L'74 STATE HORTICULTURAL SOCIETY. 



The salmon rivers of the Pacific slope and the shad rivers of the 

 East and the white fish fisheries of the Great Lakes, are now so thor- 

 oughly under control by the fish culturist, that it is doubtful if any one 

 will venture to contradict his assertion. The question is now whether 

 he can extend his domain to other species. 



Fish culture in its more restricted sense, or fish-breeding, must 

 sooner or later be resorted to in all densely populated countries, for 

 with the utmost protection nature, unaided, can do but little to meet 

 the natural demand for fish to eat. This necessity has been felt by 

 many people from earliest times. 



The discovery of the art of artificially fecundating the ova offish 

 must apparently be credited to Stephen Ludwig Jacobi, of Hohen- 

 hausen, in Westphalia, who successfully conducted experiments in 

 breeding' salmon and trout as early as 1748. The importance of this 

 discovery was thoroughly appreciated at the time, and until 180(» was 

 a fruitful subject of discussion in England, France and Germany. It 

 was nearly one hundred years after the discovery before public opinion 

 was ripe for general acceptance of its usefulness, a period during 

 which its practice was never entirely adandoned by the Germans. 



The fertilization of fish eggs is the simplest of processes, consist- 

 ing, as every one knows, in simply pressing the ripe ova from female 

 fish into a shallow receptacle and then squeezing out the milt of the 

 male upon them. The eggs having been fertilized, the most difficult 

 part of the task remains, viz : the care of the eggs until they are 

 hatched, and the care of the young fry until they are able to care for 

 themselves. 



The apparatus employed is various in principles, to correspond to 

 the physical peculiarities of the eggs. Fish culturists divide eggs into 

 four classes, viz. : (1) Heavy eggs, non-adhesivse, whose specific grav- 

 ity is so great that they will not float, such as the eggs of the salmon 

 and trout; (2) heavy, adhesive eggs, such as those of the herring, 

 smelt and perch ; (3) semi-buoyant eggs, like those of shad and white 

 fish; and (4) buoyant eggs, like those of cod and mackerel. 



Heavy, non adhesive eggs, are placed in thin layers, either upon 

 gravel, grilles of glass, sheets of wire cloth, or perforated metal. 

 Through the receptacles containing the eggs a current of water is con- 

 stantly passing. Any description of the numerous forms of apparatus 

 of this class would occupy more than the extent of this paper. 



The heavy, adhesive eggs were formerly received upon bunches 

 of twigs or frames of glass plates, to which they adhered and which 

 were placed in receptacles through which water was passed. Within 

 the last two years a scientist. Prof. Eeighard, of the University of Mich- 



