DEPOSITING THE OVA. 231 



exceedingly slow; that afterwards it is wonderfully 

 rapid, but in salt water only. Once a grilse or a 

 salmon, in fresh water its growth is stationary. 



I shall, before I enter into detail, give in a 

 very few words the salient points of the salmon's 

 natural history. The female salmon, viz. the fish 

 with what is commonly called the 'hard roe,' 

 deposits its eggs, spawn, or ova, in gravel beds, in 

 the autumn and winter months. Simultaneously 

 with deposition, the ova are impregnated by the 

 spawn (the milt) of the male fish, or 6 soft roe,' 

 being exuded over them. That is the active 

 process of procreation. The deposited ova are 

 hatched on an average in from one hundred to 

 one hundred and forty days; duration of time 

 depending on the temperature of the water. The 

 warmer the water the more rapid is the work of 

 incubation. In a few weeks after expulsion from 

 the ova the incubated matter assumes the fish 

 shape. This embryo salmon grows slowly, and 

 remains for the first year the diminutive fry or 

 smolt. On completing its first year it changes 

 its coat, and indeed its shape. The transverse 

 bar-marks and spots disappear, and it becomes the 

 silver-grey smolt, salmon fry, or lastspring. Its 

 first year or thereabouts being completed, it mi- 

 grates for the first time to the sea, and in two or 

 three months or more returns to its parent river 

 a peal or grilse, having increased two pounds or 



