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NOTICES OF NEW BOOKS. 



Concealing -Coloration in the Animal Kingdom, d-c. Being a 

 Summary of Abbott H, Thayee's Discoveries. By Gerald 

 H. Thayer. New York : The Macmillan Co. 



The " obliteration " theory of Mr. A. H. Thayer has been 

 enunciated by its author in several scientific papers, and so is 

 known to most students of philosophical zoology ; the present 

 beautifully illustrated volume condenses previous advocacy, and 

 gives further evidence for the theory, thus presenting the whole 

 argument in its favour. That concealment by "obliteration" 

 cannot very well be accepted as supporting the usual theory of 

 the purposes of animal disguises is clear from a paragraph in 

 the " Introduction " by Mr. A. H. Thayer himself. He writes : — 

 " This discovery that patterns and utmost contrasts of color 

 (not to speak of appendages) on animals make ivholly for their 

 ' obliteration,' is a fatal blow to the various theories that these 

 patterns exist mainly as nuptial dress, warning colors, mimicry 

 devices (i. e. mimicry of one species by another), &c, since these 

 are all attempts to explain an entirely false conception that 

 such patterns make their wearer conspicuous." Even in birds, 

 " changeable colors of all sorts strongly tend to conceal the 

 birds that wear them, and iridescence is extraordinarily potent 

 in this way. Its power is of two kinds, which are, however, 

 practicably inseparable in their working. First, it goes far 

 toward annulling the normal lights and shadows, with their 

 color- effects, of the surface on which it is placed ; and, second, 

 its great and vivid versatility of color and shade almost in- 

 sures the ' matching' of some part of that surface with whatever 

 forms its background." 



These two extracts will more or less focus the Thayerian 

 argument, which must almost certainly greatly modify much 

 theory as regards present advanced mimicry and phases in 



Zool. Uhser. vol. XIV., June, 1910. t 



