14 



REPORT 1865. 



Experiments on the Matching of Oyster-spat. 



It is my firm conviction that one of the chief reasons why the yonng spat 

 have died in such countless numbers in the open sea is, that the water is not 

 of a sufficient temperature to allow them to live and thrive during the period 

 in which the process of adhesion takes place. Sudden alterations of tempe- 

 rature, especially from warm to cold, are also particularly fatal in their re- 

 sults. I have therefore instituted a series of experiments to endeavour, if 

 possible, to give the young spat a continuous supply of water at a constant 

 and unvarying temperature. In doing this I have gone to some considerable 

 expense ; but, as a set-off against this, I have been greatly aided by Mr. 

 Dilnot, a tradesman of Heme Bay, who has most kindly placed his premises 

 at my disposal. 



By a somewhat complicated bit of machinery we have been enabled to keep 

 up a constant supply of sea-water continually flowing for several weeks, the 

 temperature being arranged by an application of artificial heat. Upon exa- 

 mining the stones, shells, and other materials in this artificially warmed 

 water we were much pleased to find the shells adhering in the position 

 usually chosen by the young oyster itself, viz. the underside of the shell, 

 The adhesion was pretty firm, but as the water dried the shell became loose, 

 and ultimately fell off. I cannot, however, but look at this as a partial ap- 

 proach to success. It appears to me that the young creatures had taken up 

 the position they intended to occupy, and that they died from some other 

 causes. What those causes were I am hardly at present able to state ; but I 

 am qiute certain and positive that I know what two of them were, and trust 

 to be able to meet the difficulties in future trials. The task of applying 

 heat artificially is no easy one, and presents many mechanical difficulties, 

 which at present I can hardly see how to meet. I do not, however, despair, 

 and propose further experiments during the next season. I mentioned this 

 idea at the last Meeting of the Association, at Bath, and have since endea- 

 voured to carry it out. Experiments of a similar kind have, I have heard, 

 been instituted by Mr. William Crofts ; but I have not seen his apparatus. 

 Experiment has shown me the exact temperature the spat like best. 



The Question of Green Oysters. 

 This is, both commercially and socially speaking, a most important ques- 

 tion. The Biver Roach, situated on the coast of Essex, has for a hundred 

 years or more produced large quantities of oysters ; but, strange to say, 

 none of these oysters are ever sent to the English market, being all, with- 

 out exception, sent to the markets at Dunkirk and Ostend, and thence to 

 Baiis, Berlin, and even, I bebeve, as far as St. Petersburgh. The reason 

 why they are not sent to the English market is simply that they are green 

 in appenrance. I have examined into this question with very great care, and 

 in doing so have been greatly assisted by my friend Mr. W. Wiseman, of 

 Pagles'ham. The oysters, strange to say, are only green in the winter, and 



