26 THE SCIENTIFIC ANGLEE. 



Erne, and Lough Lomond, too, are stocked with them. 

 They feed, like the charr, upon the fly and other aquatic 

 insects, etc. The prevailing color is silvery gray, the 

 head and back being bluish brown. They spawn in De- 

 cember and January, and afford good sport during the 

 genial months to the angler. 



THE GRAYLING (Thymallus vulgaris.)* This is a 

 much more fastidious and delicate fish than the trout; 

 and, although it abounds to profusion in some streams, 

 yet it is very local when compared with the trout. Both 

 Scotland (including the Tweed, Clyde, and the Orkneys) 

 and Ireland are graylingless; neither do they occur in 

 Wales, except in the border streams. They require a 

 peculiar combination of favorable surroundings fco enable 

 them to flourish and locate permanently, when introduced 

 into strange streams. A moderate temperature of water 

 is requisite for their well-being, and a succession of stream 

 and still deeps. They generally frequent the lower por- 

 tions of trout streams in hilly districts; a fair volume of 

 water, too, is essential, as, when there flows less than two 

 tons or thereabouts per minute, grayling descend to a 

 lower point, where their needs in this respect are satisfied. 

 The bottoms of our best grayling rivers usually consist of 

 an alternate mixture of loam, marl, sand, and gravel. 

 The brown trout, in his habits of migration, penetrates 

 still further up stream to more rapid water. The gray- 

 ling, on the other hand, more generally descends to slower 



* The coloration of the English grayling consists of a general tint of 

 light blue silvery gray, covering nearly the whole surface of the body, 

 excepting the belly, which is white, or nearly so, and the scales often 

 exhibit iridescent lines of great beauty. The back and head are of darker 

 gray than the rest of the body. A few lines of brown are intermixed 

 with the gray of the sides, ard a few black spots appear on the shoulder. 

 The back fin has a purplish tint, studded with large black spots. The 

 tail is of a slate color. The English fish I judge to be somewhat stouter 

 than the American (Thymattus tricolor), and is certainly far inferior to it 

 in beauty of coloration. 



