At first sight this reasoning may seem very convincing. But consider for a moment the process by which the hiss originated and gradually increased by natural selection. We must suppose that the rattle-snake was formerly incapable of making any sound. One day a variety appeared in which the skin was slightly hardened, so that when the creature moved its body rapidly there issued a slight sound. This must have caused an enemy to refrain from attack; it thus lived to transmit this peculiarity to its offspring, and those which made more noise than their ancestors escaped, while those that made less succumbed to their enemies. For ourselves, we find it quite impossible to believe that the rattle was thus gradually evolved by means of natural selection. Indeed, we are inclined to think that neither the hiss of the cobra nor its “intimidating attitude” has any terrifying effect on its adversary. In the case of the cobra we are able to cite positive evidence that dogs and cattle show no alarm at the attitude. “Dogs,” writes D. Dewar of this display, “regard it as a huge joke. Of this I have satisfied myself again and again, for when out coursing at Muttra we frequently came across cobras, which the dogs used invariably to chase, and we sometimes had great difficulty in keeping the dogs off, since they seemed to be unaware that the creature was venomous.” Colonel Cunningham writes, on page 347 of _Some Indian Friends and Acquaintances_: “Sporting dogs are very apt to come to grief where cobras abound, as there is something very alluring to them in the sight of a large snake when it sits up nodding and snarling; and it is often difficult to come up in time to prevent the occurrence of irreparable mischief.” Colonel Cunningham also states that many ruminants have a great animosity to snakes, and are prone to attack any that they may come across. We may therefore well be sceptical as to the value of intimidating attitudes to those creatures which are in the habit of striking them. Mimicry In a work of this kind it is neither possible nor necessary to consider in great detail the mass of evidence which has been advanced in favour of the theory of mimetic resemblance. Chapters vii. and viii. of Professor Poulton’s _Essays on Evolution_ contain an up-to-date statement of the facts in favour of the theory. Professor Poulton believes that in all cases mimetic resemblance is the result of the action of natural selection. He admits that there is no direct evidence in its favour, but asserts that “the facts of the cosmos, so far as we know them, are consistent with the theory, and none of them inconsistent with it” (page 271). Theory of Protective Mimicry