ENEMIES AND FRIENDS 183 



young leaves and flower-buds, eats them off 

 nightly. The small mud-turtles, if not numer- 

 ous, are harmless, though it is well not to let 

 their number increase too greatly. The best 

 method of guarding against them is seining, 

 though a bounty offered to the small boys in 

 the neighbourhood will prove very efficacious. 



Sunfish in too great numbers are harmful 

 because they eat the snails which do not 

 harm the older plants and are also beneficial 

 in keeping down the growth of algae. The 

 latter may become obnoxious in the summer. 

 The best way to get rid of them is by tying a 

 bag of copper sulphate to the end of a boat 

 and rowing up and down the pond, trailing 

 the bag till the salt is entirely dissolved. For 

 this purpose one should use one pound of 

 copper sulphate for every million gallons 

 of water. Where the pond is too small 

 to allow the use of a boat, the salt can be tied 

 in a bag at the end of a stick, which is worked 

 about in the water until the contents are 

 dissolved. 



Since the amount of copper sulphate (blue 



