AXT COMMUNITIES 



atrophied. Still, under the stimulus of special favoring 

 conditions, the latent ancestral tendency springs into 

 active force, and shows itself in the occasional and 

 temporary structures above described. 



I have alluded to this phase of ant industry and vent- 

 ured on the suggestion of its origin, not simply because 

 of the intrinsic interest of the facts, but because they 

 lead up to what is (seventh) a distinct and well-defined 

 form of nesting architecture. Not only Cremastogaster, 

 but other genera have acquired the habit of making 

 carton nests in and upon trees. They are at times quite 

 large (a foot or more in diameter), and they form true 

 habitations, as are the nests of hornets, in which larvae 

 are reared, dependents housed, and all the functions 

 of an ant commune carried on. 



These tree-dwellers are for the most part habitants of 

 tropical and subtropical countries, and the accounts of 

 travellers give one a vivid conception of their power, 

 when excited by intended or accidental aggression, to 

 swarm forth in legions from their domiciles and punish 

 invaders with stings that seem pointed with fire. 



Of the ants of this form of arboreal nest, Fig. 24 is 

 taken from Dr. Forel's Ants' Nests, and shows a paste- 

 board nest of Dolichoderus bituberculatus Mayr, taken 

 from the bough of a tree from Bankok, Siam. Fig. 25 

 is a tree-nest after a figure published by Dr. von Ihring 

 [Yon 1. 1, p. 334] of Camponotus rufipes, of South America. 



We come now to note (eighth) the existence of nests 

 for which the framers have called in the use of silk. 

 That this should turn up at even the most unexpected 

 points in the insect world will not seem strange to one 

 who knows how largely the spinning habit enters there- 

 into. Many ants in their larval forms follow the role 



32 



