of the, Salmon in Fresh Water. 



61 



cent., were free from liquefying growths, and of these, two occurred 

 in July out of 12 tested, or 16 per cent. Of the 87 cultivations 

 made from the fish from the mouth, 18 developed no liquefying 

 colonies, or 20-7 per cent. Of the 18, eight were obtained in July and 

 August, out of 27 cultivations, or about 29 per cent. ; six in late autumn 

 out of 27, or 22 per cent. ; three in May and June out of 12, or 25 per 

 cent. ; and one in March out of 21. 



But to obtain the correct figures, the number of occasions on which 

 no growths or moulds only were present should be deducted' from the 

 total numbers. Doing this we find that no liquefying organisms were 

 found in : 



Thus it is clear that colonies of bacteria which liquefy gelatine and 

 cause putrefaction are much more frequently absent in the fish caught in 

 the tidal waters than those caught in the upper reaches of the river. 



If the numbers of the cultivations in which no organisms, only 

 moulds, or only non -liquefying forms, developed, be added together, we 

 find the following : 



A total in the upper-water fish of 16 in 36, or 44-4 per cent., and 

 in the lower of 52 in 87, or nearly 60 per cent. 



Putrefactive organisms are therefore less common in the alimentary 

 tract of salmon living in tidal waters throughout the year, while they 

 are almost entirely absent in fish caught in May and June either at the 

 mouth or the upper reaches of rivers. 



The Bacillus coli communis was grown on 19 occasions, 14 of these 

 occurring in July and August. Five cultivations from fish caught in 

 the upper waters contained this organism. 



On several occasions fish caught on succeeding days, or a short time 

 after one another, afforded evidence of the presence of the same 

 organism. Thus the same diplococcus was given from two fish caught 

 in November 1895. 



Moulds are more common in the alimentary tract of fish living in 

 tidal waters, especially during the earlier part of the year. 



The two series, each of three fish, which are separately noted, show- 

 that the bacteriological conditions may be very different in salmon 

 caught about the same date. In the first series the three fish were 

 captured on the same day and at the same place, but the colonies grown 

 from them differ in both character and distribution. In the second 

 case two of the fish came from the same river, one from the mouth and 

 one from the upper part, the third from the upper part of another 



