80 
MR. F. DAT ON THE LOCH-LEVEN TROUT. 
same size and sex as published by Dr. Gunther are very mis- 
leading ; for I cannot find such examples in the British-Museum 
collection showing what he has represented, neither can I in 
nature *. 
Having thus seen that in its external form either the differ- 
ences which have been stated to exist between this fish and the 
brook-trout are erroneous, or else liable to alteration when 
the fish is removed to another locality, all must allow that such 
non-persistent differences are no basis upon which to found a 
species. 
As to external colour, we find Parnell asserting, as among its 
specific characters, “ body without red spots ; ” and that these 
fish are generally seen without them up to a certain age is of 
very common occurrence, they being of a grey colour densely 
spotted with black, and if males, with the fins almost black. At 
Howietoun, three main types of colour are observable amongst 
these fish — a slaty or greenish grey, becoming lighter beneath, 
and the upper two thirds of the body and dorsal fin spotted with 
black, and the fins generally greyish black. This form of colour 
is prevalent up to the end of the fourth season, and may almost 
be looked upon as equivalent to the silvery stage of the salmon 
smolt or grilse, but I have never seen one over four years of age 
continuing this livery. The second f or adult form is of a general 
purplish golden, densely covered with black spots, among which 
some red ones are usually to be seen, and many old females get 
a dark line along the middle of the belly, which, as well as the 
under surface of the head, is more or less black in males. In one 
female 18 inches long, on November 24th, three bright orange 
spots were present on the adipose dorsal fin, which as a rule is 
of a lead-colour, with two or three black spots J. The third form, 
which will have to be again referred to, consists of small under- 
* Specimens and diagrams were shown at the Meeting. 
t When old enough to feed on clams, which are about the size of marbles, 
this yellow colour shows itself. In some small examples, hatched in 1883, the 
“ finger-marks” were very distinct on netting the pond at the end of November 
1886. 
| We must not forget that brook-trout vary greatly in colour even when in 
the same locality ; thus “ Ephemera ” in 1853 remarked of those in the Wandle 
that such as “ feed under the cover of the trees, or lie perdu under banks or arti- 
ficial ‘ hides ’ during sunshine, are dark brown and yellow ; those that frequent 
the unshaded streams with a clear sandy bottom are of a silvery hue ” (p. 274). 
