360 OBJECTIONS TO THE THEORY [Chap. VIII. 



from the analogy of ordinary variations, that the succes- 

 sive, slight, profitable modifications did not first arise 

 in all the neuters in the same nest, but in some few 

 alone; and that by the survival of the communities 

 with females which produced most neuters having the 

 advantageous modification, all the neuters ultimately 

 came to be thus characterised. According to this view 

 we ought occasional! v to find in the same nest neuter 

 insects, presenting gradations of structure ; and this we 

 do find, even not rarely, considering how few neuter 

 insects out of Europe have been carefully examined. 

 Mr. F. Smith has shown that the neuters of several British 

 ants differ surprisingly from each other in size and some- 

 times in colour; and that the extreme forms can be 

 linked together by individuals taken out of the same 

 nest : I have myself compared perfect gradations of this 

 kind. It sometimes happens that the larger or the smaller 

 sized workers are the most numerous ; or that both large 

 and small are numerous, whilst those of an intermediate 

 size are scanty in numbers. Formica flava has larger 

 and smaller workers, with some few of intermediate size; 

 and, in this species, as Mr. F. Smith has observed, the 

 larger workers have simple eyes (ocelli), which though 

 small can be plainly distinguished, whereas the smaller 

 workers have their ocelli rudimentary. Having care- 

 fully dissected several specimens of these workers, I 

 can affirm that the eyes are far more rudimentary in 

 the smaller workers than can be accounted for merely 

 by their proportionally lesser size ; and I fully believe, 

 though I dare not assert so positively, that the workers 

 of intermediate size have their ocelli in an exactly inter- 

 mediate condition. So that here we have two bodies of 

 sterile workers in the same nest, differing not only in 



