HISTORY OF THE PACIFIC SALMON. 583 



cells having died, i.s devoid of concentric lines. In botli text- 

 figs. 100 &■ 101 the first winter band formed in the sea is shown 

 between the ends of the lines A A. The second winter band is 

 between the lines BB. The first spawning mark in each case 

 is at the end of the line marked C and the second spawning mark 

 at D. Text-fig. 100 is a scale from a 33 lb. salmon caught in 

 the Tay in August 1903. It can be seen, from the few wide! v 

 spaced lines between the band BB and the spawning mark C, 

 that when it first spawned it was a summer fish about 4| years 

 of age. After spawning the scale had become much worn, so 

 much so that, except in front, not only the summer growth but 

 the band BB had disappeared, and the new growth formed after 

 the fish returned to the sea can easily be distinguished, its lines 

 being again continuous round the scale. In text-fig. 101 the 

 winter band of the 5tli year had begun to form before the 

 spawning mark C, so it was evidently a late autumn salmon. 

 In text-fig. 100 the second spawning mark is indicated by the 

 line D. The fish must have returned to the sea after the first 

 spawning eai-ly in the year, and the lines between the two 

 spaAvning marks show it to have come in to spawn the second 

 time late in the summer of the same year. The following summer 

 it was coming back to spawn a, third time when it was captured. 

 The thickening on the posterior part of this scale, due to both 

 spawning periods, is clearly visible in the form of dark lines. 

 In text-fig. lOl the second mark D, like the first mark C, denotes 

 an autumn fish. It is not a very cleai- spawning mark, but I 

 have chosen it for that very reason, because it is so like the mark 

 on the scale of the Quinnat which I believe to have spawned 

 (see text-fig. 95, p. 574) and because I have undoubted evidence 

 that mark D on text-fig. 101 is a true spawning mark. The fish 

 was caught as a kelt, weighing 22^ lbs., and marked by my own 

 gamekeeper, Peter Bowie, at Netherdale on the River Deveron, 

 on Mai^ch 23vd, 1908. He put in its fin one of the Scottish 

 Fishery Board labels numbered 3613 B. The scales then showed 

 only the first spawning mark 0. The fish was recaptured as a 

 clean salmon, weighing 33j lbs., in a bag-net at Port Gordon on 

 the Aberdeenshire coast on August 19th, 1908, after only five 

 montlis' interval. The mai'k I) thus certainly represents the 

 second spawning period during which my keeper caught and 

 marked the fish. 



Manj^ other instances have occurred in which fish that have 

 been marked with distinctive numbers as kelts have been caught 

 again, and in every case they have proved the truth of Mr. John- 

 ston's theory by showing a spawning mark on their scales. On 

 the other hand, no fish that one knows from its age could not 

 have spawned has ever been found to bear quite the same sort 

 of mark, although various marks indicating sudden checks in 

 feeding may appear. 



I have entered somewhat fully into the above description of 

 spawning iiiarks, because I ^■ope that now many scales of Pacific 



