740 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



"Salmj liamatus? of which the one has only two teeth in the vomer, and 

 the other none at all. A younger specimen, marked likewise Salmo 

 liamatus, has four teeth in two rows, one behind the other; while another 

 somewhat younger specimen, marked Salmo solar, has only two vomerine 

 teeth. 



It is not necessary to go into further details, as Siebold has explained 

 this whole matter sufficiently, and has satisfactorily proved Valenciennes' s 

 errors. 



To 3 : "In none of our native fish is there such variety of color, ac- 

 cording to the different influences of food, water, light, and temperature, 

 as in the toothed salmons." 1 Giinther likewise lays special stress on 

 this change of color in the Salmo solar. Scientifically, we are scarcely 

 justified in distinguishing two different species merely on account of 

 this difference in color, when the other distinguishing marks cannot be 

 sustained. 2 



To 4 : Block has shown how much the color and quality of the flesh 

 varies in one and the same species of salmonoids. 3 Siebold likewise, in 

 several places, 4 has directed attention to this peculiar variation. It must 

 also be borne in mind that in all species of animals the flesh of old 

 ones 5 which have propagated for many years has become of au inferior 

 quality. It is well known that the Bhine salmon is more savory than 

 that of the Oder, the Weser, and the Vistula j but nobody ever enter- 

 tained the idea that they were different species. 



To 5 : The projecting hook of the lower jaw in some specimens is so 

 peculiar, that certain ichthyologists were thereby induced to distinguish a 

 separate species — Salmo hamatus, i. e., the hooked salmon. But Block 

 had already proved that these hooks occur only in old male fish. Agassiz, 

 all the modern English ichthyologists, 6 Siebold, 7 Scklegel, 8 and others are 

 of the same opinion. The observations which I made on this point, and 

 the information which I gathered from experienced fishermen, led to the 

 same result : the hook is only found in male fishes, and — I must empha- 

 size it — only in such as have milt nearly ready for impregnation. I 

 have, by observing a large number of specimens, convinced myself that 

 this hook gradually forms in the male fish as it is growing old and the 

 milt is getting mature ; fishermen, by this mark, distinguish even the 

 young male from the young female. If, therefore, Valenciennes (p. 213) 



1 Siebold, op. cit., p. 276. 



2 1 may as well remark here that, according to my observations, this difference of 

 color, which Valenciennes considered as a distinguishing mark of the species, can only 

 serve as such for distinguishing the fruitful specimens of the Salmo salar from tempo- 

 rarily barren ones. 



3 Block, Oekonomische Naturgeschichte der Fische, Berlin, 1782, p. 139. 



* Siebold, op. cit., pp. 276, 299, &c. 



6 It will bo presently seen why I only speak of old animals. 



6 Valenciennes, op. cit., p. 22.4. 



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



8 Schlegel, Do Dieren van Nederlandj Visschen, p. 127. 



