FAMILY SALMONID^E, OR SALMON TRIBE. 45 



by having all the rays of the first dorsal fin soft or jointed; 

 and the second dorsal entirely adipose, being merely a fold of skin 

 inclosing fat. The species of this family are at once distin- 

 guished from the Siluridse, by having the body covered with 

 scales ; they are generally very muscular, and possessed of great 

 strength ; and they are voracious in their habits, feeding rather 

 upon Insects, small Crustacea, &c., than upon other Fishes. 

 The different subdivisions of the group vary considerably in 

 regard to the position of the fins, and the degree in which the 

 mouth is armed with teeth. Most of them frequent the estuaries 

 of rivers, and ascend the stream at regular periods to deposit 

 their spawn in its higher parts ; and it has been ascertained that 

 the same fish and their descendants resort in successive years to 

 one particular locality. Nearly all the members of the family 

 are clouded with transverse dusky patches when very young, and 

 undergo considerable changes in their livery before they arrive at 

 their full growth. Hence there is much difficulty in determining 

 their species ; which is increased by the circumstance, that the 

 male, in many instances, appears to be capable of propagation long 

 before arriving at its full growth. The Salmon of our own. 

 rivers is one of the largest of the whole family ; but in conse- 

 quence of the eagerness with which it is pursued by fishermen, 

 it does not often attain its full size in this country. Enor- 

 mous specimens, however, are now and then captured ; a weight 

 of 40 Ibs. does not seem very uncommon ; and in 1821, a speci- 

 men was exhibited in London, weighing 83 Ibs. The usual time 

 at which the Salmon leaves the sea, is the autumn ; it remains 

 in the rivers during the winter ; and returns to the sea, after 

 having deposited the spawn, in the spring. The young fry, 

 termed Smalts, are carried down to the sea in the months of 

 April and May. In some rivers, however, they do not make 

 their ascent until the winter ; and in others they even delay it 

 until the spring. These variations appear to depend upon 

 differences of temperature in the rivers themselves ; since, when 

 these are very cold, the fish avoid passing the winter in them. 

 Before depositing its spawn, the Salmon makes a furrow with 

 its nose in the gravelly bed of the river ; and its eggs, when 



