown into
the leafy shoot bearing the inflorescence. The growth took place
at the expense of the material stored in the old tuber, which is
now practically emptied of its contents. From the stem im-
mediately above the tuber a number of long, cylindrical, un-
branched roots have developed, and above this the stem bears
two or three scale-leaves. These are hidden below the soil, and
are brown or colourless. The bud mentioned above as connected
with the new tuber was borne in the axil of the lowest or second
lowest of these scales, but has enlarged and burst through the
base of the scale-leaf ; it is thus visible without any dissection.
The new root-tuber springs from the base of this bud.

We can now form a clear idea of how the growth of this Orchid
continues from season to season. When the plant dies down in
the autumn all that is left in the soil is a tuber, stored with food

200 THE BOOK OF NATURE STUDY

material and bearing a bud. In the spring the bud grows into a
foliage and flowering shoot, which forms a few absorbent roots

*H 6

FIG. 92. — Spotted Orchis, i, Complete plant early in the season showing the origin
of the new tuber ; 2, portion of stem of inflorescence with a bract in the axil of
which a flower, seen from behind, stands ; 3, flower seen from in front ; 4, the pair
of pollinia, magnified ; 5, point of a pencil depressing the rostellum, and coming
in contact with the sticky discs ; 6, movements of the pollinia, removed on
the pencil. (After Schumann.)

at the base of the stem. Preparations are at once begun for the
continuance of the plant in the following season by the enlarge-

EARLY SUMMER FLOWERS 201

ment of one of the lowest lateral buds and the development of a
root-tuber on this. During the season this new tuber enlarges,
and is stored with food materials manufactured by the foliage-
leaves, and it, with the related bud, remains to carry on the growth
of the plant in the following spring.

The unbranched stem bears, as mentioned above, several
scale-leaves at its base, and above this a number of green foliage-
leaves. Each leaf is distant from the preceding one by about one-
third of the circumference of the stem, and on passing from the
lowest scale-leaves, which are merely colourless sheaths, to the
upper foliage-leaves a gradual increase in size of the leaf-blade
is apparent. The sheathing base of each of the larger foliage-
leaves completely embraces the stem for some distance above the
node. The narrow leaf -blade is not flattened, but remains
folded at the midrib, so as to show a chanelled upper surface.
The colour is deep green marked with irregular blackish
spots on the upper surface, while below it is of a uniform paler
tint and shows clearly the parallel course of all the main veins.
The spotting of the leaf, to which the English name refers, varies
in degree in different specimens, and may be almost wanting.

Above the largest foliage-leaves we find a gradual diminution
in size of the leaf-blade, which becomes more pointed and has
a shorter leaf-sheath, until we come to the bracts of the inflores-
cence. These are evidently reduced leaves with a small, pointed
leaf-blade and practically no leaf-sheath. In the axil of each
bract is a single flower, and, since the internodes in this region
are short, the shoot of the Orchid ends as a dense spike of flowers.
At first sight each flower appears to have a thick green stalk
marked by spirally running ridges, but further examination will
show that this is really the inferior ovary, and that the flower
has no stalk.

If a fully opened flower is removed and looked at from the
front (Fig. 92, 3) it is at once clear that only the plane of division
passing from front to back would divide it into two similar halves ;
it is an irregular flower. Seated at the end of the stalk-like
ovary are six perianth-leaves, which are all delicate and petal-
like in texture, and of a whitish colour marked with streaks or
spots of lilac. The perianth-leaves form two whorls of three.

202 THE BOOK OF NATURE STUDY

As looked at from in front one of the three leaves of the outer
whorl stands in the middle line behind, while the other two stand
to either side of the flower. The three leaves of the inner whorl
alternate with those of the outer whorl. Two, standing towards
the back of the flower, are small and narrow, like the leaves of the
outer whorl, and their tips bend inwards so as to meet. They
form, together with one of the leaves of the outer whorl, a hood-
like structure overarching and protecting the parts within. The
third leaf of the inner whorl is very different in shape and size to
the others. It forms a wide apron-shaped lip to the front of
the flower (Fig. 92, 3), and is continued back as a tubular spur
(Fig. 92, 2). It is called the lip or labellum.

The parts of the flower within the perianth may be seen on
looking into the flower (Fig. 92, 3), or by removing all the perianth-
leaves from a flower (Fig. 92, 5). Looking into the opening above
the labellum which leads into the spur, the back wall of the open-
ing appears to be formed by two dull white surfaces, which are
continuous across the middle line and have their edges defined
by a coloured line. These areas are the two receptive lobes of
the stigma. Immediately above the stigma is the single stamen,
which is not very like in appearance to the stamens of most
flowers. The two anther lobes are shaped like Indian clubs
with their dilated ends pointing upwards (Fig. 92, 3). They lie
parallel to one another, and their narrower ends come in contact
with a small globular structure overhanging the entrance to the
spur. This is known as the rostellum, and corresponds to the
third lobe of the stigma specially modified to perform a particular
function.

The anther lobes have a purple colour, but when opened by
a longitudinal slit the greenish mass of pollen is visible in each.
This is not as usual loose and powdery, but all the pollen of each
anther lobe is joined together to form a club-shaped mass or
pollinium. The lower part of this forms a tapering stalk which
is connected to the membrane forming the back of the rostellum.
The rostellum when mature consists of a thin membranous wall
enclosing a sticky substance, which has resulted from the breaking
down of the central tissue. The sticky material has collected
in two little hemispherical masses against the parts of the mem-

EARLY SUMMER FLOWERS 203

brane to which the stalks of the pollinia join on the outside.
These two circular discs of the membranous wall of the rostellum
are defined by a split which forms in the membrane when the
flower is mature. Anything that presses against the front of
the rostellum will press down that part of the membrane and
expose the two sticky discs. These will adhere to the object
touching them, and carry away with them the pollinia from the
anther lobes.

Touching the front of the rostellum with the point of a pencil
will show the general structure and remove one or both of the
club-shaped pollinia (Fig. 92, 4, 6), which can then be examined
with a lens. In each we distinguish the little patch of membrane
at the base, the stalk, and the mass of pollen grains held together
in packets by sticky threads.

To either side of the single fertile stamen a small whitish
projection will be seen on careful inspection (Fig. 92, 5). Each of
these is the last remains of a stamen, and they mark the position
of two other stamens in the flower, though these no longer form
pollen. If (having recognised the single stamen, the two rudi-
mentary stamens and the stigma, one lobe of which forms the
rostellum) the relative positions of these parts are considered in
a flower from which all the perianth-leaves have been removed,
they will be found to be joined together. The stamens appear
to be joined to the back of the style (Fig. 92, 5), or more
correctly the stamens and the stigma are carried up together,
forming a region known as the column.

If we now return to the intact flower we shall be in a position
to understand how the various parts of this complicated mechan-
ism work together in pollination. In the first place, it is obvious
that if a flower is left undisturbed there will be no likelihood
of self -fertilisation taking place. The flower is completely
dependent on insect visits for pollination. Bees and flies visit
the flower for a sweet juice, which is not as in most Orchids
accumulated in the spur, but is obtained by probing the soft
walls of this. The insect alights on the labellum, and in inserting
its head into the opening of the tube comes in contact with the
rostellum. It depresses the lower part of this, and so exposes the
viscid discs. These adhere to the head or proboscis of the insect,

204 THE BOOK OF NATURE STUDY

and the pollinia are removed when the insect withdraws its
head.

The method of removal of the pollinia can be studied by
inserting a sharply pointed pencil into the spur (Fig. 92, 6). This
reveals a further important feature in the behaviour of the pollinia.
As the viscid disc dries it contracts unequally, and as a result
of this the pollinia are bent forwards, and at the same time diverge
slightly from one another. The importance of this movement
will be evident if the position of the stigmatic surface is taken
into account. If it did not occur, the insect on visiting another
flower would tend simply to replace the pollinia in the cavities
of the anther lobes. Owing to the movement, however, the
tips of the pollinia now come in contact with the stigmatic sur-
faces situated below and to either side of the rostellum. This
surface is very sticky, and it will be found that when a pollinium
is brought in contact with it and then pulled away a greenish
stain remains on the stigma. The latter has removed a number
of pollen grains, but has not taken the whole pollinium. One
pollinium thus serves to pollinate a number of flowers. The
whole mechanism, on the one hand, makes self-fertilisation im-
possible, and on the other, is beautifully adapted to ensure cross-
pollination as the insects pass from flower to flower.

So far we have considered the flower in the position it occu-
pies on the spike when fully open. If, however, the buds near to
the tip of the inflorescence be looked at, the labellum will be found
to stand at the back of the flower. This is its proper position,
and comparison with flowers lower down will show that it is only
brought into the anterior position occupied in the open flower
by a twist of the ovary. This explains the spiral course of the
ridges on the latter. The inferior ovary is composed of three
carpels and encloses a single cavity. The minute ovules stand in
three rows, corresponding to the lines of junction of the carpels.

Later in the season inflorescences will be found bearing fruits.
The perianth has withered and fallen off. The ovary has en-
larged into the fruit, and the ovules have developed into the very
numerous and small seeds. The dry fruit opens when ripe by longi-
tudinal splits, and the seeds escape and are readily carried by the
wind. The young plant developed from such a minute seed

EARLY SUMMER FLOWERS 205

cannot grow at once into a plant like the parent. It is some years
before it is able to flower, and during this time it increases in
size and forms a larger tuber each year. The young plants can
be found in situations in which the plant grows abundantly, and
a series of different ages may be collected and will make a portion
at least of the life-history clear.

The account given above will serve as a guide to the study
of several British Orchids with root-tubers. In other British
species we find an ordinary root-system. The methods of polli-
nation are described in the earlier chapters of Darwin's Fertilisa-
tion of Orchids, and the more advanced student should consult
this work.

THE GREATER PLANTAIN (Plantago major, L.) AND THE RIBWORT
PLANTAIN (Plantago lanceolata, L.).

The two kinds of Plantain to be described here are among our
commonest weeds. They can be found by every roadside in
waste places and in grass land. If not known by name they
will be identified by two uses to which their inflorescences are
commonly put. Those of the Greater Plantain when in fruit
are gathered for canaries, while every child knows the black,
long-stalked inflorescences of the Ribwort Plantain which are
used in the game of " Soldiers." Both plants are perennial
and can grow on very bare and unpromising spots, so that they
compete successfully with other plants in the colonisation of such
places.

The Greater Plantain (P. major] (Fig. 93), as can be seen in a
specimen that has been carefully dug up, has a short, swollen,
main stem which continues its growth year after year without
forming any vegetative branches. A number of sparingly
branched roots fix the almost globular stem in the soil; no
main or tap-root can be distinguished. Toward the upper part
of the short stem are the crowded leaves, which spread out on
all sides and often have their large blades more or less closely
applied to the soil. Each leaf has a wide sheathing base, which
narrows gradually into the leaf-stalk. This is strongly concave
above, and at its upper end expands rather suddenly into the

206

THE BOOK OF NATURE STUDY

broad, oval leaf -blade. The course of the veins in the leaf-
blade is clearly seen on looking at the lower surface. Three to
seven main veins enter from the leaf-stalk and run almost parallel.
Those near the middle of the leaf reach nearly to the tip, while

FIG. 93. — Greater Plantain. 2, Plant bearing inflorescences cut in
half ; 5, single flower. (After Schumann.)

the lateral ones die out before this is reached. Between the
main veins is a network of fine branches.

Since vegetative branches are not produced even old plants
show an unbranched stem. The axillary buds mostly develop
into inflorescences, the existence of which is limited since they

EARLY SUMMER FLOWERS 207

wither after the fruits have ripened. The inflorescences destined
to grow up in the next summer may be found in the autumn
as small pointed bodies protected by a felt of white, silky hairs,
and standing in the axils of the foliage-leaves.

The inflorescence grows into a long, erect spike with a bare
stalk below, while the numerous small flowers are crowded on the
upper part. Each flower stands in the axil of a small, green, scale-
like bract. The flower (Fig. 93, 5) though of small size has calyx,
corolla, stamens, and pistil. The calyx is composed of four
separate greenish sepals. Within this we find a corolla composed
of four petals united together in the lower part. The corolla is also
greenish, and is of more delicate texture. As Fig. 93, 5, shows, the
free upper parts of the petals expand almost at right angles to the
lower tubular part of the corolla. The four stamens alternate
with the petals and are attached to the inner surface of the corolla
tube. The long, slender filaments project freely from this, and
carry the anthers clear of the other parts of the flower. In the
centre of the flower the small greenish ovary will be found by
carefully slitting up the corolla with the point of the knife. It is
usually two or three chambered, and the few ovules are attached
to a thick, central placenta, between which and the wall the thin
septa extend. The ovary is surmounted by a single style con-
tinuing into a long stigma, the surface of which is clothed with
papillae.

The flowers of the Greater Plantain, though individually in-
conspicuous, are prominent by reason of the stamens projecting
from the open flowers massed together on the inflorescence.
The anthers before dehiscence have a purplish colour, and when
they open liberate dusty pollen, which escapes readily and is carried
by the wind. The large and hairy stigma is well suited to catch
such wind-borne pollen grains, and the whole aspect of the flower
suggests its suitability for wind-pollination. It is doubtless often
pollinated in this way, but, although the flowers contain no nectar,
they are sometimes visited by bees. These come to collect pollen,
which they have to moisten with saliva in order to carry away.

These insect visitors may carry pollen from one flower to
another, and we may look upon the flower as in some degree
intermediate between a wind-pollinated and an insect-pollinated

208 THE BOOK OF NATURE STUDY

one. Its general features are, however, more those of a wind-
pollinated flower. Since the stigma is usually capable. of receiving
pollen at the time that this is being shed by the stamens of the
same flower, self-pollination is not prevented as it is in the
Ribwort Plantain.

The small, dry fruit developed from the ovary after fertilisation
is of interest owing to the way in which it opens to liberate the
seeds. A circular split forms about one-third way up the fruit,
and the upper portion separates as a lid from the cup-shaped
lower part. Some of the seeds fall off with the lid, while others
remain for a time in the lower portion.

The Rib wort Plantain (Plantago lanceolata) is similar in the main
features of growth and floral structure to the Greater Plantain,
but differs in details. It is represented in the accompanying
plate. There is a long, stout, tapering tap-root growing vertically
into the soil, and giving off thin lateral branches. The stout
main stem has no vegetative branches. It bears below the remains
of the leaves of former seasons, and farther up the present foliage-
leaves. The leaf -blade is narrower than in the Greater Plan-
tain, and the almost parallel main veins project very strongly on
the lower surface. The inflorescences, which develop from the
axillary buds, have a long, leafless, strongly ribbed stalk, six inches
to a foot in length, and at the summit a short spike of flowers.
The bracts are greenish, edged and tipped with brown, and each
has a single flower in its axil. The structure of the flower is
similar to that of the Greater Plantain. The way in which the
flowers open presents an important difference, however. The
opening begins with the flowers at the base of the spike, and pro-
ceeds towards the tip, and the different stages in the flowering
can be made out in a single inflorescence, though better if a
number of different ages are gathered and compared. It will
be found that the stigma matures first, projecting from the partly
closed flower. Only after the stigma has withered does the
flower open fully, and the stamens project and liberate their
dusty pollen. Self-fertilisation is thus prevented, and the flowers
are usually cross-pollinated by means of the wind. Inflor-
escences of various ages are represented in the plate. The
arrangements for preventing self-pollination and for facilitating

Sbg

RIBWORT PLANTAIN (Plantcgo lanceolate^ Z.).

I. COMPLETE PLANT. R. Root. L. Leaf. A, B, C, D. Inflorescences of successive ages.
II. INFLORESCENCE IN A\ TARLY STAGE SHOWING THE STIGMAS PROJECTING FROM THE

CLOSED FLOWERS WHICH STAND IN THE AXILS OF THE BRACTS.

III. SINGLE FLOWER, FULLY OPENED. Cal. Calyx. Pet. Petals. St. Stamens. Stig. Stigma.

EARLY SUMMER FLOWERS 209

the conveyance of pollen by the wind may be instructively
compared with those in the Field Woodrush (p. 52), an unrelated
plant which grows in similar situations.

THE CHARLOCK (Brassica sinapis, Visiani).

The Charlock is one of the commonest and most abundant
weeds of cornfields and other cultivated ground. From May
onwards whole fields may appear bright yellow owing to its
flowers, and even when less abundant specimens can readily
be found. The plant is an annual one, growing up from seed
in the spring, and reaching its full size, which varies according
to the conditions from a few inches in ill-nourished specimens to
two feet in strong, branched examples. The plant bears numerous
flowers, and fruits freely. The seeds shed from the fruits remain
in the soil and give rise to the crop of the next spring. Such
annual plants, in which the individuals do not persist from year
to year, are dependent on an abundant production of seed for
their success in competition with others. They are not well
suited to take possession of ground already occupied with a
close growth of plants, but find suitable conditions in the bare
soil of cultivated fields. Many of the weeds of our gardens and
crops are annual plants.

The Charlock is best studied in a fully grown plant bearing
flowers and fruits. It has a stout tapering tap-root, which grows
vertically down into the soil and gives off slender, branched, lateral
roots. The main stem of the plant bears a number of fairly large
leaves, which are situated singly at the nodes and are separated
by long internodes. The stem is green, cylindrical, and slightly
ribbed, and its surface bears short, stiff, white, bristly hairs. The
leaves have a short, wide stalk, hardly distinguishable from the
leaf-base, and a leaf-blade, which is either oval with a toothed
margin or more deeply divided into pinnate lobes. Stiff hairs are
sparingly scattered on both surfaces and at the margin. After
bearing the two seed-leaves, which may be found at the lowest
node even in mature plants, and four or five foliage-leaves, the
main shoot of the plant continues as an inflorescence. In strong
plants the buds in the axils of several of the foliage-leaves develop

VOL. III. — 14

210

THE BOOK OF NATURE STUDY

into lateral shoots, which bear a few leaves and end in inflor-
escences ; the lateral shoots may in turn branch and bear in-
florescences.

The inflorescence consists of the main axis of the shoot bearing
laterally placed flowers. It continues to grow for a long time,
producing a succession of flowers, and in old plants buds may
still be found near the tip of an inflorescence that lower down
bears almost ripe fruits. Each flower corresponds to a lateral
branch, but, as is the rule in the group to which the Charlock and

the Lady's Smock belong, the bracts
are wanting below the flowers.

The flower has a well-marked
green stalk. There are four, pale
green sepals, which completely cover
in all the other parts in the bud.
The sepals are in two pairs, those
of the outer pair being flatter than
those of the inner pair. The two
pairs alternate, the sepals of the
outer pair standing front and back
in the middle line. The corolla is
composed of four petals inserted at
the same level on the receptacle of
the flower, and alternating with the
four sepals. Each petal consists of
a narrow, erect, flat, stalk-like part
of a greenish colour, which widens
out into the oval yellow upper portion. The four yellow
expansions are bent at right angles to their stalks, and diverge
in the form of a cross. Within the corolla, as is best seen on
removing the sepals and petals from a flower, are six stamens.
These stand at two levels on the receptacle. To either side of
the flower, and at the lower level on the receptacle, is a single
stamen which is shorter than the stamens of the inner whorl.
These are four in number, one pair standing to the front and the
other to the back in the flower as it stands on the main stem.
The filaments bear fairly large anthers which on opening liberate
yellow pollen. In the centre of the flower is the pistil. This is

FIG: 94. — Shoot of the Charlock
bearing flowers and fruits. (After
Baillon.)

EARLY SUMMER FLOWERS 211

formed of two carpels, and consists of a pale green, cylindrical
ovary clothed with downwardly pointing hairs, an ill-defined
style, and a stigma composed of two yellowish lobes standing
front and back in the flower. The structure of the ovary will
be best considered along with that of the fruit.

The flowers of the Charlock are conspicuous, not merely on
account of their individual size, but by their aggregation in the
inflorescence. They are visited by numerous insects which come
partly to collect or feed off the pollen, but also in search of nectar.
This is secreted in abundance by the nectaries, which are very
easily seen in a flower from which the calyx and corolla have been
removed. One large green nectary stands just within the in-
sertion of each short stamen, while a smaller gland is situated to
the outside of each pair of long stamens. Owing to the way in
which the sepals diverge the honey could be reached from the
outside of the flower, but insects, as a rule, approach in the more
usual way, and, alighting on the petals, pass their tongues down
the centre of the flower. All the anthers at first face inwards
towards the centre of the flower, and those of the two short
stamens remain in this position. Since they stand at a lower
level than the stigma, there is little likelihood of the pollen
effecting self-pollination. The anthers of the two pairs of long
stamens are situated at a slightly higher level than the stigma.
As the flower opens they make a more or less complete half-
turn, and so come to face outwards. An insect sucking the
honey at the base of the short stamens will have one side of its
head against the stigma while the other is being dusted with
pollen. When getting honey from the nectary at the base of
the long stamens it will be dusted with pollen from their anthers,
but will not touch the stigma. Insects passing from flower to
flower will thus effect cross-pollination. Should this not take
place, after the flower has been open for some days the anthers of
the longer stamens bend backwards, and the stigma as it grows
up comes in contact with them and is self -pollinated.

The fruit (Fig. 95) is simply the greatly enlarged pistil after
the sepals, petals, and stamens have fallen away. It is a long,
green, pod-like structure with a flattened beak, at the summit of
which is the remains of the stigma. There are no seeds in the beak-

212

THE BOOK OF NATURE STUDY

like part. The two carpels forming the pistil are joined by their
edges to enclose a single cavity, and the ovules are attached along
the lines of junction of the carpels. Ingrowths from these lines
of junction form a partition, which divides the cavity of the
ovary into two. The fruit shows the result of the further de-
velopment of all these parts. It is smooth, or bears stiff hairs like
those on the stem. Looked at from the outside, it is readily seen
to be formed of two carpels. The curved part of each of these
shows three veins, while the lines of junction are of a darker green.
If one of the valves be split away from the rest of the fruit the
seeds, which have developed from the ovules as a result of polli-
nation, will be seen. They are rather large
rounded bodies, which are attached by slender
stalks to the wall of the ovary. The en-
larging seeds have pressed the partition
aside, and since some are on the near side of
the septum and some on the other half of the
fruit, about half the seeds appear covered by
the thin partition. If both valves are re-
moved, which happens naturally when the
ripe fruit opens (Fig. 95, B), they leave the
partition stretched between the two strips of
ovary wall from which the seeds sprang.

The seeds then fall to the ground. They
are relatively large and have no special
method of being scattered to a distance.
Each round, smooth seed consists of the seed-coat enclosing the
embryo plant. The food material is stored in the thick seed-
leaves, which on germination expand as a pair of small, notched,
green leaves. These can sometimes be seen at the base of the
shoot even of well grown plants.

B

FIG. 95. — Fruit of the
Charlock, showing in
B the mode of dehis-
cence. (After Baillon.)

THE SHEPHERD'S PURSE (Capsella bursa-pastoris, Moench).

The Shepherd's Purse belongs to the same natural family of
plants as the Charlock and the Lady's Smock. It is, however,
such a common weed, and can be found in flower and fruit from
spring to autumn, that a brief account of its main features will be

EARLY SUMMER FLOWERS

213

useful. Specimens can readily be obtained from gardens, waste
ground, by the side of walls, or round farm-steadings, for the
Shepherd's Purse accompanies human activity like the Sparrow.
It gets its English name from the shape of the flattened and
heart-shaped fruits (Figs. 96, 97).

The plants vary greatly in size, probably owing to the con-
ditions of their life. They grow from the seed, flower and fruit
and then die, the usual life of a plant
being under a year, though individuals
may persist over the winter. The well-
marked whitish tap-root extends vertic-
ally into the soil, giving off branched
lateral roots. At the base of the shoot
is a rosette of long-stalked leaves, and
above this the stem has elongated inter-
nodes and bears a few foliage - leaves
before passing into the long inflorescence.
Larger plants branch from the axils of
the leaves. Each branch bears a few
foliage-leaves and ends in an inflorescence.
The general appearance of the plant will
be gathered from Fig. 96.

Both the stem and leaves bear short,
pointed white hairs. The leaves of the
basal rosette have an ill-defined leaf-
stalk. In the upper leaves on the main
shoot the stalk is less marked, while the
leaves on the lateral shoots may be de-
scribed as without stalks. The leaf-blade
has a strong midrib and, though often deeply divided, is not
compound or branched. All intermediate forms can be found
between leaves with the margin merely toothed and those in
which the divisions reach almost to the midrib.

The inflorescence, as in the Charlock, has no bracts beneath the
flowers. Growth proceeds at the end of the shoot throughout
the season, so that buds and open flowers will be found near the
tip, while fruits of all ages are present lower down. The flowers
have fairly long stalks and, though much smaller, are composed of

FIG. 96. — A small complete
plant of the Shepherd's
Purse. (After Baillon.)

214 THE BOOK OF NATURE STUDY

the same parts as in the Charlock or Lady's Smock. It is therefore
unnecessary to describe the arrangement of the parts in detail.
There are two pairs of sepals, four small white petals, two short
stamens and two pairs of longer stamens, and the pistil. Since
the anthers of the longer stamens stand at about the level of the
stigma, pollen will easily get upon this, and the flower be self-
pollinated. Nectar is, however, secreted by a pair of nectaries at
the base of each of the shorter stamens and, when the flower is
visited by insects, cross-pollination may be effected. The flower
is thus of interest in being constructed on the plan of an insect-
pollinated flower, but relatively reduced and inconspicuous and
mainly dependent on self-pollination.

The pistil, composed of two carpels, is short and flattened, and
extended in the plane of the shorter stamens
in the flower. It consists of the ovary, a
short style, and a rough two-lobed stigma.
The fruit (Fig. 97) is derived from the pistil,
the other parts of the flower falling away. It
is flattened, and widens gradually from below
FIG. 97.— Fruit of the upwards. At the broad upper end is a de-
Shepherd's Purse pression, from the middle of which the remains

opening to liberate f ^ ^ projects. The fruit Consists of

the seeds. (After

Baiiion.) two chambers separated by a partition which

lies in the plane at right angles to that of the
flattened pod. The greater part of each of the carpels can be
pulled away, leaving the seeds attached to the margin of the
septum. What can be done artificially happens naturally when
the fruit is mature (Fig. 97), and in this way the seeds become free.
In its construction the pistil and fruit of the Shepherd's Purse
thus resembles that of the Charlock (p. 212), although it is short and
broad instead of elongated. Owing to the certainty of pollination,
every flower produces a fruit, and the large number of seeds pro-
duced explains the abundance of the plant in suitable situations.

THE COMMON AVENS (Geum urbanum, L.).

The Common Avens is a perennial herb growing by roadsides
and often in the shade of woods, and flowering from June to

EARLY SUMMER FLOWERS 215

August. Its general appearance is shown in the accompanying
plate. The young plant has a main root, but roots also spring
from the stem and in older plants only these may be found. The
short thick stem grows on year after year, producing a number
of long-stalked foliage-leaves each year. The older parts of the
stems are clothed with the withered brown bases of the leaves of
former seasons. According to its size, the plant may bear one or
several erect shoots with a number of foliage-leaves at the lower
nodes and flowers above. These shoots stand in the axils of
leaves of the preceding season ; usually only the withered base of
the leaf can be seen.

Each of the large leaves has a wide sheathing base of a reddish
colour. This is thick in the middle, and thins out into margins
fringed by long hairs. To the sides of the leaf-base just where it
passes gradually into the leaf-stalk the small green tips of the
stipules can usually be made out. The leaf-stalk is chanelled
above, convex below, and like the rest of the plant is clothed with
short hairs. The leaf-stalk ends in a large, thin, three-lobed blade,
and the leaf at first sight appears a simple one. But below this we
find one or two pairs of small leaflets, so that it is clear that we
have to do with a pinnate leaf, the tip of which is greatly developed
while the lateral pinnae are small. The margins of the pinnae and
terminal blade are cut into rather wide teeth, each ending in a sharp
point. The main veins project on the lower side of the leaf -blade,
which is hairy on both surfaces.

The erect shoots have a stout green stem, marked with pro-
jecting ribs extending down from the sides of the leaf -bases. The
internodes are elongated and each node bears a leaf, which consists
of a leaf -base with a large green leafy stipule to each side, a longer
or shorter leaf -stalk, and a leaf -blade consisting of a terminal leaflet
and a pair of lateral leaflets. The axillary buds of these lower
leaves may give rise to lateral flowering shoots. Higher up on
the main shoot the leaves become still simpler in form, and consist
of the pair of leafy stipules and a short stalk expanding into the
single terminal leaflet.

The main axis of the inflorescence ends in a flower which is the
first to open, and the lateral shoots similarly terminate in flowers.
A short distance below the flower a pair of small bracts standing

216 THE BOOK OF NATURE STUDY

almost opposite to one another are borne, and flowers are produced
in the axils of these.

The flower has a cylindrical, green, hairy flower-stalk. At the
base of the flower where it passes into the floral receptacle this
widens out distinctly. On cutting a flower in half it will be seen
clearly that the receptacle forms a plate-like expansion similar
to that in the Strawberry flower, but more distinct. Around the
margin of this stand the five triangular green sepals, and below
and between these (as on the Strawberry) are five, smaller, pointed,
green structures, which here also may be explained as derived
from the stipules of the sepals.

The petals are also borne on the margin of the flattened recep-
tacle, and alternate with the sepals. Each is bright yellow, has a
rounded outline, and is attached by a narrow base. Within the
corolla we come to numerous stamens inserted on the upper
surface of the receptacle near its edge. Each has a greenish
stalk and a small bright yellow anther. Centrally, on a rounded
projection of the summit of the receptacle, are the numerous
small carpels. The insertion of each carpel is distinct from that
of the others, and its swollen basal part forms a little green hairy
ovary, while the upper part forms the style and stigma. There is
a little kink or bend in the upper part of the style, while the portion
above this bears the stigmatic surface. Each ovary encloses a
single ovule, but the structure of the ovary will be best made out
after it has enlarged in the fruit.

The fruit develops from the whole group of carpels after
pollination. The petals fall away, the sepals bend back round
the flower-stalk, while the withered remains of the stamens are
visible beneath the enlarged end of the receptacle bearing the
globular group of carpels. Each of these now forms a fruitlet.
The flattened green portion developed from the ovary can now
be opened with the point of the knife, and will be found to contain
a single developing seed. The style has persisted and elongated ;
it bears near the upper end the little bend or hook already referred
to, and beyond this the remains of the stigma. When mature the
fruitlets are readily detached from the receptacle. The hooked
style assists in their dispersion. It would catch readily in the
fur of an animal, as it will be found to do in the cloth of a coat-

THE COMMON AVENS (Gettm urbanum, L.}.

EARLY SUMMER FLOWERS 217

sleeve, and the fruitlet may thus be carried to a distance before it
drops on the soil. Since the fruitlet contains only one seed, it
does not open, and the seed remains protected by the walls of the
fruit until germination. It is very interesting to contrast the
mode of dispersal of the fruitlets in the Avens with what occurs in
the fruit of the Strawberry, which is developed from a very similar
pistil.

Nectar is secreted in the flowers by a ring of the receptacle
between the innermost stamens and the pistil, and the flowers
are visited by a number of insects. The arrangements of the
parts is such as to favour cross-pollination, though self-fertilisa-
tion is possible. The stigmas begin to be mature when the
flower opens, and project in front of the stamens. The latter
are bent inwards in the bud, owing to the curvation of the fila-
ments, but straighten and diverge as they are ready to open.

Besides the Common Avens, the Water Avens (Geum rivale, L.)
and a form which is intermediate between the two, and is prob-
ably a hybrid, are found in Britain.

THE BUGLE (Ajuga reptans, L.).

The Bugle is to be found in grassy land, usually in moister
spots and in the shade of woods. It often grows in numbers in
one spot. The flowering season is from May to July, and for the
proper study of the plant a number of specimens with intact
branches should be collected. It will be found that each plant
(Fig. 98) consists of a short, underground stem, from which long
whitish roots extend downwards. This bears a rosette of crowded
foliage-leaves or their remains, and in the axils of some of the
leaves buds can be seen, some of which have developed into
prostrate branches or runners. The main stem continues into
the erect flowering shoot. All these parts must be considered
if we are to understand how the Bugle maintains itself and
extends in the struggle with other plants.

The stem of the erect main shoot is square with somewhat
rounded angles. Each node bears a pair of leaves, the pairs alternat-
ing at successive nodes. The leaves have simple blades, narrowing
below where they pass into the leaf-base, but not very distinctly

218

THE BOOK OF NATURE STUDY

stalked. The leaf-bases of the two opposite leaves may meet
around the stem and form a short sheath. The leaves of the
basal rosette have longer stalks. In the axils of the lower pairs
of leaves only small buds may be present, but on passing up-
wards the leaves gradually dimmish in size, and in the axil of each

a cluster of flowers is
present. As Fig. 98
shows, the two oppo-
site groups of flowers
appear to completely
surround the stem.
Each axillary group
of flowers is a little
inflorescence with
greatly shortened
flower - stalks. The
central flower, imme-
diately above the
bract, is the first to
open, and is then fol-
lowed by flowers to
either side borne later-
ally on the stalk of
the central flower and
so on. The whole ar-
rangement resembles
that in the Dead-
nettle, a close relation
of the Bugle.

The flowers of the
two plants are also
constructed on the

same plan, though with important differences of detail. In the
Bugle (Fig. 99) the sepals are united to form a wide bell-shaped
calyx, with five large teeth at the margin that indicate the number
of the sepals. The margins and back of the lobes bear stiff
hairs, while the lower tubular portion of the calyx is smooth and
often bluish in tint. The petals are united to form a narrow

FIG. 98. — Plant of the Common Bugle in flower.
(After Baillon.)

EARLY SUMMER FLOWERS

219

FIG. 99. — Flower of the Bugle seen from
the side. (After Baillon.)

tube almost one-third of an inch in length. This is somewhat
widened at the lower end within the calyx, and at the free end
is divided into two lips of very unequal size. The upper or
posterior lip is very short, and
is formed of the projecting tips
of two petals, which can be
distinguished as small rounded
lobes. The lower lip, on the
other hand, extends in front of
the tube as a three-lobed expan-
sion of considerable size. The
lobing indicates the three petals

of which it is composed ; the large petal forming the middle lobe
is notched. The whole corolla is of a bright blue colour, some
of the veins on the lower lip being a darker blue.

As in the Dead-nettle, there are only
four stamens, the stamen which might be
expected to alternate with the posterior
petals being completely absent. In the
Bugle, owing to the shortness of the upper
lip, the stamens project beyond it, and
are visible from the outside of the flower.
They form two pairs, a longer and a
shorter, so that two of the anthers stand
in advance of the other two. All the
anthers face downwards. On slitting up
a corolla-tube the filaments will be found
^ , to be attached to the inside of this. The

FIG. TOO.— Pistil of the Bugle

showing the four-iobed anthers, which project clear of the upper
ovary, the style and the ^p^ at first stand close to the middle line,
two - lobed stigma, in Behind the stamens is the forked stigma

front of the ovary is the «? •

nectary. (After Baillon.) which ends the long style. If a corolla is
carefully pulled away from the rest of the

flower the style will be left in position, and will be seen to spring
from the middle of four green shining bodies (Fig. 100). These
are the four lobes of the ovary, and each encloses a single ovule.
As the stigma, with its two lobes directed forwards and back-
wards, indicates, these lobes are derived from two carpels, as in

220 THE BOOK OF NATURE STUDY

the Dead-nettle. On removing the calyx from around the ovary
a yellowish gland will be seen at the base of the latter in front.
This is the nectary, and the nectar secreted by it accumulates
in the lower portion of the corolla tube.

If we now look at the flower as a pollination mechanism we
shall obtain an explanation of some of the differences between
it and the Dead-nettle. The flower of the Bugle is visited by
a number of kinds of insects, of which bees are the most im-
portant. These come after the nectar stored in the base of the
corolla, and, owing to the length of the tube, it is clear that only
insects with fairly long tongues can reach the nectar and will
visit the flowers. The insect alights on the expanded lower lip,
and the back of its head and body will come in contact with the
downwardly directed anthers and be dusted with pollen. Since,
however, the stigma has its lobes, which are receptive on the
inner surface, separated while the pollen is being shed, we might
expect that the flower's own pollen would be deposited on the
stigma. This may ultimately occur, but cross-pollination is
favoured by the position of the stamens. The two shorter
stamens, which are at first close together in the middle line, come
between the insect and the stigma. In older flowers these
stamens diverge somewhat from one another, and the style is no
longer supported so that the stigma bends forward. The position
that it now occupies is such that it comes in contact with the
portion of the insect's back which is dusted with pollen from
younger flowers.

The four lobes of the ovary enlarge after fertilisation, and
the ovule within each develops into a seed. The lobes of the
fruit do not open to set the seeds free, but the four lobes separate
and are shed, each enclosing a single seed.

While the spread of the Bugle to any distance, and its establish-
ment in a new locality, must depend upon the transport of seeds,
the local spread of the plant is effected vegetatively. The pros-
trate branches, which were seen to be developed at the base of
the plant, resemble in general features the erect shoots, but have
a thinner stem with long internodes. Their leaves have longer
stalks, and twist round so that the blades are exposed to the
light. Roots spring from the nodes where they rest on the

EARLY SUMMER FLOWERS 221

ground. At any of these points or from the terminal bud a
new plant may be established. It becomes free from the
parent by the ultimate decay of the intervening region of the
runner, and is at such a distance from the parent as to lessen
the danger of competition. If we examine the base of a flower-
ing plant we can often distinguish the end of the runner passing
into the somewhat swollen stem described above.

THE YELLOW IRIS OR FLAG (Iris Pseudacorus, L.).

Two kinds of Iris, of which much the commoner is the Yellow
Flag (Coloured Plate), grow wild in Britain. The following de-
scription of this will, however, assist the student in examining
other kinds of Iris, whether wild or cultivated, allowance being
made for differences in detail. The Yellow Flag grows best in
damp spots, in marshy ground and by the sides of small streams
and ditches. It often occupies a considerable area, and its long
erect bluish-green leaves and large yellow flowers make it a con-
spicuous plant during the summer. If the spot where it grew is
examined in winter no trace of the foliage will be seen, only the
underground parts remaining, as is the case with so many of our
perennial plants.

Plants should be carefully dug up and the underground stem
and roots washed free from the soil. Many of the stems will be
found to end in vegetative shoots. Others, however, have pro-
jecting from among the foliage-leaves a tali inflorescence, which
bears a succession of large flowers. The two kinds of shoot
require separate study.

In a plant without an inflorescence we recognise the thick
horizontal stem more or less completely covered by the soil. Its
surface is brown, but when cut across the tissue within is pinkish.
The older parts bear the remains of foliage-leaves of former years ;
these are transverse scars almost encircling the stem. Projecting
from them are long, brown, bristle-like threads, the remains of the
more persistent tissues of the leaf -base. Two kinds of roots spring
from the stem. From the lower surface a number of stout cylin-
drical whitish roots grow vertically down into the soil. They are
at first unbranched, but later become attached to the soil by a

222 THE BOOK OF NATURE STUDY

number of fine lateral roots. If the younger roots of this kind be
compared with older ones the surface will be found to be at first
smooth, and later to become wrinkled transversely. This shows
that contraction has taken place, and these roots, in fact, serve to
pull the horizontal stem firmly down into the soil, and are of
subordinate use for obtaining food material. From the sides and
upper surface of the stem, however, roots of a different nature
spring. They are more slender, and bear numerous fine branches.
Their appearance shows them to be purely absorptive in contrast
to the fixing and contractile roots.

At the end of the leafless region of the stem we find the tip
of the shoot turned somewhat upwards, and bearing the foliage-
leaves. Through the bases of these leaves a number of young
attaching roots project, and it is easy to realise how they correct
the upward curve of the tip and pull it down into the ground. To
either side of the terminal leafy shoot are smaller shoots, evidently
developed from lateral buds of last year, and similar lateral buds
may be seen farther back on the main shoot. Evidently this
grows on for a number of years, producing lateral shoots most
of which do not develop farther.

The leaves of the Iris are very remarkable. Each has a large
sheathing base completely encircling the stem, and they succeed
one another closely on opposite sides of the stem, so that they
alternate in two ranks. The erect blade of the leaf is not, however,
flattened in the horizontal but in the vertical plane. It appears
as a pointed, sword-shaped outgrowth of the back of the leaf-
sheath, showing not an upper and lower surface, but two similar
flat sides. The veins run parallel in the leaf -blade.

We can carefully remove the leaves one after another from the
shoot, and recognise how perfectly they enclose the summit of
this. Small lateral buds will be met with in the axils of the leaves.
Centrally the shoot terminates in a series of smaller and smaller
immature leaves overlapping one another, and ready to develop
into next year's foliage-leaves. The study of these with a lens will
show the origin and enlargement of the leaf-blade.

When an inflorescence is not formed the shoot grows on year
after year. If, however, a plant bearing an inflorescence such as
that represented in the plate is examined the general features of

EARLY SUMMER FLOWERS 223

the underground stem (Rh.), the contractile roots (R1), the
absorptive roots (R2), and the lateral buds borne on the sides of
the stem (B) will be found as has been described above. The
terminal leafy shoot, however, ends in a long green erect stem, the
stalk of the inflorescence. Since the apex has grown into this,
it cannot continue the growth of the shoot next season, and this
must be carried on by one or more of the lateral branches.

The inflorescence consists of a cylindrical green stem with
elongated internodes. It bears a few leaves of diminishing size,
and with no branches in their axils. Then come smaller bracts,
and the stem ends in the first flower. In the axil of one of these
bracts stands the second flower, the stalk of which bears a single
small bract ; in the axil of this the third flower develops, and so on.
Each axis ends in a flower, and produces another flower as its
single lateral branch. The succession of flowers, which is not
clearly shown in the plate, requires to be carefully looked for,
since the opening flower always appears to stand at the summit
of the shoot. Branch inflorescences may be developed in the axils
of one or more of the lower leaves on the inflorescence.

The flower of the Iris is one of the most beautifully constructed
arrangements to ensure cross-pollination by means of insects. Its
structure and mode of working were made out by Sprengel, the
discoverer of insect-pollination, and should be carefully studied
in several specimens. Each flower has a rounded flower-stalk,
which bears the bracteole mentioned above near its base. The
flower-stalk, which lengthens just before the flower opens and
thus carries it clear of the bracts, continues into the three-sided
green, inferior ovary. If this is cut across it will be found to have
three flattened sides, while the angles are truncated, and each shows
a narrower groove. The three partitions extend inwards from the
middle of the flat sides, and each of the three cavities has two
rows of ovules springing from the central angle.

The perianth of the flower (Fig. 101) consists of six yellow leaves
forming two whorls. The leaves of the outer series are broader and
recurved, while the inner ones are narrow and erect. All six join
together to form a short tubular region just above the inferior
ovary. The inner surface of the tube is yellowish, and secretes
the abundant nectar, which accumulates around the base of the

224

THE BOOK OF NATURE STUDY

style. There are three stamens, attached to the inner surface of
the larger perianth segments, and standing up opposite to these.
Each stamen has a strong curved stalk and a large anther, the
two lobes of which face and open outwards and downwards.
Three styles spring from a cylindrical portion in the centre of
the flower terminating the inferior ovary. The styles are broad
and leafy, or petal-like, and they lie opposite to the broad outer
perianth segments, and thus above the three stamens. Each

stamen is thus enclosed
between the perianth seg-
ment and the leafy lobe
of the style, which fit
closely together and hide
the stamen. The tip of
the style is two-lobed, and
has a wide thin margin
and is bent upwards. Just
before this bend takes
place a little projecting lip
can be seen on the under
or outer surface of the
style. This is the stigma,
the upper surface of the
lip being the receptive
surface. The fact that
the branches of the style
do not alternate with the
stamens indicates that an

inner whorl of three stamens is wanting in this flower. As a work-
ing arrangement in pollination each third of the Iris flower can
be compared with an irregular flower. Humble-bees are mainly
concerned in the pollination. These alight on the broad landing-
place formed by one of the outer perianth segments, and, guided
by the brown lines or honey-guides on this, will force it and the
style apart. Having crept in between the perianth-leaf and the
style, the bee can reach the nectar by a passage to either side of
the stalk of the stamen, where this is attached to the perianth.
In thus creeping into the flower the bee first rubs its back against

FlG. 101. — Flower of Yellow Flag cut in half, y^
outer segment of the perianth ; z, inner segment
of perianth ; s, stamen ; gt branch of the style ;
a, the stigmatic lip. (After Warming.)

YELLOW FLAG (Ins Psetid-acorus, L.).

Rh. Underground stem. R1. Attaching roots. R2. Absorbent roots.

Infl. Base of inflorescence. B. Lateral bud.

EARLY SUMMER FLOWERS 225

the stigmatic lip and then against the downwardly directed open
anther. On creeping out of the flower the pollen on the bee's
back will only come in contact with the non-receptive side of
the stigmatic lip. When a bee with pollen on its back enters
another third of the same flower or another flower, the pollen
will be deposited on the stigmatic surface of the scoop-like lip.
If the visit is to another flower, cross-pollination will result.
Consideration of the very beautiful arrangement of the parts in
this flower shows that pollen cannot possibly fall on the stigma
in the absence of insect visitors, and that insect visits may
result either in pollination of the stigma of one third of the flower
by pollen from the stamen of another third or in cross-pollination.
The close fitting of the style on the perianth segment excludes
small and weak-bodied insects which would be useless to the
flower.

The fruit of the Iris consists of the enlarged inferior ovary,
from the summit of which the withered remains of the rest of
the flower has fallen. This becomes a dry capsule, which, like
the ovary, is triangular on cross section. When ripe it splits
along the three angles, thus opening the cavities from which the
flattened seeds escape.

THE GERMANDER SPEEDWELL (Veronica Chamadrys, L.).

A number of kinds of Speedwell are found commonly in
Britain ; some grow in ditches and damp places, while others prefer
drier spots. The Germander Speedwell is readily recognised by its
bright blue flowers and by the two lines of white hairs running
down opposite sides of its stems. It can be found everywhere in
dry grassy land and by roadsides, preferring open sunny situations.

The plant is perennial, and has a smooth cylindrical under-
ground stem sending out numerous roots at the nodes. Branches
arise from the axils of the reduced leaves borne on this stem, and
grow up into the leafy shoots. Each of the latter has a
cylindrical green stem, often tinged with purple, and bears a pair
of leaves at each node. The successive pairs of leaves alternate,
and they are separated by rather long internodes. The leaf,
which has hardly any stalk, is inserted on the stem by a broad

VOL. III. — 15

226 THE BOOK OF NATURE STUDY

sheath-like base. The blade is triangular in outline, and its edge
is cut into large teeth pointing towards the tip. The surface is
wrinkled, and the veins project strongly on the lower surface.
Small stiff white hairs are scattered on both surfaces, and are
more numerous on the veins below. Down each internode of the
stem from the interspaces between the two leaves of the whorl
run two lines of long white hairs. These rows of hairs thus
alternate in successive internodes.

Inflorescences are developed in the axils of a number of the
upper leaves. The lower portion of the stem of this is leafless,
but on the upper part are numerous narrow simple green bracts,

in the axil of each of which is a single
flower. The stem is round and bears hairs
on all sides, not in two definite rows.
Another point of difference from the vege-
tative shoot is that the leaves are inserted
singly and not in whorls of two. The flowers
open in regular succession from below
upwards.

Each flower has a slender flower-stalk,

FIG. 102.— Flower of Ger-
mander Speedwell, seen and consists of the following parts. The
from in front. (From calyx is green and hairy, and consists

aPParently °f f°Ur S6Pals- TheS6 are naiTOW

and pointed, and only united for a short
distance at the base. Comparison with the flowers of related
plants, such as the Foxglove, shows that the sepal which
should stand in the middle line behind is wanting. The petals
forming the corolla are united, and the corolla is very readily
removed or falls off in a piece carrying the stamens with it.
It appears to be composed of four petals, which alternate in
position with the sepals. Comparison with related plants shows,
however, that the posterior petal is really the equivalent of two
petals fixed together. This lobe of the corolla is broader than
the others ; the two lateral petals are also fairly broad, while the
anterior petal is narrow (Fig. 102). The tubular portion of the
corolla, from which the lobes in full-blown flowers expand almost
at right angles, is very short. Looked at from in front, the blue
petals are seen to be marked with deeper blue lines converging

EARLY SUMMER FLOWERS 227

towards the centre of the flower, and here the tubular portion of
the corolla and the bases of the petals are white. The entrance
to the tube is protected by a fringe of hairs around the lower
margin.

There are only two stamens, which diverge widely in a fully
open flower. They are inserted on the inner surface of the
corolla tube, opposite the gaps between the broad middle segment
behind and the lateral petals. The stalks are thin and curiously
curved at their insertion on the corolla. Farther up the stalk has
a blue colour, while the anther and the pollen contained within
it are white.

The style, which projects from the corolla tube, is also slender
and blue. It slopes downwards in front of the narrow anterior
petal, and bears the small stigma farther forward than the other
parts of the flower. The style springs from a flattened, green
ovary, as is readily seen on removing the corolla from a flower.
Careful dissection of the ovary, with the help of a good magnifying
glass, will show that it is divided into two by a septum. Each
half is, in fact, formed by one of the two carpels, which are united
to form the pistil. In each cavity are a few ovules.

Around the base of the ovary is a narrow yellow rim which
secretes the nectar, and it will be evident that this is accessible
even to short-tongued insects. The nectar is not, however, openly
exposed, as in some flowers, but is protected by the circle of hairs
within the corolla-tube. The flowers are visited by a number of
insects, but especially by small flies, to which they are specially
adapted. These come in search of the nectar. If, as is usually the
case, the fly approaches the flower on the wing immediately in front,
the first part of the flower to come in contact with the lower surface
of its body will be the stigma. Alighting on the flower, the insect
may be seen, in trying to gain a foothold, to grasp the bases of
the stamens and to draw them together with its legs, thus rubbing
the anthers against the under surface of its body. This region
will, after visiting a flower, be dusted with pollen, and on the
insect going to another flower the stigma will receive some of
this. If the position of the various parts in the open flower is
taken into account it will be readily understood that the pollen
would not be likely without insect agency to get from the anthers,

228 THE BOOK OF NATURE STUDY

borne to either side on long stalks, to the stigma, projecting in
the middle line in front. The whole apparatus is, however, suited
for cross-pollination by the help of small flies, and the way in
which it works can be verified by careful observation of a group
of the plants on a sunny day. The reduction in number of the
stamens to two is an indication of the precision of the method of
pollination.

That fertilisation is effectively carried out is evidenced by the
number of ripe fruits borne by the inflorescences later in the
season. These are developed from the enlarged ovary, and are
still surrounded by the calyx. The capsule has the shape of a
flattened, inverted heart, and in each cavity are several seeds.
These are shed when the ripe fruit opens.

END OF VOL. III.

Printed by MORRISON & GIBB LIMITED, Edinburgh

THIS BOOK IS DUE ON THE LAST DATE
STAMPED BELOW

AN INITIAL FINE OF 25 CENTS

WILL BE ASSESSED FOR FAILURE TO RETURN
THIS BOOK ON THE DATE DUE. THE PENALTY
WILL INCREASE TO SO CENTS ON THE FOURTH
DAY AND TO $1.OO ON THE SEVENTH DAY
OVERDUE.

6 1934

LD 21-100m-7,'33

ITY OF CALIFORNIA LIBRARY