SAL3ION. 39 



second winter in the river, during which period the males 

 shed their milt, and are found continuing their kind along 

 with the female adult Salmon, although still bearing all the 

 external markings of the Parr, as I shall afterwards more par- 

 ticularly mention. A specimen eighteen months old, taken 

 from pond No. 1, on the 1-ith of November, 1838, measures 

 six inches in length, and has now attained that stage when 

 all the external characteristic markings of the Parr are strik- 

 ingly developed, and, in point of health and condition, can- 

 not be exceeded by any taken from the river. All the males, 

 at the age of eighteen months, of the several broods in my 

 possession, last autumn (1838) attained a most important 

 corroborative stage, viz. that of showing a breeding state, by 

 having matured the milt, which could be made to flow freely 

 from their bodies by the slightest pressure of the hand. 

 The females of the same broods, however, although in equal 

 health and condition, did not exhibit a corresponding appear- 

 ance in regard to the maturing of roe. The male and female 

 Parrs in the river, of a similar age, are found respectively in 

 precisely a corresponding state, which may surely be admitted 

 as most important evidence in support of the fact, that all 

 these individuals are, in truth, specifically the same. 



" A specimen, two years old, taken from pond No. 1, on 

 the 20th of May, 1839, is six inches and a half long, and 

 has assumed the migratory dress. The commencement of 

 the change, which was perfected by the whole of the broods 

 about the same time,* was first observable about the middle 

 of the previous April, by the caudal, pectoral, and dorsal fins 



* " One or two of each of the three broods assumed the migratory or Smolt 

 dress at the age of twelve months. This circumstance I am disposed to attribute 

 to the high temperature of the spring-water ponds, which I have no doubt has 

 hastened the change. I am greatly strengthened in this opinion by the fact of 

 no instance of a similar change having occurred with individuals reared in 

 similar ponds supplied with water from a rivulet, the temperature of which 

 throughout the year ranges pretty nearly with that of the River Nith. 



