554 W. H. LONGLEY 



flight, and, moreover, the movement alone is enough to betray it, 

 even if it is of a dull color." (Weismann, '04, p. 74.) ''No ob- 

 server of Nature can have failed to remark how the least move- 

 ment on the part of an animal will betray its whereabouts, 

 even though in color it assimilates very closely to its environ- 

 ment. . . . Thus in order that protective coloration may be of 

 use to its possessor the latter must remain perfectly motionless." 

 (Dewar and Finn, '09, p. 200.) The same sentiment is expressed 

 by Werner ('07), Selous ('08), Palmer ('09), and is quoted from 

 Beddard with approval by Roosevelt ('10, p. 493). It reappears 

 in Allen's ('11) review of Roosevelt's Revealing and Concealing 

 Coloration in Birds and Mammals, yet is diametrically opposed 

 to the just inference from the facts noted in the present section 

 of this paper. It is one of the 'obvious' things, the number of 

 which used in constructing theories of coloration is so great, that 

 if all were eliminated, the skeleton remaining would be scarcely 

 recognizable. It is so inconsistent with the fact that an un- 

 usually active fish, such as Iridio bivittatus, which seems never 

 to rest by day, possesses three color phases, which it changes 

 appropriately as it passes from one environment to another, that 

 farther comment is unnecessary. 



Some of the species whose color changes have been discussed 

 in the preceding pages wear bright colors and bold patterns 

 commonly considered conspicuous. Five are included in and 

 constitute 25 per cent of a list of fishes for which, among other 

 animals, Reighard has felt it desirable, if not imperative, to 

 restate and extend Wallace's ('67) hypothesis of immunity color- 

 ation. There is some reason for believing that adaptive color 

 changes may yet be demonstrated in other listed species. There- 

 fore one feels safe in saying that the advocates of the color 

 hypotheses which postulate conspicuousness must face the fact, 

 that in an important group of animals, whose colors and patterns 

 rival those of any other group in brilliancy and contrast, many 

 which to the casual observer seem among the most conspicuous 

 possess, in addition to countershading, an elaborate mechanism 

 which enables them to reproduce upon their own bodies the 

 dominant hues of the different environments in which they 

 normally find themselves. 



