The Making of Species 



Plains, D. Dewar records an instance of a num- 

 ber of crows killing in revenge so powerful a 

 bird as the kite. 



Since very many species seem to throw off 

 melanistic variations, it may perhaps be asked, 

 How is it that more black species do not exist ? 



The reply is twofold. In the first place, it is 

 quite likely that in some organisms black varia- 

 tions are not correlated with courage or extreme 

 pugnacity, and when such is the case the melan- 

 istic varieties will be more likely to be exter- 

 minated by foes, on account of their conspicuous- 

 ness. It must be remembered that, other things 

 being equal, the inconspicuously coloured organ- 

 ism has a better chance of survival than the 

 showily coloured one. This is, of course, a very 

 different attitude from that which insists on the 

 all-importance to animals of protective coloura- 

 tion. Secondly, it is not difficult to see how too 

 much courage may be fatal to an animal in lead- 

 ing it to take risks which a more timid creature 

 would refrain from doing. This, as we have 

 already suggested, is probably the reason why 

 the black panther is so scarce. The black colour 

 is readily inherited, so there must be some cause 

 which tends to kill off the black varieties of the 

 panther. 



Lest it be thought the idea that excessive 

 courage and pugnacity are harmful is mere fancy, 

 let us quote from the account of the nesting 



360 



