Proceedings. 65 



Nith, which is believed to have gone to sea in order to get 

 rid of the fungus, had the fungus growing vigorously on 

 several parts of its body. The fungus must either have 

 instantly attacked the fish on its return to the river or not 

 have been destroyed during their stay in the salt water.] 

 Whether this arises from too high or too low a condition I 

 am quite unable to say, but I may remark that while some of 

 the fish examined were in the kelt stage, others were in a 

 condition perfectly fit for food." I have found dead fish in 

 an advanced state of decomposition covered from head to tail 

 with a furry coat. "Whether this was Saprolegna or not I 

 cannot say, for the examination is not inviting ; but it would 

 be interesting to know whether, if it be Saprolegna, it attacks 

 the body after death, and is in fact a form of putrefaction. 

 If so, it would suggest the theory that from some cause the 

 protoplasm has died in the parts where the fish is affected, 

 and the destroying spores of the fungus seize upon the spot 

 at once. 



Mr. Tegetmeier and Mr. Stirling are agreed that the disease 

 appears first upon unhealthy fish, unhealthy from possibly 

 many causes. I would only add to this that the first cause 

 is change from high to low temperature ; secondly, any 

 change of any sort. We can produce it at will amongst 

 Goldfish by lowering the temperature ; we see it daily on the 

 solitary Eoach or Gudgeon in the chemist's shop. It is 

 plainly not produced by overcrowding where temperature and 

 water are unaltered. It is omnipresent and ineradicable ; it 

 is hopeless to dream of cure. It must be taken as a great 

 and hostile factor in all attempts at fish-cultm-e, except under 

 purely natural conditions, and plainly not altogether under 

 those conditions. The only gleam of satisfaction is, that as 

 it is rare in natm-e and as we have no data to show that it 

 destroys the Salmon in rivers of Canada or the extreme 

 Highlands, where there are neither mills nor agricultural 

 drainage, it may possibly be these causes which, in con- 

 junction with low temperature, so weaken the vitality of the 

 fish that it falls a ready prey to the disease. 



In discussing Mr. Boyle's paper Dr. Bossey suggested that 



