236 The Colors of Fishes 



sometimes with spots of black or violet. In still others the body 

 may be pink or brown, or violet-black, the fins all yellow, part 

 black or all black. Finally, there are forms deep indigo-blue in 

 color everywhere, with cross bands of indigo-black, and these 

 again may have bars of deeper blue on the head or may lack 

 these altogether. I find no difference among these fishes ex- 

 cept in color, and no way of accounting for the differences in 

 this regard. 



Certain species of puffer {Tetraodon setosus, of Panama, and 

 Tctraodoi! nigropitiictatns, of Polynesia) show similar remark- 

 able variations, being dark gray with white spots, but varying 

 to indigo-blue, lemon-yellow, or sometimes having coarse blotches 

 of either. Lemon-yellow varieties of several species are known, 

 and these may be due to a failure of pigment, a sort of semi- 

 albinism. True albinos, individuals wholly without pigment, are 

 rare among fishes. In some cases the markings, commonly 

 black, will be replaced by a deep crimson which does not fade 

 in alcohol. This change happens most frequently among the 

 Scorpccnidcc. i\n example of this is shown in the frontispiece 

 of Volume II of this work. The Japanese okose or poison- 

 fish (Iiiiiincits) is black and gray about lava-rocks. In deeper 

 water among red alg:e it is bright crimson, the color not 

 fading in spirits, the markings remaining the same. In still 

 deeper water it is lemon-yellow. 



