APPENDIX E 
495 
white rump mark. Now, in the first place, the chance of the benefit 
happening to any individual prongbuck is so inconceivably small that it 
can be neglected, and, in the next place, in reality the white rump mark 
is exceedingly conspicuous under all ordinary circumstances, and for 
once that it might help the animal to elude attention, must attract at¬ 
tention to it at least a thousand times. At night, in the darkness, as 
any one who has ever spent much time hunting them knows, the white 
rump mark of the antelope is almost always the first thing about them 
that is seen, and is very often the only thing that is ever seen; and at 
night it does not fade into the sky, even if the animal is on the sky-line. 
So far as beasts of prey are guided by their sight at night, the white rump 
must always under all circumstances be a source of danger to the prong- 
buck, 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 conspicuous; 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. Any one acquainted 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; ex¬ 
cepting 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 conspicu¬ 
ous; 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 
