CHAPTER SECOND. 



GENERAL PROPERTIES OF ORGANIZED BODIES. 



SECTION I. 



OKGAISTIZED AXD UNORGANIZED BODIES. 



30. NATURAL HISTORY, in its broadest sense, embraces the 

 study of all the bodies which compose the crust of the earth, 

 or which are dispersed over its surface. 



31. These bodies may be divided into two great groups ; 

 inorganic bodies (minerals and rocks), and living or organic 

 bodies (vegetables and animals). These two groups have 

 nothing in common, save the universal properties of matter, 

 such as weight, colour, &c. They differ at the same time in 

 form, structure, composition, and mode of existence. 



32. The distinctive characteristic of inorganic bodies is 

 rest; while that of organic bodies is independent motion, 

 LIFE. The rock or the crystal, once formed, never change ; 

 their constituent parts or molecules invariably preserve the 

 position which they have once taken in respect to each 

 other. Organized bodies, on the contrary, are continually 

 in action. The sap circulates in the tree, the blood flows 

 through the animal, and in both there is, besides, the inces- 

 sant movement of growth, decomposition, and renovation. 



33. Their mode of formation is also entirely different. 

 Unorganized bodies are either simple, or made up of elements 

 unlike themselves ; and when a mineral is enlarged, it is 

 simply by the outward addition of particles constituted like 

 itself. Organized bodies are not formed in this manner. 

 They always, and necessarily, are derived from beings similar 

 to themselves ; and once formed, they always increase inter- 

 stitially by the successive assimilation of new particles derived 

 from various sources. 



34. Finally, organized bodies are limited in their dura- 

 tion. Animals and plants are constantly losing some of their 

 parts by decomposition during life, which at length cease to 



