FRESH- WATER TROUT— LOCHLEVENS, THEIR COLOURS. 225 



seen one over four years of ago continninpf tin's livery. The second is that of an 

 older form, and a general |n;rplisli golden, densely covered with blaek spots, 

 among which some red ones are usually to bo seen, while in many old females a 

 dark line shows itself aloug the middle of the belly, which, as well as the under 

 surface of the head, is more or less ])lack in males at the breeding season. In ono 

 female 18 inches long, on November 24th, 1880, three bright orange spots were 

 present on the adipose dorsal, which fin as a rule is of a lead colour, with two or 

 three black spots. Males appear generally to have the pectoral, ventral, anal, 

 and end of caudal fin dai'ker than the females.* The third form, which will have 

 to bo again referi'ed to, consists of small undersized fish, which, owing to sickness 

 or some other cause, have the colours of the brook trout, with orange-tipped 

 adipose dorsal fins. The most distinct white edging to the fins, when it exists, 

 appears to be seen in males, but the amount of spots in all is very various. 



Here the question again arises (see p. 8-3 ante) whether any alteivation in 

 the colour occurs, if these fish are transferred to new localitiesf dissimilar in 

 some respects to where their parents reside ? Ten thousand yearlings from 

 Howietoun were turned into Loch Goldenhoof, about two miles away, and fed by 

 the same stream, which passes through the fish farm ; this loch is nine acres in 

 extent, and averages six feet in depth. In July, 1886, I examined some of these 

 introduced fishes, and found them of a purplish colour shot with gold, and 

 covered with black ocellated spots, but rarely red ones. Dorsal fin spotted with, 

 black, but without any white edging, its outer surface grayish ; a little orange 

 upon the adipose dorsal fin. The colours, in fact, of these fish were not what is 

 seen in the Howietoun ponds, but nearly approaching those in the Loch where 

 they had been placed, a few had some red spots. As the water in the two 

 localities was the same, food, possibly deficiency of it, would seem to have been 

 the principle reason of this change in colour. 



The last experiment shows that some alteration in colour may follow new 

 environments ; J but a still more conclusive result as to the change in colour 

 which may take place in these fishes under like circumstances occurred in 

 Gloiicestershire. The proprietor of Cowley had two ponds in a wood on his 

 estate, each about an acre in extent, situated one above the other, and from the 

 lower of which emerges a small stream ; these he wished to have stocked with 

 sporting fish, The two ponds are supplied by underground springs, while there 

 is a fall of about IG feet from the outlet of the upper pond, and a rather greater 

 one from that of the lower where the stream commences. It will be apparent that 

 no fish could obtain access from above, there being no water there, neither could 

 they ascend the IG-feet perpendicular fall from the stream to the lower pond. It 

 was determined to try the Lochleven trout; so these ponds were drained, 

 mudded, and then puddled with clay. 



During December, 1884, and January, 1885, one thousand yearling Lochleven 



* The upper anterior angle of the dorsal fin rarely has a light black-based edging in these 

 fishes, and Parnell in figuring it and the burn trout correctly gives it to the second but not to 

 the first. However, it is seen like this elsewhere. 



t In the jear 18G8, the late Mr. Mclvor, of the Government Gardens at Ootacamund in the 

 Madras Presidency, succeeded in introducing some Lochleven trout and other European fish to 

 that elevated region, where they are, or were, doing well {sec Journal of the Linnean Society, 

 Zoology, vol. xii, p. 562). In January. 1876, Mr. Thomas, f.l.s., of the Madras Civil Service, 

 sent me a specimen from the Hills which was 6^ in. long, and on its body were red spots. In 

 this instance it was clear that if a young Lochleven trout could assume red spots when removed 

 to Asia, there was no reason why any similar movement in Europe might not occasion the same 

 results. 



I The assumption of the general colours of the trout in any given locality by introduced 

 breeds is of very common occurrence, at least after the third year. Now this is the period 

 at which the young of the imported forms would be in a condition to be observed by the fisherman, 

 whether angler or nctter. This is generally asserted to be owing to the imported fish liaving 

 interbred with the local race, and the hybrid (as it is wrongly termed) or mongrel form has 

 the local colours. It is therefore interesting to ascertain whether, were eggs removed to a given 

 spot quite distinct from the waters where the parents reside, the young which emerge from those 

 eggs would retain the colours of their parents, or assume those peculiar to the locality ; for if this 

 latter occurs, it must be evident that such has been consequent upon local surroundings. 



15 



