NATURAL SCIENCES OF PHILADELPHIA. 217 



it was a blind salmon ; and ui)on examination, I found this fish 

 had various sears on liis head, the left e3'e had sloughed out, 

 the riglit eye had a cut across it, and a thin film had formed over 

 the eye, causing him to be entirely blind. I learned from the 

 Indians that it often occurred tliat large salmon became blind, and 

 did not return to the sea with the rest of the fish for feeding, but 

 remained in the deep pools of the river, and eventually starved to 

 death. The Indians have many theories regarding the cause of this 

 blindness, none of which are plausible. During this trip I had 

 several chances of seeing salmon that were either blind in one or 

 both eyes, but did not at that time find out the true cause. But 

 during the past summer, while fishing on the tributaries of the 

 Saguinay River, in Canada, I again saw the same disease present- 

 ing itself in the salmon of those streams. I noticed that no small 

 salmon are found in this condition, and that all the blind ones 

 have cuts across the eyes and head, producing scars as if some line 

 or thread had been drawn tightly across the eyeball. 



M}^ view of the matter is that the fish in ascending or descend- 

 ing the streams come in contact with gill-nets that are set for the 

 capture of this fine fish for food, which the inhabitants of that 

 region use during their long cold winters. The meshes of the nets 

 are of the proper size to allow a large salmon to pass his head 

 through as far as the eye, while the smaller fish pass the head fur- 

 ther through, and thus escape the cut of the fine linen thread across 

 the delicate membranes of the e3'e. 



This cut if deep produces sloughing, but if slight, inflammation 

 and infiltration of the conjunctiva, thereby rendering it opaque. 



It is only the large noble fellows that escape capture by these 

 nets, with their heads scarred and their tails slit, showing the fear- 

 ful struggle tliey had in clearing themselves of the nets spread for 

 their capture, and living to become blind never again to return 

 to their feeding grounds, and soon to die of starvation. 



November 24. 



The President, Dr. Ruschenberger, in the chair. 



Thirty-tAvo members present. 



Paul Beck, George Gerrj^ White, James G. Pease, George F. 

 Barker, W. J. Hoffman, M.D., Joseph D. Potts, David "E. Dallam, 

 W. W. Jeffries, and Miss Adeline S. Trj'on were elected members. 



15 



