ANTS CAMPONOTIDES 



155 



is ])j something of the natiu^e of odour. One observer has noticed 

 that if an ant fall into water it is on emerging at first treated as 

 if it were a stranger l)y its own friends ; bnt other naturalists have 

 found this not to he the case in other species. Contact with 

 corrosive sublimate deprives ants for a time of this power of 

 recognising friends, and under its influence they attack one 

 another in the most ferocious manner. 



The nests and colonies of the species of Camponotides we 

 have considered are all constructed by societies comprising a 

 great number of indi- 

 viduals ; there are, 

 howeA^er, in the tropics 

 numerous species that 

 form their nests on 

 foliage, and some of 

 these contain only a 

 few individuals. The 

 leaf- nests (Fig. 64) of 

 certain species of Po/y- 

 rhachis are said to be 

 formed of a paper-like 

 material, and to con- 

 tain each a female and 

 about 8 or 10 worker 

 ants. Forel ^ has ex- 

 amined nests of several 

 Indian species, and finds they differ from those of other ants in 

 consisting of a single cavity, lined with silk like that of a spider. 

 These nests are further said to be constructed so as to render 

 them either inconspicuous or like other objects on the leaves ; 

 F. argcntca covers its small dwelling with little bits of vegetable 

 matter, and a nest of P. rastella was placed between two leaves 

 in such a manner as to be entirely hidden. All the species of 

 the genus do not, however, share these habits, P. mayri making 

 a card-nest, like JJolichoderus and some other ants. The species 

 of the genus Polyrliachis are numerous in the tropics of the Old 

 World. 



Forbes noticed that a species of this genus, that makes its 

 paper-like nest on the underside of bamboo-leaves produces a noise 



Fig. 64. — Nest of Polyrhachis sp. (After Smith.) 



^ Forel, J. Bombay Soc. viii. 1893, p. 36. 



