OYSTER AND MUSSEL REPORT. 61 
is teeming with microscopic life, and it is probably this 
rich feeding alone which is necessary in order to bring the 
oysters in a very short period—a few weeks usually, some- 
times 10 days or a fortnight is sufficient—to the desired 
condition of fatness and flavour. 
It is said that the oyster can be colowred under favourable 
circumstances in 36 hours. It is only the gills and the 
labial palps of the animal which become green. The 
pigment of the Diatom (which has been called ‘‘ marennin’”’ 
by Prof. Ray Lankester) is really blue, but when deposited 
in minute granules in the yellowish coloured gills it gives 
rise to the greenish tint. 
From the oyster’s point of view the claire is a very 
unhealthy place. The mortality is very high, and those 
that survive are probably in an enfeebled, if not actually 
a diseased, condition. They have had far too much to 
eat, their food is highly nutritious, the water is very 
stagnant and badly aerated, and is probably unhealthily 
warm. However the healthy natural oyster is not what 
is desired by the epicure, and of course it is the business 
of the éleveur to produce what will fetch the highest price 
in the market, so he regulates the condition of the claire 
in such a way as to favour as much as possible the pro- 
duction and growth of an abundant supply of microscopic 
plants and animals. 
The oysters are generally laid down in the claires in 
August, and the autumn and even early winter months 
are supposed to be the best times for “‘ greening.’ During 
my visit in July most of the claires were being prepared 
for the reception of the oysters, but some were full. I 
found very considerable differences in temperature and 
specific gravity between some claires and others, as is to 
be expected when one recollects that the fresh supplies 
of water are admitted at very irregular intervals, so that 
