FOUNDING OF SLAVE-MAKING COMMUNES 



This method of founding a colony the discoverer called 

 "temporary social parasitism," and he inferred that a 

 number of these mixed colonies known to exist, and 

 which had been thought to be abnormal or accidental 

 consociations of two species, were in all probability 

 merely cases of temporary parasitism. And he pre- 

 dicted that various species of the Formica rufa group 

 would be found to establish their colonies after the 

 manner of F. consocians that is, by the aid of some one 

 of that group most affected as auxiliaries among slave- 

 makers. 



It seemed to follow, as an almost necessary conjecture, 

 that this might give the clew to the true phylogeny of 

 the slave-making or dulotic habit first discovered by 

 Pierre Huber. He therefore entered upon a series of 

 remarkable experiments, from which we may conclude 

 that the method, as it occurs in nature, has been un- 

 covered. A strangely interesting story it is. [W. 2, 

 pp. 33-105.] Twenty-one experiments were made with 

 young queens of Formica sanguined (of the prevalent 

 American variety rubicunda) and artificial colonies of 

 siibsericea, a widely distributed American form of 

 Formica fusca, which is commonly found as an auxiliary 

 in slave-holding communes. Two of these were partially 

 and ten completely successful. The following accounts 

 of two experiments will show both the professor's meth- 

 ods and the results. 



The artificial nest used was divided into two connected 

 chambers, one illuminated, the other darkened. Herein 

 was placed, within the dark chamber, a colony of twelve 

 large Siibsericea workers and a number of worker co- 

 coons. To these a female Rubicunda was introduced. 



Some of the workers snatched up cocoons and fled 



265 



