TREATISE ON FLY-FISHING. 87 



inches. On the 10th May, 1838, the fish being 

 then twelve months old, were improved in condi- 

 tion, and measured four inches : they had changed 

 their winter coating for that which may be called 

 their summer dress. On the approach of autumn, 

 the whole of the salmonidee, while resident in 

 fresh water, acquire a dusky exterior, accompa- 

 nied by a considerable increase of mucus or slime. 

 As the summer advanced, they continued to 

 increase in size; and on the 14th November, 

 being then eighteen months old, they measured 

 six inches in length, and had attained that stage, 

 when all the external markings of the parr are 

 strikingly developed. On the 20th May, 1839, 

 the fish being then two years old, they measured 

 six inches and a half long, and had assumed the 

 migratory state. 



This change commenced about the middle of 

 the previous April ; the caudal, pectoral, and 

 dorsal fins assuming a dusky margin, while the 

 whole of the fish exhibited symptoms of a silvery 



