114 THE SEA-TROUT 



of the fish's existence should not continue its foraging in the sea or 

 estuary when the fish have become smolts and indeed thenceforward, 

 at least, as I shall suggest, until they have become whitling. 



On reaching the brackish water of an estuary the sea-trout smolts 

 show no great anxiety to push far afield. In this way they differ 

 essentially from the salmon smolts which, it must be remembered, are 

 descending towards salt water at and about the same time, many of 

 each kind being actually in company. Mr. Caiderwood and Mr. Knut 

 Dahl have, with some degree of definiteness, proved that, estuary or 

 no estuary, the salmon smolt makes directly for the sea and does not 

 linger for any length of time in brackish water — it makes a bolt for the 

 blue. I shall venture to state here what Mr. Caiderwood discovered 

 concerning salmon smolts in course of a special netting expedition 

 which he conducted in the Tay in 1903, for some valuable facts 

 regarding sea-trout were ascertained at the same time. The object of 

 the expedition was to trace the descent of salmon smolts down the 

 estuary. 



" From the time we left the neighbourhood of Klnfauns," Mr. 

 Caiderwood writes — the passage is from his valuable work on " The 

 Life of the Salmon " — " the smolts became fewer, and when we had 

 descended about two miles and a half, and had reached a point a short 

 distance below the mouth of the river Earn, where sea-weed begins to 

 make its appearance upon the shore, smolts could not be found at all. 

 We proceeded down the estuary, however, and, thanks to the courtesy 

 of the Tay Fisheries Company, who granted the use of their steam 

 yacht, completed a survey of all available fishing places, both on the 

 shores of the lower estuary and on the shallow banks in mid-stream 

 near the Tay Bridge, till eventually we reached Budden Ness and the 

 open sea, some twenty miles below our starting point. Not another 

 salmon smolt did we catch, however, although sea-trout smolts were 

 everywhere in evidence, as well as brown trout, herrings, flounders, a 



