APPENDIX. 289 



" Then make another set of wire screens, of about three 

 wires to the inch, so that the spawn will fall through with 

 ease, and nail these on to a frame one by two inches. 

 Have handles on all of them, so as to take them up easily. 

 Place these over the fine ones, which will give a space of 

 one inch between the top and bottom screens. Now sift 

 gravel through a sieve of two wires to the inch, so as to be 

 sure to get out all the gravel that would pass through the 

 upper screen. Wash this coarse gravel clean, and put it 

 about two inches thick on the upper screens. Then make 

 small nests, within every foot or eighteen inches of each 

 other, by digging nearly down to the wire of the upper 

 screen. 



" The female trout will whip the gravel in these nests clear 

 down to the wire and deposit their spawn, which will mostly 

 fall through to the lower screen, and be plainly in sight. 

 The male will eject his milt as usual upon them, with the 

 whip of his tail to agitate the water, and thus impregnate 

 them all. The female will now cover them up, and likely 

 sift all the spawn that has lodged in the gravel, through 

 the upper screen on to the lower one, and thus in time 

 deposit all her spawn in perfection and perfectly impreg- 

 nated. 



" The water should be from ten to twelve inches deep over 

 the gravel in the race, with a gentle current. Should any 

 spawn remain in the gravel, they will be very likely to fall 

 down by raising the upper screens up and down a few 

 times in the water, or with a little sifting at most, so that 

 nearly all will find their way on to the under screen. I 

 would take out all the screens in from one to six days, and 

 place the spawn in my form of hatching box. 



" Firstly, this method will always ensure perfect impreg- 

 nation ; 



" Secondly, it will save three-fourths of the time at least; 

 25 ' T 



