244 Fortieth Annual Meeting 



Indeed, I have had to reject for this reason several of the 

 lantern slides representing the appearance of the fishes 

 upon white or pale gray backgrounds. And, finally, to 

 properly appreciate these photographs one must compare 

 them carefully side by side and not, as is necessarily the 

 case with a lantern exhibition, in series. 



(Twenty-two lantern sHdes were then shown). 



DISCUSSION 



Dr. C. H. Townsend, New York : I would like to ask Dr. Sumner 

 if he found any instantaneous changes of coloration? 



Dr. Sumner: I have observed changes which were almost instan- 

 taneous. Some of those fishes which had been changed back and forth 

 a number of times and become habituated to making these changes, 

 would change in a very few moments; and I have noticed that if you 

 stir flounders and cause them to swim, spots will become visible which 

 were invisible before, and vice versa. 



Mr. E. N. Carter, St. Johnsbury, Vt. : Do fish that are blinded 

 always become white? 



Dr. Sumner: No, fish that are blinded in a dark condition will 

 remain dark although not as dark as the maximum. Fish that are 

 blinded when white remain white for a little while and then gradually 

 turn dark. 



The ones I showed which became pale immediately after blinding 

 were so only because they had been on a pale background for some 

 weeks and had become accustomed to that before being placed on a dark 

 background. The dark condition is normal to this species. 



Mr. Carter : Some years ago in passing by a pond I noticed a black 

 bass gradually becoming darker. After several weeks the fish became 

 almost coal black, and I then discovered it was blind. It was a small- 

 mouth black bass. 



Dr. Sumner: The dark color probably represents the normal resting 

 condition of the color cells. 



