28 CLASSIFICATION. 



deprived of the organs of flight, and possessing a slow and 

 embarrassed gait, are condemned never to leave the rock on 

 which they were born. These birds exercise their patience in 

 awaiting for prey that is brought to them by the rolling in of the 

 waves ; and it is only when it escapes them, and they become 

 hard pressed, that they venture into shallow depths in pursuit of it. 



15. Birds also differ very much from each other in their diet 

 or food ; some seek living prey only, and feed exclusively on 

 the produce of their hunting or fishing ; sometimes they catch 

 other birds of prey and force them to disgorge the food which 

 they were about to eat. There are others which, with appetites 

 not less carneous, but wanting in the strong arms and courage of 

 the first, only prey upon dead bodies. Others live exclusively 

 on worms or insects, and others again, eat nothing but grains. 



Of the Classification of Birds. 



16. Birds differ much less from each other than the different 

 mammals ; except some modification in the plumage, in the 

 general form of the body, in the disposition of the beak, and in 

 the conformation of the feet, they resemble each other very much ; 

 hence, it is very difficult io subdivide the class which they form. 



17. The number of species of birds known by naturalists is 

 about five thousand. Their classification, like that of mammals, 

 is foimded chiefly upon the modifications that are remarked in 

 the organs of mastication and prehension, or of locomotion, that 

 is, the beak and feet. 



18. According to these characters they are divided into six 

 Orders, namely ; Rapaces, or Birds of Prey ; Passerinae, or 

 Migratory Birds; Scansorise, or Climbing Birds; Gallinaceae; 

 Grallatorice, or Waders; and Palmipedes, or Swimming Birds. 



19. The principal characters by which these groups are dis- 

 tmguished from each other may be seen in the following table. 



15. Upon what substances do birds feed ? 



16. What renders it difficult to sub-divide the class of birds into 

 genera, &:c.? 



17. Upon what is the classification of birds founded? 



18. Into how many orders is the class of birds divided ? What are the 

 names of these orders ? 



19. {Answered by the table.) What orders compose the division of ter- 

 res'irial birds ? What are the disiinguishing characters of the Accipitres or 

 Rapaces ? What are the distinguishing marks of the Passerinse ? By what 

 means are the Scansoriae distinguished from the Passerinae? What are the 

 distinguishing cliaracters of the Gallinaceae ? What orders compose the 

 division of Aquatic birds ? How are the Gral'atoriae distinguished ? How 

 are the Palmipedes recognised ? 



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