LIFE AND PROTOPJASM I37 



hyposmotic solution. In plants, the cell walls prevent the cells from 

 swelling up, while in animals there are special ways of ridding the 

 body cells of excess water. 



SUGGESTED READINGS 



Calkins, G. N., Biology of the Protozoa, Lea and Febiger, 192(). Cli. L 



A full and scientific approach to the cell. 

 Plunkett, C. R., Outlines of Modern Biology, Henry Holt & Co., 1930. Chs. 



I and IV. 



A chemical and physical approach to the study of protoplasm. 

 Singer, C. J., The Story of Limng Things, Harper & Bros., 193 L Chs. IV 



and IX. 



An interesting history of biology. Chapters IV and IX deal with the 



historical approach to the cell theory. 

 Wilson, E. B., The Cell in Development and Heredity, The Macmillan Co., 



1925. 



A classic authority on the ceU. 



