24 CONS. 
reach the stigma of the same flower ; and it appears to be a natural 
law that the offspring of plants “cross fertilized ” shall be stronger 
than those of similar plants if by any chance “ self-fertilized.” 
“Cross fertilization” is largely accomplished by insect aid. 
Bees and other insects come to the flower in search of food and 
are made the unconscious servants of the plants. For an example 
hunt up the Common Furse—always in bloom. Observe the way 
in which the five petals are linked together, so that by pressing 
lightly just where an insect’s weight would act, they become 
suddenly unlinked and the flower bursts to scatter a shower of 
pollen. Thus when a bee alights on a blossom sufficiently mature, 
he gets his breast covered with pollen, which he thereupon conveys 
to another flower ata more mature stage and rubs it against the 
stigma. The whole order of plants to which the Furse belongs— 
the Leguminosa—abounds with contrivances for the same purpose 
and the beginner is strongly recommended to make frequent 
observations in this direction. 
Again, in the Primrose there are two sorts of flowers, which 
differ in the relative positions of the stamens and stigmas. In one, 
the stamens are at the top of the corolla tube and the stigma half- 
way down, and in the other these positions are reversed. It is easy 
by thrusting a long pointed pencil down the tube, to see that the 
proboscis of an insect will serve to carry away pollen from the 
stamens of the one kind to the stigmas of the other. 
Among the Compositae—Daisy, Thistle, Coltsfoot, etc.,—the 
corolla tubes are very small and instead of the insects being 
required to dive into the flower in order to reach the pollen the 
latter is pushed up to the top by the growth of the stigma which, 
when the pollen is all gone, spreads itself out to catch the powder 
from neighbouring flowers as insects drag it along on their legs and 
bodies. In many composites a portion of the florets contain pistils 
but yield no pollen, while others produce pollen and have no pistils. 
Another interesting spring study is to be found in the flowers 
of trees. They are often so small as to be overlooked, especially 
as they in many cases come before the leaves. ‘The Mistletoe has 
its stamens on one bush and its pistils on another, the latter can 
of course only bear the berries. The Yew is another case of the 
same kind. Examples may be multiplied, but go and see for 
yourselves. 
