[21] OYSTER-CULTURE UPON SHORES OF BRITISH CHANNEL. 693 



cement, which are suitable for the storing and the cultivation of the 

 oyster. 



The spat (naissain) is brought from Auray from the breeding ponds 

 {pares cle reproduction) which MM. Manduit and Solmiuihac have estab- 

 lished at Fort Espagnol. Upon its arrival it is emptied into the nursing 

 frames, which are supported at a distance of 25 or 30 centimeters from 

 the bottom, upon stakes driven into the mud, or upon wooden frames 

 maintained in position by stakes. The young oysters remain in the 

 frames in the open sea from the month of April to the month of October, 

 when they are transferred to the reserve basins to i)ass the winter. 



The following spring they are evenly spread over the bottoms of the 

 ponds appropriated to their fattening. The average growth of the oys- 

 ter each year is from three to four centimeters; with the larger oyster it 

 is not quite so much, but it never amounts to less than from 2^ to 3J cen- 

 timeters. The rate of growth also varies with the source from which 

 they are obtained and with the ponds in which they are placed. The 

 oysters which increase in size most rapidly are those brought from 

 Quimper. Of the oysters obtained by dredging at Auray many become 

 sulky and refuse to grow the first season, but during the following 

 season they make up for lost time. 



The oysters in frames are left undisturbed during the fine weather.. 

 In handling them often there is danger of injuring the new growth which 

 forms during this period. Then, before consigning them to their winter 

 quarters, they are passed through riddles in order to classify them ac- 

 cording to their dimensions. The spawn and the small oysters obtained 

 in dredging are subjected to this sorting, consequently all those in a 

 frame have the same dimensions. 



The oysters nearly ready for market are placed flatwise on the bot- 

 tom and often displaced and cleaned. The workmen charged with this 

 duty, at the same time fill up with sand the excavations produced by the 

 washing of the water or made by the crabs, so that the shells rest upon a 

 perfectly smooth, even bottom. 



MM. Manduit and Solminihac have made in their pares some inter- 

 esting observations which should find a place in this report. Where 

 the object to be attained is the fattening of the oyster, they have ob- 

 served that they do hotter the oftener they are handled. They have also 

 noticed that the oysters in frames increase more especially in length 

 and breadth, while on the other hand with those bedded in the ponds 

 the increase is mainly in the thickness. Lastly they have demonstrated 

 that the growth is more vigorous and sensible in proportion as the oys- 

 ters are brought nearer to the channels where there are continual cur- 

 rents. 



Attempts at propagation made in the upper parts of the concession 

 and in the vicinity of some pares filled with oysters have not been 

 unfruitful. This season they could count upon each tile from 70 to 

 80 fry. MM. Mauduit and Solminihac began operations at Belou only 



