388 ZOOLOGY. 



sionally to the height of four or five metres (fifteen feet) in 

 the air, and so as to fall beyond the obstacle which stops them. 

 Salmon ascend rivers even to their source, and search in the 

 small streams and tranquil places a bottom of sand and 

 gravel adapted for the deposition of their eggs. Then, feeble 

 and thin by such fatigue, they descend in autumn towards 

 the mouth of the rivers, in order to pass their winter in the 

 sea. The eggs are deposited in a trough dug by the female 

 in the sand; they are afterwards fecundated by the male. 

 The young salmon grow very rapidly ; and when they are 

 about a foot long, they leave the rivers to repair to the sea, 

 which they quit in its turn to again enter the rivers, when 

 they are about four or five decimetres in length (from sixteen 

 to twenty inches), that is to say, towards the middle of the 

 summer that followed their birth. We have already seen 

 that the swallows, which at the approach of the cold season 

 emigrate to the south, return annually to the same places. 

 It appears that salmon have the same instinct. To be assured 

 of it a naturalist of the name of Deslandes put a copper ring 

 in the tail of twelve of these fishes, and restored them to 

 liberty in the river Auzou, in Brittany. Soon afterwards they 

 all disappeared, but the year following they caught in the 

 same place five of these salmon ; in the second year three, and 

 in the year following still three. 



[The history of the Scottish salmon, which I have investigated 

 with much care, differs in many essential points from that given 

 in the text by my friend, the author. The precise habitat of the 

 salmon whilst in the ocean is unknown ; but at stated periods it 

 ascends the rivers even to their sources, in general during the 

 autumn and early winter months. Under the gravel of these 

 fresh-water streams it deposits its eggs, which in early spring, 

 usually about the beginning of May, leave the gravel to pass 

 into the stream. The period intervening* between their escape 

 through the gravel to their descent to the ocean as smolts (that 

 is, young fish covered with silvery scales), has not yet been fully 

 determined, some viewing it as a year, others only a few weeks. 

 One thing is certain ; when the ova or eggs of the salmon have 

 been removed from the salmon artificially and deposited under 

 the gravel of an artificial pond in October or November, the 

 young are found to ascend through the gravel in the waters of 

 the pond in April of the following year, and at that time are 

 about an inch in length. If detained in the pond they grow but 

 little ; nevertheless, in the month of May of the year following 

 their ascent through the gravel they undergo the metamorphosis 



