NATURAL HISTORY. 



[Lesson VEL 



P. Yes, because there is a general con- 

 formity of type, and therefore it is difficult 



Fig. 10. 



to decide what characters are of greater or 

 lesser importance ; because there are not 

 those prominent distinguishing charac- 

 teristics that we find in the other classes of 

 vertebrate animals. 



81. T. Are there any orders of this class 

 possessing marked peculiarities ? 



P. Yes, there are six; 1, ACCIPITRES, 

 or birds of prey ; 2, INCESSORES, or perch- 

 ing birds; 3, SCANSORES, or climbing 

 birds ; 4, GALLING, or scratchers ; 5, 

 ORALLY, or stilt birds; 6, PALMIPEDES, 

 or web- footed birds. 



82. T. Give me an example of the first 

 order. 



P. The golden eagle, or condor vulture. 



83. T Give me examples of the second 

 and third orders. 



P. In the second order we find the 

 humming-birds, fly-catcher, thrush, jay, 



raven, sparrow, &c. ; and in the third order, 

 the cuckoos and macaws. 



84. T. Give some examples of the 

 fourth and fifth orders. 



P. The fourth contains such birds as 

 pigeons, pheasants, fowls, peacocks, \c. ; 

 and the fifth, the rail, snipe, heron, crane, 

 and ostrich. 



85. T. Give examples of the sixth 

 order 



P. Here we find gulls, penguins, ducks, 

 geese, swans, &c. 



86. T. Is there anything very peculiar 

 in the anatomical configur-ition of birds, 

 that assists naturalists in their classifica- 

 tion ? 



P. Yes ; the form of the sternal appa- 

 ratus, and the modifications ef the diges- 

 tive organs. 



87. T. Is there anything else ? 



P. Yes, many things; but especially 

 the modifications of the vocal organs. 



GENERAL QUESTIONS ON LESSON VI. 



1. What peculiarities have naturalists 

 paid attention to in the classification of 

 birds ? 



2. Is there any great difference in the 

 beaks or bills of birds ? 



3. Why do the bills of birds differ ? 



4. Is there any difference in the feet of 

 birds? If so, why ? 



5. Does the osseous, or bony structure 

 of birds, differ from that of mammalian*? 



6. Why have birds feathers ? 



7. Are birds warm, or cold-blooded 

 animals? 



8. How are the various orders of birds 

 distinguished? 



9. How many orders are there of the 

 class Aves? 



10. What additional peculiarities assist 

 the naturalist in the classification of birds I 



LESSON VII. 



WE have now to consider the third class of vertebrate animals the Reptiles. There 

 is this peculiarity in the class, that their form is more varied than that of any other. 

 As their blood is imperfectly aerated, they only maintain a low degree of animal heat, 



Fig. 10. a, foot of Egyptian neophron ; b, foot of nuthatch ; c, foot of thrush ; d, foot of solan gooM. 



