60 PRACTICAL TROUT CULTURE. 



when oth at once cover them with a few sweeps 

 of their tails. 



It is rarely that the most practiced observer can 

 see the ova emitted, his first knowledge of the fact 

 being obtained by the clouding of the water by 

 the ejected milt, which follows so instantaneously 

 as at once to obstruct the view. 



Thus far, nature has done its work, and done it 

 well ; but, alas ! the enemies, which nature sends, 

 soon appear. Another pair of trout, seeking a 

 spawning ground, may appear upon the field, and 

 while excavating their own nest, discover the eggs 

 deposited and impregnated by their predecessors, 

 and regarding them as a savory mor.se!, at once 

 eat them up before proceeding with their own 

 work, which may, in turn, become the food of an- 

 other happy pair. A duck or goose arriving on 

 the ground, seems to recognize, by intuition, the 

 precious deposit below; his head disappears be- 

 neath the surface, his broad bill dips deep into 

 the gravel, and the eggs pass into his voracious 

 maw. A freshet may bring down upon the clean, 

 shining gravel a mass of mud, covering up the 

 spawn and depriving it of the oxygen so indispen- 

 sable for its existence. But not only above the sur- 

 face appear the enemies of the spawn ; others and 

 more dangerous, being more concealed, are found 

 below. The larva? of many insects are aquatic in 



