November 25, 1898.] 



SCIENCE. 



739 



copper in the green American oj'ster than 

 in the colorless one, and more proportion- 

 ately in the greener parts than in those that 

 are less green. We, therefore, conclude that 

 their green color is due to copper. We also 

 find a greater quantity of iron in these 

 green American oysters than in the color- 

 less ; but this excess is, proportionately, 

 considerably less than that of the copper. 



6. In the Falmouth oysters containing an 

 excessive amount of copper we find that 

 much of the copper is certainly mechanically 

 attached to the surface of the body, and is 

 in a form insoluble in water, probably as a 

 basic carbonate. In addition to this, how- 

 ever, the Falmouth oj'Ster may contain a 

 much larger amount of copper in its tissues 

 than does the normal colorless oyster. In 

 these Falmouth oysters the cause of the 

 green color may be the same as in the 

 green American oj'sters. 



7. The colon group of bacilli is frequently 

 found in shellfish, as sold in towns, and es- 

 pecially in the oyster ; but we have no evi- 

 dence that it occurs in Mollusca living in 

 pure sea-water. The natural inference 

 that the presence of the Colon bacillus in- 

 variably indicates sewage contamination 

 must, however, not be considered estab- 

 lished without further investigation. 



8. The Colon group may be separated 

 into two divisions — ( 1 ) those giving the typ- 

 ical reactions of the Colon bacillus, and (2) 

 those giving corresponding negative reac- 

 tions, and so approaching the typhoid type; 

 but in no case was an organism giving all 

 the reactions of the B. typhosus isolated. It 

 ought to be remembered, however, that our 

 samples of oysters, although of various 

 kinds and from different sources, were in 

 no case, so far as we are aware, derived 

 from a bed known to be contaminated or 

 suspected of typhoid. 



9. Consequently, as the result of our in- 

 vestigations, and the consideration of much 

 evidence, both from the oyster -growers' and 



public-health officers' point of view, we beg 

 to recommend : 



(a) That the necessary steps should be ta- 

 ken to induce the oyster trade to remove any 

 possible suspicion of sewage contamination 

 from the beds and layings from which oysters 

 are supplied to the market. This could 

 obviously be effected in one of two ways, 

 either (1) by restrictive legislation and the 

 licensing of beds only after due inspection 

 by the officials of a government depart- 

 ment, or (2) by the formation of an asso- 

 ciation amongst the oyster-growers and 

 dealers themselves, which should provide 

 for the due periodic examination of the 

 grounds, stores and stock, by independent 

 properly-qualified inspectors. Scientific as- 

 sistance and advice given by such inde- 

 pendent inspectors would go far to improve 

 the condition of the oyster beds and lay- 

 ings, to reassure the public, and to elevate 

 the oyster industry to the important posi- 

 tion which it should occupy. 



(6) Oysters imported from abroad (Hol- 

 land, France or America) should be con- 

 signed to a member of the ' Oyster Associ- 

 ation,' who should be compelled by the 

 regulations to have his foreign oysters as 

 carefully inspected and certificated as those 

 from his home layings. A large proportion 

 of the imported oysters are, however, de- 

 posited in our waters for such a pei'iod 

 before going to market that the fact of their 

 having originally come from abroad may be 

 ignored. If this period of quarantine were 

 imposed upon all foreign oysters a great 

 part of the difficulty as to inspection and 

 certification would be removed. 



(c) The grounds from which mussels, 

 cockles and periwinkles are gathered should 

 be periodically examined by scientific in- 

 spectors in the same manner as the oyster 

 beds. The duty of providing for this in- 

 spection might well, we should suggest, be 

 assumed by the various Sea Fisheries Com- 

 mittees around the coast. 



