12 10 OYSTERS, AND ALL ABOUT THEM. 



tance of this condition : High and even temperature by day 

 and night, and quiet atmosphere. He summarised these 

 conditions as " Heat and tranquillity," which words have 

 acquired some considerable degree of notoriety, and have 

 from first to last led to a good deal of argument, not 

 tranquil but heated, between oyster-culturists. 



The opponents of the tranquil theory say that the water 

 must be well oxygenated, so as to be in the most favourable 

 condition for the reproduction of oysters ; they admit the 

 necessity of some heat, but do not want anything above 

 68 degrees (F.) 



The balance of the evidence we have been able to 

 collect is that warm and tranquil summer days and nights, 

 if undisturbed by bad weather and night frosts, will as 

 assuredly result in a heavy fall of spat, as a cold ungenial 

 summer will occasion an oyster famine. It appears that in 

 the English waters young oysters must have the water at a 

 temperature of from 65 to 72, to put them in the best 

 condition to adhere. If the spat is in a sticking humour, 

 it will adhere to anything that is free from weed or slime 

 old oyster-shells, cockle-shells, stones, glass, old tobacco- 

 pipes, iron slag, old shoes in fact anything that offers a 

 clean hard surface will satisfy the young oysters in warm 

 weather, though their after development greatly depends 

 upon the ease with which they are separated from the sub- 

 stances to which they are primarily attached. 



In Bucldand's Museum there is a large collection of 

 various materials on which spat has been deposited ; 

 amongst them is an ordinary flat iron, concerning which 

 poor Mr. Buckland quaintly remarked that the spat was in 

 such a sticking humour that "if the washerwoman who had 

 used the flat iron had been at the bottom of the sea, the 

 spat would have stuck all over her." 



