106 AMEEICAN FISH CULTURE. 



from Bea on this side of the Atlantic. This is necessarily 

 the case, as most of the rivers are rigidly closed with ice 

 for some months, and many of them for half of the year. 

 On the coast of Great Britain, where the rivers are always 

 open, their migrations occur nearly every month; still there 

 is a throng time when the greater number enter fresh 

 waters. Smolts and grilse have frequently been marked 

 and have gone to sea and returned in six or eight weeks. 

 In Ireland there are fresh run fish in January and fair fly- 

 fishing in February. 



In the rivers of the British Provinces north of us there 

 is also what may be termed a throng time. This is gene- 

 rally when the first schools come in. In some rivers they 

 are found at the lower rapids within a week (earlier or 

 later) of the middle of June, and in others, even of the 

 samij latitude or district of country, somewhat later. There 

 are difi'erent "runs" up to the middle of September; the 

 schools being influenced by easterly storms to enter the bay, 

 and by a rise in the river to ascend. Unlike the shad, 

 which are deterred or driven back by a freshet, salmon 

 seem to delight in a heavy rise, after which, there is always 

 good fishing as the water clears. 



When a school of salmon, coming from sea, reaches a 

 bay or the mouth of a river entering the sea, some weeks 

 are occupied in working up towards the head of tide,* the 

 fish in the mean while undergoing a change of system 

 which fits them for tlieir habitation in fresh water. Dur- 



* As the season advances the time so occupied grows shorter, 

 until only a few days are spent in tide-water. 



