ii4 A BOOK OF THE RUNNING BROOK: 



refilled. Another excellent reason for drying, 

 ploughing, and planting ponds from time to 

 time is that it is one of the few efficacious ways 

 of getting rid of that aquatic plague, the Ameri- 

 can weed, which is one of the greatest nuisances 

 offish-ponds in this country as well as of the 

 rivers. As a rule, the process of drying and 

 ploughing will be found a sufficiently drastic 

 remedy for this pest ; but if it is in any very 

 great quantity, it is well to make assurance 

 doubly sure by a dose of common salt also. 



Fishponds should not be made too deep. 

 With the exception of a few deep holes, to 

 which the fish like to retire at times, the best 

 fish-ponds are generally shallow. In compara- 

 tively shallow ponds fish find a greater quantity 

 of the insects and larvae, on which they love to 

 feed, than they do in deep waters, and many 

 of the aquatic plants which they prefer such 

 as those of the Ranunculus and Potamegeton 

 tribes do better in water that is not too deep. 

 Rushes and weeds should also be encouraged 

 in fish-ponds, as the fish like them, not only 

 for shelter, but chiefly for depositing their eggs 



