SEA-FISHEEIES LABOBATORY, 169 



including the addition to the sea water of fluid from 

 alkali works, such as may enter our estuaries, in the hope 

 of getting some clue to the cause of the green inflam- 

 mation, but have so far failed to reproduce exactly in the 

 laboratory the changes which seem to take place when 

 the oyster is left in its natural (?) surroundings. 



Our present opinion, however, is that oysters exhibiting 

 this pale green leucocytosis are in an unhealthy state, 

 and we may add that we find the liver in these specimens 

 is histologically in an abnormal, shrunken and degenerate 

 condition. Whether actually "unfit for food" or not, 

 they are at any rate in very " poor " condition, and have 

 lost the aroma and flavour of the normal healthy oyster. 



It is clear that, so far as our present knowledge goes, 

 oysters only share along with many other food matters — 

 such as tinned foods, meat pies, fish under certain 

 conditions, and diseased or infected meat — the responsi- 

 bility of occasionally being capable of conveying poison, 

 parasites, or disease germs into the human body ; and 

 that is, taken by itself, no sufficient reason why an 

 important and highly esteemed food matter should be 

 avoided. What is evidently necessary is that the precise 

 conditions under which the oyster may become dangerous 

 as human food should be investigated, and that when these 

 are determined precautions should be taken to insure that 

 the unhealthly conditions can never arise in our oyster beds. 



It is all important that perfectly healthy grounds should 

 be chosen for fattening the oysters upon. The water in 

 which they are kept should be above suspicion. Oysters 

 have to be fattened in water that is to some extent 

 estuarine, and unfortunately estuaries are the places 

 where a certain amount of sewage must find its way into 

 the sea. When sewage is present in water the number 

 of micro-organisms, pathogenic and otherwise, becomes 



