PLANTS 



317 



tissue, bony tissue, and the skin covering the bodies of 

 animals. 



Organs. Each part of a plant or animal which has 

 a special work to do is called an organ. Tissues are com- 

 bined in various ways to produce organs such as leaves; 

 roots, and veins in plants and the many organs of the 

 human body. 



Multiplication of Cells. When a cell reaches its max- 

 imum size, it may divide into two cells, each containing 



FIG. 272. Showing the Method of Cell Division. 

 Note the division of the nucleus. 



half of the nucleus and the protoplasm of the old cell 

 (Figure 272) . These new cells may grow to maximum size 

 and again divide. The multiplication of cells in this way 

 is the usual process of growth in plants and animals. 



Flowers. Flowers grow on the higher forms of plants 

 at a comparatively mature stage in their development 

 (Figure 273). The flower is grown for the purpose of 

 producing other similar plants. In order to understand 



