3o6 APPENDIX 



salmonis pestis. The scrupulous care with which he has 

 proceeded from stage to stage in his investigations, and the 

 patience with which he has checked them by experiments, 

 preclude all reasonable doubt that a great advance has been 

 effected in our knowledge of the pathogenic cause of the 

 disease, which must form the basis of all future endeavour 

 to mitigate the evil. At present, no suggestion of preventive 

 or remedial measures can be put forward, beyond that con- 

 tained in No. 5 of the conclusions contained in Mr. Patterson's 

 report. It will be observed that nothing in this important 

 discovery lends the slightest support to the popular and 

 mischievous delusion that the salmon disease arises from too 

 large a stock of fish. 



Mr. Patterson's Conclusions 



(i) "The fungus Saprolegnia ferax is not the cause of the 

 salmon disease. 



(2) " The disease is due to the invasion of the tissues 

 of the fish by a special bacillus {Bacillus salmonis pestis). 



(3) "The bacillus gains access through abrasion or ulcera- 

 tion of the skin, and the disease is apparently not contracted 

 when the skin of the fish is in a healthy state. 



(4) " Bacillus salmonis pestis can be transmitted from dead 

 diseased fish to other dead fish in the same water. 



(5) " Bacillus salmonis pestis can be transmitted from dead 

 fish to living fish in the same water ; and since dead fish 

 are a suitable nidus for the growth of the bacillus, it is 

 obviously desirable to have all dead fish removed from the 

 river, immediately they are observed, and burned ; because, 

 by simply burying, the germ is left in a condition to be 

 carried again into the stream. 



(6) " The fact that the bacillus grows profusely when placed 

 in a freezing mixture of salt and ice, while a temperature of 



