REPORT ON ARTIFICIAL FISH-CULTURE. 65 



shell-fish; experiments which I have made under 

 the hope of applying them to salt water shell- 

 fish, whose multiplication would not be difficult 

 to secure. Here, then, is an account of these 

 experiments: I placed at the College of France, 

 in a basin, like that wherein my young salmon 

 live, fed by a rivulet, a certain number of female 

 craw-fish, all carrying under their tail their eggs. 

 At the end of twenty-five days all these eggs 

 were hatched, and the basin was usurped by n 

 myriad of young craw-fish, which grew percepti- 

 bly. This result proves how easy it is to restock 

 all running streams which an abuse of fishing 

 has devastated, as though they had never been 

 supplied. The question is reduced simply to- 

 setting apart at the breeding season, in the 

 reservoirs in the form of little brooks commu- 

 nicating with creeks or rivers, all the females 

 who have their eggs attached to the appendices 

 of the tail, and not to allow their consumption 

 until their offspring is hatched. This offspring, 

 retained afterwards for a period in propagating 

 streams, would not be allowed to swim through 

 the gratings until capable of taking care of 

 themselves. 



As to salt water shell-fish, France possesses 

 on the Mediterranean shore, immense salt marshes, 

 where the females of these animals could also 



