APPENDIX 



RECENT RESEARCH ON THE SALMON DISEASE 



Since the observations upon the salmon disease (pp. 210-212) 

 were printed, Mr. J. Hume Patterson, Assistant Bacteriologist 

 to the Corporation of Glasgow, has published an account 

 of the important discovery he has made in the course of his 

 researches into the nature of the disease.* His report contains 

 a detailed description of the experiments whereby he has 

 established the fact that the fungoid growth known as Sapro- 

 legnia ferax does not constitute in itself, as Professor Huxley 

 supposed, the active agent in the disease. Saprolegnia is 

 simply a mould or fungus, which finds its appropriate soil 

 in dead animal matter, and is no more capable of growing 

 upon living flesh of fish than it is upon the surface of a 

 flint. 



But Mr. Patterson has discovered a micro-organism which 

 does establish itself in the bodies of living fish, especially 

 those of the salmon kind. Apparently this micro-organism 

 can only invade the body of the fish where the superficial 

 tissues have been wounded ; in other words, where the skin has 

 been injured or broken. Having obtained entrance in this 

 way, it multiplies with great rapidity, forming areas of necrosed 

 or dead muscle, which offer a suitable nidus for the Saprolegnia. 

 Mr. Patterson has named this new micro-organism Bacillus 



* The Cause of the Salmon Disease : A Bacteriological Investigation. 

 By J. Hume Patterson. Presented to Parliament by command of His 

 Majesty. Price \s. 2d. 



3°s 20 



