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Show 1882.] ON HYBRIDS BETWEEN SALMON AND TKOUT. 751 5. On Hybrids between Salmon and Trout. By F.DAY, F.Z.S. [Received December 7, 1882.] The hybridism of fishes is a question of very great interest to the zoologist and importance to the pisciculturist, but which, for obvious reasons, is difficult to investigate, it being only those who possess large stock-ponds or peculiarly adapted waters that are able to assist inquirers in this direction or personally afford the desired information. Among the Salmonidae hybrids have frequently been adverted to as occurring in a state of nature, as well as due to the manipulations of pisciculturists. Fitzinger informs us that Salmo schiffermuelleri must be considered a cross between a Trout and a Charr, and that in the young the reproductive organs merely exist in a rudimentary condition, while they degenerate into adipose tissue in the adult. At Sir J. Gibson-Maitland's magnificent piscicultural establishment at Howietoun near Stirling some experiments on this subject have been made, at first under the impression that all our freshwater forms of Trout were distinct species; while others are now in progress, the results of which will be watched with great interest. November 25th, 1879, a man arrived at Howietoun with some salmon-milt obtained the previous night; and this was employed for the purpose of fertilizing some eggs from a four-year-old Lochleven Trout. A few of the progeny were successfully reared ; and one of the last examples was captured in the stock-ponds in m y presence, November 14th, 1882. It was given m e by the owner, and is now on the table. The age of the fish is consequently about 2 years and 9 months, being in fact a grilse in good condition and 11 inches in length. B. x. D. 12 (|). P. 12-13. V. 9. A. 11 (f). C. 19. L. 1.118. L. tr. 25/30. Caac. pyl. 62. inches. Total length of specimen 11*0 Length of head 2*4 Length of pectoral fin 1*7 Distance from snout to base of dorsal fin . . 4*5 Distance to centre of base of caudal 9*8 Diameter of eye 0*4 Distance of eye from end of snout 0*7 Distance apart 0*8 Heightof body 2*5 Preopercle forming an almost regular curve, with but very slight appearance of a lower limb. Lower jaw with a slight hook at its extremity. A line taken from the snout to the furthest point of the posterior edge of the opercle passes through the lower third of the eye. Teeth in a double row along the body of the vomer. Scales: 12 rows passing downwards and forwards from the hind edge of the adipose dorsal fin to the lateral line ; 25 rows PROC. ZOOL. Soc-1882, No. L. 50 |