.578 STRANGE DWELLINGS. 



wards, and are stuck into a strong, glutinous material of which 

 the body of the case is composed, and they look for all the 

 world like the spikes of chevaux-de-frise. A web-like skein of 

 singularly strong material serves as a rope whereby to swing the 

 caddis-case from the branch to which it is attached And a 

 nest more difficult to swallow, and hard to digest, its enemies 

 would be rather puzzled to find.' 



As is frequently the case with such nests, the peculiar form 

 serves a double purpose, namely, protection and concealment, 

 the sharp points of the thorns performing the former duty, and 

 their similarity to surrounding objects the latter. Acacias are 

 conspicuous for the thorns with which their branches and some- 

 times their trunks are studded, and in several species the 

 wooden bayonets are several inches in length, and as large and 

 sharp as porcupine quills. These thorns are crowded thickly on 

 the branches, and always diverge from each other, so that the 

 hand can scarcely be insinuated among the boughs without 

 suffering several wounds. The nest being surrounded with 

 these thorns, it is evident that all ordinary foes would be baffled 

 by such an array of points, no matter how anxious they might 

 be to get at the creature witliin. 



The thorns are equally efficient as a means of concealment, 

 for, as they are taken from the tree itself, they cause the nest to 

 harmonise so perfectly with surrounding objects, that it is not 

 very easily perceived. 



As long as the caterpillar remains in its larval state, and is 

 obliged to feed, it traverses the branches freely, carrying with it 

 the prickly home, and bearing the whole of its weight as it 

 moves. But wlien the pupal stage has nearly arrived, the nest is 

 suspended to the branch by strong silken threads, and thence- 

 forth remains immoveable 



