90 SALMONID/E. 



smallest of them of the size of beans, and some larger than 

 hazel-nuts. This last is done, that upon the surface of the 

 smaller gravel many deep holes may be formed, that the 

 continual motion of the water may not carry away the eggs, 

 but that they may remain where they were at first 

 sprinkled in. 



" 4. Then let the water run into the trough as directed in 

 2, and raise it higher or lower, according to the instructions, 

 Section I. 4, so that the water covers the gravel always one 

 or two inches. 



" This done, you have accomplished all that is necessary 

 to the apparatus for breeding Trouts and Salmon. 



" SECTION III. 



" 1. The time of spawning begins the latter end of No- 

 vember, and commonly ends the latter end of January, or 

 beginning of February. But the spawning time of each 

 separate Trout continues only about eight days, as the eggs 

 of the female and sperma of the male become in some sooner 

 in others later ripe. 



" Trouts meet in rivulets in great numbers, in the before- 

 mentioned months, and such as are ready for spawning fix 

 upon a place where there is large gravel, and where the water 

 has a quick current ; there they rush and rub their bellies 

 against the stony bottom, and so violent, that they often 

 make great holes ; and by means of this motion both female 

 and male get rid of their spawn and sperma. 



" As a single drop of sperma contains vast numbers of 

 animalcula sufficient to animate hundreds of eggs, and as the 

 water is loaded at this time with the sperma, it is no wonder 

 that almost every egg becomes a fish. 



" Every egg or spawn in the female comes to its perfec- 

 tion and ripeness at the same time and day ; but it is not so 



