302 AMERICAN GAME. 



fish in different streams, even of the same region and 

 neighborhood, and flowing over soils apparently identi- 

 cal, to such an extent, that the casual observer not 

 unnaturally believes them to be distinct varieties, if not 

 species, and can be with difficulty convinced, on the im- 

 mutable evidences of structural sameness. 



This fact has led, in a great measure, to the compli- 

 cating and confounding the science of Natural History, 

 by the undue multiplication of names, species, and 

 genera, where no specific differences exist ; rendering 

 the science infinitely difficult to the beginner, and 

 causing the unlearned to undervalue the lore of the na- 

 turalist, and to deny the reality of all scientific distinc- 

 tions whatsoever. 



On differences of structure, such as the situation and 

 texture of the fins, the number of spines or soft rays in 

 each, the form of the gill covers, the character and 

 position of the teeth, perfect reliance may be placed, as 

 indicating unchangeable specific characteristics, by ob- 

 servation, of which the educated naturalist will name at 

 a glance the species, genus and sub-genus of any fish, 

 unseen before ; and will unerringly determine his habits, 

 his food, and in some degree his habitation. 



Thus of the Per cold family we distinguish the sub- 

 genera Perca, perch proper, from Gristes and Centrar- 

 chus, to which are referred the types black basse of the 

 lakes, and the little rock basse of the St. Lawrence 

 basin, by the fact that the Percca have one spine to the 



