PROTECTIVE (X)LORATION 50.5 



their siorht at night, the white rump must always under all circum- 

 stances be a source of danger to the prongbuck, and never of any 

 use as an obliterative pattern. In the daytime, so far from using 

 this white rump as obliterative, the prongbuck almost invariably 

 erects the white hairs with a kind of chrysanthemum effect when 

 excited or surprised, and thereby doubles its conspicuousness. In 

 the daytime, if the animals are seen against the sky-line, the white 

 rump has hardly the slightest effect in making them less con- 

 spicuous ; while if they are not seen against the sky-line (and of 

 course in a great majority of cases they are not so seen), it is much 

 the most conspicuous feature about them, and attracts attention 

 from a very long distance. But this is not all. Anyone ac- 

 quainted with the habits of the prongbuck knows that the adult 

 prongbuck practically never seeks to protect itself from its foes by 

 concealment or by eluding their observation ; its one desire is 

 itself to observe its foes, and it is cjuite indifferent as to whether or 

 not it is seen. It lives in open ground, where it is always very 

 conspicuous, excepting during the noonday rest, when it prefers to 

 lie down in a hollow, almost always under conditions which render 

 the white rump patch much less conspicuous than at any other 

 time. In other words, during the time when it is comparatively 

 off its guard and resting it takes a position where it does not stand 

 against the sky-line— as, according to Mr. Thayer's ingenious 

 theory, it should ; and, again contrary to this same theory, it 

 usually lies down, so that any foe would have to look down at it 

 fi'om above. Whenever it does lie down, the white patch becomes 

 less conspicuous ; it is rarely quiet for any length of time except 

 when lying down. The kids of the prongbuck, on the other hand, 

 do seek to escape observation, and they seek to do so by Iving 

 perfectly flat on the ground, with their heads outstretched and the 

 body pressed so against the ground that the effect of the white 

 rump is minimized, as is also the effect of the "counter-shading'"'; 

 for the light-coloured under parts are pressed against the earth, 

 and the little kid lies motionless, trusting to escape observation 

 owing to absence of movement, helped by the unbroken colour 

 surface which is exposed to view. If the adult prongbucks really 

 ever gained any benefit by any " protective "' quality in their 

 coloration, they would certainly act like the kids, and crouch 

 motionless. In reality the adult prongbuck never seeks to escape 

 observation, never trusts in any way to the concealing or protec- 

 tive power of any part of its coloration, and is not benefited in 

 the slightest degree by this supposed, but in reality entirely non- 

 existent, concealing, or protective power. The white rump 

 practically never has any obliterative or concealing function ; on 

 the contrary, in the great niajority of instances, it acts as an 

 advertisement to all outside creatures of the prongbuck's existence. 



