200 -SPORT IX NORWAY. 



filling again morning and evening. When necessary, 

 fresh moss-stalks can be substituted. 



It is of course best to procure the male and female 

 fish to be operated upon direct from their breeding- 

 ground, and as short a time as possible before the 

 spavming commences. Where this is impossible, they 

 should be kept in fish-boxes or reservoirs ; care, how- 

 ever, being taken that they be not kept too long in 

 confinement before being used, as this would have an 

 injurious effect both on the ova and on the milt. One 

 male fish is sufficient to fructify the ova of a great 

 many females, and can be used from six to eight days 

 in succession. 



It is not difficult to ascertain when the female is 

 ready to spawn. Her distended abdomen gives easily 

 to a gentle pressure, and an undulating movement 

 which is perceptible on touching it, shows that the 

 spawn is already disconnected from the ovary. She 

 should then be held by the head in a vertical position, 

 so that the ova will of their own weight fall down 

 towards the vent. When the fish are large, it is best 

 to have three persons to assist. One takes the fish by 

 the head, and the other by the tail, holding it hori- 

 zontally over a dish, the vent downwards, whilst the 

 third very gently presses along her stomach and sides. 

 When the bottom of the dish has been covered with 

 ova, in layers of two or three deep, the fish can be 



