498 



MY GARDEN. 



bottom of this wooden tray being composed of glass rods about one- 

 eighth of an inch apart. 



The breeding troughs are placed in a house of the simplest construc- 

 tion, roofed with reed hurdles (fig. 1099). 



A set of these boxes is so 

 arranged one over the other that 

 the spouts out of which the 

 water runs are alternately right 

 and left, so that the water in 

 passing from one box to an- 

 other runs entirely over the 

 surface of the ova in each box. 

 It is necessary that the current 

 FIG. io 99 .-Fish House. o f wa t e r should be maintained 



for the entire time requisite for the development of the ova. 



To procure ova, fish must be caught during the spawning season. 

 The male fish are slimmer than the female. When ready for spawning 

 the females emit ova on the slightest pressure, and the males emit milt. 

 The ripe female is taken in the hand, and the spawn pressed out by 

 drawing the hand slowly, firmly, but gently from the head to the vent ; 

 and care should be taken that every single egg is emitted from the 

 fish, which can be told by the feel. The spawn should be received in 

 an earthen vessel, as a basin, containing just sufficient water to cover 

 it, and simultaneously the milt from a male fish should be mixed with 

 the ova, which then become fertilized. I generally begin with the milt 

 of a male, then proceed with the ova of a female, and then use the 

 milt, when males and females are equally abundant. In the early part 

 of the season ripe males are more abundant than ripe females, but at 

 the end of the season the females will be found ready, whilst the males 

 will be spent ; and I have known a considerable difficulty in obtaining 

 an adequate supply of milt. 



The fertilized ova should be arranged on the glass gridirons in the 

 hatching boxes. Each box holds about two thousand eggs, and no 

 delay should ensue in causing the water to run over the ova. 



