APPENDICES 427 



illustrative of the diametrically opposite methods in which 

 subjects such as this are approached. In the Proceedings of the 

 Zoological Society (1915, p. 679), a highly elaborate article sets 

 forth the precise angles and distances at which "colours or 

 colour-patterns blend or become obliterative." With meticulous 

 exactitude the details are worked out in centimetres and 

 millimetres. [To be of value I suggest that such measurements 

 should be made in miles rather than millimetres ; and the 

 experiments conducted, not under the roof-lights of a museum, 

 but under the open roof of heaven.] 



Secondly, I quote a pertinent remark of Roosevelt's : 

 " No amount of ingenious closet-guessing can take the place 

 of trained first-hand field-observation undertaken, not to twist 

 facts into the support of a theory, but with the ability and 

 purpose to find out the truth" (African Game- Animals, vol. i., 

 p. 78). 



c 



COLOUR-PROTECTION IN RELATION TO BIRDS 



That " Every colour and every colour-pattern on every 

 creature has been expressly designed by Nature for the pro- 

 tection and well-being of that creature " or words to the like 

 effect may be taken, I imagine, as summarising the creed of 

 colour-protectionists. 1 My own proposition is a direct negation 

 of the statement. The issue, therefore, is clean-cut and precise. 



A slight initial difficulty is that my case involves proving 

 a negative. An affirmative is easily supported (and thereby 

 mistaken by the credulous as proved) by adducing a few dozens 

 or a few scores of instances that may appear to substantiate its 

 thesis, while ignoring hundreds, or thousands, that are adverse. 

 The opposite rule applies to a negative. Absolute proof of 

 the latter would involve citing all creation ; but, since neither 

 the slopes of Ararat nor the space of an encyclopaedia are at 

 my disposal, I am content to select certain specific bird-groups 

 as sufficient for the purpose. 



1 If memory serves me aright, the words quoted, or similar words, occur 

 in an American treatise on this subject. 



