Birds. 1 07 



American birds to be contained in a book and arranged without 

 regard to classification, or again suppose our amateur collector pays 

 no attention to classification if present ; he will either search at 

 random amongst seven hundred and sixty eight descriptions, or 

 read over perhaps the greater number of them before finding his 

 bird. 



What, on the contrary, is the method of one who knows the 

 uses of classification. 



Being a North American bird, it must belong to one of the 

 seventeen "orders," having traced it (by reading the seventeen 

 descriptions or less) to the OxAtx Passeres or Perchers, he finds that 

 there are twenty " families" to which it may belong; their descrip- 

 tions having told him it is a member of the family '"Turdidas " or 

 Thrushes, he must now trace it to its proper "genus" through 

 seven descriptions. The genus Alcrula describing it correctly, 

 there remain three descriptions only to read, that being the number 

 of North American species in the genus. 



To recapitulate, we have traced our specimen through 



17 Orders to Passeres, 



20 Families of Passeres to Turdida^, 

 7 Genera of Turdidce to Merula, 

 3 Species of Vlerula to migratoria. 



47 descriptions in all, as contrasted with 768 had we no classi- 

 fication to depend upon. The name of our bird, then is a 

 compound of its generic and specific names, viz: 



Merula migratoria. 



Now, supposing our collector to have sufficient knowledge of 

 structure aud classification to refer his bird at once to its proper 

 "family" or "genus," his labor of identification is still more di- 

 minished. 



Some of the more important structural and physiological 

 peculiarities of Birds, Mammals and Reptiles are contrasted in the 

 following table. 



