SEA-FISHERIES LABORATORY. 147 



sea- water, or the alimentary canal of a shellfish. In particular, 

 do dulcite-fermenting organisms isolated from faeces continue 

 to ferment dulcite after they have been living in sea-water 

 for some time ? This question was suggested to me by 

 Dr. MacConkey as a possible subject for experiment. I regret 

 that I have few data to give which might conceivably answer 

 the question. 



Some mussels, taken from Roosebeck Scar, were put 

 into a clean tank in the Piel Hatchery. These mussels are 

 very clean, so that no micro-organisms, capable of growing 

 on neutral red, bile-salt, lactose agar, can usually be found 

 in l/50th part of a single animal. A culture of an organism 

 isolated from faeces was made in dulcite broth. This organism 

 had the following characters : — Glucose +> lactose +, cane 

 sugar +, dulcite -f, adonite — , inulin — , indole -f , Vosges 

 and Proskauer's reaction — . About a dozen mussels were 

 taken, and then, the valves of the shell being very slightly 

 forced apart, about 1 c.c. of the culture was injected, by means 

 of a hypodermic syringe, into the mantle cavities. The 

 mussels were then kept out of water for about six hours, so 

 as to allow the culture to be taken into the alimentary canal, 

 when they were placed in a small glass aquarium through 

 which clean sea-water was circulated at the rate of about 

 1 litre per five minutes. 



After a period of eighteen hours, five mussels were taken 

 out and the soft parts were emulsified in 250 c.c. of sterile 

 water. 1 c.c. of the emulsion was inoculated in each of five 

 plates, and the latter were incubated. The colonies were 

 so very dense that they formed a very fine haze in the medium. 

 There must have been very many thousands of colonies on 

 each plate. The remainder of the mussels were kept in the 

 aquarium for another five days, when they were again sampled. 

 Two plates were made from an emulsion of the soft parts 

 of five mussels in 250 c.c. of water, and each plate contained 



