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Show 584 MB. F. DAY ON BACES A N D [Dec. 2, the ova of Trout, as the young suffered from dropsy, and on August 28th only about 100 (out of some thousands hatched in February 1884) were still alive. Many still moved about in the zig-zag manner of their younger days, and most appeared weakly ; one, however, was 2 inches in length. Great care had been taken in feeding them, otherwise none would have remained, while in a state of nature such fish would soon have been destroyed. On November 14th these fish seemed to be doing well; one, 2\ inches long, is on the table; it has eleven parr-bands and several short intermediate ones, while it has only eleven rows of scales on a line from the adipose dorsal to the lateral line l. So far I have shown that parr and smolts and grilse come from a common origin, that milt and ova may be present in them without their having gone to the sea; while the probable reason that the male parr has milt2 at the early period of October or November is because it is at that time that the grilse deposits its ova3. Should the milt of Salmon-parr be employed to fertilize Trout-eggs, what will be the result ? These experiments at Howietoun, as I shall now show, have so far gone to demonstrate that the offspring are sterile. November 25th, 1879, some eggs of the Lochleven Trout were fertilized from the milt of the Salmon, and up to this time all which have been observed have been sterile. I saw several on November 14th at Howietoun, pond no. 11, the largest being \6\ inches long, but all were sterile. On August 26th, 1884, a hybrid 6\ inches in length was taken 1 On April 30th, 1883, Mr. Douglas Ogilby captured a young Salmon in a lake which has no access to the sea. Its abdomen was so distended that be considered that it would have spawned within a few days, the more so because it was taken at the mouth of the only stream which enters the lake (Lough Ash, Co. Tyrone). The way in which the fish obtained access to this place was, that two years previously Mr. Ogilby took about 100 Sea-Trout and Salmon Smolts and turned them in. The lake is also curious in this respect, that in the dozens of other small lakes about these mountains, the Trout average about three to the lb., while here there are some of as much as 151b. weight. On April24th, 1884, I examined this specimen (at Mr. Douglas Ogilby's re quest) at the Natural History Museum. It was a Salmo salar 14"5 inches long, with its abdomen much distended with ripe ova; these measured 0'25 of an inch in diameter, but they are compressed one against another forming lateral facets. There are 11 rows of scales between the adipose dorsal and lateral line, and 4 teeth cn the front end or head of the vomer. Tail black. Did not examine pyloric ca?ca, as to do so injury must have been done to the ovisac. 2 That milt of parrs will fertilize Salmon-ova, bas been shown by Shaw, probably from such as are in their third season. Fertilizing Lochleven eggs with parr a year older than employed last year has been tried this season at Howietoun. 3 The sea-trout ascend tbe streams near Stirling to breed at the same time as the grilse, but when I was at Howietoun the water-courses were rather full, owing to rains. However, on November 13th a frost set in, and keepers were sent to obtain some sea-trout for breeding-purposes, for with a frost the brooks &c. subside, because the rills and small affluents are frozen ; from the same cause the temperature of water in the streams usually rises two or three degrees. Although two pairs of small sea-trout were observed at their redds the fishers failed in capturing them. |