64 Bulletin of Laboratories of Denisuu University. [Voi xii 



young fishes, like their adults, spend much of their time buried 

 under the debris of the bottom, wiih perhaps a barblet or a 

 portion of the tail only projecting. Under these circumstances 

 it is easy to apply the stimulus to various parts of the skin with 

 the assurance that the contact is wholly invisible to the fish. 

 Many such experiments ;-,how decisively that the reaction takes 

 place in the same way whether the fish is able to see the stim- 

 ulus applied or not. The visual factor being so conclusively 

 ruled out, I have not thought it necessary to blind the fish for 

 further control. 



This conclusion of course must be limited strictly to fish 

 of the species and age under investigation. It by no means 

 follows that they may not subsequently learn to use their eyes 

 in findmg food, as well as in escaping from their enemies. In- 

 deed, during the later experiments of this series, after the fishes 

 had been fed for several weeks almost daily with meat on the 

 end of a wire, 1 saw some slight evidence that they took note 

 of the bait by the means of sight, but the observations were in 

 no case conclusive. Whether the adult Anieiiims nebiilosns 

 ever uses the eyes in the capture of food, I have no definite 

 information, though from the habit of spending much of the 

 time during the day completely buried in the mud and of feed- 

 ing chiefly at night, it is very improbable that they do so. 

 With the channel cat fish, Icialunis, the case is certainly 

 different. 



Mr. I. A. Field tells me that while fishing for bass in the 

 Black River, Ohio, he has sometimes caught large specimens of 

 Ictahirus with live minnows as bait. The current was swift and 

 the minnows were kept off the bottom of the river and in mo- 

 tion all the time. At the meeting of the American Association 

 for the Advancement of Science at Pittsburg. July i, 1902. in 

 the course of a^brief report upon these experiments, I asked 

 the question whether any one ever caught a cat fish on a spoon 

 hook. Dr. L. L. Dyche stated that he has occasionally caught 

 the channel cat {letahti'ns) on a spoon in a small lake, but only 

 in bright sun light. Dr. Eigenmann stated that letaliirus has 

 much better eyes than Ameitittis. They are not only larger, 



