560 THE POPULAR SCIENCE MONTHLY 



merely their heads into holes for their prey, go boldly under ground 

 and attack such prey as hares and marmots, or fasten upon fowls much 

 larger than they themselves. From all such prey their foreheads have 

 nothing to gain by being white, since in the hole all is dark, and in the 

 case of these large victims attacked above ground, the attacker, if it be 

 a weasel, is looked down at, not seen against the sky, while the mar- 



Fig. 12 shows the animal's white top performing its perhaps cardinal function, 

 viz., that of effacing his top contour against the sky to the eyes of inhabitants of 

 the turf. 



This is the only function of the skunk's white top that is practically unceasing 

 as long as the animal is above ground. We have already seen that his white and black 

 cause each other, especially at night, to fade from sight at a short distance, and even 

 at a near view, confuse themselves with forest details. But the obliterating power of 

 night itself largely suffices to render all devices for concealment unnecessary. The 

 great development of the ears of nocturnal animals attests their difficulty in seeing at 

 this time. On the other hand, the night is scarcely ever so dark but that a solid form 

 within a foot of one's eye would show dark against the sky or the light parts of the 

 forest ceiling, and surely this must be the reason why skunks and the other grubbers 

 of small surface life wear this wonderful counterfeit of sky on their foreheads. By its 

 aid, they must constantly come close to many kinds of small surface-life on which they 

 so largely feed, which would evade them if they could see them. This must be espe- 

 cially obvious to any one who has often tried in vain to creep within catching-distance 

 of grass-hoppers. A single night's out-of-door experimenting will convince students of 

 the importance of the white top to such an animal as a skunk. 4 



tens, arboreal, acrobatic, swift and bloodthirsty, catch doubtless much 

 after the bold manner of the small weasels, and obviously would not 

 seem to have so much use for concealment from any particular view- 

 point. The pine marten, however, is enough light-foreheaded to save 

 his head from too much silhouetting in his above-ground forest 

 operations against small terrestrial life. 



In tall grass, to catch small terrestrial prey like mice, cats creep 

 low, and fling themselves high in air, dropping flat outspread upon the 

 dazed victim. Foxes vary this by coming down head-first upon it. 

 In neither case would top-white help them — and they haven't it. 



