492 
APPENDIX E 
experience, of trained mind, of keen powers of observation, and, in addi¬ 
tion, a man possessing the ability to portray vividly, clearly, and with 
interest what he has seen. 
Experience in the field is of great value in helping to test various bio¬ 
logical theories. One of the theories which has had a very great vogue 
of recent years is that of the protective coloration of animals. It has 
been worked out with a special elaborateness in Mr. Thayer’s book on 
‘‘Concealing Coloration in the Animal Kingdom.” I do not question 
the fact that there are in all probability multitudes of cases in which 
the coloration of an animal is of protective value in concealing it from 
its prey or its foes. But the theory is certainly pushed to preposterous 
extremes; its ultra-adherents taking up a position like that of some of 
the earlier champions of the glacial theory; who, having really discov¬ 
ered notable proofs of glacial action in parts of Europe and North America, 
then went slightly crazy on their favorite subject, and proceeded to find 
proofs of glacial action over the entire world surface, including, for in¬ 
stance, the Amazon Valley. As regards many of the big game animals, 
at any rate, which are claimed by the ultra-exponents of the protective 
coloration theory as offering examples thereof, there is not the least parti¬ 
cle of justification for the claim. 
I select Mr. Thayer’s book because it is a really noteworthy book, 
written and illustrated by men of great ability, and because it contains 
much that is of genuine scientific value.* I have no question whatever, 
for instance, that concealing coloration is of real value in the struggle 
for existence to certain mammals and certain birds, not to mention in¬ 
vertebrates. The night hawk, certain partridges and grouse, and numer¬ 
ous other birds which seek to escape observation by squatting motionless, 
do unquestionably owe an immense amount to the way in which their 
colors harmonize with the surrounding colors, thus enabling them to lie 
undetected while they keep still, and probably even protecting them some¬ 
what if they try to skulk off. In these cases, where the theory really 
applies, the creature benefited by the coloration secures the benefit by 
acting in a way which enables the coloration to further its concealment. 
A night hawk, or a woodcock, or a prairie chicken, will lie until nearly 
trodden on, the bird showing by its action that its one thought is to es- 
* In passing I wish to bear testimony to the admirable work done by various mem¬ 
bers of the Thayer family in preserving birds and wild life-work so admirable that if 
those concerned in it will go on with it they are entitled to believe anything in the world 
they wish about protective coloration! 
