ZOOLOGY. 345 



two men into its service and made them apply the system to different 

 waters. They have done so with the most singular success ; rivers and 

 lakes in which there were no fish are now teeming with them. Nor 

 have they confined their operations to trout alone, but have extended 

 them to salmon, pike, tench and perch, and in each case with com- 

 plete success. Indeed, their system is applicable to all sorts of fresh 

 water fish, and to those which after spawning in rivers, descend to the 

 sea. 



Among the rivers that they have already stocked, are those of the 

 Isere, Haute Loire, Allier, Lozere, Meuse, jMeurthe, and the Haute 

 Saone. Several gentlemen of property have also tried the system 

 with success on the estates in Burgundy, Brie, and Normandy. In 

 addition to the breeding of fish, different species can be naturalized in 

 strange waters or removed from river to river. So great is the import- 

 ance which the government attaches to the plan, that it has nominated 

 a commission of eminent scientific men to superintend the operations 

 of Gehin and Remy. The Moniteur announces that the minister of 

 Marine and Colonies has also ordered that experiments shall be made 

 to apply it to salt water fish, at the mouth of rivers, and off the coasts, 

 especially to lobsters. M. Valenciennes, an eminent ichthyologist, 

 and member of the Institute, has been charged to examine the mouths 

 of the rivers and the coasts from Havre to La Teste, and to state in 

 what places the experiments may be tried with most chances of 

 advantage. Milne Edwards and M. Coste, both members of the Insti- 

 tute, have been directed to make similar investigations. 



From the discussions in the French Academy, and from other sources 

 we obtain the following additional particulars relative to this sub- 

 ject : " The loves of fishes," says Cuvier, " are cold like themselves, 

 cold like their abode. As for most species, it is remarked that the 

 stronger sex does not seek the society of the more feeble. The only 

 object of concern with the male fish is the eggs of the female, and the 

 spot where she has deposited them. These eggs he fecundates, with- 

 out knowing their mother ; nor cares he afterwards to behold the 

 progeny they are to produce. The mother herself is equally indiffer- 

 ent. Unknown to her are the pleasures of maternity. The role 

 assigned to her by nature is simply the laying of the eggs, which are 

 often immediately devoured by a neighboring fish ; and sometimes 

 even by a famished father himself." The productive power of fishes 

 is greater than that of any of the higher animals. In the spawn of 

 the tench there have been counted 38.000 eggs at once ; a perch of 

 common size contains 70,000 eggs ; a pike weighing 20 Ibs. 166,000 ; 

 in a carp weighing 2^ Ibs. 167,000 ; in another carp weighing 10 Ibs. 

 were found 621,600 eggs. Rousseau estimates at 7,635,200 the num- 

 ber of eggs in a sturgeon ; and Leuwenhock has counted 9,344.000 in 

 one codfish. The numerous causes which prevent the maturing of 

 the greater portion of the eggs that have been laid by the female : the 

 failure to be fecundated by the milt of the male ; destruction by other 

 fish; freshets which wash them away; droughts which leave them dry; 

 of late years the passage of steamers on all navigable rivers, causing 



