274 TiiK fi;esii-\vati:i{ fishks of FriMtPK. 



estimated that for every 30,000 e<?<4-s deposited by a larc^e Salmon under natural 

 conditions, only four or five develop into fishes fit for table. 



The eggs of Salmon vary in size, accordino^ to Mr. Day. Those of small 

 fish are two-tenths of an inch in diameter, and in larger fishes the diameter is 

 three-tenths of an inch ; but even in the same fish the oggs vary in size, and 

 it has been shown by Sir Maitland Gibson's experiments that the young fishes 

 raised from large eggs are stronger, and grow faster, than those raised from 

 small eggs. The small eggs from puny fishes, yield fry which are liable to a 

 greater percentage of deaths than those taken from older fishes. 



The time required for hatching depends somewhat on the season of the 

 year and the river, varying from ninety to about one hundred and forty days, 

 but the period is influenced a good deal by temperature. 



Signs of life appear in about forty days, and in a few days before the eggs 

 are hatched the eyes become visible as dark spots. The eggs require cold, and do 

 not thrive well if the temperature is above 45". They are commonly hatched 

 in February or jVIarch, when the young are five-eighths of an inch long. When 

 the fry are about two months old the umbilical sac, which has the aspect of a 

 pale red currant, is entirely absorbed ; and at first their growth is extremely slow. 

 Shaw recorded that by the middle of jVIay they were an inch long, with large 

 heads and wedge-shaped bodies, on which the transverse bands of the Parr 

 were already marked. In a year they increased to a length of three and a 

 half inches, and in two years had a length of six and a half. 



In the early months of their existence they attract but little attention, 

 darting under stones and seeking gentle eddies ; but in June they begin 

 to scatter themselves over the shallow parts of the river, rarely leaving their 

 birthplace while they remain Parrs, until, at two years of age, they become 

 silvery Smolts, and flit from their native river. The young Smolt descends 

 the river slowly and cautiously ; when it comes to a rapid or waterfall, its 

 head is turned up stream, until, carried to the brink, a determination is taken 

 to descend. All through May the Smolts are travelling. They revel in the 

 sea, and when they come back in a few months it is as Grilse, with 

 boisterous energy. They find out the parent river in some instinctive way, 

 and possess a homing faculty like that of pigeons, or some dogs, which enables 

 the fishes to find their way home rapidly, even when taken far away by boat. 

 Buckland suggests that they smell out their home. The Grilse certainly 

 travel back to the land they left as Smolts ; and, like the great romping 

 Salmon they travel with, learn to leap up weirs, and waterfalls, and other ob- 

 stacles in the way. They ascend the Rhine to the falls of SchafPhausen, and 

 go up by the Aar into the Lake of Zurich, ],:230 feet above the sea, and 

 pass on into the AVallenstadt Lake, seventy-eight feet higher. They reach 



