30 



Allowing for the much greater number of B. typhosus 

 introduced into the oysters of the first experiment, the 

 results of Experiment II harmonise well with those obtained 

 in Experiment I, namely: the rapid decrease and equally 

 rapid total disappearance of B. typhosus from the oysters 

 which, after infection, were kept in clean sea water repeatedly 

 changed; while in oysters at the same time and manner 

 infected, but afterwards kept out of the water (dry), the 

 decrease, though taking place, is much slower: after the first 

 day dry (oyster 2) no decrease being noticeable, the oyster 

 containing the same number of B. typhosus as the oyster 1 

 immediately after infection, viz., 40,000 ; whereas in oyster 3 

 that had been kept 24 hours in clean sea water the number 

 had decreased considerably to 1380. 



' Also from this experiment we are justified in concluding 

 that the decrease of the B. typhosus in the oysters could not 

 have been due to a simple " washing out " process, but must 

 be due to the capability of the oyster to directly devitalise 

 the B. typhosus, being something alien to the tissues of the 

 oysters and not capable of maintaining its existence therein ; 

 the dry oysters are clear proof for this conclusion. 



That this function of the destruction of the B. typhosus 

 by the tissues of the oysters per se would be more marked 

 and extensive in those that were kept after infection in clean 

 sea water constantly changed than in those kept out of the 

 water is to be expected, since in the former the ordinary pro- 

 cessesof the tissueswould go onunabatedand innormal fashion, 

 which could not be the case in oysters kept out of the water. 



All the oysters of this experiment were, on opening, found 

 in all respects normal, plump and juicy, their shell well closed. 



EXPEEIMENT III. 



This experiment is in reality a continuation of Experi- 

 ment II in this sense, that several oysters of the same batches 

 left over from Experiment II were subjected to reinfection 

 and analysis ; at the same time the sea water into which 

 after infection they were transferred, and which was frequently 



