THE SALMON 185 



its existence, but within the limits of a single year. Beginning 

 ab ovOj we may trace this noblest of British fishes as a tiny 

 The Alevin " alevin," r larva, with the relatively large umbilical 

 stage. sac attached to the throat or breast behind the 

 gill-opening. For a period varying from three weeks to twa 

 months, the alevin draws its nourishment from this sac ; by 

 the time this is absorbed the fish is generally about an inch 

 and a quarter long. 



It now enters upon life as a " parr," and assumes a very- 

 lively colouring. The back becomes dark olive with bronzy 

 reflections, and this colour extends down the sides, below the 

 The Parr lateral line, in nine or ten vertical bars, arranged upon 

 stage. a paler ground of olive green shot with golden, 

 coppery, and silvern hues, and liberally spangled with spots, 

 some black, some scarlet. The lower parts are pearly white ; 

 the iris golden ; the pectoral, ventral, and anal fins are tinged 

 with orange-brown ; the dorsal fins are grey, the first dorsal 

 being dotted with black. The chief marks distinguishing a 

 salmon parr from a river-trout at the same stage are : first, 

 the head is shorter and rounder ; second, the salmon or 

 salmon-trout parr generally has two or three more lateral 

 bars than the river trout parr ; and third, the adipose fin of 

 the river-trout parr is more or less deeply tinged with red, 

 while that of the salmon parr is a light slate colour. The 

 last-mentioned distinction cannot be relied upon in the case 

 of the parr of migratory trout, which often have a ruddy or 

 orange colour in the adipose fin. 



It scarcely strengthens one's faith in the acumen of 

 classifying authorities that the parr was, until very recently, 

 unanimously regarded by them as a distinct adult species. 

 Willughby in 1686, Ray in 1713, Pennant in 1776, Turton 

 in 1807, Yarrell in 1836, even Couch in his edition of 1877, 

 adduce cogent reasons, founded upon organic differences, for 

 classing the samlet (Salmo salmulus] as a separate species, the 

 smallest of British Salmonid<e. It is not often, perhaps, that 



