1884.] HYBRIDS AMONG THE SALMONID.E. 585 



from the Octagon pond at Craigend. These fish were raised from the 

 eiigs of Lochleven Trout, fertUized by Salmon-milt December 2-4th, 

 1881, and hatched March 9th, 1882. The specimen was a barren 

 female, the ovisac 1 inch long, and 0-15 of an inch wide and very 

 thin. Colours— dorsal fin with 3 rows of black spots along its base. 

 On November 14th, 1884, the pond was again drawn, but all the fish 

 appeared to be sterile. One specimen, 10 inches long, was removed ; 

 it had 37 csecal appendages, which were well loaded with fat ; its colours 

 were silvery with black spots, while the parr-bands were still visible : 

 it was a sterile male. These fish have not shown the tendency to 

 jump out of the pond -as seen in the young Salmon, which at this 

 age are fertile, as are also hybrids between Trout and Char, and 

 hybrid Char a year younger. As all live at the same place, the 

 supposition is raised that sterility is the rule in hybrids between 

 Salmon and Trout, and if so, such must prevent the continuation of 

 such races in rivers. 



November 14th, 1884, about 12,000 Lochleven-Trout eggs were 

 fecundated with the milt of three parrs and smolts, the smallest 

 being 10 inches long, the middle-sized one 11, and the largest 12 : 

 the last had the parr-bands still visible. The eggs were placed in 

 box no. 1 of the hatching-house. It will be interesting to ascertain 

 if dropsies will occur, as they did last year when the male was a 

 season younger ; while it seems probable that Shaw's fish, ten inches 

 long, which were successfully employed to fertilize Salmon-ova, must 

 have been of the same age as these. 



August 28th, 1884, a hybrid 6| inches in length was removed 

 from fish-culture pond no. 3 at Howietoun. This pond is 20 feet long 

 by 5 wide, and contains about 36 inches of water ; it is of the same 

 size as pond no. 4. Of these fish about 190 existed at this date, 

 and all were in excellent condition. They are the progeny of Loch- 

 leven-Trout eggs which were fertilized by the milt of the American 

 Char, Salmo fontinalis, on November 15th, 1882. The appearance 

 of these fish was most striking and due to their bands ; the race for 

 distinction's sake was named and will in future be termed the 

 Zebra^, in order to distinguish them from the other hybrids (Plate 

 LVI. figs. 1 & 2). 



The following is a description of a specimen removed from the 

 pond : — 



B. X. D. 13(f'^). P. 13. V. 9. A. f . C. 19. 

 L. 1. 128. Csec. pyl. 39, longest \ inch. 



inches. 



Total length 67 



Length of head 1'5 



Length of pectoral fin TO 



Length of ventral fin 0-8 



Length of caudal fin 1"0 



Height of body 1 '5 



Eyes, diameter of 0'3 



^ See Proc. Zool. Soe. p. 376 ante. 



