1906.] Wheeler, Habits of the Tent-building Ant. 13 



a very partial view of the nesting instincts of ants in general. For in 

 addition to the excavation of galleries and chambers, the workers of 

 many species, like F. rufa, range far afield in search of vegetable 

 debris such as twigs, bits of dead grass, leaves, pine-needles, pellets of 

 earth, etc., and with these construct large mounds, in which the 

 young can be more rapidly incubated than in the cold soil. These 

 building instincts, which may be called positive and centripetal as 

 distinguished from the negative and centrifugal excavating instincts, 

 are so widely distributed among ants as to suggest very forcibly that 

 the primitive ancestral forms of the family must have been architects 

 like the wasps and bees, working the soil or vegetable debris up into 

 rude nests and attaching them to plants and the sides of stones. 

 From such a condition a great number of species have lapsed into 

 mere excavators of the soil, a change the more easily accomplished 

 because the under surfaces of stones and logs furnish such excellent 

 roofs for their galleries and chambers as to render the constructive 

 instincts superfluous. Whether this has been the universal tendency 

 in the Formicidae can be decided only after further investigation. 

 That it has been the tendency in the genus Cremastogaster appears to 

 be satisfactorily shown by the following observations. 



The most elaborate and perhaps the most primitive form of archi- 

 tecture among ants is found among the species that use carton in the 

 construction of their nests. These species are members of the genera 

 Caniponotus, Polyrhachis, Lasius, Azteca, Liometopum, Dolichoderus, 

 and Cremastogaster, and represent three of the five subfamilies of 

 ants. The carton-building species of Cremastogaster, with which 

 alone we are here concerned, are nearly all confined to the tropics. 

 As they are distributed over both hemispheres, however, we may infer 

 that the instinct to agglutinate vegetable detritus, dried cow-dung, 

 etc., and build it up into the form of spherical or subspherical nests, 

 is fundamental and of long standing in the genus. Among the 

 Indian species, these carton nests, which are suspended to the branches 

 of trees like the nests of certain hornets in more northern latitudes, 

 were long ago described and figured by Sykes ^ for C. kirbyi. Kirby 

 has reproduced Sykes's figures in the Seventh Bridgewater Treatise.* 

 Later Mayr, Wroughton, and Rothney called attention to similar 

 habits in two other Indian species (C. rogenhoferi and ebeninus).^ 



• Descriptions of New Species of Indian Ants. Trans. Ent. Soc. London, I, 1836, pp. 99- 

 103, pi. xiii, fig. I. 



^ On the Power, Wisdom, and Goodness of God as Manifested in the Creation of Animals and 

 in their History, Habits, and Instincts. Second Am. Edit., Phila., 1^*3 7. pl- xi. 



^ Mayr, BeitrSg-e zur Ameisenfauna Asiens. Verhandl. k. k. Zcol. bot. Gesell. Wien, 

 1878, pp. 39,40; Wroughton, Our Ants. Jotim. Bombav Nat. Hist. Soc, 1892, p. 23; Rothtiey, 

 Notes on Indian Ants. Trans. Ent. Soc. London, 1895, Pt. II, p. 205. 



