COMMON TROUT. 
234 
Peal^ nostjils about balf way between tbe eyes and snout. 
Beginning of the dorsal fin five inches back, with twelve rays, 
decreasing in length; pectoral rounded, with thirteen rays; 
ventrals close to each other, nine rays; anal ten, the two last 
from one root; the tail wide, concave, the upper and lower 
portions rounded, twenty-two rays. The colour varies with the 
colour^ of the ground, and also with the health; the back 
yellowish or reddish brown; cheeks and sides grey, or a rich 
yellow, white below. Gill-covers often sparely spotted, as is 
the dorsal fin, of the colour of the back; anal yellowish; but in 
both these fins, and almost invariably the anal, the first ray has 
a white border, becoming broader upward; sometimes dark at 
the dorsal; pectoral yellow; the adipose fin bordered rvith red. 
The sides studded with dark spots; red spots along the lateral 
line, and some above and below, each spot with a light-coloured 
border or circle. It is material to remark, as distinguishing 
closely -allied species, that the vertebrae of the Trout have been 
counted as fifty-six, and the caeca, or processes at the beginning 
of the intestine, under fifty in number; and the stomach itself 
has a membranous character, by which among other things it 
is distinguished from the Gillaroo. 
In the several varieties of the Trout mentioned by Sir William 
Jardine, or otherwise observed, it is instructive to notice the 
accompanying influences of soil, elevation, degree of light and 
shade, and also the nature of the food on which the varieties 
are chiefly fed, and to which we have already referred; and all 
of which, with their combinations, will efiect material changes 
of colour on the surface and within the flesh; as they will also 
on the configurations of particular organs, even, as we shall 
have occasion to point out, to a considerable amount of abnormal 
structure; or, as it is commonly expressed, of monstrosity. And 
this effect is rendered more considerable, so as to become even 
hereditary, by the circumstance that these fish in their usual 
habits are not able commonly to mingle with others of a different 
stream; so that by breeding only among themselves, a peculiaiity 
once obtained is likely to become a permanent character of the 
race or district. 
Sir William Jardine remarks in connection with the fish 
which he describes as his first variety of the Trout, and which 
he found in Loch Craigie, in Sutherlandshire, that the country 
