HATCHING FISHES' EGGS IN JAES 179 



viously were nearly all lost or wasted. It lias 

 also rendered possible the gathering and hatch- 

 ing of eggs which, through their being unpro- 

 tected after being deposited by the parent fish, 

 would have been nearly all devoured by spawn- 

 eaters. In some instances valuable kinds of 

 fishes which had become very scarce have been 

 restored in such numbers as to make their 

 catching a profitable industry. 



The hatching of fish by the jar method is at 

 present useful chiefly to governments for pub- 

 lic work, or to fishing clubs that own lakes which 

 they desire to stock very heavily, or for per- 

 sons who desire to hatch useful fishes which 

 they intend to sell as soon as hatched. There 

 are at least five different hatching- jars promi- 

 nently in use in the United States : the Chase, 

 McDonald, Downing Improved, Meehan, and 

 Clark. All have their staunch supporters, and 

 all are effective egg-workers and incubators. 

 A choice would depend upon local or individual 

 circumstances and intentions. 



Water for Jars. In projecting a site for a 

 station for jar work the water question is as 

 important as in hatching trout, but fortunately 



