480 THE LAW WHICH UNDERLIES PROTECTIVE COLORATION. 



their sides, so that when you look down on them you see that their 

 backs match the mottled ground about them; whereas, when you 

 assume a lower point of view nearer their level, and see more and more 

 of their sides, you find them painted to match the more intricate 

 designs of the vegetation which is a little farther off, and which, from 

 this new standpoint of the observer, now forms the background. In 

 this latter position the head of the animal, being the highest part of 

 its body, is seen against the most distant part of the background, whose 

 details are still more reduced by perspective. To correspond with this 

 reduction of strength in the more distant background, the details on 

 the sides of the animal's head are likewise reduced in their emphasis, 

 and like the more distant details are smaller in pattern. 



It is a most significant fact that throughout the animal kingdom the 

 highest development of the arrangement of color and light described 

 in this article, and the highest development of the habit of standing or 

 crouching motionless in full daylight to avoid discovery, seem to coin- 

 cide very closely. For instance, gallinaceous birds, most waders, and 

 the cat tribe have both the color arrangement and the standing or the 

 crouching habit highly developed. Contrasted with these, for example, 

 are the skunks and the bears. Neither of these quadrupeds has the 

 gradation of color nor the standing or crouching habit. They are both 

 nocturnal, and therefore do not need either gradation or crouching for 

 concealment. 



It is XDlain, then, that while nature undeniably completes the conceal- 

 ment of animals by pitching their whole color gradation in a key to 

 match their environment, the real magic lies in the gradation itself 

 from darkest above to lightest below, wherever this gradation is found. 

 This is why it is so hard to see the partridge in the tree, the sandpiper 

 on the mud, or the tiger crouching in the jungle. 



FURTHER REMARKS ON THE LAW WHICH UNDERLIES PROTECTIVE 



COLORATION. 



Since writing my article on protective coloration in the April Auk I 

 have alighted on the means of still more complete ocular demonstra- 

 tion of the law of protective coloration. 



I made some wooden eggs about the size of a woodcock's body, and 

 provided them with wire legs to poise them 6 inches above the ground. 



Most of these I colored in imitation of the color gradation of a 

 grouse or hare — earth color above, to pure white beneath — while to two 

 others I gave a coat of earth color all over, above and below ; then set 

 the whole like a flock of "shore birds" on the bare ground in a city 

 lot.^ 



I then summoned a naturalist and let him begin at 40 or 50 yards 

 to look for them. He saw immediately the two monochrome ones, but 



iTo give the gradation its complete effect, the paintiug of the wooden eggs should 

 be done after they are placed on the ground and of course by an artist. 



