holes) * catch anything more active than a tortoise, as everyone knows who 

 has watched a cat, dog, or ferret falteringly nosing out the whereabouts of a 

 bit of flesh, or a setter pointing a bird. The dog commonly points the stream 

 of scent that is passing his nose, without the slightest appearance of knowing 

 where the bird is. In fact, for the purpose of knowing just where their game 

 is, scent offers animals no immediate aid; and the same is true of sound. For 

 scent and sound can go round corners, whereas sight operates solely in a 

 straight line. Sight is also out of all proportion the swiftest; for while scent 

 moves practically only at the air's rate, and sound only 1,121 feet a second, 

 light, which means sight, travels 182,000 miles a second! This combined 

 straightness and swiftness gives sight, and sight alone, the power to tell the 

 predator exactly where his quarry now is, and the quarry where his enemy is. 

 Thus, at these crucial moments in the lives of animals, when they are on the 

 verge of catching or being caught, sight is commonly the indispensable sense. 

 It is for these moments that their coloration is best adapted, and, when looked at 

 from the point of view oj enemy or prey, as the case may be, proves to be 1 obliter- 

 ative. 1 All experiment corroborates our supposition that human and animal eyes 

 bear essentially similar relations to light vibrations. (And, in fact, almost all 

 theories about the functions of animal's colors are based on this hypothesis.) 



All naturalists perceive the wonderful perfection of the twig mimicry by 

 an inchworm, or of bark by a moth, or of a dead leaf by the Kallima butter- 

 fly. It is now apparent that almost equally marvelous concealment-devices, 

 in one shape or another, are general throughout the animal kingdom; the 

 most gorgeous costumes being, in their own way, climaxes oj obliterative color- 

 ation scarcely surpassed even by moths or inchworms. 



This discovery that patterns and utmost contrasts of color (not to speak 

 of appendages) on animals make wholly for their 'obliteration,' is a fatal 

 blow to the various theories that these patterns exist mainly as nuptial dress, 

 warning colors, mimicry devices (i. e., mimicry of one species by another), 

 etc., since these are all attempts to explain an entirely false conception that 



* In the case of the weasel family, this exception is doubtless a large one. 



4 DSf 



