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XII.— CONDITION OF OYSTER BEDS AND LAYINGS. 
It has been known for some time that many of the places in estuaries or 
harbours where oysters are laid down to fatten, or to await their market, have been kept 
in a most insanitary condition, either because the water as a whole is polluted, or 
because the opening of some drain-pipe is in such close proximity that the discharge 
from the drain is liable to pass over the shellfish. We showed in 1895, in our 
preliminary paper, that oysters have a very remarkable power of withstanding organic 
impurities in the water, and can continue to live in water much polluted w^th sewage. 
In fact they are able, if kept sufficiently aerated, to render water almost opaque with 
sewage clear in a wonderfully short time. 
As the result of our observations on oyster-beds, and our experiments on the 
kinds of water in which oysters will live, we recommended, in January, 1896,* 
" 1st, A strict examination of all grounds upon which oysters are grown or 
bedded so as to ensure their freedom from sewage ; and 
2nd, If practicable, the use of ' degorgeoirs ' or disgorging tanks, in which the 
oysters should be placed for a short time before they are sent to the 
consumer." 
Towards the end of the same year, the Local Government Board Report on 
Oyster culture in relation to Disease, containing sections by Sir Richard T. Thorne, Dr. 
H. T. Bulstrode, and Professor E. Klein, appeared, giving detailed statements as to the 
insanitary conditions under which oysters are grown or kept on various parts of our 
coasts. Dr. Bulstrode has shown conclusively, by his descriptions and plans, what was 
known previously only to those who had taken the trouble to look into the matter, 
that while some of the localities from which our oysters come to market are excellently 
suited for the purpose and free from reproach, other " layings " are in a disgraceful 
condition of .sewage contamination. That is undoubted ; but as to the further question, 
whether the typhoid organism, if it gains access to the body of the oyster from sewage, 
finds itself in a suitable medium for continued life and multiplication, it is difficult 
to arrive at any definite conclusion. Professor Klein's experiments, like our own (see 
below, p. 45), are not sufficiently extended to be positive upon this point. There is, however, 
a marked difference between the cultures obtained from oysters taken from a contaminated 
source and those from pure water free from all possible sewage pollution. The body 
of the oyster is probably not a favourable medium for the growth of pathogenic organisms, 
the risk of infection is probably therefore never great, and if a little more care were 
exercised there would be practically no danger at all. 
* Report to the Lancashire Sea Fisheries Committee : Trans. Biol, Soc. Liverpool. Vol. X., p. 174. 
