Trout Breeding. 135 



the silkworm, mixing them with flour, and he writes me 

 that after having used this food for four years, he finds 

 that the fish thrive on it remarkably well. An analysis 

 of this food shows that it contains nitrogen substance in 

 abundance, besides a suitable quantity of oily matter. 

 It seems that the Japanese, for the last 200 years, have 

 employed a method for propagating salmon by letting 

 them spawn naturally and confining this reproduction 

 to a fixed locality. 



In the River Tenegawa there is a natural spawning 

 bed some 1,200 yards long by 50 wide. A fence is 

 made above, and after the salmon ascend another fence 

 is thrown across the stream below. After the fish have 

 been inclosed for a week, their eggs become naturally 

 fertilized, and the parent fish are caught. Another lot of 

 fish are allowed to enter, and so the process is continued. 



Mr. Akekio states that in May, a year afterward, the 

 healthy young fish go down to sea. The profits from 

 the river must be large, as it supports, by netting the 

 fish, some 750 families. Our most intelligent Japanese 

 fishculturist has been in receipt of some McCloud River 

 trout eggs, sent to him by Mr. B. B. Redding, Fish 

 Commissioner of California, in 1877, and other species 

 sent by Prof. Baird. Great difficulty was experienced 

 at first in finding water of a right temperature, as the 

 weather was warm, and there was no ice; still, in the 

 face of a great many obstacles, 1,000 fish were saved. 

 "From 1877 till the present time," Mr. Akekio writes, 

 "the fish have grown satisfactorily, and their average 

 weight is five pounds, and their greatest length one and 

 a half foot." Both Japan and Germany are indebted 

 to the United States for practical lessons in fishculture, 

 and so far our American fishculturists have not been 

 obliged to go abroad to learn their business. 



