246 SEASON 1877-78. 



SEASON 1877-78. EXPERIMENTAL WORK. 



I spent most of this winter abroad ; the work under this head 

 is therefore almost nil. In the statement for December 1876, two 

 lots of hybrids appear, viz. 1000 in the lower 20-feet pond, and 180 

 in the octagon pond at Craigend. The former were hatched from 

 the ova obtained from "Queichy" on 25th November 1875, and 

 milted by a S. fario at Craigend dam. These I would now call a 

 cross or mongrel, and not a hybrid at all. No other mention 

 occurs in the note-book of this lot, so I suppose the 20-feet in 

 which they were got frozen which the lower 20-feet, from its posi- 

 tion, sheltered by the hatching-house, has a tendency to do, or 

 that the remains of them were freed in the burn next spring, when 

 the pond would be required for fry. The hybrids in the octagon 

 number all left of Experiments 1, 2, 3, 5, 7, 8, 9, and 11 of 1874, 

 which had been mixed for want of room. On 5th October 1877, 

 on emptying the octagon pond, 61 remained. They were 

 then two years and nine months old, and the males had milt in 

 them ; but as Experiments 1, 2, 3, and 5 were mongrels, not 

 hybrids, and as it does not appear to what experiments the 

 survivors belonged, no deduction as to fertility can, so far, be 

 made. 



Perhaps the most important experimental note yet made is : 

 " 13th October. Caught a male fish in the centre 130-feet pond at 

 Howietoun. Pure Loch Leven, the milt running freely : length, 

 12 inches ; weight, 12 oz. Hatched 22d January 1875, and 

 thus thirty-two and a half months old. Noticed two rows of 

 bright yellow spots with black centres ; belly very black ; under- 

 jaw slightly hooked ; hind margin of caudal convex. I sent him 

 to be cast." Here is a trout whose parents were spawned at Loch 

 Leven, and undoubtedly mature representatives of the S. levenensis, 

 developing marks which had hitherto constituted one of the most 

 trusted barriers of the species. In Giinther's Catalogue of the 

 fishes in the British Museum, vol. vi. p. 101, S. levenensis is thus 

 described : 



