234 Charles Darwin. 



and not through inheritance ; that rudimentary or- 

 gans plainly declare their origin and meaning. 



Finally he brought together a large body of 

 interesting facts in entomology, bearing on the de- 

 velopment and perpetuation of mimicry, and of 

 secondary sexual characters — all more or less ex- 

 plicable by, and furnishing convincing argument for, 

 the general theory of natural selection ; while he 

 freely acknowledged that he found among insects 

 facts that seemed to be most fatal to the theory. 

 This is especially the case in social insects where the 

 colony contains neuters and sterile females which 

 often differ widely in instinct and in structure from 

 the sexual forms, and yet cannot propagate their 

 kind. This is not the place to enter into a discus- 

 sion of the subject, and I will simply remark that 

 there are reasons for the belief that, in his candour, 

 he has been led to exaggerate the difficulties in this 

 case. 



But Darwin's chief investigations into insect life 

 were in its relations to plant life, and his work " On 

 the Various Contrivances by Which British and For- 

 eign Orchids are Fertilized by Insects, and on the 

 Good Effect of Crossing," as also that on " Insecti- 

 vorous Plants," are monuments of skill, industry, 

 and lucid exposition. 



Entomologists had often noticed the pollen masses 

 of orchids attached to the proboscis of various moths, 

 and in commenting upon the fact had pronounced 

 it " curious." Darwin in this, as in so many other 

 cases, gave meaning to the curious, and brought 

 light out of darkness. 



