THE WAVY-LEAVED OAK. 3801 
remain, and develope into the fruit—the beautiful 
_‘corn of the Oak’ seated in their elegant cups. In 
times past the acorn has served, not only for the 
food of many of the wild inhabitants of the wood- 
land, but of man. What schoolboy does not re- 
member the taste and flavour of the Oak fruit? 
Not least amongst the characteristics of the 
Oak are its ‘apples,’ and its ‘ galls ’—abnormal 
vegetable growths on stem, on leaf, and even on 
fruit, and about which there is much mystery. 
The Oak ‘apple’—so called, is often beautifully 
coloured with shades of brown and pink, deriving 
its name from a rough resemblance to the fruit of 
the Apple-Tree. It is formed by the action of a 
small insect, which punctures the tender skin of 
the Oak twig, or sometimes the leaf-bud, and in 
the hole thus made by its ovipositor, it lays its 
eggs. This act disturbs the sap which flows from 
the trunk into the wounded twig, causing it to 
flow round the foreign substance of the eggs, 
solidifying as it flows, and encompassing the eggs 
with soft vegetable tissue, but leaving room 
enough for the grubs, which are soon hatched, 
become flies, make their way to the surface, and 
