66 



shows a number of changes in the nomenclature and 

 classification of the genera and species. 



SECTION V. 



Investigations on Oysters and Disease. 

 (By Professor Heedman.) 



From the earliest times more or less well grounded 

 suspicion has been cast from tiine to time upon shellfish — 

 chiefly oysters and mussels — as being the cause of 

 outbreaks of disease amongst consumers. These outbreaks 

 fall into two categories :— 1st Cases of sudden poisoning 

 due to the presence of putrefactive products, and 2nd 

 Diseases due to a specific micro-organism, where there is 

 a period of incubation and where therefore a considerable 

 interval has elapsed between the infection and the actual 

 illness. In the latter case it is obviously much more 

 difficult to determine with certainty the source from 

 which the disease germ has entered the body ; and 

 although many positive assertions have appeared of late 

 years attributing outbreaks of enteric or typhoid fever to 

 the consumption of oysters, still it must be pointed out 

 that the connection between the two has not yet been 

 scientifically proved, and is only at present more or less 

 of a possibility or, at most, probability. 



Under these circumstances I suggested to my colleague 

 Professor R. Boyce that the subject was one well worthy 

 of our attention, and during the past year we have been 

 making a number of observations and experiments, both 

 in our Liverpool laboratories and at Port Erin, upon the 

 conditions under which oysters live healthily, and upon 



