CHAPTER X 



SUGGESTIONS FOR FURTHER STUDY 



Root and Stem Flower, Fruit, and Seed The Web of Life once 

 more Systematic Botany Morphology of Organs and Tissues 

 Evolution. 



Root and Stem. The general idea of the function 

 and structure of the leaf which we have now obtained, 

 obviously prepares us to ask questions as to the stem and 

 root. How does the leaf get its water of transpiration, its 

 salts of assimilation? And as these have obviously to be 

 absorbed before they can be carried up to the leaf, it may 

 be literally as well as metaphorically most profitable to 

 begin " at the root of the matter." Let us watch then the 

 growth of rootlets in germinating barley, in a hyacinth and 

 a potato, each in a hyacinth glass and the like. Let us 

 carefully wash away the soil from a well-grown pot-plant, to 

 get an idea of the enormous development of the root-system, 

 while the attachment of the fine root-hairs to the particles of 

 soil may be readily studied under the microscope from 

 a gently washed seedling of grass. Thus questions will 

 accumulate: How do these root-hairs absorb, and what? 

 What elements are essential? Or again, in a different order 

 of ideas, How do roots grow? The former is a matter for 

 physical and chemical experiment, the latter for observa- 

 190 



