Distribution. 65 



markable, for the eharaeteristically American forms of 

 fishes are, generally speaking, rare or absent in the waters 

 of those sections. This fact was noticed by Louis Agassiz, 

 who called New England " a zoological island," on account 

 of its faunal peculiarities as compared with the rest of the 

 United States. Thus, of more than a hundred genera of 

 fresh-water fishes now known ^o occur in the waters east of 

 the Mississippi Eiver, only about one-fourth occur in New 

 England, and of these, all except a half-dozen genera are 

 represented by but a single species each; and not more 

 than thirty-five genera occur in the waters of the Pacific 

 slope. Almost any stream of any extent of the Ohio or 

 Mississippi basins will furnish double the number of genera 

 and species as the entire waters of either of the above- 

 named sections. Thus, as Dr. Jordan states, " In the 

 little White Elver, at Indianapolis, seventy species, repre- 

 senting forty-eight genera, are known to occur — twice as 

 many as inhabit all the rivers of New England." 



The distribution of the black bass does not seem to be 

 much affected by geological formations, climatic influences, 

 or the character of waters ; for although one or both species 

 may have been absent originally in certain localities, they 

 readily adapt themselves to the waters of these sections 

 when transplanted, and rapidly increase. 



Originally, both species were at home among the primor- 

 dial rocks of the eozoic period of Lake Champlain, north- 

 ern Wisconsin, and along the Appalachian chain in the 

 Carolinas and northern Georgia. They flourished amid 

 the paleozoic rocks of the Great Lake region and the Mis- 

 sissippi Valley, and in the coal measures of the Ohio, Illi- 

 nois, and Missouri Eiver basins; while in the marine 

 tertiary formations of the cenozoic period, along the At- 

 5 



