THE LIFE OF A PLANT 



267 



by the removal of fertile soil and the formation of deep gullies. 

 (LABORATORY MANUAL, Exercise XXV.) 



299. Stems and their Functions. Stems bear the leaves 

 and hold them out in the most advantageous positions for 

 receiving light and air. They also serve as pathways for 



FIG. 141. SIMPLE AND .COMPOUND LEAVES 



1. Which compound leaf does A resemble? 2. What would make the 

 resemblance closer? 3. Compare another compound leaf with one of 

 the simple ones. 4. State some resemblances in veining between one of 

 the simple leaves and a compound leaf. 



transmitting liquids between the roots and the leaves. In 

 a very young plant, the stem depends largely upon water in its 

 cells to keep it stiff. In order that stems may be able to stand 

 upright and bear the weight of branches and leaves, they 

 are strengthened, as they grow, by many tough fibers. We 

 are all familiar with such fibers in the ''strings" of celery. 



