ON THE LIFE CONDITIONS OF THE OYSTEB. 363 



Life GoTiditions of the Oyster : Normal and Abnormal. — Second Report 

 of the Committee, consisting of Professor W. A. Herdman {Chair- 

 man), Professor R. BoYCE {Secretary), Mr. G. C. Bourne, and 

 Professor C. S. Sherrington, appointed to Report on the Elucidation 

 of the Life Conditions of the Oyster under Normal and Abnormal 

 Environment, including the Effect of Sewage Matters and Pathogenic 

 Organisms. '{Draion iip by Professor Herdman and Professor 



BOYCE.) 



The Green Disease. 



Since our Report, read at the Liverpool Meeting of the British Associa- 

 tion 4ast September, in which we announced that we had discovered a pale 

 green disease, accompanied by a leucocytosis, in certain American oysters 

 laid down on our coasts, two papers have appeared which require brief 

 notice. One of these is an article by Dr. D. Carazzi in the ' Mittheilungen ' 

 of the Naples Zoological Station for 1896, and the other is the ' Supple- 

 ment to the Report of the Medical Officer for 1894-95,' which deals with 

 oyster culture in relation to disease, and which appeared towards the end 

 of 1896. 



Dr. Carazzi has worked with the ordinary European oyster {Ostrea 

 edulis) at Spezia. The green oysters which he has investigated are 

 the ' Huitres de Marennes,' and some oysters of unknown origin which 

 he obtained from the bottom of a yacht. He has also had specimens of 

 the Portuguese oyster, but, so far as appears, no American oysters. He 

 considers that all the green oysters he has examined have been healthy. 

 He has apparently not seen any condition at all resembling the pale chalky 

 green, unhealthy state that we find in certain American oysters, and so he 

 seems inclined to deny its occurrence ! We have endeavoured to demon- 

 strate to Dr. Carazzi the existence of this diseased condition by sending 

 him both living specimens and also pieces of the affected mantle, etc., 

 fixed, preserved, and imbedded in paraffin ready for sectioning. Dr. Bul- 

 strode, in the Medical Officer's Report referred to below, has clearly met 

 with the green disease we described last year ; and we have also had the 

 satisfaction of showing it to Dr. P. P. C. Hoek, of Helder, who visited 

 our laboratories last February for the purpose of seeing our oyster work. 

 Our specimens and preparations have also been seen at all stages of the 

 investigation by our assistants and colleagues ' at University College, 

 Liverpool. 



The latter of the two works, a book of 174 pages, and many illus- 

 trations, consists of reports by Dr. Thome Thome, Dr. E. Klein, and 

 Dr. Bulstrode, upon the conditions under which oysters are cultivated 

 and stored, and upon the connection between unhealthy conditions and 

 the presence of pathogenic organisms in the oysters. Although these 

 reports contain little that was not known to those interested in the 

 subject, still they served to draw public attention to what had been only 

 previously known to oyster investigators, viz., that some— by no means 



' Our thanks are especially due to Professor Sherrington, Dr. C. Kohn, Dr. 

 Abram, Mr. Cole, and Mr. Scott. We are indebted to Mr. G. Petrie, Liverpool, and 

 Mr. Rupert Vallentin, Falmouth, for help in obtaining special kinds of oysters. 



