224 Recent Literature. \_Kp^\ 



tends to deceptive visibility. On sandy deserts birds, mammals, and 

 reptiles are counter-shaded from sand-color to white, and on dark-colored 

 ground, from very dark to white. 



Chapters III-IX deal especially with obUterative coloration, or the use 

 of markings ("picture-patterns") on counter-shaded birds, illustrated 

 mostly by photographs from life of Woodcock, Snipe, Ruffed Grouse, 

 Whip-poor-wills, Nighthawks, Ptarmigan, Sage Grouse, Meadowlarks, 

 Eider Ducks, Short-eared Owls, Plovers, etc. (figs. 14-52) . These chapters 

 .are designed to show the perfect obliterative coloration of terrestrial birds 

 that live among weeds and grass, fallen leaves and sticks, patches of mud, 

 and pools of water — the perfect merging of their forms and markings 

 with the background. The two next succeeding chapters (X and XI) 

 treat of the markings of rails, bitterns, and other swamp birds, of oblitera- 

 tively shaded ducks, and the uses served by spots and patterns in bird 

 costumes (figs. 53-55). 



In Chapter XII the birds of the ocean are taken up. Chapter XIII 

 discusses the "inherent obliterative power of markings," which tend to 

 obliterate or cancel, "by their separate and conflicting pattern, the visi- 

 bility of the details and boundaries of form," and is illustrated by diagrams, 

 both colored and in black-and-white, and photographs of birds from life 

 (figs. 56-63). The same general subject is continued in Chapter XIV, 

 in which are considered the special functions of markings, and the protec- 

 tive coloration of nestlings, illustrated with numerous figures of birds 

 from life (figs. 64—82). Chapters XV-XIX deal with other features of 

 coloration in birds, as the bright colors of bills and feet, the brilliant hues 

 and iridescent patches of color so charactersitic of hummingbirds and other 

 tropical birds, etc., in connection with their surroundings (pi. vi and fig. 

 83). 



Chapters XX-XXII deal with mammals, which are treated along much 

 the same lines as the birds, the consideration of which occupies the nineteen 

 preceding chapters. Fishes are considered in Chapter XXIII, reptiles 

 and amphibians in Chapter XXIV, and caterpillars, butterflies and moths, 

 and a variety of other insects in Chapters XXV-XXVII, followed by sup- 

 plementary matter in two appendices. 



The text is devoted to a definition of principles and the presentation and 

 illustration of facts; hypothetical conclusions from the facts are left to the 

 reader. Optical illusions are disclosed and explained, some of the most 

 important parts of the text being the explanatory legends accompanying 

 the figures and colored plates. It is not to be overlooked that the work is 

 by an artist, a vision-expert, who is qualified to contribute experience and 

 expert knowledge in the field of optical effects. A striking feature in a book 

 of this character is the absence of argument. 



Mr. Thayer's position in the matter of animal coloration is directly the 

 opposite of that of most naturalists, who assmue that patterns of color or 

 markings reveal the wearer, while Mr. Thayer convincingly shows that in 

 reality they conceal when the animal, in its normal surroundings, is seen 



