QUESTIONS. 323 



trunk results from the annual development of the alburnum.-' What 

 is said of the formation of bark ? 



What, then, is the principal seat of the growth and nutrition of 

 plants ? What important difference between plants and animals, in 

 respect to their growth ? Are the processes through which the fluids 

 of plants pass perfectly understood ? What are some of the vege- 

 table principles that are mentioned as found in plants? Is it easy or 

 difficult to examine minutely the structure and organization of vegeta- 

 bles ? (P. 15.) What general principle in regard to the growth of 

 plants results from the preceding statement? Is there an important 

 distinction in this respect between plants and animals ? What distinc- 

 tion between plants and animals, in respect to absorption^ is stated in 

 the note ? 



CHAPTER III. 

 SECTION I. 



GENERAL CLASSIFICATION OF ANIMALS. 



(P. 15.) What is the object of a classification of the animal king- 

 dom ? On what is such a classification grounded ? Who was the 

 author of that system which is generally received by naturalists ? 

 What are the characteristics of the first grand division, in which all 

 animals are arranged ? (P. 17.) Wkat are the characteristics of the 

 second division ? What difference in the blood of these two classes ? 



Describe some of the principal bones and general structure of the 

 Vertebral Animals. Describe the structure of the Invertebral Animals. 

 Mention the examples that are given of animals belonging to these two 

 classes. 



How are the vertebral animals subdivided ? Name the examples of 

 warm-blooded animals j the examples of the cold-blooded. 



How are the warm-blooded animals subdivided ? Describe the 

 Mammalia or Mammiferous animals, and name the examples. Describe 

 the other class, and name the examples. 



Into what classes are the cold-blooded vertebral animals divided? 

 Describe Reptiles, and give the examples. How do Fishes differ from 

 them ? Are Whales fishes ? Why ? 



(P. 18.) Are the vertebral or invertebral animals capable of the most 

 accurate classification ? Why ? Into how many classes are the inver- 

 tebral animals divided ? Name them in their order. 



Into how many grand divisions, then, and how many classes, is the 

 whole animal kingdom divided ? 



