220 



REPORT OF THE COMMISSIOTSTER OK FISHERIES. 



Table XIV. — Anahjuis of oysters from Warren River. 



Specimens and date of collection. 



Dextrose, 

 fermented. 



Red eolo- j 

 uieson lit- 1 

 mus lac- 

 tose agar. 



B.coli. 



Other fecal 

 bacteria. 



Oysters, October, 1902. 



1. Jnicc 



3. Juice 



4. J u ice 



5. Juice 



6. Juice 



1. Intestine 



2. Intestine 



3. Intestine 



4. Intestine 



5. Intestine 



6. Intestine 



7. Intestine 



8. Intestine 



5. Stomach 



6. Stomach 



8. Stomach 



(") 



a No growth. 



The intestines of 5 of the 8 oysters examined contained J3. coU, 

 which was also found in the juice of these 5 specimens. The stomachs 

 of 3 were tested for colon forms, and two tests gave negative reactions; 

 the tube inoculated from the third oyster remained sterile. 



The next lot of oysters examined was obtained from the beds situated 

 under the lee of Pine Hill Point, Prudence Island. These beds are 12 

 miles from Fields Point, out of the direct course of the river, which 

 is continuous with the eastern passage of the bay, and are farther 

 removed from any source of sewage pollution than are any other o3\ster 

 beds in the river or bay. The intestines of 10 specimens from this 

 bed did not contain colon forms. The juice and stomachs of 5 were 

 found to be free from any sewage bacteria. 



A more extended studj^ was made of the oysters from Wickford 

 Harbor, which, as has already been stated, is well down the western 

 pas.sage of the baj' and far removed from sewage pollution. The water 

 over these oyster beds has been analyzed a number of times, and B. coll 

 has never been found. About 30 oysters were obtained from this 

 locality in March and April, 1902, and examined by the fermentation- 

 tube methods already described. No bacteria resembling organisms 

 of the colon group were found in the intestines, though organisms fer- 

 menting dextrose broth were occasionally observed. No growth devel- 

 oped in 70 per cent of the tubes inoculated with the stomach content, 

 and when growth occurred it was not due to the colon bacillus. The 

 juice of 8 of these 03^sters did not contain B. coll. 



In addition to the above series of fermentation tests for B. coll on 

 Wickford 03^sters, a second series, with a gelatin medium containing 

 0.05 per cent carbolic acid, was carried out on another lot from this 

 same localit3^ The intestinal content onlv of the oysters was subjected 

 to anal3^sis; no tests were made for the juice or stomach content. 



