402 BULLETIN OP THE BUREAU OP PISHERIES. 



advanced to a stage where any definite statements can be made as to the practicability 

 of rearing fresh-water mussels in waters other than the natural mussel streams. 



Two years ago an interesting discovery was reported by Lefevre and Curtis, when 

 it was foimd that some glochidia of the squaw-foot mussel {Strophihis edentuhis) devel- 

 oped into young mussels without becoming parasitic. Howard, in our laboratory, has 

 since extended these obser\rations by showing that the glochidia of that species will also 

 develop by the customary mode of parasitism and by the discovery that another spe- 

 cies, a small "floater" (Anodonta imbecillis), will develop without parasitism. Neither 

 of these species, the only ones that have ever been made to develop without the use of a 

 fish as host, is of any commercial importance, but it suggests itself as an important 

 investigation that methods should be sought for causing other and useful species to 

 develop without the fish. Whether the problem should prove simple or difficult, it is 

 worthy of the endeavor. 



The interesting and very practical discoveries which have been made, as a result 

 of the close association of practical and investigational work, and the direct bearing of the 

 information gained upon the promotion of the natural resources are held to demonstrate 

 the essential wisdom of Congress in providing at the beginning that the propagation of 

 mussels and the investigation of mussels should go "hand in hand." 



The most clearly outstanding feature of our work is the absolute dependence of mussel 

 conservation upon fish conservation in the broadest sense. There can not be abundant 

 mussels if there are not abundant fishes. There can not be varied mussel resources 

 if there are not varied resources in fin fishes. Probably no step for the promotion of 

 the mussel fishery would yield greater benefits to that fishery than effective efforts for 

 the conservation of fin fishes. 



The interlocking interests of shell fishers and fin fishers is properly a matter of par- 

 ticular interest and worthy of emphasis, although, of course, the conservation of fishes 

 rests upon a far broader basis than any consideration of value derived from the depend- 

 ence of shell fisheries. 



PROPAGATION AND RECLAMATION OF FISH WITH EXPERIMENTAL AND PRACTICAL ENDS. 



The pond-cultural operations are planned to be carried out with particular experi- 

 mental objects. It is hoped by careful observational and experimental methods to 

 contribute to the improvement of methods of cultivation of pond fishes, especially as 

 relates to the rearing of fish to a size suitable for the table. It is held as a most impor- 

 tant responsibility of the station to stimulate and to guide the development of fish 

 farming as a more widespread industry. This function as a fish-cultural experiment 

 station should rightly be regarded as second to none, but its full accomplishment will 

 depend upon the future provision of means proportionate to the labors involved and 

 the far-reaching benefits to be gained. 



Meantime the propagation of mussels and of fishes is well carried on hand in hand. 

 While it is not feasible now to rear the quantity of fish requisite for the propagation of 

 mussels, it is attempted by means of the experimental operations of pond culture at the 

 station to obtain a reserve stock of young fish of several species which in the fall are 

 infected with mussels and liberated in the river. A threefold purpose is served in the 

 increase both of the fish and of the mussels in the public waters and in the acquisition 

 of experimental data. 



