584 MR. F. DAY ON RACES AND [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, how- 

 ever, 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 milt 2 at the early period of October or November is 

 because it is at that time that the grilse deposits its ova 3 . 



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 16| 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 he con- 

 sidered 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 April 24th, 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 dis- 

 tended with ripe ova ; these measured 025 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 en the front end 

 or head of the vomer. Tail black. Did not examine pyloric casca, as to do so 

 injury must have been done to the ovisac. 



2 That milt of parrs will fertilize Galmon-ova, has been shown by Shaw, pro- 

 bably 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 Howie- 

 toun. 



3 The sea-trout ascend the 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. 



