The Scottish Naturalist. 
119 
Until 1890 the entire district had enjoyed an immunity from 
the fungoid disease which has been so fatal to the salmonidae in 
other parts of Scotland, but in that year the Saprolegnia made its 
appearance, though not in a virulent form. I observed about 
half-a-dozen cases amongst salmon and trout taken in the nets 
belonging to the Duke of Montrose, and the fishermen told me 
they had occasionally, in the same year, got a stray fish so affected ; 
a circumstance which had never occurred in their previous ex- 
perience. The only other fish attacked at this time were the 
minnows, which were frequently covered with large snow-white 
patches of fungus. It remains to be seen whether this slight 
attack will develop into a severe epidemic in the coming years. 
Salmo eriox, Linm^ the Grey Trout or Bull Trout. This 
species is somewhat scarce, and but little is known of its habits. 
It is, however, probable that it does not enter the loch so early as 
the true salmon, at least, I have never seen one taken earlier than 
x\ugust, and I have not been able to get any reliable information 
on the subject from the fishermen. The largest example I have 
taken^ or indeed seen, weighed lbs. Nothing is known as to the 
time of spawning, or the migration of the young in this district, 
the present species being generally confounded with the true 
salmon or the sea trout. 
Salmo trutta, Fkjuing, the Sea Trout. The sea trout is to 
be found during the entire year, but there are probably very few 
clean fish in the loch before the end of April. The heaviest fish 
make their appearance in May and June, and a smaller sort from 
July onwards. The whitling, or blacknebs, run from the middle 
of July until the end of the season, the principal migration being in 
August. The sea trout of Loch Lomond are exceptionally large 
and fine, ranning ordinarily up to 4 or 5 lbs., and occasionally up 
to 8, 9, and even 14 lbs., a fish of the latter weight having been 
taken with rod and line a few years ago. The variations in shape, 
proportion, colouring, and marking are infinite, and it is not easy 
to tell where Salmo trutta ends and fario begins. The sea trout 
enter the tributary streams with the first floods in June, and con- 
tinue passing up during the whole summer. They do not spawn 
until late in October or November, by which time the earlier fish 
have pushed their way up to the very head waters of the streams. 
After spawning they gradually drop back into the loch, where they 
remain for some time, and have not all gone to the sea until the 
