56 



" Natural Selection " 



to the " survival of the average, under the potent 

 influence of marriage." And this is supported by 

 Professor Morgan Lloyd, who writes in " Animal Life 

 and Intelligence " : " That perfectly free inter- 

 crossing between any or all of the individuals of a 

 given group of animals is, so long as the characters of 

 the parents are blended in the offspring, fatal to 

 divergence of character, is undeniable." Man, by 

 selection, can bring about varieties of pigeons and 

 horses, as everyone knows, but nature never does this. 

 As soon as man ceases to select and protect most 

 carefully, we get our pigeons back to the common rock, 

 and our horses, race and draught, similarly returning 

 to the average. 



Dewar and Finn deal with this matter with clearness 

 and certainty. They quote Romanes in " Darwin and 

 after Darwin " to the effect that " divergence between 

 the average qualities of a species, and those of an 

 isolated section, if the isolation continues sufficiently 

 long, differentiation of type is necessarily bound to 

 ensue." Their comment on this is most illuminating 

 (p. 374) : "This assumption is unfortunately not 

 founded on fact. If we were to take one hundred 

 racehorses and shut them up in one park, and one 

 hundred carthorses and shut them up in another park, 

 and prevent the inter-breeding of the two stocks, we 

 should, if Romanes' tacit assumption be true, see the 

 two types diverge more and more from one another. 

 We know that as a matter of fact they will tend, 

 generation after generation, to become more like one 

 another." In support of this, they bring forward 

 Galton's Law of Regression, and they show forth the 

 second fallacy in Romanes' reasoning, which is " based 

 on the assumption that there is no limit to the amount 

 of change which can be effected by the accumulation 

 of fluctuating variations ; but, as we have already 



