ALWAYS PRODUCE MALES. 37 



the same is the case among ants ; and my nests have 

 supplied me with some facts bearing on the question. 

 ]Most of my nests contained queens ; and in these it 

 would be impossible, or at least very difficult, to dis- 

 tinguish and follow the comparatively few eggs laid 

 by the workers. Some of my nests, however, con- 

 tained no queen ; and in them therefore all the eggs 

 must have been laid by w^orkers. 



One of these was a nest of Formica cinerea, which 

 I brought back from Castellamare in November 1875. 

 At that time it contained no eggs or larvae. In 1876 

 a few eggs were laid, of which fifteen came to maturity, 

 and were, I believe, all males. In 1877 there were 

 fourteen pupse, of which twelve came to maturity, and 

 were all males. 



Again, in a nest of Lasius niger, kept in captivity 

 since July 1875, there were in 1876 about 100 young ; 

 and these were, as far as I could ascertain, all males. 

 At any rate there were about 100 males, and I could 

 not find a single young female. In 1877 there were 

 again some pupae ; but owing to an accident none of 

 them came to maturity. In 1878 fifteen came to 

 maturity ; and fourteen were males. The other I could 

 not find after it left the pupa skin ; but I have no 

 doubt, from the appearance of the pupa, that it was 

 also a male. 



Another nest of Lasius niger, taken in November 

 1875, brought in 1878 only one young ant to maturity ; 

 and this was a male. 



