66 



F. sanguínea. We are unable to agree with this conclusion, 

 since, as we have shown by our experiments, the F. sanguínea 

 female was always killed, when introduced into a colony of the 

 slave species containing many workers. Emery concludes, on 

 his experiments on the subject of food, that ants in small numbers, 

 however well fed, only rear very small workers, yet surely 

 in course of time, as their numbers increased, the large workers 

 which Emery says are necessar}- to form an Amazon army 

 would be produced. 



As Wasmann states, from his own and other experiments, 

 Polyergus females are readily adopted by workers of the slave 

 species without a female, though they are always attacked and 

 killed by their own workers. If, therefore, a Polyergus female 

 should happen to find a queenless colony, the matter would be 

 simple. 



Genus Strongylognathus. 



The females of the M\Tmecine slave-makers Strongylognathus,, 

 it is clear, cannot adopt the tactics practised by the females 

 of F. sanguínea and P. rufescens, owing to their small size and 

 weakness ; moreover, the colonies of the host, Tetramorium cœspi- 

 tum, are as a rule on a much larger scale than that reached b}' 

 F. fusca. From the observations of Wasmann and Viehmeyer, 

 since confirmed by Forel and Wheeler, it is clear that the 

 presence of the queens of 5. testaceus in a Tetramorium colony 

 does not affect the queen of the latter, who remains in the nest 

 with the parasitic queen. Such colonies reach a great size, 

 one observed by Wasmann in Bohemia containing about 20,000 

 Tetramorium workers and about 1,000 of the Strongylognathus 

 with pupie, and a fertile queen of both species. 



Wasmann is of opinion that such mixed colonies were formed 

 by an alliance of the two queens in the first instance, but Wheeler 

 is inclined to take the view that the Strongylognathus female 

 enters a colony of Tetramorium, after the latter has been 

 established. 



Strongylognathus testaceus has nearly, if not entirely, lost the 

 power of making slaves. Nothing appears to be known of the 

 colony-founding of the other species of the genus. 



