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these circumstances. In one experiment in Juh' 1908 the 

 workers of a small F. fusca colony- attacked the strange female, 

 but the F. fusca female was friendly to her. The Polyergus 

 female, however, eventually killed the F. fusca female by a 

 bite in the head, and the workers thereupon became friendly and 

 adopted her. Next year, on May 5th, the queen laid eggs, 

 which disappeared, and again on May 30th. On June 21st 

 larvai hatched, and pupated irom Jul}' 8th onwards. On 

 August 6th the first callow appeared, but only two completed 

 their metamorphosis. During the winter of 1909-10 both the 

 Polyergus workers died, and only three F. fusca workers were 

 left with the Polyergus female. 



Another experiment in Jul\' 1909, with a larger colony of one 

 hundred F. fusca workers and females, resulted in the Polyergus 

 female seeking the F. fusca female and standing over her, the 

 workers meanwhile ])ulHng at both females. The next da\' the 

 F. fusca female was dead with a pierced thorax, and the Polyergus 

 female was adopted. Other experiments confirm the above. 

 Emery concludes that the grounding of a new Polyergus colony 

 can without doubt take place by the entrance of one or more 

 females into a nest of F. fusca and its subspecies. 



The Polyergus female, when not prevented b\- the workers, 

 seeks the rightful queen of the colony and kills her. The eftect 

 of this assassination is that the workers adopt the strange female 

 and eventually bring up her young. 



Emery goes on to say that one would suppose that the 

 adoption of a Polyergus female would be more likeh' successful 

 in a small colony of the slave species of one or two 3'ears' standing. 

 This he says was his own view, until his experiments in observa- 

 tion nests caused him to change his opinion. Thus in the experi- 

 ment quoted above only two small Polyergus workers reached 

 maturity, and they died by the winter. He therefore thinks 

 that, in order to be successful in founding a colon\-, a female 

 must enter and be adopted by a strong colony of the slave species. 

 We do not, however, see why a fair number of workers in a small 

 colony of F. fusca should not be able to support the Polyergus 

 female and her offspring, for the two or three years that Kmerv 

 himself thinks must elapse before the first slave-raid takes place. 

 He also thinks that thi- will appl\- to all " robber " ants, including 

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