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. 
