SeptembeeSI, 1900.] 



SCIENCE. 



443 



schools whose teachers recognize that most of 

 their pupils are studying zoology for use in 

 everyday life and not as preparation for ad- 

 vanced study in college. Moreover, college 

 ofiicers in charge of admission requirements 

 ■will probably give more favor to such a course 

 in elementary zoology than they have accorded 

 the purely morphological study which is now so 

 much in vogue in secondary schools. 



MAtTEICE A. BiGBLOW. 



Teachees College, Columbia Univeesity. 



Oysters and Disease. An account of Certain Ob- 

 servations upon the Normal and Pathological 

 Histology and Bacteriology of the Oyster and 

 other Shell- fish. By W. A. Hbrdman, D. Sc. , 

 F.R.S., and Rubert Boycb, M.B., London. 

 George Philip and Son. 1899. Lancashire 

 Sea-fisheries Memoir No. 1. 

 In this thin volume Professors Herdman and 

 Boyce, record the results of an investigation 

 extending over a period of three years and, al- 

 though they have not actually established a 

 connection between oysters and disease, they 

 have produced the most important contribution 

 which has yet appeared upon the subject, which 

 is one of considerable scientific and unusual 

 popular interest. 



The disputed question as to the cause of green 

 oysters has been re-examined, with the result 

 that several forms of greenness have been recog- 

 nized and studied. But little is added to our 

 knowledge of the well-known oysters of Maren- 

 nes, the authors being in practical accord with 

 most previous investigators, but concerning the 

 green oysters of Falmouth and certain green 

 American oysters laid down in the vicinity of 

 Liverpool they reach results divergent from the 

 views held by previous workers and more in 

 accord with popular beliefs. 



Copper in minute quantities is normally pres- 

 ent in all oysters, but in the green Falmouths 

 and Liverpool Americans it is found in unusual 

 amounts. In the greenest of the American 

 oysters as compared with the whitest, the pro- 

 portion is 3.75 : 1, calculated per oyster, and 

 3.63 : 1, calculated on the ash, and a careful 

 study of the distribution of the copper by 

 chemical and histo-chemical methods demon- 

 strates that it is the cause of the greenness. 



Some years ago Dr. Kyder, as noted by the 

 authors, studied a case of leucocytosis in Amer- 

 ican oysters, although he did not determine the 

 presence of copper nor appreciate the true cause 

 of the greenness. The reviewer has examined 

 during recent years, a great many green oysters, 

 but in no case has the greenness been in the 

 leucocytes of the blood of the heart and the 

 sinuses and tissues of the mantle, as described 

 by Ryder and the present authors, nor in those 

 which were tested, has the copper been present 

 in abnormal quantities or unusual distribution. 

 The specimens rather resembled the poor but 

 harmless Dutch oysters described by Herdman 

 and Boyce, and it would appear that we have 

 in America, as in Europe, several kinds of green 

 oysters, that in which the color is due to copper 

 being comparatively rare. 



The connection of oysters with the trans- 

 mission of infectious diseases, especially ty- 

 phoid and enteric fevers, is carefully consid- 

 ered. Bacilli of the colon group are frequently 

 found in oysters sold in towns, but there is no 

 evidence that they occur in those living in pure 

 sea-water. The experiments show that pure 

 sea-water is inimical to the growth of typhoid 

 bacilli and that they do not multiply either in 

 the alimentary tract nor in the tissues of the 

 living oyster. B. typhosus was not found in 

 any of the oysters obtained from dealers or 

 directly from the sea, but from inoculated 

 specimens the bacilli were obtained up to the 

 tenth day, although the results indicate that 

 they perish during passage through the intes- 

 tines. 



Oysters and other mollusca obtained from 

 dealers frequently contain a bacillus possess- 

 ing the characters of Klein's B. enteritidis sporo- 

 genes, presumptively resulting from sewage 

 contamination, but it was found that the in- 

 fected oysters could be cleansed by washing in 

 clean running sea-water. It is evident, there- 

 fore, that by changing oysters from an infected 

 bed to one where the surroundings are pure 

 they may be purged of their dangerous quali- 

 ties. The authors urge, in conclusion, that, 

 by legislative action and cooperation among 

 growers, steps be taken to prevent sewage 

 contamination of the oyster beds from which 

 the markets are supplied. 



