28 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



whicli the receptacles are placed may be enclosed by protecting wallSj, 

 which, whilst afTording protection, will allow of the passage of water as- 

 the tide rises or falls ; or the receptacles may be placed in water-tight 

 wooden troughs. Drawing, Plate XII. 



2^0. 1447 of 1877. — Mewbuen. — Apparatus used in Breeding Oysters. — 

 A box made of any suitable material communicates with the exterior 

 by water and air supply cocks, or has the upper part open without an 

 air-cock, when the apparatus is situated away from the sea and fed arti- 

 ficially, or is closed hermetically when the apparatus is placed so that 

 it emerges at each tide. In this apparatus the collecting hives and the 

 breeding oysters are placed at spawning time, or spawn or spat obtained 

 elsewhere may be put therein. A piece of silk, the meshes of Avhich 

 are too fine to allow the spawn to pass through, is then placed over each 

 water inlet and outlet, so that no si)awn or spat can escape when the 

 water is renewed. 



Whether the apparatus emerge or not, the collectors should offer the 

 greatest possible surface for the deposit of the spat, and be fed by water, 

 sufficiently clarified by filtering, to insure and maintain the cleanness 

 of the collectors. The water must be renewed without sensible agitation^^ 

 its introduction be regulated by means of cocks, and a slow current 

 obtained, continuous or intermittent, according to the position of the 

 apparatus. The water is renewed sufficiently often to put the spat in 

 the best conditions of vitality, filtered water being always employed. 



The apparatus consists of a box provided at its lower ])nvt with a cock 

 which communicates with a filter situated a little below. The cover of 

 the box, which closes it hermetically with the aid of strong bolts or 

 screws, is provided with two India-rubber tubes having valves, one of 

 which opens outward to allow the escape of air at the rise of the tide, 

 while the other opens inward to allow air to enter at the fall of the 

 tide or when the apparatus empties. The box is firmly secured in the 

 water by stakes, to which, it is only pinned, to aUow of its being re- 

 moved when required, and the India-rubber tubes are placed on rigid 

 pipes long enough to give the apparatus time to fill before the water 

 reaches their top or the waves pass over. 



' Inside the apparatus is placed a hive composed of a series of frames 

 containing wire or other gauze, and placed one above the other. The 

 frames are filled with a layer of shells, broken and sifted, and a certain 

 number of parent oysters placed at intervals. There is fixed at the side* 

 of and below the box a filter of any suitable kind, through which the 

 water wiU pass before its introduction into the box. The water arriving 

 at the rising tide will pass into the filter and be deprived of all foreign 

 matter, and finally enter the apparatus above, driving out the aii' through 

 one of the valves, and carry sustenance to the breeding oysters placed 

 among the frames. The water in retiring allows the second valve to 

 open and admit air to the aj^paratiis. 



