Thomson. — Protection of the Undersized Fish 177 



Mr. Cranston : Is it your opinion that a mark in the nature of a 

 hole cut out of the gill cover, would be an enduring mark sufficient 

 to identify fish at any time thereafter. 



Mr. Fearing: I did not refer to the gill cover; but to a round hole 

 cut in the fin or tail. Could such a hole unite. Perhaps the tail will 

 grow, but will not the hole remain? 



Mr. Schaeffle: We have experimented with marks on the rainbow, 

 the steelhead and the salmon. 



Mr. Fearing: Is it true that you found the only way of marking 

 salmon was with silver or copper wire? 



Mr. Schaeffle : That is what we are doing. 



Mr. Thomson: In my hatchery the fish lost the entire fin; if that 

 fin had been marked it would have been lost. There was not a thing 

 to show for it. The caudal, dorsal and pectoral fins come right off 

 close to the fish's body. 



Mr. Fearing: Then you idea is that in the case of a fish marked 

 in that way, nature would make it lose the entire fin or tail ? 



Mr. Thomson : Yes. 



Mr. Fearing: That would explain the thing. 



Mr. Thomson : I had several fish there at the time, and they were 

 all cured of fungus growth. 



Mr. Fearing: We have cured any number of fish of fungus by 

 putting them in a salt water bath, and we do that as a rule. 



Mr. Thomson : That is proper. I have not marked the fish that 

 way ; but it would have disappeared anyway. 



Mr. Fearing : That would explain the fact that we never saw them 

 again. It has never been brought up to my knowledge. 



Mr. Thomson : I know absolutely ; I have watched the thing right 

 through. There was not a thing to the fish ; it was a bobtailed fish. 



Mr. Fearing: Then your idea is that they grow new fins as a 

 lobster grows a claw. 



Mr. Thomson : Why shouldn't they — just as a bird will grow a 

 new claw. 



Mr. Fearing : It is very interesting. I never heard this view taken 

 before. No one seems to know of it. 



Mr. Thomson : I am speaking of my own investigation. 



Professor Dyche : You have suggested some very remarkable 

 things in connection with the moulting of the fins of the fish. I have 

 been looking through fish literature and making experiments for a life- 

 time, and this is entirely new to me. It is so new and interesting that 

 I would be glad to come out and spend a month or two with you and 

 have you help me to perform some experiments. 



Mr. Thomson : I give you a standing invitation to do so. 



Professor Dyche: I am building a laboratory for carrying on in- 

 vestigation ; but I cannot handle trout in my laboratory. 



Mr. Thomson : Trout in cold water streams are quite different 

 from fish of warm water streams. 



