20 BACTERIOLOGY OF THE OYSTER. 



illations. Moreover, Clark apparently assumes that the bacteria 

 isolated in this manner all came from the intestinal tract and that no 

 contaminating organisms from the mucus on the outside of the body 

 entered into the bacterial flora of the macerated intestine. The writer 

 in some experiments to be given in detail later has shown that on the 

 average there are more — often many times more — bacteria in the 

 mucus on the body of the oyster than in the total amount of shell 

 liquor and further that volume for volume the contents of the stomach 

 do not contain so many bacteria as the shell liquor. Since the stomach 

 contains more liquid on the whole than the rest of the intestinal tract, 

 it is but natural that it should contain more B. coli than the remainder 

 of the intestinal tract. This would be all the more evident when it is 

 understood that B. coli do not grow in oysters, but probably diminish 

 as they pass through the intestinal tract. ^ 



In his second article cited above, the whole contents of the oyster 

 shell, "the shell water and the crushed body of the oyster were ex- 

 amined together by inserting the entire mass in a fermentation tube. " 

 Obviously this would allow of no comparison between the bacterial 

 flora of the shell liquor and the body of the oyster. Yet in a following 

 paragraph and also in a table he gives the results of the analysis in 

 "Percent, of Samples Giving Positive Tests," in "Shell Water, 

 Intestine" and "Mash." Obviously there is some discrepancy, for 

 if he followed out the method described it would be impossible to 

 make such a differentiation. It is possible, however, that Clark was 

 using a combination of the technique as stated in the two reports. 

 The shell water and the "intestinal content" were examined as stated 

 in his report of 1902, and his "mash" consisted of the shell liquor 

 and crushed body, the entire mass of which was inserted into the fer- 

 mentation tube. It would appear, however, that in order to carry 

 out a combination of these two pieces of technique, two oysters would 

 be necessary, one for the shell liquor and intestine and another for 

 the "shell water and the crushed body." If this were true the 

 individual variation of course, would allow of no definite comparison 

 between all the parts tested. It may mean that the remains of the 

 body tissue after dissecting out the intestine and the unused portion 

 of the shell liquor were mixed and constituted the shell water and 

 crushed body. But, in whatever manner we try to explain the matter , 

 the fact remains that the method as described is insufficient to account 



^Hardman & Boyoc, loc. cit. 



