THE SALMON, THE TROUT, AND THE SHAD. 753 



fruitful variety (spawn-salmon) and a temporarily barren one (winter- 

 salmon 1 ) exist. The former ascends the Rhine for the purpose of spawn- 

 ing from September till November ; the latter appears sporadically, and 

 for a brief season from September till May, and probably remains in the 

 Ehine for a longer time, or permanently from May till the spawning- 

 season. These results answer — at least as far as the grown salmons 

 are concerned — the question, Is it injurious to catch "Eiimpchen" be- 

 cause thereby valuable fish are deprived of their food. As these 

 salmons do not eat anything while in the Ehine, the catching of the 

 " Etimpchen" cannot possibly deprive them of any food. The case will 

 be somewhat different with the young " Salnilinge," (salmon one to three 

 years old, which have never yet made the journey to the sea.) Prof, de 

 La Valette St. George, who is thoroughly acquainted with our native fishes, 

 and occupies himself with artificial pisciculture, has informed me that 

 he feeds his u Salmlinge" (specimens of Trutta trutta and Trutta lacus- 

 tris measuring on an average. 8 inches in length) chiefly on "Eiimp- 

 chen," and that they devour them eagerly. As this in all probability 

 will also be the case in the Ehine, and as the young Trutta trutta cer- 

 tainly does not differ from the Trutta salar with regard to the taking of 

 food, the catching of " Eiimpchen" will deprive these young salmon of 

 a considerable amount of food. 2 



I shall secondly examine the question whether the catching of "Etiuip- 

 chen" deprives the trout (Trutta fario) to any extent of their food. 



II. 



The food of Trutta fario. 



Next to the two above-mentioned species, the trout 3 is with us the most 

 common salmonoid, and is highly esteemed on account of the delicate 

 flavor of its flesh. It prefers small, rapidly-flowing, clear waters, and is 

 therefore chiefly caught in small rivers and mountain-streams — the 

 Ahr, Sieg, Eoer, Wupper, Wied, and Anbach near Neuwied, and the 

 Kyll near Gerolstein. But as the "Eiimpchen" are likewise caught in 

 these very waters, it is of special importance to ascertain whether the 

 catching of the " Eiimpchen" deprives the trout of food. 



The first material for my investigations I obtained November 25, 1873, 

 from Mr. Brenner in Bonn. 4 Among twenty-two fishes, I found four- 



1 This must be understood in this manner : that of those salmon which return to the 

 sea from the Rhine after having done spawning, quite a number remain barren the 

 nest year, as probably the too rich food and the rapid accumulation of fat prevent 

 the development of the sexual organs. 



* I must, however, remark here that these young salmon go into the sea at a very 

 early age— according to Siebold (p. 2W) in their second year, when they are about 4 

 inches long ; according to the recent observations of English naturalists, in their third 

 year, when they are about 8 inchea long — and that therefore the existence of the 

 Riimpchen is no matter of life and death with them. 



3 As to the character of this kind, see Siebold, op. cit., and Valenciennes, op. cit., p. 320. 



4 To this gentleman I am also indebted for the material for all my later investiga- 

 tions; also those made on Alausa vulgaris. 



48 F 



