xii DEPARTMENT OF TEE ^'AYAL SERVICE 



8 GEORGE V, A. 1918 



bacteriological studies were arranged, and cultures made of iDortions of' 

 the flesh, liver, kidney, swim-bladder, milt, and heart's blood. Diseased 

 portions of the skin were studied in microscopic sections, and in teased fragments. 

 The latter afforded the best results. The first stage of the disease was noticed in 

 fish conveyed in pontoons from the fishermen's nets. The fungus was Saprolegnia, 

 but it remained to be seen if it were a primaiy or secondary cause of the trouble, and 

 no live salmon could be inoculated; but an experiment was made with gold-fish. In 

 all the organs, apparently healthy, of the salmon examined, bacteria were found in 

 great numbers, but of a few species only. Very exact technical methods were used, 

 and ten different forms of bacilli were distinguished in the cultures made, in about 

 a dozen media, with results tabulated by the author on page 165. 



The important Bacillus salmonis pestis, a short thick bacillus, with rounded ends, 



varying in length, and occurring singly and in pairs, end to end was not found. 

 It is actively mobile, non-sporebearing, and survives for a week, and indeed grows 



profusely in the temperature of ice-and-salt mixture, but is killed at 98-6° F., and is 

 apparently a strict aerobe ,pathogenic to fish, but not to frogs, mice, etc. 



It gains access through wounds, or ulceration in the fish's skin. It grows well in 

 sea-water, and can be transmitted from dead, diseased fish, to live fish in tho same 



water. Attempts failed to inoculate live gold-fish with the various bacilli described. 



The author's conclusion is that numerous bacteria associated with the fungus, may 

 be the cause of the disease. 



IX. AFFECTED ^kllEAMICHI SAL:M0X, NEW BRUNSWICK— 

 (By. Dr. A. G. Huntsman). 



The author, after noting that an epidemic of disease such as this had not been 

 noticed in the previous year, and that the temperature was lower than in 1914. and the 

 water temperature in the salmon hatchery pond was never higher than 65° F. after 

 September 11 the author concludes that temperature is not a factor. The lower tem- 

 perature in October doubtless restrained the spread of the disease, as no new diseased 

 fish appeared. The fish were less crowded, there being 328 fewer impounded than in 

 1914. The salmon parasite (Lepeophtheirus) occurred in a considerable portion of 

 the fish trapped by the fishermen, and as it injures the skin it must deteriiiime the 

 location of the fungus (Saprolegnia ferax). The internal organs of the diseased 

 salmon showed no lesions, but the bacteriological phase of the epidemic is treated in 

 Dr. F. C. Harrison's report. Removal and destruction of all diseased and dead salmon 

 alone can help to lessen the trouble, and steps are necessary to secure improvement in 

 the renewal of the water supplying the pond. The most suitable temperature also should 

 be maintained. The eggs from diseased fish were naturally of lowered vitality, and 

 great losses, 40 to 60 per cent, resulted. Saprolegnia may attack eggs only of low 

 vitality. Bacteria possibly cause the disease, but may not affect the eggs, and fry 

 could not in this way have the disease transmitted ; but it may be carried in the water 

 used for shipping eggs and fry. 



