MIGRATIONS OP SALMON. FISHERIES. 25 



bottom of sand and gravel, fit to deposit their eggs. Afterwards, 

 when thinned and weakened by so much fatigue, they descend 

 in autumn to the mouth of the river, in order to pass their winter 

 in the sea. The eggs are deposited in a hole, which the female 

 digs in the sand. The male then comes to fertilise them. The 

 young Salmon grow very quickly ; and when they have attained 

 to about the length of a foot, they, leave the rivers to proceed to 

 the sea, which they quit in turn to enter the streams, when they 

 have attained the length of 16 or 18 inches, which is towards 

 the middle of the summer that follows their birth. We have 

 already seen that the Swallows, which at the approach of the 

 cold season migrate towards the south, every year return into 

 the same places. It appears that the Salmon has the same 

 instinct. To ascertain this, a naturalist, named Deslandes, placed 

 a ring of copper on the tail of twelve of these fish, and set them 

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

 they all disappeared; but the following year, five of these 

 Salmon were caught in the same place ; the second year, three ; 

 and the year after, three more. 



549. The habits of Fish show but few curious peculiarities ; 

 but the history of these animals ought nevertheless to interest 

 us, if only on account of the fisheries to which they give origin. 

 At a period which is not very far removed from our own, this 

 branch of industry occupied a fifth of the population of Holland ; 

 and for the herring-fishery alone, that country covered all the 

 northern seas with its vessels. In England it has supported a con- 

 siderable number of good and hardy sailors ; and even in France, 



where it has less 

 importance, there 

 are computed to be 

 thirty or forty thou- 

 sand fishermen, of 

 which nearly a third 



FIG. 266 COD. 



venture every year 



as far as Iceland and Newfoundland to seek for the Cod, a large 

 and excellent fish, which abounds in those parts of the sea, and 

 which is found also, in a comparatively small number, in our 

 own seas. 



