Permanence and Evolution. 147 



graphical races marked mainly by colour often 

 correspond with geographico-climatic areas ; but 

 there is no evidence of a race or a family strain 

 changing its colour through climatic influences ; 

 in fact, our most ordinary experience with 

 domestic animals is enough to show us that 

 strains of any and every colour may be kept 

 for any length of time under every sort of 

 climatic conditions without any change. But 

 these writers of whom I am now speaking 

 generally refuse any kind of definition of the 

 conditions of life on which they lay such stress. 

 Witness Dr. Andrew Murray, "Geographical 

 Distribution of Mammals." The only other 

 form I know of the evolution hypothesis is that 

 which supposes types to develop fresh sub-types 

 in a way somewhat analogous to the growth 

 of the organic individual, and to this I can see 

 no particular objection ; but neither do I see any 

 particular reason in its favour, and I do not 

 think that much is explained by supposing it 



