BULLETIN OF THE UNITED STATES FISH COMMISSION. 409 



the effectiveness and radically change the manner of the propagation of 

 this most valuable of all food shell-lish. Besides, the great ciimbrous- 

 uess of tiles, &c., involves a great outlay of labor, such as would be a 

 serious item in their practical utilization in the United States, where labor 

 is much more expensive than in continental countries. Not only is this 

 objection valid, but a still more serious one is the uncertainty of the set 

 of spat, which catches on any sort of natural or artificial cultch. In some 

 seasons the collectors will be overcrowded, in others no spat will be 

 found to adhere. The same element of risk is encountered in the use 

 of old oj'ster shells as cultch for the spat, and, as I have been told by 

 oystermen of large experience, several thousands of dollars' worth of 

 shells may be strewn upon good oyster bottom, upon which not a single 

 spat will be found at the end of the season, thus involving a loss of both 

 material and labor. I do not see that any method in which tiles or 

 mortar-covered slates are used will be a particle more likely to afford a 

 nidus for spat than old shells or the cheapest kind of cultch, except in 

 some places where the latter is liable to be covered with mud or sedi- 

 ment. 



This uncertainty, it appears to the writer, can be overcome by a to- 

 tally different method of procedure. We must have the temperature of 

 the water and conditions of the artificially fertilized and confined em- 

 bryos under control. The uncertainty which has hitherto attended 

 oyster propagation must disappear measurably in the face of intelligent 

 experiment, and it is to be hoped that in a few years we will hear of 

 oyster nurseries or incubating establishments in successful operation, 

 from which millions of spat will be annually bred from artificially im- 

 j)regnated eggs to be sold as seed to planters, who will enter upon the 

 business of oyster cultivation on an entirely new and scientific basis. 

 "Whether all that we have pictured can be realized may be a matter of 

 doubt with manj^, but at any rate it is a stage of the oyster industry 

 which, if possible of attainment, ought at once and vigorously' to be 

 striven for under the auspices of both public and private enterprise. 

 Unlike the propagation of many kinds of fishes, the results of oyster 

 culture can be watched from the earliest fixed stages onwards and pro- 

 gress noted ; they do not, like fishes, move about from i>laceto place, but 

 after fixation may be kept under observation in the same situation until 

 they have reached a marketable size. This is a most satisfactory feature 

 of the work, and ought to attract observers. 



Of no less moment than the introduction of radically new and more 

 certain methods of propagation is the question, upon what materials 

 does the oyster feed ? How does its different kinds of food affect its 

 flavor and appearance "? What are the conditions which will most quickly 

 bring it into a plump, marketable condition ? The most contradictory 

 and confusing statements are made by different persons in regard to the 

 feeding habits of the animal, and anomalous as some of them may at 



