ON SALMON. 87 



rivers (see Tables XV. and XVI.). These tables show clearly that an over 

 whelming majority of the fish under 58 centimetres length are males. In 

 some years there can be more females of this size, but over a period of years 

 far and away the larger number are males. As will be seen, fish of this 

 size consist almost entirely of those which have spent only one winter in. 

 the sea, although there may be some fish of two winters age among them. 

 It is quite possible that it is just these latter fish which are females. 



We can therefore safely conclude from these tables that the salmon 

 which we catch and which have only spent one winter in the sea are almost 

 entirely males. 



And, when this is compared with what has previously been set forth, 

 it provides us with a striking proof that the salmon which, after one, two, 

 or three winters in the sea, approach the coast, and which form the material 

 for the fisheries in our waters, form only a portion of the year-classes to 

 which they belong. They consist of that portion torn away from the others 

 by force of the spawning instinct. 



Let us now again examine the tables on p. 35. If we compare the 

 proportion of maiden fish to those which, as seen from the spawning mark, 

 have previously spawned, we find that the number of the former is far and 

 away the larger. If we arrange the latter in the form of percentages for 

 the various districts in the two years under examination we obtain the 

 following tables : 



As is clearly shown, only a very small portion of the whole have 

 spawned before and are returning to spawn for a second time. 



It would appear, therefore, that the operation of spawning is a factor 

 which has serious effect in shortening the fish's life, or, indeed, in abruptly 

 ending it, and this is easily understood when one thinks of all the dangers 

 the fish has to pass through during its spawning journey, and among which 

 by no means the least are the snares and traps of mankind. The violent 

 changes of conditions to which it is subjected during its long journey, 

 during the long fast in fresh water, and during the labours in the actual act 

 of spawning, are bound to be fatal in their effects. Many die, many are 

 like living corpses when they again make back to the sea, and they must 



