PROTECTIVE COLORATION 
505 
their sight 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 quite 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 
from 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 lying 
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 majority of instances, it acts as an 
advertisement to all outside creatures of the prongbuck’s existence. 
