INFANCY OF CRABS AND CATERPILLARS 251 



its own excrement, woven together with silk. This is a 

 sufficiently remarkable fact, but it is even more remarkable 

 to find that there are other caterpillars which construct 

 these excremental habitations. Such, for example, are 

 those of the hammock-moth {Perophora sanguinolenta) 

 of South America. Exactly how these unsavoury cradles 

 are made we do not know, but of their nature there is no 

 doubt. In form, as may be seen from our illustration, they 

 have certainly some pretensions to beauty. 



Certain other caterpillars form large communities living 

 together, either under a tent-like web of silk, or in a more 

 solid, oval case. The larvae of the Small Ermine moth 

 are such tent-dwellers, while the case-forming species are 

 illustrated by the African moth, Anaphe panda, whose 

 dwellings form so conspicuous a feature on trees in parts 

 of Africa. The young of the American Bull's-eye moth 

 (Saturnia io) live in communities of a different kind. 

 They construct no house, but live in crowds, all on the 

 underside of the leaf of the food-plant, with tails in and 

 heads out, and bodies curved to fit nicely together. They 

 eat the edges of the leaf. When disturbed, all draw back 

 together into a compact mass, and heads drawn in so as to 

 be protected by the branched poisonous hairs which cover 

 their bodies. When they wish to remove to a fresh feeding- 

 ground, they move in procession, marching in single line, 

 head to tail. The leader's head is constantly moved from 

 side to side as he spins, from his mouth, a carpet of silk for 

 himself and his followers to walk on. If the leader stops 

 to nibble a leaf, the rest wait patiently till he moves on 

 again, till finally the new camp is decided on. 



That caterpillars display considerable powers of adapta- 

 tion there can be no question, after the instances cited in 

 these pages. But there are some which have gone to the 



