HATCHING THE EGGS. 125 



quence. Indeed, the eggs kept in clean running water 

 will hatch themselves. Nature provides with the egg 

 all that it needs for its nourishment, and what is re- 

 quired of the breeder is simply to see that nothing 

 interferes with nature's work. 



This negative task, however, of guarding the eggs 

 from danger, though, with the present improved appli- 

 ances for hatching, it requires no great skill, is not by 

 any means a sinecure, but, on the contrary, calls for 

 caution, vigilance, and labor, as will be seen by the 

 following general remarks on hatching eggs. 



The main dangers to which the eggs are subjected 

 are four in number, and are all fatal. They are, 



1. Alga.* Fungus. 



2. Sediment. 



3. Living enemies. 



4. Byssus.* Fungus (Septomitris clavatus.) 

 Carbonized wood is a protection against the first, 



fungus. The system of filtering is a protection against 

 the second, sediment. Tight covers are a protection 

 against the third, live enemies. The daily examina- 

 tion of the eggs is a protection against the fourth, 

 byssus. 



It follows, then, that the dangers are all guarded 

 against by the provisions themselves of the hatching 

 apparatus, in connection with the daily examination of 

 the eggs. 



It may be well here, however, to allude briefly to 



* These are both fungi, but the first enumerated is usually 

 called, in trout breeding, by its generic name, fungus, and the 

 fourth by its specific name, byssus. 



