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 workers. 
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 larve. In 1876 
a few eggs were laid, of which fifteen came to maturity, 
and were, I believe, all males. In 1877 there were 
fourteen pups, 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 
uot find a single young female. In 1877 there were 
again some pups; 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. 
