THE OYSTER AND THE OYSTER INDUSTRY. 25 



stage is relatively small. For that reason too complete removal of 

 the adult oysters from a bed destroys lioj^e for an ensuing generation. 

 During the past 40 years certain methods of oyster culture have 

 been developed, especially in certain regions, whereby new beds have 

 been built up and a constructive system of increasing the oyster 

 supply has been initiated in addition to the negative one of restric- 

 tions on fishing, such as close seasons and the like. Biologists have 

 become concerned in this work, and efforts have been made to pro- 

 mote, by experimentation, methods for the improvement of oyster 



culture. 



CULTIVATION. 



From the table on page 5 it will be seen that about half the 

 oysters produced in the United States are taken from private or 

 planted beds, the rest coming from natural or uncultivated areas. 

 It will also be noted that in New England over 90 per cent of the 

 oysters are produced on planted beds, that in the Middle Atlantic 

 States the natural beds are considerably in excess, and that in the 

 South Atlantic and Gulf States the proportion of natural beds is 

 much higher yet. The table shows, however, that the value of the 

 oysters from the planted beds is nearly twice that of those from the 

 natural. This is due largely to the better quality and shape of the 

 oysters produced by cultivation. 



It is intended mainly to set forth here the methods of oyster culture 

 which so far have proved to be commercially successful on the 

 Atlantic and Gulf coasts, together with such suggestions concerning 

 their improvement as biological science has to offer. Since there yet 

 occasionally arise false hopes that the so-called artificial propaga- 

 tion, or the hatching and rearing of oysters in tanks or ponds, as is 

 done in the case of fish, is on the verge of practical accomplishment, 

 it may be well to dispose of this matter before proceeding to the 

 treatment of the successful methods mentioned above. 



ARTIFICIAL PROPAGATION. 



This attempted method of oyster culture can be treated most 

 simply by stating that its perfection and practical application are 

 substantially no nearer solution than when the problem was opened 

 up by Brooks (1880, pp. 10 to 18). He succeeded in artificially 

 fertilizing the oyster eggs with spermatozoa of the male oyster and 

 in rearing some free-swimming larvce to the age of four or five days. 

 Brooks's methods are in themselves not difficult, and the experiment 

 has been repeated time and again both by biologists and laymen. 

 Owing, however, to the immense practical difficulties of restraining 

 the microscopic larvae in receptacles or tanks and at the same time 

 providing for a change of water and the introduction of the proper 

 food and removal of waste, no one has succeeded in rearmg many 

 of the larvse until they attach to cultch. It would seem, moreover, 

 impossible to do this on a scale sufficiently large to be of practical 

 application in the oyster industry. 



The same statements are true regarding the adaptation of this 

 method, in which attempts were made to substitute for the tanks 

 ponds connected by narrow inlets or ditches Avith tidewater. Wliile 



