xxvi INTRODUCTION. 



Pisciculturists, interested in the artificial rearing of the SalmonidcE, should bear in mind 

 the following, as I think, important essentials for success : — * 



1. The water in which the ova or young fry are placed should be cold, at a temperature 

 of 37° to 47°. 



2. The fry should be always supplied with gravel, stones, or projecting pieces of rock- 

 work, under which they can shelter. 



3. The pond, tank, or reservoir should always be covered over with boards or other 

 material, to exclude the hot rays of the sun. 



4. Overcrowding must be avoided, or the fish will be attacked with Saprolcgnia fcrax, an 

 epidemic which when once begun, it will be found almost, if not quite, impossible to stop. 



5. A stream of pure cold water should incessantly be running, day and night, briskly 

 through the preserve. 



* The best food for young Trout and Salmon is a hard-boiled ^gg, passed b_v pressure and friction through 

 the gratings of a fine strainer. 



