Page - 293 - in The Origin of Species

OBJECTIONS TO THE THEORY 293 It will indeed be thought that I have an overweening con- fidence in the principle of natural selection, when I do not admit that such wonderful and well-established facts at once annihilate the theory. In the simpler case of neuter insects all of one caste, which, as I believe,havelbeen rendered dif- ferent from the fertile males and females through natural selection, we may conclude from the analogy of ordinary variations, that the successive, 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 ad- vantageous modification, all the neuters ultimately came to be thus characterized. According to this view we ought occa- sionally 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 dififer surprisingly from each other in size and sometimes 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 carefully dissected several specimens of these workers, I can affirm that the eyes are far more rudi- mentary 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 size, but in their organs of vision, yet connected by some few members in an intermediate condition. I may digress by adding, that if the smaller workers had been the most useful to the com-