23 



es long and no thicker than a fine knitting needle ; they 

 grow as they eat, hiding most cunningly in the sand or 

 gravel from human eye, and making their way through 

 narrow passages and small holes that a person would not 

 suspect them of being able to enter. One half grown 

 eel will destroy an unlimited number of trout fry or eggs. 

 Ducks are equally destructive, thrusting their long bills 

 down into the nests of spawn, or seizing and swallowing 

 the young ; frogs, mice, rats, fish, many birds, and 

 animals, and the larvae of beetles and devil's darning- 

 needles, and other water flies before they have developed 

 into the perfect insects do their share of damage. Most 

 water creatures loye fish spawn as most human creatures 

 admire omelettes. 



Unpromising as all this is, however, for a good crop of 

 trout in the natural way, it is only the beginning of the' 

 trouble. The danger of disease or physical injury is al- 

 ways present. Heavy rains come and foul the water ; when 

 this settles the silt or sediment covers the whole batch of 

 eggs, and smothers the life out of them. Conferva makes 

 its appearance and soon spreads from one to another kill- 

 ing all it touches, and seems to be contagious, as a single 

 dead egg will affect all those which are near it 

 till the infection spreads through the entire heap. 

 Accident or a great flood may even disturb the 

 whole and leave the displaced eggs to perish mis- 

 erably wherever they may be carried by the water. 

 Amid such vicissitudes the wonder is not that so many 

 perish but that any survive, and the need of na- 

 ture's superfluity is thus made manifest. Exposed to all 

 these dangers the eggs of the salmonidcB must remain in 

 their natural defencelessness for from two to five months, 

 according to the temperature of the water. A very large 

 percentage fail to become impregnated, the current of 



