OF THE SALMON. 23 



home with the greatest precision, for scarcely ever is 

 one of them seen in its neighbour's possessions. This 

 precision is yet a mystery among many others, for 

 although we see rivers of different temperature aris- 

 ing from the size or situation of the lakes from which 

 they are fed, we find others of the same situation and 

 temperature, and yet the fish must know a distin- 

 guishing quality that leads them to their own native 

 streams. It is true that salmon have their summer 

 and winter courses for travelling in the same river, 

 and that is also kept with the most exact precision ; 

 for in winter, and up to the 1st of May, salmon inva- 

 riably run up the north side of rivers, whereas from 

 the 1st of May to November the fish run on the 

 south side. We have now shown that salmon un- 

 doubtedly return to the rivers where they have 

 spawned, and where they belong to the race of fish 

 that inhabit that particular river. It may be, that 

 they know their own race, for a river has at all times 

 plenty of the young fish, as well as the old, either 

 clean or foul : be that as it may, it is evident that they 

 go there, and to no other. 



The large majority of fish that I marked were ab- 

 sent from the river only two months, out and in ; they 

 were only two months in going to the sea in their 

 foul lean state, feeding there till they found them- 

 selves fat and fully satisfied with the abundance of 

 food the sea produced, and in returning to their native 

 rivers : of course among these we found some excep- 

 tions, for few of them might have remained in the river 

 for some time after they were marked and registered, 

 and some of them might have left the sea sooner than 

 the time required by the larger body of them, which 

 cases would produce the exceptions to the general rule. 

 But with these exceptions the time of their sojourn 

 will be found most correct. The most rapid return 

 c 4 



