SALMON. 19 



examine them more particularly, and at the same time to 

 convince others of the fact of their having changed their 

 external character, I caught them with a casting-net on the 

 17th May, 1834, and satisfied every individual present that 

 they had assumed the usual appearance of what are called 

 Salmon smalts or fry. They were now of a fine deep blue 

 upon the back, with a delicate silvery appearance on the 

 sides, and the abdomen white ; these silvery scales came 

 easily off upon the hand. A circumstance occurred about 

 the first week of May, which it may be proper to mention, as 

 illustrating in some manner what may be deemed the migra- 

 tory instinct of these fishes. They seemed to me at this 

 time to be decreasing in numbers, and I found, on examina- 

 tion, that some had leapt altogether out of the pond, and 

 were lying dead at a short distance from its edge. 



" In March 1835, I again took twelve Parrs from the 

 river of a larger size, that is, about six inches long ; they then 

 bore the perpendicular bars, and other usual characters of 

 that fish. These I also transferred to a pond prepared for 

 the purpose, and, by the end of April, they too assumed the 

 characters of the Salmon-fry, the bars becoming overlayed 

 by the new silvery scales, which Parrs of two years old in- 

 variably assume before departing towards the sea. From 

 these experiments I had no doubt that the larger Parrs ob- 

 servable in rivers in autumn, winter, and early spring, were 

 in reality the actual Salmon-fry advancing to the conclu- 

 sion of their second year, and that the smaller summer 

 Parrs (called in Dumfriesshire May Parrs), were the same 

 species, but younger as individuals, and only entering upon 

 their second year. This, then, I conceived to be the detec- 

 tion of the main error of preceding observers, who had uni- 

 formly alleged that salmon-fry attain a size of six or eight 

 inches in as many weeks, and after the lapse of this brief 

 period take their departure to the sea. It is the rapidity 



