64 SALMON TROUT. 



actually rounded : the fish altogether at this time loses 

 a great deal of its former elegance. The tails of the 

 females of a corresponding age are more square, and 

 their general shape is more slim. 



These fish may be crossed with Salmon ; I mean 

 that by artificial impregnation hybrids may be thus 

 produced. Mr. Shaw says in a letter to me, dated 

 November 25th, 1840: — "I put some of your sug- 

 gestions regarding the ova of the Salmon, and the com- 

 mon Trout, Sea Trout, and Salmon, into practice about 

 a month ago, and shall let you know the result." The 

 following year I had the pleasure of a letter from 

 him, dated October 14th, 1841, saying that " The hy- 

 brids which I produced by artificial impregnation last 

 autumn are all in a very healthy state, the cross not 

 having in the slightest degree affected their consti- 

 tution. Those produced between the Salmon and the 

 Salmon Trout (Salmo Truttd) appear to partake more 

 of the external markings, silvery coating, and elegance 

 of form of the Parr (young Salmon) than any of the 

 others. Those produced between the Salmon and com- 

 mon Trout (Salmo Fario), and between the common 

 Trout and Salmon Trout, have in every respect more 

 the appearance of the common Trout than the former." 



Some have imagined that the Whitling or Hirling are 

 the young of the Bull Trout. But this is a mistake, as 

 the Hirling abounds in the Annan, where the Bull 

 Trout is very rarely seen ; and also in the Nith, where 

 Mr. Shaw has never been able to discover one of the 

 other species. Lord Home likewise, whom I consider 

 the very best practical authority, says, " The Whitling 



