752 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



In many cases, some outward cause may induce the fish to ascend the 

 Ehine long before they are able to spawn. I will give the following 

 observations on this point which I have made. 



On the bodies of the winter-salmon I frequently found wounds caused 

 by the teeth of other animals. These bites I found on different parts of 

 the body ; they were of different size, and most of them had healed 

 over. The fishermen of the Ehine are well acquainted with this fact, 

 and the Messrs. Bidder and Lisner, in Wesel, furnished me with the 

 interesting information that a rich salmon-year (with regard to winter- 

 salmon) might be expected if comparatively many fish appeared having 

 such wounds. It is but natural to draw certain conclusions from these 

 observations. Not only man but also other beings are eager for the 

 fine flesh of the winter-salmon. The greatest enemy of the salmon 

 are the seals (Phoca vitulina and annellata 1 ). These nimble robbers 

 pursue the salmon, 2 which seeks a place of refuge in the Ehine. If its 

 enemies increase in number and their attacks become more violent, the 

 winter-salmon in consequence appears in the Ehine more frequently, and 

 the above-mentioned observation would thereby be explained. Eegard- 

 ing the second question, " How long does the winter-salmon remain in 

 the Ehine," I think I can assert on the strength of my observations 

 that from September till May it only makes a temporary sojourn in the 

 Ehine. 3 and that it becomes permanent ouly from May. 4 



Of the temporarily barren salmon which occurs in the English rivers, 

 von dem Borne says (p. 338) that it remains in the river nearly a whole 

 year. This may be possible in the English rivers; but, as far as the 

 Ehine is regarded, I must deny it emphatically, for the simple reason 

 that the winter-salmon while in the Ehine eats next to nothing. The 

 fishermen say that it gets into the Ehine only by " losing its way." It is a 

 fact that near the mouth of the Ehine it is caught frequently all the 

 year round; near \v~esel quite frequently, but near Bonn only rarely, up 

 to May. As the growth of the eggs — as I have remarked above — becomes 

 considerable only from May, I believe that its sojourn in the Ehine 

 becomes settled only from that time. 



The results of the investigations which I have been able to make so far 

 regarding the salmonoids occurring in the Ehine are briefly the following : 

 In the Ehine, only two species are found, viz, Trutta salar and Trutta 

 trutta ; neither take any food while in the Ehine. Of Trutta salar, a 



1 See on this point Block, op. cit., p. 139. 



s This probably takes place chiefly in winter, because the seal is at that season 

 without any other food, and because the wiuter-salinon does not, like other fish, live 

 deep in the water, but rather near the surface. Thus, Mangold (quoted after Sicbold, 

 p. 309) says that the barren Trutta lacustris lives near the surface, while the fruitful 

 Grundforelle keeps near the bottom of the lake. 



5 The great strength of its muscles enables it to travel long distances in a very short 

 time. According to Cornelius, (p. 199,) it can swim twenty-three to thirty English 

 miles ; according to von dem Borne, (p. 338,) it swims about 1,500 feet in one minute. 



4 N. Loberg, Norges Fiskerier, Christiauia, 1864, p. 280, says of the Norwegian salmon 

 that they stay in the rivers all summer. 



