50 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



aspersa, Botryllus smaragdus and B. schlosseri — about the same 

 total number, but rather a different assemblage of species. 



It may be of interest to know that in that first year of 

 Mr. Chadwick's curatorship the number of visitors who paid 

 for admission to the Aquarium was 500, while in the past 

 summer (1919) the number was over 23,000. 



The work on the green colouration of certain oysters, and 

 on the connection between oysters and certain bacterial 

 diseases, which had been started a couple of years previously 

 by Professors Boyce and Herdman, with the help of Dr. Charles 

 Kohn, was continued and brought to an end during this and 

 the following year when the detailed evidence and results were 

 published by the Lancashire Sea-Fisheries Committee in the 

 form of a Memoir entitled " Oysters and Disease." A summary 

 of the results is given in our 12th Annual Report, showing 

 that there are several distinct kinds of greenness in oysters, 

 some of which are quite healthy, and are due to the natural 

 vegetable food of the animal, as in the case of the green 

 Marennes oysters in France and those of some rivers on the 

 Essex coast ; while others are diseased conditions due to the 

 storing up of an abnormal amount of copper in the blood or other 

 tissues. For the bacterial results we must refer those interested 

 to the details given in the Memoir. But it may be added that 

 our work showed the necessity for the periodic examination 

 by scientific inspectors of all oyster beds and other grounds 

 from which mussels, cockles or periwinkles are gathered for 

 human food. 



The Report which appeared during this year of the Manx 

 Industries Commission recommended that a Fish Hatchery 

 should be established in connection with the Biological Station 

 at Port Erin. Another new departure, which was proposed 

 in the 12th Annual Report, was the issue of a series of L.M.B.C. 

 " Memoirs," each giving a full account, by one of our specialists, 



