58 



the other hand, performed experiments with young fertile females 

 of the European F. sanguínea, and found that the F. fusca 

 workers adopted them readily. But Viehmeyer, and Wasmann 

 himself later, found that F. sanguínea females pillaged the cocoons 

 and killed the F. fusca workers. It seems fairly clear that this 

 violent method is the more general. 



Donisthorpe's experiments, particularly the more recent 

 ones, support this theory. 



Experiments in 1909. — No. i. An artiftcially deälated F. 

 sanguínea female, taken at Aviemore, was introduced on June 24th 

 to a small queenless F. fusca nest from Sherwood. The workers 

 ran away but finally attacked the female, who killed six or seven 

 of them. On the 28th the female appeared to be accepted 

 by the workers, as they were all sitting together and some of 

 the workers were cleaning the female, but on July 2nd she was 

 dead. 



No. 2. On July 4th an old female from Woking was intro- 

 duced into a small colon\- of F. fusca workers with pupœ. The 

 female approached the pupae and seemed interested in them. 

 The workers removed the pupae, the female was attacked and 

 repulsed the workers. The female and workers then fed side by 

 side at some honey. Next day the female had collected all the 

 pupai into one corner and was reposing on them. Two workers 

 were with her, but several others were dead and injured. The 

 following day only three workers survived, and the female was 

 still in possession of all the pupae. The three workers removed 

 pupa; from time to time, but the female brought them back. 

 Some strange F. fusca larvae and pupae were put into the nest 

 and collected by the female. On the 15th only two workers 

 were left and appeared to be friendly with the female, all being 

 together on the pupae. On July i8th all were well and friendly. 



No. 3. On July 15th a small F. fusca colony of workers with 

 pupae, from Shotover, near Oxford, was placed in a combined 

 Fielde and Janet nest with a deälated F. sanguínea female 

 from Woking. The female was at once fiercely attacked, but 

 was not very aggressive herself. Next day she had lost an 

 antenna, but was not attacked. July 17th she was alone, but 

 not attacked, and on July i8th she was dead. 



No. 4. An artificially deälated female F. sanguínea from 



