260 BRITISH ANTS. 



join together to found a colony, but without success, as the rufa 

 female has always died, after a longer or shorter period, without 

 laying eggs, even in those cases where she has become quite 

 friendly with the fusca female. The following experiments will 

 serve to illustrate how a rufa female is accepted into a fusca 

 colony. 



On January 28th, 1910, I confined some forty workers of F. 

 fusca v. glebaria, obtained at Whitsand Bay in July, 1909, in one 

 chamber of a two-chambered Fielde- Janet nest, blocking the 

 passage between the two chambers with cotton-wool, and in the 

 empty chamber I placed a deflated F. rufa female from Nethy 

 Bridge. After a few days to allow the female to get rid of her 

 " nest aura," as would be the case in nature, the barrier was re- 

 moved, when several workers entered her compartment, and she 

 repeatedly entered their compartment, and returned, at first 

 avoiding the workers. On February 2nd she was attacked, but 

 regained her own compartment which now contained five workers, 

 and the barrier was replaced, shutting her in with these five workers 

 for the night. February 3rd she was again attacked, and she 

 killed one persistent worker after first attempting to conciliate it 

 by tapping and stroking it with her antennae ; the remaining 

 workers appeared more friendly and one fed the female. Other 

 workers were now allowed to enter, which the female stroked with 

 her antennae, but on February 6th she was again attacked by one, 

 which she killed. The other workers were then introduced gradually, 

 only one attacking her and being killed, and by February 9th all 

 the workers were quite friendly ; later she was again fed by a worker 

 and was clearly adopted 79 . On March 1st she laid eggs, which 

 came to maturity on June 20th ; the eggs and larvae had been 

 attended to by the glebaria workers ; the callow rufa workers, 

 however, were cripples. She laid again on November 20th, 1910 82 , 

 and again on July 27th, 1911, and by August 16th, 1911, over 

 twenty pupae were present, five of which hatched on September 

 25th, when there were over thirty pupae, all of which hatched by 

 November 1st, being perfect, though small, rufa workers. The 

 rufa queen, having lived in the nest for nearly two years, died on 

 October 5th, 1911, from what cause is unknown, but it was certainly 

 not through attacks by the glebaria workers 84 . 



In an experiment made by Wasmann, in May, 1909, a rufa 

 female, which had been accepted by a fusca colony which pos- 

 sessed a fusca queen, after a few days bit off the head of the latter 73 , 

 and the following experiment also shows how when there is a fusca 

 female present she may be got rid of. 



On April 2nd, 1910, I brought home from Darenth Wood a num- 

 ber of fusca workers and three queens, which I had dug up out of a 

 small sandy bank, and introduced them into a four -chambered 

 Janet nest. On April 17th I placed a rufa female, taken at Welling- 



