THE BEST KINDS OF FISH FOR RIVEKS. 119 



voracious devourers of small fry, and in such places 

 are not worth their keep. 



Eels are, perhaps, better suited to muddy than 

 gravelly rivers, though they abound in both and are 

 better flavoured when taken from the latter. They 

 are great spawn-eaters, and it has been questioned 

 whether the eel pays for his keep owing to this cir- 

 cumstance. In some salmon rivers I have seen the 

 lower pools in a perfect boil, when the eel fry is 

 migrating, with the constant rising of the fish as the 

 small eels wriggled along the top of the water ; so 

 that the salmon, if the eels be supposed to be de- 

 structive to them, exact summary vengeance. Their 

 ravages, however, amongst salmon and trout spawn 

 cannot be very extended, as the spawn is in the 

 gravel during the winter, and eels are not active in 

 frosty weather. They may, and no doubt do, how- 

 ever, take a heavy toll from the helpless fry when 

 first developed in the spring, as the eels then begin 

 to move. The Dutch keep eels out of their carp 

 ponds as much as possible, as carp spawn in June 

 and the eels would no doubt do damage to them. 

 Eels, where they have the chance, migrate about 

 autumn in larsre numbers towards the brackish water 



o 



near the rivers' mouths, the water there being usually 

 several degrees warmer than that higher up. Those 



