738 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



With a view to answering the above questions as far as possible satis- 

 factorily, I have made the following investigations : 



I. 



The food of trutta salar Siebold, (Sahno salar and hamatus Yal.,) 

 and trutta trutta Siebold (Fario argenteus Yal.) IN THE KIVER 

 Ehine. 



The fishes belonging to the genus Salmo occurring in the Ehine are, by 

 the fishermen, distinguished as "Salm," "Lachs," and " Lachsforelle." 

 The Lachsforelle has been described as Fario argenteus by Valenciennes, 1 

 and as Trutta trutta by Siebold. 2 But, respecting the proper ichthyological 

 definition of the species which are brought to market under the popular 

 name of "Salin" and "Lachs," the views of zoologists still differ con- 

 siderably. Cuvier was the first to distinguish two species, and Valen- 

 ciennes described them at length as Salmo salmo, le saumon commun, z 

 and Salmo hamatus, le becard.* lie was followed by Heckel and Kner, 5 

 Troschel, 6 and others ; while Agassiz considered the Salmo hamatus as the 

 old male of the Salmo salar, and recognized only this latter species. 

 The same view was -taken by Siebold, 1 Gunther, 6 and many others. 



Such a diversity of opinions seems surprising, as the question is about 

 such valuable and well-known fishes. It must, however, be remarked that 

 no other genus of fishes Las given the ichthyologists so much trouble as 

 the genus Salmo. Even such a thorough systematist as Gunther 9 says: 

 " There is no other group of fishes which offers so many difficulties to 

 the ichthyologist with regard to the distinction of the species, as well as 

 to certain points in their life-history, as this genus." 



Although a critical examination of these different views, properly 

 speaking, does not come within the reach of this treatise, and would 

 lead us too far, the nature of the question demands that I take my part 

 in this dispute. 



After the investigations which I have made in this matter, I agree 

 with Agassiz and Siebold; i. e., I recognize only one species, viz, the 

 Salmo salar. My reasons for this I will state in brief. 



Valenciennes mentions the following chief distinguishing marks be- 

 tween Salmo salar and Salmo hamatus : 



1. The Salmo hamatus has more pyloric cceca (appendices pyloricce) 

 than the Salmo salar. 10 



1 Valenciennes, Histoire naturelle des poissons, Paris, 1848, tome xxi, p. 294. 



2 Siebold, op. cit., p. 314. 



' J Valenciennes, op. cit., p. 169. 

 4 Valenciennes, op. cit., p. 212. 



6 Heckel and Kncr, Die Siisswasserfisclie der osterreicbiscben Monarcliie, Leipzig, 1858, 

 pp. 273 and 276. 



e Troschel, Handbuch der Zoologie, 7tb ed., 1871, p. 266. 



7 Siebold, op. cit., p. 293. 



8 Gunther, Catalogue of tbe fisbes in tbe Britisb Museum, London, 1866, vol. vi, p. 11. 

 » Gunther, op. cit., p. 3. 



' 5 Valenciennes, op. cit., pp. 176 and 217. 



