THE LARVA 31 



head, it stretches its body at full length, and takes a series of bites 

 as it brings its head backward in a curve. When the head has 

 thus been brought close to its fore legs, the body is again extended, 

 and the same ground is gone over again. 



If the caterpillar is a fairly large and hardy one, it will bite 

 through the smaller veins, and perhaps even the larger ones ; but 

 the smaller species often change their position on reaching a 

 moderately thick vein, and so devour little else than the soft cellular 

 substance of the leaf. In any case, it is astonishing to see how 

 rapidly the leaf disappears under the influence of the powerful jaws 

 and marvellous digestive apparatus of the hungry grub. 



Those who take a delight in watching the movements of cater- 

 pillars are sure to be interested in observing them when at rest ; 

 for at such times the various attitudes assumed are as pleasing 

 and instructive as are their active moments. And these attitudes 

 are all the more interesting on account of the mimicry by which 

 the creatures often baffle their numerous enemies. We may 

 profitably spend a little time in studying a few cases in point. 



Many species, when at rest, fix themselves by means of their 

 claspers to a small twig or leaf stalk, or on the midrib of the leaf 

 itself. Here they remain perfectly still, with their bodies perfectly 

 straight or with head slightly raised. I need hardly say that these 

 generally fix themselves on the under side of the leaves and stalks, 

 thus securing themselves against the attacks of the feathered foes 

 above. But some birds are equal to the caterpillars in this matter ; 

 and it is really amusing to see them' hopping about beneath the 

 leaves in our gardens, every now and again slyly turning one 

 eye upward, and smartly plucking an unwary grub from its resting 

 place. 



The precautions of the caterpillar, however, do not end merely 

 with the selection of an under surface. You will find that the 

 bright green species invariably settle on a leaf or a green stalk, 

 while the darkly coloured insects often choose a twig covered with 

 a brownish bark. Some even make for the trunk of the tree on 

 which they feed, and here remain quite still in a vertical position, 

 so that they look just like a ridge in the bark, the colour of which 

 is faithfully imitated by their skin. Further, many of the cater- 

 pillars that resort to this stratagem have bodies that are notched 

 or knotted and spotted in such a manner that the resemblance to 

 their surroundings is so perfect as to defy any but the most 

 experienced eye. And even this is not all, for a number of these 



