172 TRANSACTIONS iSqQ-'oO 



Two methods of fertilisation have been adopted, the wet and 

 the dry, and the latter has almost universally superseded the 

 former. In the dry method no water is added until some 

 moments after the ova and milt have been mingled and gently 

 stirred with a feather or the fingers. In the early days of 

 Canadian fish-culture the wet method was followed, and the eggs 

 were placed in water before the milt was added, and a propor- 

 tion of eggs always failed to be fecundated, hence the universal 

 adoption of the so-called dry method. 



Some of the different methods followed in obtaining eggs or 

 fry may be here instanced. 



(i) The parent fish are secured some time (days or even 

 months) before spawning, and impounded until they become 

 ripe and swollen. Whitefish are often kept in this way, and the 

 plan has been adopted in Canada of confining salmon in tidal 

 ponds for many months, and apparently without harm. Indeed 

 the salt water prevents fungus, and as salmon take no food 

 after leaving the sea, there is no difficulty in retaining them until 

 the spawning season, and then taking the eggs and milt. After 

 being kept from June or July until October or November the 

 parent fish are liberated on being artificially spawned. 



(2) The parent fish are netted at the spawning time near the 

 breeding beds. Salmon, in British Columbia, are treated in this 

 way, also Great Lake trout and whitefish. The parent fish are 

 rarely injured, and are thus liberated in their native waters. 



(3) Parent fish are captured and the eggs taken and fertilis- 

 ed, but the fish are killed and sent to market. This is the plan 

 adopted in some cases by U. S. fish-culturists, especially with 

 the Great Lake trout. It is unavoidable as a rule, with black 

 bass and sturgeon, 'even when very ripe, as they refuse to yield 

 their spawn. It is not adopted in Canada. 



(4) Parent fish are impounded in ponds or enclosures, where 

 they deposit and fertilise their spawn naturally. The spawn is 

 then transferred to the hatchery and incubated artifically. Bass, 

 maskinonge, perch, carp, sturgeon, etc. , have been treated in this 

 way. 



(5) A similar plan to the last is followed excepting that the 

 eggs are allowed to hatch out in the ponds where deposited. 



