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APPENDIX E 
common birds around our own homes, it is only necessary to 
consider the bobolink and the scarlet tanager. The males of 
these two birds in the breeding season put on liveries which are 
not only not the “ very best conceivable,” but, on the contrary, are 
the very worst conceivable devices for the concealment of the 
wearers. If the breeding cock bobolink and breeding cock tanager 
are not coloured in the most conspicuous manner to attract atten¬ 
tion, if they are not so coloured as to make it impossible for 
them to be more conspicuous, then it is absolutely hopeless for 
man or Nature or any power above or under the earth to devise 
any scheme of coloration whatsoever which shall not be concealing 
or protective ; and in such cases Mr. Thayer's whole argument is 
a mere play upon words. In sufficiently thick cover, whether of 
trees or grass, any small animal of any colour or shape may, if 
motionless, escape observation ; but the coloration patterns of the 
breeding bobolink and breeding tanager males, so far from being 
concealing or protective, are in the highest degree advertising ; 
and the same is true of multitudes of birds, of the red-winged 
blackbird, of the yellow-headed grackle, of the wood-duck, of the 
spruce grouse, of birds which could be mentioned offhand by 
the hundred, and probably, after a little study, by the thousand. 
As regards many of these birds, the coloration can never be 
protective or concealing; as regards others, it may under certain 
rare combinations of conditions, like those set forth in some 
of Mr. Thayer’s ingenious but misleading coloured pictures , 1 serve 
for concealment or protection, but in an infinitely larger number 
of cases it serves simply to advertise and attract attention to the 
wearers. As regards these cases, and countless others, Mr. Thayer’s 
theories seem to me without substantial foundation in fact, and 
other influences than those he mentions must be responsible for the 
coloration. It may be that his theories really do not apply to a 
very large number of animals which are coloured white, or are pale 
in tint, beneath. For instance, in the cases of creatures like those 
of snakes and mice—where the white or pale tint beneath can never 
be seen by either their foes or their prey—this “ counter-shading” 
may be due to some cause wholly differing from anything concerned 
with protection or concealment. 
There are other problems of coloration for which Mr. Thayer 
professes to give an explanation where this explanation breaks 
down for a different reason. The cougar’s coloration, for instance, 
is certainly in a high degree concealing and protective, or at any 
rate it is such that it does not interfere with the animal’s pro¬ 
tecting itself by concealment, for the cougar is one of the most 
1 Some of the pictures are excellent, and undoubtedly put the facts truthfully 
and clearly ; others portray as normal conditions which are wholly abnormal and 
exceptional, and are therefore completely misleading. 
