THE LIFE OF THE SALMON 229 



which now encloses them, and of emerging as alevin amid 

 the crevices of their pebbly surroundings. Even here, while 

 yet in the egg in the apparent security of the redds, their 

 tiny existence is continually threatened. Fish may root 

 them out ; the larvae of the stone-fly, caddis-fly, May-fly, 

 and dragon-fly may penetrate the crevices of the redds, 

 and seize them in their voracious grasp ; the water-rat 

 and moorhen may gobble them up, floods may destroy them, 

 or droughts may leave the redds high and dry, and the ova 

 exposed to frost or dry air. All these dangers are possible, 

 and many of them are but too common. 



But haply none of these dangers may disturb the eggs in 

 the redds we are observing. Each egg is now in itself a 

 separate and detached entity, and as such is individually 

 affected by its own particular and immediate surroundings. 

 In appearance it is a translucent elastic ball, less than 

 J inch in diameter, of which a gallon measure would hold 

 some 25,000, about the number deposited by a 27-pound 

 salmon during any one spawning season ; and yet, think 

 you, what possibilities may lie in any one such minute atom ! 

 As I write this I have lifted my eyes from my paper, and 

 they have rested on the skeleton head of my 50-pound 

 Norwegian salmon, and as I recall the splendid fight he 

 made years ago, it seems difficult to picture him as being 

 once but one of the wee, small atoms now pulsating beneath 

 the gravel covering we are considering. 



The temperature of the water in each salmon stream 

 is the principal factor which determines the period during 

 which the young salmon remains in the egg. 



THE ALEVIN 



This period will, of course, vary with the particular 

 warmth or coldness of each stream : with a temperature 

 of some 43 F. the eggs may hatch out in about 100 days, 



