488 Dr KNOX on the Natural History of 



to remain there. A return of the salmon and salmon-trout caught 

 by a series of stage-nets, or even by the coble-net, in that part of 

 a salmon river, extending from the point, influenced by the 

 highest flood of tide to the lowest ebb, characterising those num- 

 bers taken during flood from those during the ebb, would settle 

 the above and many other points ; but the Committee of the 

 House of Commons found it impossible to get at such data ; in 

 my opinion they do not exist, but their value would be very 

 great. Salmon do not begin to ascend rivers much beyond the 

 tide-way, until they commence altering in condition. Hence, it 

 may be said to be the month of July or August before salmon 

 in any numbers ascend the rivers beyond the tide-way, their 

 number increases in August and September ; the causes of this, 

 together with the daily deteriorating quality of the fish need not 

 be stated. As a reply to all doubts on this point, it may be affirmed, 

 that were the Tweed the property of one man, he would fish it 

 from Berwick Bridge to the sea or bar of the river, and no where 

 else. And, on carefully observing the Tweed fishings, it has 

 often filled me with astonishment that the proprietors in a 

 body do not adopt this method. The saving of expenditure 

 would be enormous, and an effective plan for preventing the de- 

 struction of salmon at improper seasons adopted. But about this 

 time, that is in December, January, February, and March, a few 

 salmon are likewise found in high condition, with the organs of 

 generation very little developed. These are fish which had either 

 not altered into the spawning state during the preceding year, a 

 very common occurrence, as we shall find, as well with salmon as 

 with trout, or which had spawned very early, and returned as early 

 to the ocean, have recovered their good condition, and resumed 

 their usual migratory habits of ascending rivers, and that to a 

 very limited extent, during floods. 



The presence of these in the rivers has done immense injury 

 to the salmon fisheries of Britain, and has caused the loss of thou- 



