178 



to rank as a species. In these examinations, 

 the character of the internal organs also, and 

 the number of the bones forming the vertebral 

 column, should be ascertained. The normal 

 number of vertebrae in Salmo Fario, our com- 

 mon trout, I believe to be fifty-six. 



Mr. Neill, in his tour, has noticed the black- 

 moss trout of Loch Knitching, and Loch Kat- 

 rine is said to abound also with small black 

 trout; an effect considered to be produced in 

 some waters by receiving the drainings of bog- 

 gy moors. In streams that flow rapidly over 

 gravelly or rocky bottoms, the trout are gene- 

 rally remarkable for the brilliancy and beauty of 

 their spots and colours. Trout are finest in ap- 

 pearance and flavour, from the end of May till 

 towards the end of September;* an effect pro- 

 duced by the greater quantity and variety of 

 nutritious food obtained during that period. 

 Two specimens of the common trout taken ear- 

 ly in January, were unusually fine in colour for 

 that season of the year ; their stomachs on ex- 

 amination were distended with ova of large 

 size, which, from circumstances attending the 

 capture of the trout, were known to be the roe 



* Trout are in the best season in the Dove and other 

 rivers where the May-fly is abundant, towards the end of 

 June, or at the time when that fly disappears. The im- 

 mense number of May-flies they consume during the three 

 or four weeks thosa flies last is, of course, the chief cause. 



