400 MK. p. DAY OX BRITISH SALMONES. 



Salmo stomachicus : vert. 59-60, caec. pyl. 44. Salmo galUvensis : 

 vert. 59, csec. pyl. 44. Salmo orcadensis : vert. 56-57, csec. pyl. 

 50. Salmo nigripinnis : vert. 57-59, csec. pyl. 36-42. The fore- 

 going show an extreme range as followfs : — S. levenensis, vertebrae 

 57-59, csecal appendages 49-90 ; the remaining six, enumerated 

 as species, vertebrae 56-60, csecal appendages 33-50. In the 

 year 1880, Wallace, ' Island Life ' (p. 321), on the authority of 

 Dr. Giinther, introduced these forms as distinct species, ob- 

 serving, " They are in fact, as Dr. Giinther assures me, just as 

 good and distinct species as any other recognized species of 

 fish;" while Dr. Griinther, 'Introduction to the Study of 

 .Fishes ' (p. 644) reiterates, with but slight variations, his con- 

 clusioDs come to in 1866. Thus, as in the former work he 

 observed " that at least some of the species interbreed, and it is 

 probable, although at present not confirmed by direct obser- 

 vation, that such hybrids mix again with one of the parent 

 species, thereby producing an oftspring more or less similar to 

 the pure breed " (Catal. vi. p. 3), he asserts in his later work 

 that " some of the species interbreed, and the hybrids mix again 

 with one of the parent breed, thus producing an oflspring more 

 or less similar to the pure breed" (Introd. Stud. Fish. 1880, 

 p. 631). This exceedingly interesting conclusion, unfortunately, 

 is unsupported by reference to the results of any experiments or 

 observations made by competent individuals, leaving one in doubt 

 as to whether it is an opinion founded upon conjecture or fact. 



From our very earliest authors on ichthyology down to the 

 present period, the existence of hybrid fishes has been insisted 

 upon ; and o£ late years artificial propagation has clearly proved 

 that such can occur; but it is open to grave doubt whether 

 among the Salmonidse they are as numerous in a wild state 

 as some authors would have us believe; while, so far as my 

 inquiries tend, the fertility of hybrids still remains to be proved *. 

 Experiments have been instituted to test this question of hybrids ; 

 and Professor liasch, in 1867, recorded the result of his investi- 

 gations. He found that the ova of the sea- and river-trout are 

 developed regularly whichever form were the parent, and the 

 offspring are fertile ; that, of the ova of the charr fertilized by 

 the milt of the trout, 30 to 40 per cent, are developed, but many 

 young fish perish after being hatched ; trout-ova fertilized by the 

 milt of the charr gave only 10 per cent, developed, and many 

 of the young were misshapen ; salmon-ova fertilized with trout- 

 * Professor Kasch refers to the ova of a hybrid between a trout and a charr. 



