HYBRIDS— SALMON AND TROUT. 255 



46 inches long from the Tweed, the cartilaginous hook on the lower jaw is very 

 slightly developed, yet it was a male* (see p. 58 ante). As I shall show that 

 salmon and trout may interbreed and produce fertile ofispring, it would become 

 interesting to ascertain how such hybrids could be differentiated from the pure 

 races, and whether the species which forms the male or female parent occasions 

 perceptible differences in the young. I have already shown oau.se for supposing 

 that hybrid salmon and trout do not lose their anadromous propensities. 



Hybrid between Salmon and Loohlevbn Tegut. 



Day, Proceedings Zoological Society, 1882, p. 751, and 1884, p. 18. 

 Maitland, History of Howietoun, 1886. 



On November 25th, 1879, a man arrived at Howietoun with some salmon milt 

 which Mr. Napier, the local inspector of fisheries, had despatched the previous 

 evening from Stirling in a tightly corked soda-water bottle, that had been kept 

 during the night in snow, and which seemed on arrival as if it had been frozen. 

 This milt was employed for fertilizing ova taken from a four-year-old Lochleven 

 trout, and a few of the progeny were successfully reared November 14th, 1882 : 

 one, eleven inches long, was taken in my presence ; it was a male which I described 

 in the P.Z.S., 1882, and likewise gave a woodcut of its head. 



Some of these fish when young were placed in the island pond along with the 

 trout, and when that pond was drained in my presence, November 28th, 1883, 

 several were obtained ; three of these I sent to the Economic Fish Museum at South 

 Kensington, one 1 retained and examined, it also was a male {see P.Z.S., 1884). 

 Several were transferred to pond No. 11. 



November 14th, 1884, on pond No. 11 being drawn, three of the above hybrids 

 were captured, the largest being 16| inches long ; they appeared to be in good 

 health, but none had shown any tendency to spring out of the ponds at ■ the 

 spawning time. A specimen I retained was eleven inches long, or similar to the 

 first taken the previous year. They were as follows : — 



B. X, D. 12 (f ), P. 12-13, V. 9-10, A. 11 (|), C. 19, L. 1. 114-118, L. tr. 24-25, 

 30-32, Ceec. pyl. 62-69. 



In the first the length of the head was 4|, of pectoral fin 6J in the total length, 

 while in the second the length of the head was 5|, and of pectoral fin 7i in the 

 total length. Both were males. Teeth in an apparently double row along the body of 

 the vomer, and in both twelve rows of scales were present in a line passing from 

 the adipose dorsal fin downwards and forwards to the lateral-line ; and from 

 twenty-one to twenty-five from the lateral-line to the base of the ventral fin. In 

 the first the rows of scales in the upper half of the body were very irregular, and 

 in the second in the tail portion of the body. Colours — on removal from the water 

 silvery, with a rich purple gloss, and from six to eight irregularly placed rows of 

 black spots on the fore-part of the body, decreasing to three, or even two, in the 

 caudal portion : no par bands ; two to five black spots on opercle, one or two on 

 preopercle, some on cheeks and top of the head. Lower two-thirds of dorsal fin 

 with large black spots, and white anterior upper edge : the fins generally grayish 

 and darkest in the centre, the anal having a light front edge. Generative organs 

 rudimentary. 



Htbe[d between Salmon and Lochleven Tegut. 



Day, Proceedings Zool. Society, 1882, p. 752 ; and 1884, pp. 19, 376 ; and 1886, 

 p. 241. 



December 24th, 1881, about 20,000 eggs of Lochleven trout at Howietoun 

 were fertilized with salmon milt obtained from the Teith. They hatched on 



* Professor Flower, o.b., the obliging Director of the Natural History Museum, at my 

 request had the example opened, and it was undoubtedly a male. 



