SALMON AND SEA-TROUT 



number of salmon ova, this is not at all a satis- 

 factory way of obtaining them. To begin with, 

 it is impossible to get them in sufficient num- 

 bers to carry out operations on a large enough 

 scale. Salmon ova are also expensive ; and 

 it is no use working with less than half a 

 million in several stations if the river is of any 

 size. It is advisable that the ova should be ob- 

 tained from the fish. This may be done either 

 by collecting the ova deposited by the fish in the 

 spawning beds or from the gravid females. The 

 latter course necessitates the ripe female and 

 male fish being caught and artificially spawned. 

 As in nature, at best but a comparatively small 

 percentage of the ova are impregnated, and by 

 artificial spawning over ninety per cent, of them 

 may be successfully hatched out, there can be 

 but little doubt as to which is the better way. 

 It is difficult to make sure of catching the fish 

 just at the time they are ripe, so it is advisable 

 to impound them in a fenced-off portion of the 

 river, where they may be got at easily. 



In the ripe female the ova flow out very 

 readily, and but little pressure is necessary. 

 Hard pressure on the abdomen should never 

 be applied, as it is sure to injure the fish. A 



