36 



SOME SOUTH INDIAN INSECTS, ETC. [CHAP. IV. 



when it is not the individual that is at fault but merely the want of 

 training in observation. 



Protective resemblance may be (usually) general, in which case 

 the insect or other animal may exhibit in its shape or coloration or 

 in both the general pattern-effect produced by its normal surround- 

 ings, or it may be (more rarely) special, in which case the insect or 

 animal bears a close resemblance to some different object (living 

 or inanimate) found in its normal habitat. It would be tedious to 

 attempt to give any general list (even of insects) of examples in 

 each group. Those who are interested in the subject will find it 

 an easy matter to make observations of their own in their particular 

 field. There is no strict line of demarcation between the two 

 groups and some animals may belong to both ; thus, the common 

 Green Whipsnake (Dryophis mycterizans) may blend generally into 

 the general appearance of the green bush in which it is stretched 

 out or, if noticed in more detail, it may readily pass for a branch of 

 the square-stemmed jungle vine (Vitis quadrangular is). In passing 

 it may be noted that, to be successful, protective resemblance does 

 not necessarily connote inconspicuousness. 



1 ''• ■■ 19. Perisphceria, a Cockroach which rolls itself up into a ball when thi i at 

 ened with danger. (After British Museum Guide to the Insect Gallery.) 



Some insects, when threatened by danger, simply roll them- 

 selves up into a ball, at the same time generally dropping to the 

 ground if not already on it. Such are many caterpillars, especially 

 some of the hairy ones in which the hairs radiate out " like quills 

 upon the fretful porcupine," serving the purpose of directly offens- 

 ive weapons and also readily slipping through the grasp of any 

 attempting to pick up the caterpillar. Some cockroaches 

 of the K'lnis Perisphceria have also the power of rolling themselves 

 into a ball, when they greatly resemble a small Fill-millipede, the 

 two extremities of the body fitting closely together so that the head 

 and legs are completely hidden inside and protected. 



From such examples it is but a step to cases in which insects, 

 on finding themselves discovered by enemies, simply drop to the 



