BONISTHORPfiA, 209 



interest because, as a rule, even sister ants seem averse to such post- 

 nuptial partnerships." [Bull. Amer. Mus. NH. 22 41 (1906).] 



It is probable, however, that two or more nigra females may not 

 infrequently combine in starting a colony, though it is a remarkable 

 fact that colonies of this ant are very rarely found with more than 

 one queen. Crawley once found a colony, in August, 1895, which 

 contained two queens 62 , but it would seem from the experiments 

 in captivity, shortly to be mentioned, that when two or more 

 females have combined together to found a colony, one of them 

 eventually kills the others, and remains the sole queen in the nest. 



This species will not receive strange females of its own species 

 into its nests after the marriage flight. Southcombe took some 

 newly-fertilized females of D. nigra in July, 1905, and offered some 

 to wild nests, and others to a captive queenless colony. In every 

 case the females were torn to pieces, the queenless nest in particular 

 showing great ferocity towards the strange females 47 . 



A number of colonies have been brought up in captivity by nigra 

 females. Janet found an isolated dealated female, with a small 

 packet of eggs in a little cell, on September 7th, which he placed in 

 an observation nest, the first workers appearing in the following 

 spring ; in other experiments which he had carried out in previous 

 years with females of the same species taken after the marriage 

 flight during the first days of August, the first workers were reared 

 by the beginning of October 43 . 



In July, 1914, I brought home a dealated nigra female, which 

 I had found walking on a bank at Woking, and established her in 

 a small " Crawley-Lubbock " nest. She blocked up the entrance 

 to her cell, and in a day or so laid eggs. No attention was paid to 

 this nest, but by September 1st the female was found to have 

 brought up two small workers. This tiny colony is alive and well 

 to-day, and a number of small larvae are present. 



Von Buttel-Reepen took two dealated females after the marriage 

 flight on July 22nd, 1903, and placed them in a glass nest with 

 earth, in which they dug two separate holes and laid eggs by the 

 middle of August. About August 20th one female broke into the 

 cell of the other, brought her eggs, settled with her, and the two 

 females henceforward lived together, heaping their eggs in one 

 bunch. The first larva appeared one month after the eggs were 

 laid, twenty-four in all hatching ; some of these pupated after eight 

 months, and the first worker appeared about a year after the 

 females were fertilized. After five workers had hatched, the 

 females ceased to look after the brood. On August 5th the two 

 females commenced to fight, the workers attacking the female that 

 was getting the worst of the combat. This female died the next 

 day, leaving the colony with a single queen 46 . 



Mrazek's experiment, though not conclusive, as the females were 

 not actually observed to fight, points to the murder of one female 



