The Making of Species 



general acceptance are to be attributed, firstly, 

 to their simplicity ; secondly, to the fact that they 

 have thrown light on many phenomena which 

 previously had seemed inexplicable ; thirdly, that 

 if we assume, as the great majority of biologists 

 do, that evolution has been effected by the 

 accumulation of numerous variations, small in de- 

 gree and indefinite in direction, we seemed forced 

 either to accept Neo-Darwinism or admit that the 

 whole subject of animal colouration baffles us, in 

 other words, to reject what appears like cosmos 

 and substitute for it chaos. 



With a few exceptions, books that deal with 

 the colours of organisms, while emphasising 

 the evidence in favour of the generally-accepted 

 theories, seem almost entirely to ignore the host 

 of facts that do not appear to fit in with them. 



This is largely due to the almost unavoidable 

 bias of the human mind when obsessed by a pet 

 theory. There are none so blind as those who 

 will not see. It is also, in part, the consequence 

 of the prevalent neglect of the scientific method 

 of comparison which leads men to theorise on 

 insufficient evidence. This, of course, is a natural 

 result of specialisation in biology. Naturalists 

 are in the habit of confining their study to the 

 habits of the animals of one particular country 

 and then making far - reaching generalisations 

 therefrom. 



As an example of the kind of theorising to 

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