12 THE CONDOR Vol. XV on the nest. If the purpose of the difference between male and female is to lead enemies from the nest it would be a protective device, but certainly not a case of concealing coloration, so far as the male is concerned. The doctrines of Warning colors, and mimicry, besides the lack of convincing evidence of their validity, ap- pear to admit that all color patterns are not concealing. 'Another set of inconsistencies includes the croaks of frogs, the songs of birds and the cries of mammals. Why should nature provide concealing.colors for a pika, a woodchuck, or a prairie-dog, and then endow it with an instinct which in- duces it to attract the attention of every enemy which. approaches? Everyone who has studied nature in the field must know that a large percentage of birds and mammals which are observed, either by man or by lower animals, would es~ cape observation, if, to use the vernacular, they "had sense enough to keep their mouths shut" and remain motionless; These cries, croaks and songs are not for the purpose of leading enemies away from nests or young, because they are not confined to one sex or to the breeding season. To take care of the seeming exceptions to the concealing coloration doctrine it has been boldly asserted that "all patterns and colors, upon all animals whatso- ever, except such as live in the dark, or are neither predatory nor preyed Upon, are, when seen against the background against which their enemy (or prey) would see them at the critical moment, inexpressibly perfect pictures of the background, and therefore obliteratively colored." The circumstances of the critical moments of most species vary so enormously, and such moments occur in varying circum- stances so often with some species, that it is difficult to conceive how anyone at all familiar with nature could indulge in such a statement. It is quite on a level with another assertion of the same author, that "one may read on an animal's coat the main facts of his habits and habitat, without ever seeing him in his home." As the crow's color does not change, does it display "a perfect picture of the back- ground" when the critical moment occurs in a cornfield, or in a cottonwood tree, or on the rock crags Of the Rabbit Ears, or when the ground is bare, or when it is white with snow? If it be suggested that it is ?vhen on the nest, the obvious answer is that the nesting sites vary greatly, and surely that suggestion could not apply to the same query concerning the male of the redwing, or any species whose xnale takes no part in nest building or brooding. A moment's thought must flood the mind of every zoologist with specific objections to the assertions above quot- ed. '? The critical moment theory has been particularly applied to those animals which have' white rump patches or white tails, or both. I have been familiar with the prong-horn antelope since I883 and with the rabbits for a much longer peri- rod, and have never seen either dog or coyote puzzled for a second by the fact that the posterior white parts were thrown against a sky and so obliterated. Dur- ing the past two seasons I have had more opportunities to watch dogs pursue cottontails and jackrabbits than ever before, and they followed unerringly, often at close range, up hill where the rabbits were almost constantly against the sky. In case of the antelope, it is, so far as my observation goes, usually the flashing of the white patch that attracts the attention of its enemy, whether man or beast. ' It is inconceivable that nature has provided it with such a distinctive advertis- ing character, to attract the attention of all the coyotes in the vicinity, merely in order that it might sometimes be seen against a white sky and thus throw thc enemy off the trail, even if we can presume that the animal's enemies pursue their prey entirely by sight. My own observation is that most of our forest rabbits are not seen usually against a sky background, or even a forest background with
