138 BRITISH PLANTS 
protective mimicry. Others are bitter and unpalatable, 
some are even poisonous—e.g., seeds of laburnum, bitter 
almonds, and nux vomica. ; 
2. The Protection of the Seedling.—The seedling is 
exposed to many dangers, many hardships, and countless 
enemies. Nevertheless, though many perish, some sur- 
vive. At the same time, plants when very young show 
less in the way of protective devices than at any other 
period of their existence. In most cases they survive by 
sheer force of numbers. In seedlings, indeed, we do not 
look for much in the way of defensive equipment apart 
from a good constitution, and this seems all that is 
necessary. The early stages of germination are carried 
on below ground. This in itself is a protection to the 
seedling in its youngest and most helpless condition ; it is 
sheltered by the soil above it from wind and weather, and 
concealed from the observation of a host of predatory 
foes. 
3. The Adult Plant.—The soft and nourishing tissues of 
plants, besides being delicate and subject to injury from 
weather, are exposed to a multitude of living enemies of 
all kinds—animals, insects, parasites, and diseases. An 
ordinary tree—e.g., the oak—is the prey of countless foes. 
Insects deposit their eggs within its soft tissues. From 
these eggs arise destructive pests in the form of voracious 
grubs and hungry caterpillars, which devour everything 
within their reach. Some attack the stems and leaves, 
others the roots, others the flowers. The bite of insects 
and the deposition of eggs beneath the skin lead to the 
formation of unsightly galls, which, while they provide 
food for the subsequent grubs, at the same time circum- 
scribe the limits of their damage. Fungi are still more 
formidable enemies, and to them the majority of plant- 
diseases is due. No one can have failed to observe the 
damage caused by these parasites. Seedlings rot and 
perish ; spots and tumours appear upon the leaves and 
shoots of trees ; fungal outgrowths disfigure the branches. 
Even the flowers are not exempt from injury. The 
anthers may be filled with black smut instead of pollen, 
and the ovary filled with grubs instead of ovules. 
Lastly, fresh green leaves and shoots, turgid with 
nutritious and palatable sap, offer no mean inducement 
to browsing animals in search of food. Many plants may 
