F 
The Colors of Fishes 89 
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. 1 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 
Tetraodon nigropunctatus, 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 
Scorpemde. An example of this is shown on colored plate 
facing page 644. The Japanese okose or poison-fish (Inimicus) 
is black and gray about lava-rocks. In deeper water among 
red alge it is bright crimson, the color not fading in spirits, the 
markings remaining the same. In still deeper water it is lemon- 
yellow. 
