rectly ascertained of individual species, is it possible to arrive 

 at correct conclusions relating to any larger group of animals, 

 and to elucidate the great laws of animated nature. Much 

 has already been done in this direction, but very, very much 

 more remains to be accomplished. 



The very first step and the foundation of all subsequent 

 generalizations is the correct determination of the different 

 Jcinds, or species, of animals ; and this is by no means so 

 easy a task as might at first be supposed. Some species 

 approximate to others so closely as to require careful exami- 

 nation to distinguish them : others vary so much as to neces- 

 sitate the comparison of many specimens before all their points 

 of difference can be ascertained. Among large animals species 

 may generally be recognized without much difficulty ; but very 

 frequently, and particularly among minute objects, the closest 

 examination and comparison with descriptions and drawings 

 are necessary ; while often the assistance of students of the 

 particular tribe of objects must be sought as indispensable. 



Scarcely inferior in importance to science is the knowledge 

 of the range of species, to what extent, great or small, they 

 are distributed over earth or seas. Indeed Agassiz, one of the 

 greatest Naturalists of this or any other age, goes so far as to 

 assert that " every new fact relating to the geographical distri- 

 bution of well known species is as important to science as the 

 discovery of a new species. Could we only know the range 

 of a single animal as accurately as Alphonse de Candolle has 

 determined that of many species of plants, we might begin a 

 new era in Zoology. It is greatly to be regretted,- that in 

 most works containing the scientific results of explorations of 

 distant countries, only new species are described, when the 

 mere enumeration of those already known might have added 

 invaluable information respecting their geographical distribu- 

 tion. The carelessness with which some naturalists distinguish 

 species, merely because they are found in distant regions, 



