COLORATION 77 



can possibly have any effect in concealing them from their 

 foes. While drinking they are apt to start and look round. 

 They never lie down near the water; they never stand 

 motionless in cover near the water save for a few moments 

 between their forward moves; when they have satisfied 

 their thirst they move back to the open flats on which they 

 dwell ; and the long tails of the zebra and oryx are perpetu- 

 ally in motion and would of themselves catch the eye. In 

 short, the habits of the zebra and oryx are such that at the 

 only times when they are in the reeds it is an absolute 

 impossibility for any watching beast of prey to fail to dis- 

 cover them, and no coloration, whether advertising or con- 

 cealing, would either help or hurt them. This applies by 

 day; it also applies by night save when the darkness is 

 such that no coloration can be seen at all. 



But this is not all. Mr. Thayer "proves" in his "ex- 

 periment'* that relatively to the variegated oryx and zebra 

 a practically unicolored countershaded animal would in the 

 reeds be revealingly colored. Well, it happens that in 

 Africa there is an animal, about as large as the zebra or 

 oryx, which nearly fulfils Mr. Thayer's definition, which is 

 of a nearly uniform countershaded color on head and body, 

 and which does often live in the reeds. This is the water- 

 buck. It often spends over half its time in the reeds and 

 near the water's edge, standing and lying down. Mr. 

 Thayer "proves" that the zebra and oryx have a coloration 

 which in the reeds is far more concealing than is the color- 

 ation of the waterbuck when in the reeds. Yet, as a matter 

 of fact, the waterbuck often dwells in the reeds and the 

 zebra and the oryx never do. The actual facts are directly 

 the reverse of what Mr. Thayer supposes them to be. Not 



