746 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



not only did they not grow larger, remaining always the same size, but 

 also that they did not increase at all in number." 



Siebold has therefore come nearest the truth regarding the salmonoids 

 found in the Rhine, (Trutta salar and Trutta trutta,) when he says that 

 the salmon just before and after their spawning-season do not eat any- 

 thing for weeks. I even go a little further, and maintain that these 

 salmonoids do not eat at all as soon as they have entered the Rhine 

 from the ocean. 1 



The circumstance that, as I mentioned above, I found remnants of 

 food in the stomachs of three winter-salmon is not against, but rather 

 in favor, of my assertion. These three salmon were caught below Wesel, 

 therefore comparatively near the mouth of the Rhine. The food whose 

 few undigested remnants I found might therefore have beeu taken in 

 the ocean, or when the fish had not yet lived in fresh water for any 

 length of time, 2 and the desire for food had not yet become quite extinct. 

 The best proof of it is the fact that nothing was found in the stomachs 

 of those salmon which had been caught farther up the Rhine. This 

 likewise explains, in a very simple manner, the above-mentioned obser- 

 vation of the fishermen, that the stomachs of those salmon which are 

 caught in Holland near the mouth of the Rhine occasionally contain 

 parts of fish. 



The result of this whole investigation is therefore the astonishing fact, 

 that fish which stay in the Rhine a long time, and move about a great 

 deal and in a very vigorous manner, 3 take no food at all. 



Such a very astonishing fact might well awaken the belief among the 

 common people that the salmon digests everything it eats in three min- 

 utes (!), although this is a physiological impossibility. 4 I myself for a 

 moment* entertained the thought that the salmon might be able to 

 digest food taken after it had been caught, as it is frequently kept alive 

 in the fish- tanks for some time. But the fact that most salmon are 

 killed by the fishermen immediately after they are caught by being 



1 It certainly does not follow directly from my investigations that they do not eat 

 anything at all in fresh water; but it is very probable that the facts are the same in 

 the Oder, Elbe, Weser, Vistula, and other rivers frequented by the salmon. (Of the 

 English rivers, I shall speak below.) 



2 This would apply to those two specimens iu whose stomachs I found remnants of 

 insects, as no insects live in the ocean. 



3 See, on this point, Siebold, op. cit., p. 297 ; Valenciennes, op. cit., pp. 194, 200, &c. 



4 James G. Bertram (The Harvest of the Sea, Loudon, 1365) says "that one gentle- 

 man who writes on this subject accounts for the emptiness of the stomach by asserting 

 that the salmon vomits at the moment of beiug taken " (p. 192). Independently of 

 the fact that the fishermen know nothing of this strange act of vomiting, the salmon 

 could not well empty its intestines in this manner But remnants of food are found 

 neither in the intestines nor in the stomach. Bertram, whose book I unfortunately only 

 got after I had finished my treatise, confesses that hundreds of fish had been exam- 

 ined, and that but rarely traces of food had been found. He likewise confesses that 

 the salmon does not grow in fresh water, and still ho asserts that it takes food when in 

 fresh water. A recent publication will oblige me to refer once more to this point. 



