48 HOME FISHING AND HOME WATERS. 



stones. This matter contains microscopic plants 

 and animals, on which they subsist. In cleaning an 

 aquarium in which gold fish are kept, never wash the 

 stones, but take them out carefully, and replace 

 them without disturbing the slimy substance on 

 them. 



CHAPTER XIV. 

 ARTIFICIAL HATCHING OF FISH. 



IN the artificial hatching of fish eggs, there are 

 three principal conditions necessary, without which 

 success can rarely be attained. These are cleanli- 

 ness, careful handling of the eggs and plenty of 

 circulation. The importance of providing these can 

 hardly be over-estimated. 



CLEANLINESS. One of the main reasons why 

 artificial propagation is superior to the natural 

 method is in this particular. The eggs must be 

 kept free from sediment or dirt in any form what- 

 ever, or else they can never reach the hatching 

 point. We will take the clear, flowing brook as we 

 observe it casually : it has the appearance of being 

 free from all foreign substance, but, by examining it 

 closely, we discover that in the bed of the brook a 

 great deal of matter is constantly moving down- 

 ward. This has the tendency to cover up all eggs 

 which have been cast, and, when this occurs, the 

 egg will never come to maturity. In hatching eggs 

 artificially, this is guarded against by filtering the 

 water through flannel screens, and also by having a 



