50 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



evidence which, when combined with what is known regarding the ap- 

 pearance of the eggs and young, leaves Httle doubt as to the ultimate 

 destination of the autumnal migration. These eels, there is every 

 reason to believe, have approached nearly to sexual maturity, and 

 after leaving fresh water move out quite directly toward very deep 

 water of the ocean, where they deposit their eggs. In the Baltic 

 Sea the migrating eels are caught in considerable numbers; in fact, 

 a considerable fishery by means of eel traps exists in these waters. 

 These traps, however, only catch eels when set in a certain direction ; 

 that is, when the opening of the traps is in the path of the migrating 

 fish. The experience of the practical fishermen has shown that the 

 eels move parallel to the coast from the East Baltic in a westerly 

 direction, and thence outward into the North Sea. These observa- 

 tions of the fishermen were confirmed by the experiment of tagging 

 the eels w'ith a silver label. Interesting facts were revealed by this 

 method. Every tagged eel which was re-captured had moved 

 toward the open sea, and in no cases was there shown any movement 

 in the reverse direction. The eels usually kept fairly close to the 

 coast, though in isolated cases some had wandered away and crossed 

 considerable depths. 



These observations are the last glimpses of eels that we have after 

 they leave the coast; so that, in the absence of direct data relating to 

 their later fate, we have to rely upon indirect evidence only, though 

 fortunately this is of such a nature as to leave no doubt regarding 

 the most important bearing of the facts. The large silver eels of 

 the autumn migrations are never seen again; yet later, out in the open 

 ocean where the water is very deep, 500 fathoms or more, there are 

 found the eggs and young larvae of the eel. These were found l)y 

 the Danish investigators all along the 500-fathom line, from the 

 Faroes to the northwest coast of Spain, and especially to the south- 

 west of Ireland. This region lies along the steep slope where the 

 north European plateau shelves rapidly off toward the gxeat Atlantic 

 depths. Eggs and larvse of the conger eel have been taken by the 

 United States Fish Commission on the tile-fish grounds which are 



