THE BLIND FISHES OF NORTH AMERICA. 479 



I have not found the slightest difficulty in capturing Amblyop- 

 sis with a small dip net, either from a boat or while wading through 

 the subterranean stream, and I have caught one in the hollow of 

 my hand. At such a time all the noise I could make did not affect 

 the fishes found swimming in the water. Frequently they were 

 taken in the dip net without apparently noting the vibrations pro- 

 duced in the water until they were lifted out of it; very rarely 

 a fish became evidently scared. Such a one would dart off a few 

 feet or a few inches, and remain on the qui vive. If not pursued, 

 it soon swam off quietly; if pursued, it not infrequently escaped 

 by rapidly darting this way and that; when jumping out of the 

 water, often an abrupt turn in the opposite direction from which it 

 started would land it in the net, showing that their sense of direc- 

 tion was not very acute. At other times, if disturbed by the waves 

 produced by wading, one or another individual would follow a ledge 

 of rock to the bottom of the stream, where it would hide in a 

 crevice. But very frequently, much more frequently than not, 

 no attention was paid either to the commotion produced by the 

 wading or by the boat and dip net. In general, it may be said 

 that the fishes in their natural habitat are oblivious to disturbances 

 of the water until frightened by some very unusual jar or motion, 

 probably a touch with the net, when they become intensely alert. 

 The fact that they are not easily frightened suggests the absence 

 of many enemies, while their frantic behavior if once scared gives 



Fig. ^.—Brodula harbata from Havana, t"i'-- l.—Stygicola dentatm from the 



(;ju})a. caves of Cuba. 



evidence either that occasional enemies are present and that they 

 are very dangerous, or that the transmission of the instinct of fear 

 is as tenacious as the transmission of physical characters. 



Contrary to Sloan's observation, that they detect the presence 

 of a solid substance in their path, I have never noticed that those 

 in confinement became aware of the proximity of the walls of the 

 aquarium when swimming toward it. Instead, they constantly use 

 the padded, projecting lower jaw as bumpers. Even an extremely 

 rapid dart through the water seems to be stopped without serious 

 inconvenience by the projecting jaw. 



The first observations on the feeding habit of Amblyopsis are 

 those of Cope. He remarks that " the projecting lower jaw and 

 upward direction of the mouth render it easy for the fish to feed 

 at the surface of the water, where it must obtain much of its 



