70 American Fisheries Society 



of the disease, however, was made known in Keuka Lake into which 

 the hatchery stream flows some 4 or 5 miles below the hatchery 

 grounds. A large whitefish brought up from Keuka Lake was found 

 to have a large and well developed throat tumor, not in the usual site 

 on the thyroid, but between the gill lamina;, and on the cartilage from 

 which the gill lamina- spring. I don't remember the name of that carti- 

 lage, but that is where the tumor was located for the most part, and 

 only a smaller one on the thyroid proper. Xow, how was the disease 

 caused in this whitefish? No one had planted anything except whitefish 

 fry in that lake, and-none of those for a great many years. It seemed 

 to me that the lish we had liberated purposely or accidentally in the 

 hatchery stream must have gone down into Keuka Lake and acted as 

 a source of infection to other species. Of course I don't know, — one 

 swallow does not make a summer, one whitefish does not establish a 

 principle; but there was a whitefish, not reared in activity, not asso- 

 ciated with the pond lish in any way, except as they may have gone 

 into the hatchery stream and introduced the disease into this lake. It 

 seemed to me from that fact there must be some means of spreading 

 the disease in the water. An impure water supply appeared to origi- 

 nate it. As soon as we cut out that source of supply we got rid of the 

 dise'ase. And furthermore we found, just as you did, that fish lib- 

 erated in a stream where they had a rapid flow and plenty of water, 

 recovered to the extent of more than 50 per cent. Even the large fish 

 would come back to us clean. 



Mr. Meehan : Dr. Bean's remarks about the whitefish remind me of 

 another matter which would indicate the possibility of the disease being 

 communicable in some way, and which perhaps caused me to say that 

 in Dr. Marine's investigation, while he found that it was difficult to 

 inoculate the disease, yet the results were not satisfactory to him or 

 to me. 



I have not made any investigation myself in regard to the matter, 

 and therefore will not say that it is so, but it is said that the blue pike 

 in Lake Erie are generally affected, or that large numbers of blue pike 

 in Lake Erie are affected with the thyroid disease. I received that 

 statement, 1 think, from Dr. Marine and others. I have meant to look 

 into it and ascertain to what extent it was true, but have not yet 

 done so. 



It was also stated that along the shores of the Great Lakes that thy- 

 roid troubles were quite common among dogs and other animals which 

 were in the habit of eating lish offal, and even among the fishermen 

 themselves along the lakes. Whether there is anything in that or not, I 

 am unable to say. 



Mr. W. T. Thompson, Fairport, Iowa: Did you have the same 

 number of fish in each of those ponds always, and were the ponds in 

 which the disease was most prevalent larger than the others? 



Mr. Meehan: The number <>\ lish in the ponds depended on the size 

 of the latter. In one series of ponds they were about the same size and 



