408 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



valves measure one-eightietli of an iucli iu tlieir longest diameter, wo 

 have yet to find out how old it is when of this size. When we learn 

 this we will know how long it will be necessary for us to keep the young 

 in the incubating apparatus. We can reach the answers to these ques- 

 tions only by the use of the proper sort of hatching arrangement, in 

 which artificially impregnated eggs are used, being careful, of course, 

 to keep accurate records of the time of impregnation and the fluctua- 

 tions of temperature of the air and water during the progress of the 

 experiment. With the finer questions of the anatomy of the embryos 

 we will have little to do ; in fact, I do not see that they will help us much 

 in the comprehension of how the hatching process is to be conducted, 

 which goes without denying, however, that the experienced embryolo- 

 gist must be expected to determine whether the development is progres- 

 sing properly. When once the development has been carried to the 

 stage of fixation the embryologists will have an abundance of oppor- 

 tunity to make out the finer details of structure, and let us remark in 

 regard to the oyster, one of the most accessible of animals, that much 

 still remains to be done by both the anatomist and embryologist. 



Whatever may be the form of the apparatus which will finally be 

 used in artificial oyster culture, it will also be necessary to provide some 

 sort of cheap and eifective method of providing for the attachment of 

 the young fry to some substance or object which may be transferred to 

 nurseries, where the spat is to undergo further development. This cultch, 

 or collecting api^aratus, must be suitable for immersion in the shallow 

 incubating vessels among the developing fry. Clean pebbles, graded 

 through a sieve of the proper mesh, at once suggest themselves as ad- 

 mirably fitted for the x>nrpose, but what is most suitable will have to be 

 learned by experiment. To facilitate the study of the spat immediately 

 after fixation, slips of glass and mica, arranged so as to depend into 

 the water in the hat(;hing apparatus, would probably provide the micro- 

 scopist with very young fixed stages, which could be transferred to the 

 stage of the microscope without disturbing their attachments, the nature 

 of which could then be readily ascertained on such transparent cultch. 



The special merit of the proposed method of artificial culture from 

 the egg upwards would be that we could probably do without the cum- 

 brous tiles, slates, &c., covered with mortar, such as are used abroad. 

 In fact, if CO ^?ec/ors are to be used at all after the French mode, it would 

 seem to the writer that it would be just as well to use old, oyster shells 

 and the cheapest possible materials strewn over arable bottoms near 

 productive spawning oyster beds, as is i^retty extensively practiced on 

 the coast of New England, especially Connecticut, and, to some extent, 

 in places on the Chesapeake Bay. If any considerable advance is to be 

 made in the culture of the oyster, it will be by a radical departure from 

 a class of methods which have been in use for over ten centuries. The 

 old method is founded on well-ascertained natural principles, and there 

 is no reason why more modern discoveries should not greatly increase 



