14 CLASS-BOOK OF ZOOLOGY. 



ter of which they are formed, is subject to the same laws 

 which govern inorganic bodies. 



§ 6. All organic bodies derive their sustenance from in- 

 organic matter ; that is, their nourishment either is or be- 

 comes reduced to this state, before it can contribute to 

 their support. 



§ 7. Plants derive their nourishment principally frors 

 the soil of the earth ; animals, from vegetable, mineral, 

 and animal substances. 



§ 8. Animals, although in many respects dissimilar to 

 plants, are like them in certain particulars, such as 

 nourishment, circulation of fluids, respiration, and prop- 

 agation. 



§ 9. The nourishment of plants is derived by means of 

 absorbing vessels, dispersed through the leaves and root- 

 fibres ; and when this nourishment is withdrawn, the plant 

 ceases to live. 



§ 10. All plants have & fluid called sap, which circulates 

 through them, in many respects like blood through ani- 

 mals. 



§11. Respiration or breathing is performed in plants 

 through the leaves, which receive a certain portion of 

 the atmosphere. Leaves are compared to the lungs of 

 animals. 



\ 12. Plants are provided with organs of reproduction, 

 and invariably produce, like animals, objects of their own 

 species. The seeds of plants may therefore be regarded 

 as vegetable eggs, from which objects similar to the parent 

 plants are reproduced. 



QUESTIONS ON SECT. I. 



§ 1. What is Natural History, and into what departments is it divided ? 

 § 2. Upon what differences are those divisions based ? Explain it. 

 § 3. What are organic and inorganic bodies? 



§ 4. How are organic bodies further distinguished from inorganic sub- 

 stances ? 



§ 5. What is an essential condition of organic bodies? 

 ■ § 6. From what do organic bodies derive their sustenance ? 

 § 7. How do plants and animals derive their nourishment? 

 § 8. In what respects are animals like plants V 

 § 9. By what means is the nourishment of plants derived? 

 § 11). What do you know of the sap of plants? 

 1 11. How is their respiration performed? 

 § 1:2. Ilow is the propagation of plants similar to that of animals? 



