44 THE LIFE OF THE SALMON 



were, returning home. It is essential for this argu- 

 ment that the salmon be regarded as a fresh water 

 fish which has gone to the sea to feed. This forms, 

 I admit, a plausible explanation of the presence of 

 early running fish in our rivers. That they do not 

 nourish themselves in fresh water has been proved. 

 Whether they can be said to feed in fresh water 

 must not be discussed here. This point, about 

 which so much has been written, is really not very 

 important. It is in essence a dispute about terms. 

 Let us be thankful we can catch them with flies and 

 other baits. 



But can the salmon be properly regarded as a fresh 

 water fish ? Dr. Noel Paton realises the importance 

 of this for his argument when he says, in dealing 

 with the factors determining migration, in the 

 general summary (p. 169) : "In considering the 

 question it must be remembered that the Salmonidse 

 are originally fresh water fish, and that the majority 

 of the family spend their whole life in fresh water." 

 To my mind it is not clear that the majority of the 

 family do so spend their lives, but further, it is not 

 sufficient to regard the British Salmonidae in this 

 matter ; we must take into consideration the group 

 of fishes, or at least the sub-order, to which the 

 Salmonidse belong, and judge the salmon as it 

 appears in relation to its near allies. If in this way 

 we take the seventeen genera of Boulenger's classifi- 

 cation, we find that the majority are more marine 

 than fresh water, including Bathylagus (Gthr), the 

 deep sea form recently added to the British fauna ^ ; 



* Holt and Byrne, "Fisheries Sci. Invest. Ireland, 1905," II. 

 (1906.) 



