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that the talent for analysis of descriptive naturalists 

 has, above all, been directed. The illustrious 

 founder of binominal nomenclature, Charles Lin- 

 naeus, created species on a very wide basis, which 

 was, no doubt, even too wide in many cases. The 

 Linnsean species has often and rightly had to be 

 subdivided, after a more minute and precise study 

 of its morphological characters. But, carrying to 

 the extreme this necessary distinction in the forms 

 realized by nature, a certain school of conchologists, 

 represented in France by Bourguigniat and Locard, 

 have pushed the separation of species, as it were, to 

 the point of pulverization. Thus in the single 

 genus of our fresh-water mussels or Unios, Locard 

 has described, for the fauna alone of the rivers and 

 lakes of France, two hundred and twenty different 

 species which the author distinguishes by charac- 

 teristics drawn from the general outline of the 

 shell, from its length or its obliquity, and the more 

 or less eccentric position of the tip, etc. It must be 

 said, however, in defence of this patient and able 

 observer-, that these manifold species have been 

 grouped into twenty-six sections, each having as 

 its principal type a species easy to recognize, and 

 admitted by the majority of naturalists. Under 

 these conditions, it is permissible for every one to 

 admit or pass over forms and sub-species, and to keep 

 to the principal sections recognized by the author. 

 But this precaution has not always been observed 

 by the partisans of the same school, and the multi- 

 plication of specific names has become in certain 

 hands so overdone that there are no longer species, 

 but only individuals. 



