of the Salmon in fresh Water. 



2. HOW FAR MAY THE SALMON EXAMINED BE CON- 

 SIDERED TYPICAL OF THEIR RESPECTIVE 



CLASSES? 



BY WALTER E. ARCHER, 



INSPECTOR OF SALMON FISHERIES FOR SCOTLAND. 



The object of these observations is to determine how far the fish 

 examined in the course of this investigation may be taken to fairly 

 represent fish frequenting each locality in the periods named. 



The lower- water fish are represented by 34 females and 8 males, and 

 upper- water fish by 2 1 females and 6 males. The lower-water fish were 

 in each case taken at the mouths of the rivers. The fish from the upper 

 waters of the Spey were taken at a distance of about 60 miles from the 

 sea, those from the upper waters of the Dee at about 65 miles, and 

 those from the upper waters of the Helrnsdale at about 15 miles. Fish 

 from 8 to 10 Ibs. in weight were asked for, but those sent from the 

 mouths in October and November were considerably larger. It has 

 been shown that the average weight, per fish of standard length, of 

 salmon measuring from 69 to 89 centimetres does not vary one per 

 cent. provided the averages are calculated over large numbers, and the 

 fish are taken in the same locality and during the same period of the 

 year (Table II., p. 7). It is well known, however, that there is a 

 considerable variation in the weight of single fish of the same length, 

 taken at the same time and place. Table II., p. 65, shows the extent 

 of these variations ; and the question arises as to whether the averages 

 given in this table are taken over sufficient numbers, and therefore 

 fairly represent the average condition of fish iiieach period and locality; 

 or whether the fluctuations are due to the ordinary variations in the 

 weight of fish of the same length. 



With the view of throwing further light on this question, the 

 average weight, per fish of standard length, has been calculated on large 

 numbers of fish taken in different localities in each period. The cal- 

 culations which are given in Table I. refer to female salmon taken 

 on the sea coast or immediately after entering the river. It is 

 true that Kelso, in the neighbourhood of which one lot of fish was 

 caught, is some 16 or 17 miles above the tideway ; but it would seem a 

 fair inference that these fish have entered the river in the period in 

 which they were caught, and that they should be treated as mouth and 

 not as upper-water fish, since they are altogether of a larger class than 

 those taken at Berwick-on-Tweed in July ; and, since, they resemble 

 in size the large mouth fish examined by Dr. Noel Paton in October and 

 November, being in marked contrast to the samples obtained by him 

 from the upper waters in these months. 



