LESSONS WITH PLANTS 



i°3 



Plant Organs 



The principal organs of a higher plant should be stiidied 

 in order that children may get a general knowledge of the 

 structure and functions of a plant, and that they may know 

 how it lives. Only the gross structure need be studied 

 in nature-study, but attention should 

 not be confined to structure simply; the 

 adaptations and the functions of the 

 structure should also be taught. 



The root is the organ of absorption 

 and anchors the plant firmly in the soil. 

 The little root hairs that may be seen 

 on seedlings germinated on a blotter 

 are the essential organs in absorbing | 

 the soluble minerals and the water and 

 organic matter from the soil. These 

 root hairs should be examined with a 

 microscope. They are seen then to be 

 prolongations of the epidermal cells of 

 the root. They are very delicate, and 

 are torn off when a plant is pulled up 

 from the ground and hence not seen. 



Let the children dig up carefully different plants and note 

 the extent of the root growth, the shape of the roots, and 

 their branching. In a grain field pull up a hill of grain and 

 note the root extent. Then dig a hole or trench and wash 

 away the earth from the roots, exposing them carefully. 

 The root extent is then found to be surprisingly great, ex- 

 tending to a depth of several feet instead of only five or six 

 inches, as simply pulling up the plant would seem to in- 



FlG. 109. Germinating Corn. 



