194 FISH CULTURE. 



bottom being the best. Gravel, (often impregnated 

 with iron) does not do well, nor does a hard clay, 

 which is too cold and unproductive. Again, steep 

 banks with deep water all around the sides are 

 objectionable, as the iish like to push on to the 

 shallows, and lie with their backs almost above 

 water, both for spawning and for warmth ; and be- 

 sides this, the small fry, when just hatched and 

 capable of moving about, cannot exist in the deep 

 water, but require shallows as an absolute necessity. 

 This will be recognised either in rivers or ponds, if 

 the reader will remember, when he has been walking 

 along the banks at certain seasons, how often he has 

 seen the small fry start off from the margin, where 

 they have been sunning and disporting themselves 

 in myriads, and how seldom, on the other hand, he 

 has ever noticed them in deep water. Ponds that 

 have rookeries beside them have been found not to 

 answer. The reason of this is that the droppings of 

 the rooks, which are very considerable, contain a large 

 percentage of lime, which is very prejudicial to fish. 

 The best fish for ponds are Carp, Tench, Jack, 

 and Bream. It is always well, even in carp and 

 tench ponds, to have a few brace of jack among the 

 carp and tench, for the purpose of keeping the fry 

 down, so that they may not devour too much of the 



