I 



TRANSACTIONS OK SECTION D. 725 



(e) A series of oysters placed iu sea water to which was added daily- - 



(1) Healthy fecal matter. 



(2) Typhoid fecal matter. 



(3) Pure cultivations of the typhoid bacillus. 



The oysters were carefully examined to determine their condition, with 

 special reference to condition of branchite, alimentary canal, adductor 

 muscle, and viscera generally. The contents of the rectum, as well as 

 the water in the pallial cavity, were subjected to bacteriological 

 analysis to determine the number of micro-organisms present, as well 

 as the identitj- of the typhoid or other pathogenic organisms. 



C. The following is a summary of the results obtained so far : — 



"We consider that these results are based upon tentative experiments, and serve 

 only to indicate further and definite lines of research. They must not be regarded 

 as conclusive. We feel strongly that all the experiments must be repeated and 

 e.xtended in several directions. 



Our experiments demonstrate : — • 



I. The beneficial effects of aeration — 



(a) By the addition of air only ; 



(b) By change of water ; 



pointing to the conclusion that the laying down of oysters in localities where there 

 is a good change of water, by tidal current or otherwise, should be beneficial. 



II. The diverse results obtained by feeding upon various substances, amongst 

 which the following may be noted. The e.xceedingly harmful action of sugar, 

 which caused the oysters to decrease in weight and die ; whilst the other substances 

 detailed above enabled them to maintain their weight or increase. The oysters 

 thrive best upon the living Protophyta and Protozoa. Those fed upon oatmeal and 

 flour after a time sickened and eventually died. 



III. The deleterious effects of stagnation, owing to the collection of excretory 

 products, growth of micro-organisms, and formation of scums upon the surface of 

 the water. 



IV. The toleration of sewage, etc. It was found that oyster* could, up to a 

 certain point, render clear sewage-contaminated water, and that they could live for 

 a prolonged period iu water rendered completely opaque by tlie addition of faecal 

 matter ; that the faecal matter obtained irom cases vf typhoid was more inimical 

 than that obtained from healthy subjects ; and that there was considerable tolera- 

 tion to peptonised broth. 



V. The infection of the oyster by the micro-organisms. The results of the 

 bacteriological examination of the water of the pallial cavity of the oyster, and of 

 the contents of the rectum, showed that in the cases of those laid down in the open 

 water of the bay the colonies present were especially small in number, whilst in 

 those laid down in proximity to the drain pipe the number was enormous (eff. 

 17,000 as ajrainst 10 in the former c.ise). It was found that more organisms were 

 present iu the paillal cavity than in the rectum. In the case of the oysters grown 

 in water infected with the Bacillus typhosus, it was found that there was no ap- 

 parent increase of the organisms, but that they could be identified in cultures taken 

 from the water of the pallial cavity and rectum fourteen days after infection. 



It is found that the typhoid bacillus will not flourish in clean sea water, and 

 our experiments seem to show so far that it decreases iu numbers in its passage 

 along the alimentary canal of the oyster. It would seem possible, therefore, that 

 by methods similar to those employed in the ' Bassins de disgorgement ' of the 

 French ostreiculturist, where the oysters are carefully subjected to a natural pro- 

 cess of cleaning, oysters previously contaminated with sewage could be freed of 

 pathogenic organisms or their products without spoiling the oyster for the 

 market. 



It need scarcely be pointed out that if it becomes possible thus to cleanse 



