HISTORICAL SUMMARY. 5 



material on its way inwards from the surface to the liver. However, as Carazzi con- 

 tradicts* almost everything both morphological and physiological that has been stated 

 by previous workers on the oyster — Lankester, J. Chatin, Pelseneer, De Bruyne, Ryder, 

 and ourselves alike — it is a little difficult to meet him seriously and to find patience to 

 deal in detail with all his remarkable statements. Some of the points he raises, how- 

 ever, and of his so-called errors in the work of others, will be discussed further on in 

 this paper. 



There are many other papers upon both the structure and the physiology of the 

 oyster — and especially the green Marennes oyster — which we have not referred to above. 

 A very complete bibliography of the subject was published by the United States Fish 

 Commission in 1892, and so we have only considered it necessary to discuss the papers 

 which we have found useful, or which for any reason seemed to require our attention. 

 Previous work on the Bacteriology of Oysters, and the supposed connection with disease 

 in Man, we shall discuss in the latter part of this paper. 



* Mitth. Zool. Stat. Neapel. Bd. XII. ; Internal. Monatsschrift fur Anat. u. Physiol. Bd. XIV., &c. 



