Vegetable and Animal 
amongst them seem to be seldom or never poisoned. 
So that there must be some educational influence at 
work ; practical botanical knowledge is somehow ac- 
quired by the growing calf. 
One very curious instance of the close relation of 
plants and insects is found in certain fungi. There are 
no less than 708 species of fungi which grow on the 
droppings of herbivorous animals, 45 species on that of 
carnivore, and four on that of reptiles.6 The common- 
est (Ascobolus) forms the little brown-red saucers which 
cover such surfaces. The tiny transparent spores are 
squeezed or darted out of the fungus and fall on the 
grass leaves, to which they at once adhere and become 
cemented. They are eaten with the grass by cattle, and 
pass uninjured through its complex digestive system. 
The adaptations of special insects to the times and 
seasons Of plant life are very remarkable. The spruce 
gall insect, eg., forms those small, withered-looking 
galls which are exactly like diseased first year’s cones, 
and which are very common on spruce twigs. There 
are five forms of the insect. The “foundress ” wingless 
females produce the galls. Their larve live in them 
but eventually get wings, and as “colonisers”’ fly to 
the larch or pine, where they winter in crevices of the 
bark ; their children live on the larch leaves or pine 
needles, and lay eggs which become male and female 
winged insects. The females return to the spruce and 
their progeny are “foundresses.”* The changes are 
in reality even more complex than these. 
This insect continues on the spruce, but also has the 
chance of using two other trees. 
It is, however, when one tries to unravel the manifold 
relations of a green-fly to the plant and animal world 
that one begins to realise something of the way in which 
Nature works. The aphis or green-fly of the hawthorn 
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