196 SALMONIA. [SEVENTH DAT. 



Such is the energy of these little animals, that they 

 Continue to find their way, in immense numbers, to 

 Loch Erne. The same thing happens at the Pall of 

 the Bann, and Loch Neagh is thus peopled by them ; 

 even the mighty Pall of Schaff hausen does not prevent 

 them from making their way to the Lake of 

 Constance, where I have seen many very large eels. 



PHYS. You have shown, that some eels come 

 from the sea, but I do not think the facts prove, 

 that all eels are derived from that source. 



HAL. Pardon me I have not concluded. There 

 are eels in the Lake of Bourget, which communicates 

 by a stream with the Ehine ; but there are none in 

 the Leman Lake, because the Ehone makes a 

 subterraneous fall below Geneva; and though small 

 eels can pass by moss, or mount rocks, they cannot 

 penetrate limestone, or move against a rapid 

 descending current of water, passing, as it were, 

 through a pipe. Again ; no eels mount the Danube 

 from the Black Sea; and there are none found in 

 the great extent of lakes, swamps, and rivers com- 

 municating with the Danube, though some of 

 these lakes and morasses are wonderfully fitted for 

 them, and though they are found abundantly in the 

 same countries, in lakes and rivers connected with 

 the ocean and the Mediterranean. Yet, when 

 brought into confined water in the Danube, they 



