2 A TEXT-BOOK OP BOTANY 



thought that plants are alive and at work is important 

 because this fact gives meaning to their forms and structures 

 and positions. For example, the structure of a leaf has no 

 meaning until it is discovered how its structure enables the 

 leaf to do its work. 



3. The plant body. Every plant has a body, which may 

 be alike throughout or may be made up of a number of 

 different parts. If one part of the body does not differ from 

 another, the plant is said to be simple; but the most con- 

 spicuous plants, those with which every one is best ac- 

 quainted, are made up of dissimilar parts, such as root, 

 stem, and leaf, and such plants are said to be complex. 

 Simple and complex plants do the same work; but in the 

 simple plant the whole body does every kind of work, while 

 in the complex plant different kinds of work are done by 

 different regions of the body, and these regions come to look 

 unlike when different shapes are better suited to different 

 kinds of work, as in the case of leaf and root. 



4. Plant organs. The different regions of the plant 

 body thus set apart for special purposes are called organs; 

 and complex plants have several kinds of organs, just as the 

 human body has hands, feet, eyes, etc. The advantage of 

 this to the plant becomes plain by using the common illus- 

 tration of the difference between a tribe of savages and a 

 civilized community. The savages all do the same things, 

 and each savage does everything. In the civilized com- 

 munity some of the members are farmers, others bakers, 

 others tailors, others butchers, etc. This is known as 

 "division of labor," and one great advantage it has is that 

 every kind of work is better done. Several kinds of organs 

 in a plant mean to the plant just what division of labor 

 means to the community; it results in better work and more 

 work. 



5. Plant work. Although many different kinds of work 

 are being carried on by plants, all the work may be put 



