1 66 DARWINISM AND THE PROBLEMS OF LIFE 



on facts, and lends itself to abuse and misuse in all sorts 

 of cases. Many Darwinians hide behind this principle 

 whenever they cannot discover real explanations. 



We saw that an organ from which natural selection 

 has removed its hand remains of the same size, but 

 deteriorates in quality. How is it with an animal that 

 is outside the range of selection ? We see this in the 

 case of our domestic animals. Apart from cattle, 

 horses, pigs, and fowls, and especially dogs, of which 

 we produce larger and smaller races by artificial 

 selection, and the organs of which have been modified 

 by selection, we see that, as a matter of fact, the size 

 of domestic animals generally remains the same. Take, 

 for instance, the cat, the fallow deer, and the common 

 pigeon that is found on every roof The parts of these 

 animals scarcely change in size, though they do in 

 another particular — colour. The reason of this is that 

 qualities do not vary in two opposite directions, that 

 neutralise each other in crossing, but in several. Still, 

 there are colours the microscopic structure of which 

 compels them to appear either in a light or a dark 

 shade, and these will be preserved in panmixis. 



As a general rule, however, the colours of animals 

 must be preserved by natural selection ; this is seen in 

 many wild as well as tame animals, the variations in the 

 colour of which clearly involve no danger to the species. 

 Take the varying colours of the common viper, or those 

 of the male hedge-lizard. But there are also colours in 

 which variation is only possible in one direction so that 

 they can never be neutralised. The Alpine hare is 

 pure white ; and as there is nothing whiter than white, 



