MB. F. DA.T OJT THE LOCH-LEVEN TEOUT. 



81 



sized fish, which, owing to sickness or some other cause, have the 

 colours of the brook-trout, with orange-tipped adipose dorsal 

 fins. 



The question here arises whether these colours are perceptible 

 in these fishes when removed to fresh localities. In the year 

 1868, the late Mr. Mclvor, of the Grovernment Gardens at Oota- 

 camund in the Madras Presidency, succeeded in introducing some 

 Loch-Leven trout and other European fish to that elevated 

 region, where they are or were doing well (see Journal of the Lin- 

 nean 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^ inches long, and on its body were red 

 spots. In this instance it was clear that if a young Loch-Leven 

 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. 



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 netter. 



This is generally asserted to be owing to the imported fish 

 having 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 con- 

 sequent upon local surroundings. 



Ten thousand yearlings from Howietoun were turned into 

 Loch Goldenhove, 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, 1 exa- 

 mined some of these introduced fish, and found them of a pur- 

 plish colour shot with gold, and covered with black ocellated spots, 

 but no red ones. Dorsal fin spotted with black, but without any 

 white edging, its outer surface greyish ; 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 



