32 THE HABITS OF THE SALMON. 



seldom to be found until April, by which time the 



water becomes much warmer. 



The temperature of the water in the Shin — a river 

 flowing from a very large lake — is probably as high as 

 or even higher than that of either the Helmsdale or 

 Brora. It may, therefore, be asked, How is it that 

 salmon do not attempt to pass over the fall in the 

 Shin until a later date than they do in the other two 

 rivers ? The answer is this : the fall presents far 

 more opposition to the passage of the fish than the 

 falls of the Helmsdale and Brora, so much so 

 that it would appear that in a dry season, such 

 as that of 1887, ^^h could not pass over the big 

 fall in the Shin until after the back end of the open 

 season. 



In the Aberdeenshire Dee, which is a first-class 

 early river, the same effect is produced by the 

 temperature of the water on the movements of salmon 

 as in other rivers. Should it be cold in the winter 

 or spring, and plenty of snow have fallen, the fish 

 tarry in the lower pools ; but after a mild winter 



