observations on the habits of ants. 55 



On Anergates. 

 The life-history of the genus Anergates is, in the words of 

 Forel, an unsolved enigma. The species was discovered by 

 Schenck, who found a small community consisting of males, 

 females, and workers, wdiich he naturally supposed belonged to 

 one species. Mayr, however, pointed out* that the workers were 

 in fact workers of Tetramor'mm ccespitum ; and it would appear 

 that, while in Strongylocjnatlms the workers are comparatively few, 

 Anergates differs from all other ants in having no workers at all.f 

 The males and females live with Tetramorium ccEspltum, and are 

 in several respects very peculiar— for instance, the male is wing- 

 less. One might consider it rather a case of parasitism than of 

 slavery, but the difficulty is that in these mixed nests there are 

 no males and females of Tetramor'mm. It seems quite clear that 

 Anergates cannot procure its slaves, if such they are, by marauding 

 expeditions like those of Polyergus, in the first place because they 

 are too few, and secondly because they are too weak. The whole 

 question is rendered still more difficult by the fact that neither 

 Von Hagen I nor Forel found either larvte or pupse of Tetramorium 

 in the mixed nests. The community consisted of males and 

 females of Anergates, accompanied and tended by workers of 

 Tetramorium ccespitum. The Anergates are absolutely dependent 

 upon their slaves, and cannot even feed themselves. The whole 

 problem is most puzzling and interesting. On the whole I would 

 venture to suggest that the female Anergates makes her way into 

 a nest of Tetramorium and in some manner contrives to assassinate 

 their queen. It must be admitted that even this hypothesis does 

 not fully account for the facts. Still, I have shown that a nest of 

 ants may continue even in captivit)'^ for five years without a queen. 

 If, therefore, the female of Anergates could by violence or poison 

 destroy the queen of the Tetramoriums,yve should in the following 

 year have a community composed in the manner described by 

 Von Hagen and Forel. This w^ould naturally not have suggested 

 itself to them, because if the life of an ant has, as was formerly 

 supposed, been confined to a single season, it would of course 

 have been out of the question ; but as we now know that the life 



* Europ. Formic. 



t In Tomoijnathus suhlatvis, ou the contrary, a Finland species, which lives in the 

 nests of Leplotliorax mttacorum and L. accnorum. the workers only are known. 

 } Verb, des Natur. Vereins der preuss. llheinlande und Westphalens. 1867, p. 53. 



