LEAVES I I 5 



Some leaves on the branch are larger than others 

 because in the struggle for light and air they have 

 had a better chance than the others or they have 

 had more of the food which has come up from the 

 root. 



Some of the leaves have developed longer stems 

 than others in their effort to reach out after light 

 and air. 



Most leaves have the little mouths through which 

 air is taken in and water and oxygen given out on 

 the rough side, and that side is turned down toward 

 the earth probably so that rain and dust will not 

 choke the little pores. 



The leaves of the lower branches tend to spread 

 out in a broad, flat plane because in the effort to get 

 light no leaf will grow directly under and in the 

 shadow of another, while on those branches which 

 grow straight up from the top of the tree the leaves 

 can get light from all sides and so arrange them- 

 selves around the stem. 



Is it of any value to the plant grower to know 

 these facts about leaves? It is, for knowing these 

 things he can better understand the necessity of 

 caring for the leaves of his growing plants to see 

 that their work is not interfered with. 



HOW THE WORK OF SOME LEAVES IS INTERFERED 

 WITH 



Many people who grow house plants have trouble 

 in keeping them well clothed with leaves, for in- 



