114 COMMISSION OF CONSERVATION 



Island sound do not spawn and many of them die in the same season. 

 It has been observed that, when put into much warmer or denser water, 

 sperms rapidly die. If oysters are brought from distant parts they should 

 be transferred to places of similar temperature and density and given 

 time to become adapted. Spawn oysters should be put out before the 

 shells intended for the reception of the resulting larvae, and not scattered 

 too far from one another. The establishment of new beds by the 

 capture of floating larvse on dead shells is of more importance than the 

 transplanting of seed oysters. The chances are that most of the latter 

 would have lived where they were — even if they did not grow so fast, so 

 large, or so regular. The formation of a new bed by planting cultch saves 

 the lives of multitudes of larva that would otherwise have unavoidably 

 perished. It broadens the area of cultivation and increases the number 

 of possible points of attachment. Seed oysters as well as spawners may 

 likewise be used for a similar purpose, but the general if not the sole use 

 to which seed oysters are put is to l^e raised to full size for the market. 

 The object is more immediate gain, whereas a little foresight might lead 

 to much greater ultimate gain. By planting cultch on adjoining areas 

 much of the reproductive material thrown off by the growing seed oysters 

 might be saved and lay the foundation for a much greater and more 

 durable oyster bed. 



Culture in the Broadest Sense. — Oyster culture in the broadest and 

 most complete sense first became possible when Brooks (1879) discovered 

 the method of propagation by artificial fertilization of the eggs of the 

 American oyster. The method was applied by Rice, Winslow, Ryder, 

 Nelson and others, with a view to rearing the larvae obtained in this 

 manner to adult marketable oysters. 



Brooks, from artificially fertilized eggs, raised larvae 6 days old, i.e. 

 to the straight-hinge stage. The difficulties are to keep such minute, 

 free-swimming animals in a small, enclosed volume of water so as to 

 be able to find them, to effect a change of water without losing the larvae, 

 to maintain the proper temperature and to supply food. 



Rice, by a simple method, succeeded in keeping larvae alive for 14 

 days in a tumbler of sea-water. He stood a lamp-chimney in the tumbler 

 and hung a strip of white flannel over the edge of the chimney and of the 

 tumbler so as to drain away the water, while a similar strip brought fresh 

 sea-water from a supply-tank into the tumbler. One of the larva about 

 44 hours after the eggs had been impregnated thrust out a portion of its 

 velum and became attached to a glass slide upon which it had been placed. 

 He inferred that others may have attached themselves to the bottom and 

 sides of the tumbler. 



Ryder became especially enthusiastic and carried out numerous 

 experiments with the object of expanding restricted experimental methods 

 into great commercial enterprises. He wrote numerous articles such as 



