35. PLANTS WHICH SOW THEIR OWN SEEDS.
1. =The fruit of the wallflower.=—Examine wallflower fruits and make
out that each consists of the ripened pistil. Does the fruit open of
itself? How many chambers does it consist of? Where are the seeds
attached? Are they blown off at last by the wind? Draw the fruit. It is
called a _siliqua_.
2. Compare with this the fruit of _shepherd’s purse_ (Fig. 62), and
_penny cress_ (Fig. 132), and notice that they are of the type of the
wallflower fruit, but are much broader in proportion to the length.
Such a fruit is called a _silicula_. Draw.
3. =The fruit of the pea.=—Examine a ripe pea-pod and compare it with
(_a_) the pistil of an unfertilised flower, (_b_) a half-ripe pod. How
many carpels have taken part in forming the pod? How many seeds (peas)
does the pod contain? Leave a pod on the plant until the shell becomes
dry, to find out how the fruit opens. Does it open along one edge only,
or along both? How are the seeds attached? Such a pod is called a
_legume_. Draw it.
Compare and draw the legumes of the _broad bean_, _French bean_,
_scarlet runner_, _laburnum_ (remember its seeds are poisonous), and
_bird’s foot trefoil_. The legume of the bird’s foot trefoil bursts
open suddenly and scatters the seeds in the air. Is the scattering of
the seeds any advantage? Why?
4. =The fruit of the field geranium.=—Make out that five carpels are
grouped around a central rod. Examine fruits which have opened. About
noon on a bright, sunny day gently touch a ripe fruit with a small
brush, and watch the carpels spring back from the rod and jerk the
seeds into the air. Compare and contrast this fruit with a siliqua,
silicula, and legume respectively.
5. =The fruit of the poppy.=—Examine a poppy head. The top of the
fruit is the stigma. Observe below this a line of small holes running
round the fruit. Draw. Shake the fruit, and notice that seeds fall out
through the holes. Cut the fruit across to see the large number of
small seeds inside. How does the fruit hang on the growing plant? Does
the wind shake it and liberate the seeds?
6. =The fruit of the pansy and violet.=—Watch the ripening of the
fruits on the plants. Observe that the ovary swells up into an
egg-shaped body which afterwards splits into three boat-shaped valves
containing seeds. Try to make out why the seeds are one by one shot out
as the sides of the valves dry. Put a ripe fruit before the fire and
watch the process. Imitate it by placing a pea between two flat rulers
and pressing the rulers together.
=The origin of a fruit.=—When the ovules of a flower have been
fertilised (p. 92) by the pollen tubes they change into seeds
which have the remarkable power of growing up—in favourable
circumstances—into plants resembling that which produced the seeds.
This is not, however, the only result of fertilisation. Whilst the
ovules are changing into ripe seeds, those parts of the flower—the
stamens, corolla, and calyx—which have finished their work wither and
fall off, though the calyx sometimes remains. Other parts—the pistil
and sometimes the receptacle (p. 90)—take on new duties, and become
gradually modified in order to protect or scatter the seeds.
Thus, the tender wall of the pistil often becomes a woody, leathery,
or juicy seed-case; while the receptacle, or top of the flower stalk,
may become fleshy and swollen with sugary pulp, as a bait for birds
and other animals. In any case we give the name of fruit to all such
altered and persistent parts together with the seeds which accompany
them. A pea pod, for example, is as truly a fruit as a plum, and a
poppy-head as a strawberry.
What a fruit is like depends to a great extent upon the characters of
the pistil which gave rise to it. If, for example, the pistil consists
of several separate carpels, the ripened carpels or fruits will also
be separate. When, on the other hand, the pistil is composed of united
carpels, these will remain united, at least until the fruit is ripe.
Then in some cases they come apart.
[Illustration: FIG. 131.—_A_, fruits of wallflower (× ⅕); _B_, siliqua
(× 1); _C_, siliqua open.]
[Illustration: FIG. 132.—Fruits (siliculae) of Penny Cress. (Nat.
size.)]
The part of a fruit which is derived from the walls of the pistil is
called the =pericarp=.
=The fruit of the wallflower.=—After fertilisation the stamens, petals,
and sepals of the wallflower drop off, leaving the pistil alone on
the top of the flower stalk. The pistil increases greatly in size
(Fig. 131, _B_) during the ripening of the seeds. At last its wall
(the pericarp) splits into two flaps. These become free at the bottom,
exposing a central plate which bears the rows of seeds. When the seeds
are quite ripe, a slight breeze is sufficient to shake them off,
and they fall to the ground to take their chance of finding a place
favourable for germination.
A fruit with a dry pericarp, which opens of itself when the seeds are
ripe, is called a =capsule=. This particular kind of capsule—consisting
of two carpels which come apart at maturity, leaving a central
partition bearing seeds—is known as a =siliqua=. When it is short in
proportion to its length, as in the shepherd’s purse (Fig. 62) and
penny cress (Fig. 132), it is distinguished as a =silicula=.
=The fruits of the pea tribe.=—The pod of the pea (Fig. 3) and its
relatives is a capsule of another kind. It consists of one carpel only,
and opens, when ripe, along both back and front margins to liberate
the seeds. Such a fruit is called a =legume=. In the young fruit the
pericarp is somewhat fleshy and succulent, but it becomes dry during
ripening. The legume of the bird’s foot trefoil bursts open suddenly,
and throws the seeds to a considerable distance.
=The fruit of the field geranium= (Fig. 133) is a long capsule composed
of five carpels arranged round a central column (_A_). When the seeds
are ripe, the carpels suddenly spring from the rod, remaining attached
only at their upper ends (_B_), and fling the seeds into the air. The
method may be watched by stroking the fruits very gently with a small
brush, when they open in the manner described. The experiment is most
likely to succeed in dry, sunny weather, about the middle of the day.
=The fruit of the poppy.=—The pistil of the poppy swells during
ripening into a large, globular capsule known as the poppy head. The
top of the fruit (Fig. 134) is the persistent stigma. Just below this,
a line of small holes like windows runs round the head. As the fruit
hangs inverted on the top of the flower stalk it is shaken about by the
wind, and the tiny seeds fall out through the windows.
[Illustration: FIG. 133.—Field Geranium (× ¼).]
[Illustration: FIG. 134.—_A_, capsule of poppy; _B_, cross section of
capsule (× ¼); _C_, seeds.]
=The fruit of the violet or pansy.=—The arrangement by which the
violet (Fig. 134) or pansy sows its seeds is most interesting. After
fertilisation the ovary swells into a great egg-shaped capsule, in the
inside of which the seeds are arranged in three rows. When the seeds
have become ripe and hard, the capsule splits down the side along three
lines, and is thus divided into three parts. These open outwards, and
bend back as shown in Fig. 135. Each is a boat-shaped valve. The seeds
inside are thus exposed to the air, and they soon dry and become ready
for scattering.
[Illustration: FIG. 135.—Violet. _F_, explosive fruit; _S_, seeds being
shot out of fruit.]
Then the curved sides of each valve begin to straighten and come
together, and naturally allow less and less room for the hard, smooth
seeds inside. The pressure of the sides of each valve on the seeds
inside it becomes greater and greater, until one by one they are shot
out to a considerable distance. If a ripe violet ovary be warmed before
the fire the whole operation may easily be watched. The process may
be imitated by putting a pea between two flat rulers and pressing the
rulers together, when the pea may be shot to a distance of several
yards.
=Why fruits are scattered.=—A flowering plant is practically confined
for life to the place where it first sprang up, so that it is unable
to go about and select favourable situations for its offspring. On the
other hand, if the seeds simply fell to the ground beneath the parent
plant, the seedlings would generally be so crowded together that they
would interfere very much with each other’s growth. In addition, they
would often be under a great disadvantage, because the parent plant
would keep so much light from them. Hence, very many plants have some
special arrangement for scattering their seeds, so that some at least
of the seeds will have a chance of falling in a place where they will
obtain plenty of light, air, and good soil.
In this section we have studied examples of devices by which plants sow
their own seeds. We shall see next that other plants call in the help
of the wind and of animals.
36. SEEDS SOWN BY THE WIND.
1. =The fruit of the dandelion.=—Examine the manner in which the
tiny flowers of the dandelion are grouped together to form the head
(p. 113); and make out the various parts of the flower, especially
the _ovary_—a little white knob at the bottom of the flower, and the
_calyx-tube_—forming a tuft of fine hairs above the ovary. Trace the
development of the fruits: the withering of the corollas and stamens,
the elongation of the calyx-tube, and the expansion of the tuft of
hairs to form a parachute. Blow a dandelion “clock” (the head of
fruits), and notice how the parachutes float the fruits in the air.
Examine “thistle down” and contrast it with the dandelion fruit.
2. =The fruit of the willow.=—Examine the ripened catkins of a female
willow in June, and notice how each fruit has split into halves, which
come apart and expose the silky seeds inside. Pull a tuft of seeds out
and dry them in the sun. Notice that they wriggle and writhe about and
gradually become entangled together into a woolly mass, which is easily
blown away.
3. =The elm fruit.=—About the end of April look for elm fruits. Notice
the flat green plate (wing) with the rounded swelling near the middle
(Fig. 124, 5). Cut open the fruit and see that the swelling is caused
by a single seed. How does the flat wing aid in the distribution of the
seed?
Compare the winged fruits of the _ash_ and _sycamore_ (Fig. 137).
Do these winged fruits drop from the trees easily, or are they torn off
by gales?
Take a pair of sycamore fruits. Cut off the wing from one and let it
and an uninjured fruit fall at the same instant from a height. Which
reaches the ground first? Why?
4. =Pine and fir cones.=—Examine and compare pine and fir cones of
various ages. Break open a ripe cone and see the scales with the pairs
of naked seeds, each seed bearing a thin, papery wing which has split
off from the upper surface of the scale.
[Illustration: FIG. 136.—“Clock” of Dandelion Fruits. (× ¼.)]
=Wind-sown seeds.=—Many plants depend on the wind for the dispersal of
their seeds, and consequently the seeds are provided with outgrowths of
various kinds, which increase the surface greatly without adding much
to the weight, and, acting like parachutes, offer increased resistance
to the air and thus prevent the seeds from falling quickly to the
ground. In some cases the outgrowth is part of the pericarp, in others
it is an appendix carried by the seed itself, while in the lime it is
the bract upon which the flowers were formerly borne.
=The dandelion fruit.=—The fruit of the dandelion (Fig. 136) affords
one of the best possible examples of wind-dispersal. It will be
remembered (p. 113) that what is commonly called the flower of the
dandelion is really a head of perhaps 300 complete flowers: each with
a hairy calyx-tube, a yellow, strap-shaped corolla, five stamens, and
a pistil. When the flowers have been fertilised, the yellow corollas
and the stamens wither, the ovary increases in size with the ripening
of the single nutlet in its interior, and each calyx-tube elongates
until it is about an inch in length, the tuft of fine hairs being still
at its upper end. The attachment of the fruit (Fig. 86, 4) to the disc
(receptacle) is so slight when the seed is ripe that a very gentle puff
of air is sufficient to overcome it. The tuft of hairs at the upper
end has by this time expanded until it acts like a parachute, which
supports the tiny fruit for a long time in the air.
The common =thistle=—a relative of the dandelion—also distributes its
fruit by means of a tuft of fine hairs derived from the calyx. In this
case the hairs radiate from the seed. Such “thistle down” is commonly
found floating through the air in summer.
[Illustration: FIG. 137.—A pair of Sycamore Fruits. (× ⅔.)]
=The willow fruit.=—The catkins of the female willow are ripe in June.
Each catkin consists of a large number of tiny pods derived from the
ovaries of the flowers (p. 151). Each fruit splits into halves, which
bend back from each other (Fig. 121, _F_), exposing the silky seeds
within to the warmth of the sun. The seeds (_H_) turn and twist about
as they dry, and gradually entangle themselves together into a light,
woolly mass, which is easily blown to great distances by the wind. The
willow and the dandelion, therefore, use very similar devices to ensure
the dispersal of their seeds, although these plants are not at all
nearly related.
=The fruits of the elm, sycamore, and ash.=—These common forest trees
bear fruits with the seed attached to a flat plate, which is an
outgrowth of the pericarp (p. 167). In the elm fruit (Fig. 124, 5) the
plate is green and oval, and the seed forms a rounded swelling at,
or near, its middle. The fruits of the =sycamore= generally grow in
pairs (Figs. 33 and 137). Each half consists of a single seed with an
attached membranous plate, and the two seed-boxes of each pair are in
contact. The fruits of the =ash= hang from the twigs in bunches called
“keys,” each fruit on a separate little stalk. The plates which bear
the seed are long, narrow, and oval in shape.
It is plain that such plates, or wings, expose a relatively large
surface to the air and prevent the fruit from falling to the ground as
quickly as it otherwise would. The fruit is thus often blown to a great
distance before it finally settles and the seed germinates. The action
of the wing may be well shown by cutting off the plate from a sycamore
fruit and letting it and one with an attached wing fall at the same
instant from a height. The seed without a wing comes straight down as a
pea would; but the winged seed spins in the air and settles more slowly.
In the case of the round downy fruits of the =lime=, a similar service
is performed by the bract (Fig. 126), upon which the flowers were
carried.
=Pine and fir cones.=—If a ripe pine, or fir cone is broken open, it
will be seen that each seed is attached to a thin, papery wing (Fig.
130, 4), which has split off the upper surface of the scale bearing the
seeds. The winged seeds are shaken out of the cone by the wind, and
blown away.
=Trees alone bear winged seeds.=—Winged seeds would be useless to any
but fairly high trees, because if they were formed on the low plant
they would fall to the ground long before the wind could catch them
properly. It is also interesting to find that such seeds are generally
attached so firmly that they are only broken off by gales strong enough
to carry them a considerable distance.
On the other hand, the tiny plumed fruit of the dandelion or thistle is
so very light in comparison with the surface exposed to the air that it
takes quite a long time to fall even a few inches.
37. SEEDS WHICH ARE SCATTERED BY ANIMALS.
1. =Hooked fruits.=—Examine plants of _herb bennet_ (wood avens) in
summer and autumn, and find the fruits. Brush your sleeve against the
fruits, and notice how they cling to the cloth. Examine them with a
lens and observe the hooks at the ends of the styles.
Compare _goosegrass_ (cleavers) and find the hooks on the fruits.
2. =Nuts.=—Examine a _hazel_ nut. Notice the sheathing bracts at the
base of the fruit. Crack the nut and examine the broken edge of the
shell (pericarp) with a lens. Make out the three layers which compose
it. How many seeds are present? Cut the seed (kernel) across and see
that the bulk of it consists of two cotyledons (Chap. I.). Does the
fruit open of itself, if undisturbed?
Compare the acorn of the _oak_. Trace the development of the acorn from
the female flower, noticing that the cup is developed from a wrinkled
disc surrounding the lower part of the flower. Cut across the ovary
in June and notice that there are six ovules in it. In the ripe fruit
observe that the cup separates easily from the nut. Remove the shell
(pericarp) of the nut. How many seeds does it contain? What do you
think has become of the other five ovules? Cut through the seed and
observe the two cotyledons.
Compare the fruits of the _beech_. Notice that they are three-sided
nuts (each being a seed enclosed in a woody pericarp); and that two
nuts occur together, surrounded by a bristly woody cup which splits,
when the nuts are ripe, into four valves.
3. =Stone fruits.=—Examine a ripe _plum_. Cut it open and crack the
stone to see the single seed. Notice that the pericarp consists of
three layers as in the hazel nut, but that here the middle layer is
soft and fleshy, and the outer layer is the “skin.” The stone is the
inner layer of the pericarp. Is there any special means of liberating
the seed? Compare the _cherry_, and examine the seed and the three
layers of the pericarp.
Examine the fruits of the _blackberry_ and _raspberry_, and observe
that each consists of several small stone-fruits arranged on the
receptacle.
4. =Berries.=—_The gooseberry._—Notice the stalk at the bottom of the
fruit, and, at the top, the withered remains of the calyx. Cut across a
half-ripe gooseberry and observe the thick, fleshy pericarp enclosing
the seeds. Treat a ripe gooseberry in the same way, and observe that
the pericarp has now for the most part become a soft pulp, in which the
seeds are embedded. The rest of the pericarp is a membranous skin. Is
there any special means of liberating the seeds?
Compare _grapes_, _currants_, _oranges_, and _vegetable marrow_ fruits,
and notice that the structure of these resembles that of the gooseberry.
5. =The apple.=—Cut across the receptacle of the flower (apple blossom)
and notice how the five carpels are buried in it (p. 106). Trace the
formation of the fruit, and see how the _receptacle_ becomes larger
and larger during ripening. At the top of the ripe fruit observe the
withered remains of the calyx. Cut the apple through across the middle
to see the _core_. This consists of the horny walls of the five carpels
and the contained seeds (pips). From what part of the flower is the
fleshy, eatable part of the apple derived? Compare the _pear_.
6. =The rose hip.=—Examine fruits of the wild rose. Notice that they
are urn-shaped. On the flat rim of the urn observe the five scars
left by the sepals (or, in some cases, the sepals themselves). In the
opening of the urn see a tuft of greyish hairs. Cut the fruit down from
top to bottom through the middle to see the thick, fleshy wall of the
urn and the contained _nutlets_. From what part of the flower is the
fleshy wall of the hip derived? Examine a nutlet. What does the tuft
of hairs seen in the mouth of the urn consist of? Open a nutlet with a
needle and pick out the seed.
7. =The strawberry.=—Cut a strawberry down the middle and notice at the
base the persistent calyx, in the inside the fleshy receptacle, and on
the outside the yellowish nutlets. Open a nutlet with a needle and pick
out the seed.
=The help of animals.=—It has been seen in Chapter VI. that insects
play a very important part in the fertilisation of many flowers. Very
many plants also call in the aid of animals at a later stage for the
dispersal of the seeds, and the devices by which this aid is obtained
are often very ingenious.
=Hooked fruits.=—Sometimes after a country walk the reader has probably
found small fruits and seeds sticking to his clothes. They have become
attached to the cloth by means of small hooks which they carry. The
fruit of the =herb bennet= (wood avens) is a good example of this
device. When the stigma of the fruit breaks away, a little hook is
left at the top of the style (Fig. 138). Goosegrass or cleavers—a
common hedgerow plant—and many others have also hooked fruits. Sheep or
cattle, grazing near such plants are very likely to brush against them
and carry off the fruits and seeds in their hair. They may not again
reach the ground until they have been carried far from the place where
they grew.
=The position of hooked fruits.=—It is evident that these little hooks
would be quite useless if the fruits grew out of the reach of animals.
Such hooked fruits are never found, for instance, on high trees.
[Illustration: FIG. 138.—_A_, Aggregate Fruit of Wood Avens (nat.
size); most of the stigmas have broken off. _a_, _a_, _a_, fruits with
stigmas still attached; _c_, calyx; _B_, single fruit with stigma still
attached (magnified); _C_, single hooked fruit after loss of stigma
(magnified).]
=Nuts.=—A fruit which has a dry, woody pericarp and does not open of
itself is called a =nut=. The fruits of the hazel, oak, and beech are
good examples. The shell (pericarp) of the =hazel= nut (Fig. 139)
is composed of three layers, and encloses a single seed, or kernel.
The nut of the =oak= (Fig. 113) is called an acorn. Its lower part
lies in a cup developed from a wrinkled disc by which the lower part
of the female flower was surrounded. When the fruit is ripe the nut
easily separates from the cup. The acorn contains one seed only, which
consists largely of two swollen cotyledons. If the ovary of the
female flower of the oak is cut across in June six ovules are found
in it. As in the case of the hazel only one ovule is allowed to reach
maturity; the rest are sacrificed in order that the remaining one may
be more perfectly developed. In the =beech=, two three-sided nuts occur
together, surrounded by a bristly, woody cup, which splits into four
valves when the nuts are ripe.
[Illustration: FIG. 139.—_A_, group of Hazel Nuts (× ½); _B_,
longitudinal section of fruit.]
=The dispersal of nuts.=—=Squirrels= and other nut-eating animals are
instrumental in the dispersal of the seeds in a somewhat indirect
manner. They have a habit of storing up nuts and seeds in holes; but in
their active life these animals often forget where their larder is. The
seeds, thus left to themselves, sprout and grow into trees. The unripe
nuts of the beech are protected from the attacks of squirrels by the
hard bristles on the outer husk.
[Illustration: FIG. 140.—_A_, Plum; _B_, longitudinal section; _C_,
cross section; _E_, _M_, _En_, outer, middle, and inner layers of
pericarp; _S_, seed. (× ½.)]
=Stone fruits.=—A ripe =plum= (Fig. 140) or =cherry= (Fig. 77), like
a nut, consists of a seed and a pericarp; but here the pericarp is
specially modified to tempt animals and at the same time to protect the
seed from them. The inner pericarp-layer is a hard, woody shell called
the stone; the middle part swells up to form a juicy, sweet mass;
while the outer layer constitutes the “skin,” and is often beautifully
coloured.
[Illustration: FIG. 141.—Blackberry. (× 1.)]
=Blackberries= (Fig. 141) and =raspberries= consist of several small
fruits of the plum type, which are arranged round an axis derived from
the receptacle of the flower.
=Berries.=—The =gooseberry= (Fig. 142) is a type of this class of
fruit. It contains several seeds. The pericarp is thick and fleshy
before the fruit is ripe, but during ripening the greater part of it
becomes a soft, sweet pulp in which the seeds are embedded. The rest of
the pericarp is a membranous skin. =Grapes=, =currants=, =oranges=, and
=vegetable marrow= fruits are also berries. The vegetable marrow has
obviously a general resemblance to a half-ripe gooseberry but is on a
much larger scale.
[Illustration: FIG. 142.—_A_, Gooseberry; _B_, longitudinal section;
_C_, cross section. (× ⅔.)]
=The apple.=—In the apple (Fig. 143) we have an example of a fruit
in the formation of which the receptacle has taken a large share.
Even in the flower, the five carpels of the pistil are buried in the
receptacle, and as the seeds (pips) ripen, the =receptacle= swells
until it composes the greater part of the fruit and at last becomes
sweet and fleshy. The carpels with the contained seeds constitute the
=core=. The withered sepals are still to be seen at the top of the
fruit. The structure of the =pear= is quite similar to that of the
apple.
[Illustration: FIG. 143.—_A_, Apple; _B_, longitudinal section; _C_,
cross section. (× ⅓.)]
[Illustration: FIG. 144.—_A′_, Strawberry; _B′_, longitudinal section;
_Ac_, carpel, _R_, swollen receptacle. (× ⅔.)]
=The fruit of the wild rose.=—The fruits of the wild rose are called
=hips=. They are urn-shaped, and on the flat rim of the urn five scars
show the former position of the sepals.
In some cases the sepals themselves have remained. The narrower mouth
of the urn is filled by a tuft of greyish hairs which, when the fruit
is cut open, are seen to be the styles of the carpels. The carpels are
hairy, and stand on the bottom and sides of the urn-cavity. Each carpel
contains a seed. Comparison with the flower shows that the red, fleshy
urn is the developed =receptacle=.
=The strawberry.=—In the strawberry (Fig. 144) the eatable part of the
fruit is again the swollen and juicy receptacle. In this case it has
grown up on the _inside_ of the carpels—the little, yellow nutlets
(carpels) lying on the surface. Each carpel contains a seed.
=Why some fruits are sweet.=—The delicious flavours of sweet fruits
have been developed as baits for the allurement of such animals as are
likely to scatter the seeds to the best advantage. Consider such fruits
as cherries, currants, and rose-hips. Birds—such as thrushes—find
them very nice to eat, and are ready to carry them away to consume at
their leisure. The birds eat the sweet, fleshy part, but in the case
of a stone-fruit they drop the stone and leave the seed to germinate.
A seed which is in danger of being swallowed is either hairy like the
rose-carpels (and therefore rejected because it irritates the mouth
unpleasantly), or it is enclosed in a hard or horny case, upon which
the animal’s digestive juices are unable to act. When the seed is
dropped it is no worse for its experience, and with good luck grows up
into a plant.
[Illustration: FIG. 145.—Holly. The red colour of the fruits contrasts
strongly with the dark-green of the leaves. (× ⅙.)]
=Eatable fruits generally conspicuous.=—In order that birds and other
animals may easily find the luscious fruits which they may eat as
a reward for scattering the seeds, such fruits are almost always
displayed very conspicuously, and are brilliantly coloured. Oranges,
plums, red currants, apples, etc., illustrate this fact well. =Red= is
perhaps the commonest colour of eatable fruits, because it contrasts so
strongly with the green colour of the foliage (Fig. 145).
EXERCISES UPON CHAPTER IX.
1. Name and define the different kinds of self-opening
fruits. From what common plants could you collect examples
of these during an Autumn walk? (N.F.U.)
2. Describe any rough, prickly, or hairy seeds or fruits,
explaining the form and nature of the outgrowths and their
use. (N.F.U.)
3. What wild fruits and wild flowers would you expect to
find in September in your part of the country? In what
kinds of places would you look for them? (N.F.U.)
4. Describe and draw the fruit of a field geranium, and
point out the uses of some of its peculiarities. (1898)
5. Describe the seed vessels of a pansy. Draw one entire,
and also burst open. How does it scatter the seeds? (1898)
6. Shortly describe the fruit of an apple or pear, and of a
cherry or plum. Point out the chief differences between
them. (1901)
7. How are the seeds of cherry, field geranium, and pine or
birch dispersed? (1901)
8. Give examples of seeds which are dispersed by the aid of
birds or other animals, explaining in each case how the
dispersal is effected. (1893)
9. Why is it an advantage to some fruits to be (_a_)
brightly coloured, (_b_) sweet? Give examples.
10. A school museum contains, among other things, some
dandelion fluff, a dish of marrowfat peas, a few nodules
of garlic, and some hawthorn berries. How could you
employ these to illustrate a lesson on plant germination?
(Certificate 1903)