232 REPORT OF THE COMMISSIONER OF FISHERIES. 



Sixt3'^ per cent of the plates inoculated with material from the 

 stomachs of Kickemuit River oysters remained sterile. Two of the 8 

 plates that showed growth in three days contained large numbers of 

 colonies of l*s. jliiorescens^ M. luteus, M. flaviis^ M. carneus^ and a 

 species of sarcina (not described in this paper). A nonliquefying 

 fluorescent bacillus was also observed in a number of cases, forming 

 regular glistening colonies that look like small drops of water on the 

 surface of the gelatin, which takes on a pale green fluorescence. This 

 organism is described on the chart as l)acillus No. 11. 



The 10 plates inoculated from the intestinal content of these speci- 

 mens developed abundant growth in two days. Lic^uefying bacilli 

 were present in great numbers. Again Ps. JJuorescens was met with 

 in a large percentage of plates examined; also a small motile liquefy- 

 ing organism, bacillus No. 6, was found in 6 of the 10 plates. Col- 

 onics liquefy slowly and form bluish- white depressions in the gelatin, 

 some reaching a diameter of 5 mm, in four days. Microscopically 

 the}^ have a granular center around which is a clear hj^aline area that 

 usuall}^ has a distinctly wavy margin. By transmitted light they 

 "resemble a bluish star with a dark white center surrounded by a thin, 

 irregular bluish growth. Agar, gelatin, and broth cultures of this 

 organism assume a characteristic brown color after about two or three 

 weeks' growth at room temperature. Colonies of B. mesentericus 

 {\2i,Y\Qt\ fuacus)^ B. KvMills^ Bact. marltunum, and of the nonliquefy- 

 ing fluorescent bacillus No. 11, already referred to, were found in these 

 plates. J/, jiaviis and M. auriantiaca were met with on several 

 occasions. 



A more extended study of the flora of the oysters' intestines was 

 made on several lots of specimens obtained from Wickford Harbor in 

 the fall of 1902. In this series of experiments material from the 

 intestinal content of 100 oysters was inoculated into the usual gelatin 

 medium. This analysis was begun October 14, and from that date 

 specimens were obtained twice a week for over two months. Arrange- 

 ments were made with the parties controlling the Wickford 03^ster 

 beds, by which oysters caught Tuesday and Thursday mornings were 

 shipped to Providence and received in the laboratory the same day 

 they were taken from the water. They were then immediately opened 

 and cultures taken from the intestines.. 



Plates made from Wickford 03^sters as a rule developed a large 

 number of liquefying colonies, and though the organisms most fre- 

 quently observed were rod forms, colonies of micrococci were occa- 

 sionally met with. M. flaviis was found in 5 per cent of the plates 

 examined; also cultures of M. luteus and M. auriantiaca were taken 

 from colonies developing on ,3 of these plates. Another coccus form 

 more frequontl}" met with in this examination is referred to on the 



