I2l8 OYSTERS, AND ALL Al'.OUT THEM. 



course of the day and year, is less subject to fluctuations in 

 temperature than that which flows over the beds lying 

 nearer the mainland, and there is here a somewhat greater 

 percentage of salt than in the water over the beds in the 

 shallower portions of the sea-flats. To these external 

 physico-chemical properties of the Hornum banks are also 

 united faunal peculiarities. 



. . . . In Paris the green oysters of Marennes 

 and Tremblade are especially prized, on account of their 

 delicious flavour. This cannot come from the green con- 

 stituents of their body, for if old oysters are taken there 

 during the winter months, and placed in a fattening pond, 

 they will indeed become green, but by no means so well 

 flavoured as those oysters which were placed there when 

 young, and have lived there several years. 



The flavour of oysters is best at the banks them- 

 selves, if they are opened very carefully, and all the sea- 

 water which is enclosed in the shell when shut is allowed 

 to escape. This can be done most judiciously if the oyster 

 is placed upon the flat right valve, after the loosening of 

 the shell-muscle. This valve is a superior natural plate for 

 the oyster, since it has no cavities like those of the left 

 valve, filled with disagreeably smelling water, which flows 

 out when the shell is opened, and contaminates the flavour 

 of the oyster. The oyster can live for days, perfectly dry^ 

 without dying ; but it gradually loses its softness, and soon 

 begins to smell, from the dying of the animals which 

 inhabit the outside of its shell. It is very seldom that 

 these can be entirely removed by the usual means of puri- 

 fication, so that the flavour of the oyster inland is almost 

 always affected by these contaminating odours. (c) 



(c) " The Oyster and Oyster Culture," pp. 50-54. 



