DUBLIN'] 



SLA VE- MA KING HABITS OF ANTS 



143 



of queenless and aged Tetramorium workers. At first sight 

 such a colony gives the impression that only one species was 

 represented in which the males and females have a strangely dif- 

 ferent appearance. But in spite of the fact that such polymor- 

 phism does actually occur among several species, there can be no 

 doubt that this is not true in this case. Very careful studies 

 have shown that the workers belong to Tetramorium caespitum, 

 the same form described above in association with Strongylogna- 

 thus; the fertile forms on the other hand, are absolutely unlike 

 those found in Tetramorium colonies and belong to an entirely 



Fig. 3- — A species of Anergates in which there are no workers or soldiers, a, male; b, fertile 

 female; «:, abdomen of virgin female. (From Wheeler.) 



different genus. These males and females can do nothing for 

 themselves and show rudimentary characters in almost every 

 detail of their structure. The males, for example, are wingless 

 resembling larvae rather than mature ants, while the mouth- 

 parts of both sexes are most degenerate, the jaws and feelers 

 being reduced to mere stumps. 



How, then, could a colony such as this have been formed? 

 The problem is made all the more difficult because of the absence 

 of the sexual forms and the brood of the slaves. The colony as a 

 whole is thus incapable of perpetuating itself and the Anergates, 

 entirely dependent upon their aged slave-workers, and therefore, 

 doomed to die with them. The stealing of slaves is out of the 

 question and so also must be considered the possibility of an 

 alliance taking place between representatives of the two species. 

 Very novel indeed is the suggestion made years ago by Sir 

 John Lubbock who in his discussion of this very question wTote : 

 "If the female of Anergates could by violence or poison destroy 



