326 Salmonidz 
limited, will be small directly in proportion to these environing 
restrictions. The trout of the Klamath Lakes, for example, reach 
a weight of at least 17 pounds, while in Fish Lake in Idaho mature 
trout do not exceed 8 to go} inches in total length or one-fourth 
pound in weight. In small creeks in the Sawtooth Mountains 
and elsewhere they reach maturity at a length of 5 or 6 inches, 
and are often spoken of as brook-trout and with the impression 
that they are a species different from the larger ones found in 
the lakes and larger streams. But as all sorts and gradations 
between these extreme forms may be found in the intervening 
and connecting waters, the differences are not even of sub- 
specific significance. 
Dr. Evermann observes: ‘‘The various forms of cutthroat- 
trout vary greatly in game qualities; even the same subspecies 
in different waters, in different parts of its habitat, or at different 
Fia, 233 Fig 234 
Fig. 233.—Head of adult Trout-worm, Dib thrium ¢ rdicens Leidy, a parasite of 
pe clarkit, From. intestine of white pelican, Yellowstone Lake. (After 
Fia. 384 Median segments of Dib thrium c rdiceps. 
seasons, will vary greatly in this regard. In general, however, 
it is perhaps a fair statement to say that the cutthroat-trout 
are regarded by anglers as being inferior in gaminess to the 
Eastern brook-trout. But while this is true, it must not by any 
means be inferred that it is without game qualities, for it is 
really a fish which possesses those qualities in a very high degree. 
Its vigor and voraciousness are determined largely, of course, 
by the character of the stream or lake in which it lives. The 
individuals which dwell in cold streams about cascades and 
seething rapids will show marvelous strength and will make a 
fight which is rarely equaled by its Eastern cousin; while in 
warmer and larger streams and lakes they may be very sluggish 
and show but little fight. Yet this is by no means always true. 
In the Klamath Lakes, where the trout grow very large and 
