SEA-FISHERIES LABORATORY. 



129 



Some bacteriological work of the kind I mention has indeed 

 been carried out, notably by Clemesha in India, and by several 

 workers in this country, with respect to the longevity of 

 " B. coli " and " B. typhosus " in sea-water. In these latter 

 cases the characters of the organisms studied are, unfortunately, 

 not given in detail, and the observations made are not very 

 precise. 



I therefore give here some data relating to the longevity 

 of intestinal bacteria in sea-water, premising that no real 

 opportunity for a satisfactory investigation of the questions 

 suggested above has been afforded, and that the results here 

 given are to be regarded only as indicative of the possible 

 methods which might be adopted. 



An organism was isolated from human faeces having the 

 following characters : — 



Glucose +, lactose +, cane sugar -f, dulcite +, adonite — , 

 inulin — , indole -f-, Vosges and Proskauer's reaction — , 

 motility — . It was kept on nutrient agar for a month or 

 two and was then re-cultivated in all the above media : 

 the same series of reactions were again exhibited by it. A few 

 drops of the dulcite-broth culture (which had been incubated 

 for about four days) were then added to about half a litre 

 of sea-water of normal salinity (sp. gr. = 1-024 at 18° C), 

 and the numbers of bacteria in this liquid were estimated. 

 The flask containing the culture was then kept in a cupboard 

 at ordinary laboratory temperature (about 16° C.) and in 

 ordinary diffuse light, and the number of bacteria in it was 

 estimated from day to day. The results were as follows : — 



Experiment I. 



Days. 



1 



2 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



No. of bacteria per 

 1/1000 c.c 



No. of bacteria per 

 1/100 c.c 



(1321) 



309 



106 



45 



29 



20 



6 



70 



70 



65 



59 



44 



