THE LIFE-HISTORY OF THE SALMON. 295 



about the middle of May, those which become Smolts are rest- 

 less and sportive, even leaping out of the pond in their 

 endeavour to reach the river. The sluice at the east corner of 

 the rearing-pond is tb ,a left open, and those so inclined pass 

 down a wooden acr .duct to a small enclosure with perforated 

 zinc, close to t 1 " j river, and congregate there overnight. They 

 are then ms.ked by cutting off the adipose fin, and liberated 

 into the Tay. Other methods of marking formerly adopted were 

 * ' punching " out a triangular portion of the operculum, and putting 

 rings in fins (the present method) and tail. Those which exhibit 

 the migratory instinct generally show the silvery hue of the Smolt, 

 and very few Parr find their way into the " trap." The rest of 

 the young fishes remain for another year before assuming the 

 silvery coating of the Smolt and the migratory instinct. There 

 is thus a marked difference between such and the Pacific Salmon 

 which passes to the sea shortly after absorption of the yolk-sac. 

 Its scale, Dr. Masterman points out, is devoid of the primitive 

 annular ridges. 



The little fish of about an inch in length (Parr) feeds readily 

 on minute organisms, such as copepods, in the water, gradually 

 gains strength to encounter the currents, and at the end of the 

 first year is about 2|— 3 in. long, a few reared at Stormontfield 

 being larger and assuming the silvery dress of the Smolt (about 

 eight per cent.), these manifesting a desire to migrate to the 

 river. 



In the early sixties of last century the sight from the margin 

 of the pond in August, when the vegetation had recovered from 

 the annual clearing, was both interesting and beautiful, and the 

 same remarks will equally apply to the present time. The 

 bright green pond-weeds had spread in truly tropical luxuriance, 

 transforming the pond into an enchanting sub-aqueous forest, 

 under the shade of which the Parr, together with shoals of the 

 three-spined Stickleback, found both shelter and food ; whilst, 

 on a lower level, numerous Loaches and a few Eels shared the 

 same retreat. Threading their way through the sub-aqueous 

 thickets the little Salmon keep in companies, rising readily to 

 artificial food in good weather, or hunt the minute animals 

 which swarmed on all sides. Larvae of insects climbed the 

 pond- weeds or formed their tubes on the stones. Pond- snails 



