J. PISCICULTURE AND THE FISHERIES. 451 



ily escape through the wire meshes that constitute the bottom 

 of the hatching-boxes. 



As the rock-fish, or striped bass, is a far more valuable fisli 

 than the shad, and has been equally reduced in number, the fea- 

 sibility of hatching them artificially is a fact of very great im- 

 portance ; and it is to be hoped that the experiment will be 

 continued whenever the opportunity occurs, so as to restore 

 the species to its native waters. 



The eggs hatched out by Mr. Hblton came from fish of 

 about six and eight pounds resi^ectively, and he is of the 

 opinion that large fish weighing from forty to sixty pounds 

 w^ould readily yield a million of eggs. The eggs are rather 

 more delicate and tender than those of the shad, bearing any 

 compression less readily, on account of the greater thinness 

 and transparency of the shell. 



FEEDING OF CRAWFISH IX POXDS. 



In the cultivation of crawfish for market purposes in Eu- 

 rope, it is customary to have three ponds or ditches, walled 

 up with coarse stone; one of them destined for the one-year 

 old animals, a second for those of two, and a third for those 

 of three years. They are filled for three fourths of their 

 dej^th with water, a stream of fresh water being introduced 

 through a wooden trough. The fish are fed three times a 

 day in the ditches with chopped liver, and with a mixture 

 of one part flour and two parts bran, which is made up with 

 water into balls, boiled, and then chopped up again. The 

 refuse of fish is also used for the older animals. 



Crawfish, like crabs of all kinds, are best for food during 

 their breeding season, or when they are in a soft-shell con- 

 dition, about the end of June or beginning of July. About 

 six years are required to bring these crabs to maturity. 

 They may be readily kept for market purposes for a number 

 of days by inclosing them in boxes or tubs filled with grass, 

 or other fresh vegetable matter. They must, however, be 

 quite dry, and not partly immersed in water. 



According to recent writers, the female does not reproduce 

 during the first vear, and during the second, thoufrh the eo:2rs 

 are visible, they do not possess an embryo. These are held 

 under the tail by the feet. Impregnation takes place by the 

 application, on the part of the male, of a glutinous material. 



