TEMPERATURE OF WATER 273 



distance apart, the latter river is ever a month 

 earlier than the former. Nevertheless, the Test 

 rod-fishing continues good throughout the entire 

 season, whereas that in the Avon is but indifferent 

 after June. It may be that the temperature of 

 the water in the Avon is over-high, and makes 

 the fish dull and inactive. I do not say that this 

 is the cause, for I am not certain ; it is only my 

 own idea. During the early part of the season, 

 before they have left the river, the fresh fish will 

 usually be found at the tail of a school of kelts, 

 which thus frequently congregate. 



The temperature of the water has a very great 

 deal to do with fishing, much more than is sup- 

 posed. The water is frequently, especially in the 

 Northern streams, icy cold, though the day may 

 be hot and bright, and vice versa. Fishermen are 

 often at a loss to account for their want of sport 

 on days which seem all they should be for fishing. 

 Equally are they puzzled to account for success 

 on those which seem to be least suitable. The 

 cause is doubtless to be attributed to the high or 

 low temperature of the water, as the case may be. 

 Nor can it be supposed that the natural trout- 

 flies as readily hatch out in cold water as in that 

 of a more equable temperature. 



At the commencement of the present work, I 

 gave a list of some twelve or thirteen varieties of 

 Salmonidse, as classified by Yarrell. It will be 



18 



