6 THE LIFE OF THE SALMON 



form part inhabit permanently the sea, the clupeids, 

 or herring tribe, which are their nearest allies, being 

 certainly of marine origin, as proved by their abun- 

 dance in cretaceous seas, yet a few, like the shads, 

 ascending rivers to spawn without this ever having 

 been adduced as evidence in favour of a fresh water 

 origin of the family to which they belong." 



The more we learn about the salmon, the more we 

 have to realise the very considerable amount of time 

 which it apparently spends in the sea. Sea trout 

 are chiefly estuarial in habit. Loch Leven trout 

 may very possibly be sea trout, or at any rate 

 migratory trout which amounts to much the same 

 thing shut off from the sea. It is easy by a little 

 judicious feeding to make them practically indis- 

 tinguishable from ordinary sea trout. Brown trout 

 taken from Dorsetshire to New Zealand quickly 

 acquired a migratory habit and became large silvery 

 fish, inhabiting the sea for the most part, and ascend- 

 ing rivers to spawn. The brown trout which I have 

 referred to at the mouth of the Tay were clearly 

 doing the same, while in localities such as Orkney 

 and Shetland and the Outer Hebrides we have the 

 established tidal variety which has been called S. 

 orcadensis ; and in the West of Ireland we have 

 S. estuarius, the so-called slob trout. I do not agree 

 that there is any specific distinction, any more than 

 I agree that a ferox is not a brown trout. In all 

 these examples we may say that to feed is in one 

 sense the impulse which causes the change of habit 

 and consequent modification ; and in the same way, 

 taking salmonids as we now find them, it is evident 



