Lesson IV.] 



NATTRAL HISTORY. 



41 



cous animals, it is only two loner chords, 

 running longitudinally through the abdo- 

 men, and enlarged at intervals into small 

 knots, which are called ganglions Secondly, 

 the muscles cover the bones, which form 

 the framework of the body, and the impor- 

 tant organs are inclosed within a bony case 

 or framework. 



48. T. How can you assign the proper 

 place to an animal in the Cuvier: t 

 tern? 



P. Because every one of them must be 

 placed in one of the four great divisions . 

 and the peculiarities of the animal deter- 

 mine the naturalist whether it belongs to 

 the first, or the other three. 







*,. !. 



49. T. How can the naturalist know 

 where thr individti.il is to he classed, after 

 he has ilHrrmim-d that it belongs to the 

 first ml 



P. ! I'pose that I have a spe- 



eimen of a 



hat it does not belong to 

 the b - h'uhes ; and mint 



>',H that 



;st class 



of vertebrate animals. We have now to 





, or howliof monkry 



find out to which of the nine orders of 

 Mammalia it belongs ; and without running 

 through all the peculiarities of each. I 

 know that it should be placed in the 

 order, among the four-handed animals, or 

 qiindruiHtinu, which are divided into three 

 genera the monkeys, marmosets, and 

 lemurs. It therefore belongs to the mon- 

 keys. 



50. T. How do you know that t! 

 cimen you have does not belong to the 

 lemurs or marmo- 



P. Because these two genera present 

 such distinct peculiarities that it is impos- 

 sible to make a mistake. 



[The pupil should explain what these pecu- 

 liarity* are.] 



51. T. How is it that the vertebrate 

 animals have been subdivided into so many 

 parts, if they all agree in respect to their 

 general character;-' 



/'. Because, as I have explained before, 

 [ (Jm'-:ion -JliJ they diller in some impor- 

 tant particulars. 



52. T. Explain this more fully. 



P. If we examine the sub- kingdom 



ita, we shall find that tin 

 three distinct divisions of animal- 

 adapted for the earth, the air, and the 

 water. 



5-?. T. I thought that the vertebrate 

 animals were subdivided into four classes; 

 how is it that you only make three .' 



/' I do not make three classes. In 

 divisions; and, as those that are a 



.iion the earth are divided into 

 two Mammalia and llcptilia. tin ; 

 still four classes of animals ; viz. 1, Mam- 

 malia; 2, Aves; 3, Reptilia; 4, Pisces. 



64. T. Give me the reason that the 



rate animals are arranged thus. 

 P. The first group Mammalia, or ani- 

 mals that suckle tlieir young i- ranged 

 first, because the an n this 



class are superior in organization to the 

 other t!r are formed for an espe- 



cial purpose residence upon I' 

 while the liinls and fishes nave < 



: and although the 

 rirlly vpraUng. inhabit ther.irth. 



I'hiluoun. N 

 :H; they are also coU- bbodtd n \ 



66. T. What do you mean by 

 blooded animals I 



el 



