SUPPLEMENT. I 2 09 



of a little submerged iron railway, lying in the pond con- 

 nected with the works, were so covered with young oysters 

 that they were not used as rails any further on account of 

 the value of the oysters settling on the rails being greater 

 than the value of the rails themselves ! 



And now for the conclusions we draw from this : 



Firstly, the basin in the course of preparation was quite 

 clean, that is clear from weeds or deposits from water, and 

 therefore in a condition best suited for the adherence of 

 spat. Secondly, the rails of the basin in course of prepar- 

 ation were absolutely clean, having been probably almost 

 bright from the traffic along the little tramway. Hence 

 their being so covered with oysters that they were more 

 valuable for collectors than rails ! 



Another instance of the benefit arising from clean 

 collectors is that related to the writer by an owner of one 

 of the Mersey layings. In the year 1881 he had a much 

 better fall of spat on his grounds than his neighbours, who 

 were equally favourably situated. The preceding winter he 

 had purchased from France some 40,000 oysters that had 

 died during the passage, their clocks and separated shells 

 had been allowed to bleach for some months. 



When spatting time arrived, these clocks, &c., were 

 thrown overboard on his grounds on a Friday. The follow- 

 ing Monday some were dredged up covered with spat, 

 subsequently the great majority of the young brood he took 

 up were attached to these shells. 



HEAT AND TRANQUILLITY. 



The conditions necessary for the development of insect 

 life are also those which are favourable for the production 

 of the young oyster. To the late Mr. Frank Buckland 

 belongs the credit of first drawing attention to the impor- 



