FISH, THE PEOPLE OF THE SEA 



the Nassau lighthouse was pure white sprinkled 

 with smallish black spots of different sizes all 

 over. Counting these as phases not covered by 

 the doctor's description, we have nine distinct 

 changes of appearance, all of which can be as- 

 sumed almost instantaneously. In its dark phase 

 it is called a deer grouper in Nassau. 



Animal and fish coloration is usually supposed 

 to be for protection, and without doubt it is often 

 sa used; but it seems far more likely that Dr, 

 Townsend is right in suggesting that fish colour 

 changes are emotional and under perfect control 

 by the fish. All fish have probably got this power 

 in a greater or smaller degree. In the tropical 

 fish, however, the changes are often violent and 

 immediate, but even with the northern fish, which, 

 like their brothers on shore, disapprove of con- 

 spicuous attire and frequent changes, we may 

 guess that all individuals are not any more alike 

 in reality than some people erroneously suppose 

 Chinamen to be. 



Often in the neighborhood of the wharves, espe- 

 cially in the shallows, you may see two long nar- 

 row fishes lying motionless near the surface. The 

 narrowest has a long, sharp nose like a sword- 

 fish, and is pale yellowish green with bright blue 

 fins and beak. This is the houndfish waiting to 

 prey on the tiny fish fry should one seem weakly 

 or venture too far from the shoal. It can shoot 



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