OF THE SALMONWjE. Ill 



species, and it would be wise to exterminate 

 the former as far as possible in localities 

 selected by the latter as their nurseries. 

 This danger should be guarded against else- 

 where by the reservation of some rivers 

 solely for salmon and salmon-trout, though 

 the temptation to introduce the easily 

 established trout may be very strong, and 

 has, it is to be feared, already proved 

 stronger than prudence. The decreasing 

 fertility of the prisoners referred to in the 

 latest report of the commissioners suggests 

 the probable necessity of further importa- 

 tions of ova from England, and should this 

 be decided upon, the colonial authorities 

 should insist on the adoption of that plan 

 of transport which has proved successful in 

 Mr. Youl's hands, and allow no modification 

 of it. The course to be pursued by Victoria 

 is now clear. On the arrival of the ova in 

 that colony the temperature of the water 

 may be expected to range as high as 60° 

 Fahr. ; therefore, sufficient ice must be pro- 

 vided to keep the temperature of the water 

 in the hatching boxes at least down to 45°, 



