The Colors of Fishes 85 
or ventral; a hidden spot of emerald in the mouth or in the 
axil; an almost endless variety of sharply defined markings, 
not directly protective, which serve as recognition-marks, if not 
to the fish itself, certainly to the naturalist who studies it. 
These marks shade off into an equally great variety for which 
we can devise no better name than “ornamentation.’”’ Some 
fishes are simply covered with brilliant spots or bars or reticu- 
lations, their nature and variety baffling description, while no 
useful purpose seems to be served by them, unless we stretch 
still more widely the convenient theory of recognition-marks. 
In many cases the markings change with age, certain bands, 
stripes, or ocelli being characteristic of the young and gradu- 
ally disappearing. In such cases the same marks will be found 
permanent in some related species of less differentiated colora- 
tion. In such cases it is safe to regard them as ancestral. 
In case of markings on the fins and of elaborate ornamenta- 
tion in general, it is best defined in the oldest and most vigorous 
individuals, becoming intensified by degrees. The most bril- 
liantly colored fishes are found about the coral reefs. Here 
may be found species of which the ground color is the most 
intense blue, others are crimson, grass-green, lemon-yellow, 
jet-black, and each with a great variety of contrasted mark- 
ings. The frontispiece of this volume shows a series of such 
fishes drawn from nature from specimens taken in pools of the 
great coral reef of Apia in Samoa. These colors are not pro- 
tective. The coral masses are mostly plain gray, and the fishes 
which lie on the bottom are plain gray also. Nothing could 
be more brilliant or varied than the hues of the free-swimming 
fishes. What their cause or purpose may be, it is impossible to 
say. It is certain that their intense activity and the ease with 
which they can seek shelter in the coral masses enable them to 
defy their enemies. Nature seems to riot in bright colors where 
her creatures are not destroyed by their presence. 
Intensity of Coloration.—In general, coloration is most in- 
tense and varied in certain families of the tropical shores, and 
especially about coral reefs. But in brilliancy of individual 
markings some fresh-water fishes are scarcely less notable, 
especially the darters (Etheostomine) and sunfishes (Centrar- 
chide) of the streams of eastern North America. The bright 
