Fish Migration 197 



olden times the sudden appearance of 

 eels in lakes and ponds far inland led 

 to the belief that they were generated 

 from horsehair soaked in water. Not 

 until comparatively recently was the 

 mystery of the eel's origin ascertained, 

 when Schmidt, a Norwegian investigator, 

 tracked the fish to its breeding ground in 

 mid-Atlantic. It is now known that the 

 European and also the American eels 

 share a joint breeding ground off the 

 Bahamas. The eggs are probably laid 

 on the sea floor, but the actual period of 

 incubation is unknown. Once hatched, 

 the young, which are leaf-like and trans- 

 parent and measure only a few milli- 

 metres in length, commence to forge 

 their way either to the shores of Europe 

 or America according to the species. The 

 journey to Europe takes about three 

 years, during which time the young rise 

 higher and higher in the water and as 

 they progress undergo various changes, 



