608 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



if the rivers are not too low. These fish have a reddish flesh, and weigh 

 from 12£ to 22£ pounds avoirdupois, and are known by the name of 

 " rose-salmon." 



These two classes of salmon are not ready to spawn when they arrive 

 in Bohemia, and require a considerable stay in fresh water to develop 

 their ova and milt. 



The third ascent begins during the first half of September, and lasts 

 till the end of November, in mild winters even till December. These 

 fish are mostly weak, weighing from 3 to 10 and sometimes 15 pounds 

 avoirdupois. Their flesh is of a pale color, and for this reason they are 

 usually called " silver-salmon." They are fully prepared to spawn im- 

 mediately on their arrival. The process commences in the mountain 

 streams which flow into the Elbe, the Wild Adler, the Moldau, the 

 Wotawa, and other small rivers. 



Among the chief causes of the decrease of salmon in Bohemia, which 

 formerly had large numbers of this fish, Dr. Fric places the high weirs 

 built across the rivers which the salmon cannot leap over, especially at 

 low- water ; the stationary fishing apparatus, which frequently span the 

 whole breadth of a river, especially near the weirs ; the unprotected 

 •condition of the spawning places ; the spearing of the fish with tridents 

 during the spawning season, when they are half .stupefied ; and, finally, 

 the want of well-protected hatching places, where the young fish can be 

 safe from their numerous enemies on laud and in the water. 



No fisheries require proper legislation as much as those for salmon. 

 On account of the large schools which ascend the rivers, the whole 

 stream should be subjected to uniform laws and a uniform system of 

 fishing, which only becomes possible by international treaties. 



The sea-trout (Trutta trutta) does not reach the size of the common 

 salmon, but is otherwise very much like it so far as its propagation and 

 the localities which it seeks are concerned. Like the salmon, it 

 ascends to the headwaters of the Oder and the Vistula, but does not go 

 as far in the Elbe. 



The lake-trout, lake-salmon, or salmon-trout, (Trutta lacustris,) are 

 found exclusively in the fresh-water lakes of the alpine regions of Cen- 

 tral Europe, from which, during the spawning season, they go up or 

 down the stream in the rivers or brooks connected with them. Only 

 in lakes whose tributaries do not have much water, or mostly consist of 

 rapids, they are obliged to seek flat gravelly places near the shores 

 to spawn. Most of them spend the greater portion of their lives in 

 inaccessible depths, and only ascend to the surface under peculiar 

 conditions of temperature, in order to catch small fish and insects 

 During the spawning season, they come to the surface in larger numbers, 

 their excursions in the brooks and rivers sometimes extend to a great 

 distance, sometimes only to a few miles from their dwelling-place. 



Those which ascend the brooks and rivers are caught with bow 

 and stationary nets, which are placed near the mouth of the rivers or 



