COSMIC PHILOSOPHY 



his work on the " Descent of Man " may be 

 found an account of the elaborate observations 

 which have led to these conclusions. Without 

 feeling it necessary to insist upon the validity 

 of all the special explanations contained in that 

 work, we must admit that the general theory is 

 substantiated by a superabundance of induc- 

 tive evidence. And when this kind of selection 

 is taken in connection with the need for pro- 

 tective concealment, we have the means of ex- 

 plaining by far the greater part of the colouring 

 found in the animal kingdom. 



The colours of the vegetal kingdom have, 

 to a considerable extent, been no less satisfac- 

 torily explained. " Flowers do not often need 

 protection, but very often require the aid of 

 insects to fertilize them, and maintain their re- 

 productive powers in the greatest vigour. Their 

 gay colours attract insects, as do also their 

 sweet odours and honeyed secretions ; and that 

 this is the main function of colour in flowers is 

 shown by the striking fact that those plants 

 which can be perfectly fertilized by the wind, 

 and do not need the aid of insects, rarely or 

 never have gaily coloured flowers." ^ 



Returning for one moment to the case of 

 animals, which are usually benefited by conceal- 

 ment but sometimes by conspicuousness, let us 

 note Professor Shaler's ingenious explanation 

 ^ Wallace, Natural Selection y p. 262. 

 40 



