F. day: early and late salmon rivers. 



25 



Mr. Willis-Bund, chairman of the Severn Fishery Board, in Salmon 

 Problems, 1885, remarked : ' Mr. Huxley says there is no evidence that 

 it (salmon which come into the river in January and February) will 

 spawn before November. The evidence of the Severn goes to prove 

 it would spawn in October' (page 166).* ' I can only say I have in 

 several years seen fish spawning in October, and the Severn Superin- 

 tendent tells me he has constantly done so' (page 20). 'This year 

 (1885) I have heard of fish spawning as late as the end of March; 

 and one year I heard of fish, full of spawn, being caught in April. 

 On the Usk, on the 18th of May, 1861, a fish was taken full of 

 spawn' (page 59). 



Without further increasing the number of extracts from the writings 

 of authorities on fisheries, or official statements that have been more 

 or less accepted, I propose to briefly consider a few of the causes which 

 have been ascribed, and some of which probably have an influence 

 as to whether certain rivers are early or late. 



The existence of lakes near the sources of rivers has been held to 

 influence the earliness or lateness of its waters. In England and 

 Wales we find such conditions present in the Eden, 70 J miles long, 

 with a catchment basin 916 square miles in extent • the Dee, 93 miles 

 long, and with 850 square miles of catchment basin; the Derwent, 

 35J- miles long, and 268 square miles of catchment basin ; the Ehen, 

 14J miles long, with 59 square miles of catchment basin; the Irt, 

 16J miles long, with 48 square miles of catchment basin; and the 

 Le ven, 6 \ miles long, and with 123 square miles of catchment basin. The 

 two first, with the longest course, are early rivers ; but not so the 

 remainder, which are rather late than otherwise. Irrespective of 

 which some of the earliest and some of the latest rivers are among 

 such as have no lakes in their course, and are of very different lengths. 



Buckland held that large estuaries at the entrance of salmon 

 rivers must have the same influence as lakes near their sources, or in 

 their course ; but detailed investigations hardly bear out this theory, 

 while it has been remarked that in a single estuary, as of the Severn, 

 three rivers with different degrees of earliness enter. It has also been 

 suggested that the conditions which occasion the early or late ascent 

 of fish into freshwater may have some connection with the circum- 

 stances of the marine life of the salmon, the food which it is able 

 to obtain, or the enemies from which it has to escape. 



What the temperature or other conditions of the water in the 

 river, or the food that is present therein at various seasons of the 

 year, has to do with the period at which salmon ascend into it from 



* This question will be discussed in a future paper. 



Jan. 1886. 



