204 HUMAN BIOLOGY 



of the cells, whether the overgrowth is benign or mahgnant. 

 In the latter case he is dealing with a cancer and he must 

 remove in addition to the mass itself a large amount of 

 the surrounding tissue to prevent recurrences if at all 

 possible. Cytological studies on certain parts of the pancreas, 

 termed the islands of Langerhans, in human diabetes and 

 particularly in the same disease experimentally produced 

 in animals led directly to the recent discovery of insulin, a 

 substance which has given a new lease of life and usefulness 

 to thousands of sufferers whose future otherwise would have 

 been hopeless. In fact nothing further need be said in favor 

 of well-regulated animal experimentation. Persons who 

 really desire to influence human reactions for the better 

 both in health and disease will readily understand how 

 important it is not to study the body as a whole vaguely, 

 but rather to base the investigations upon the behavior 

 of the constituent vital units of which the body is built, 

 in other words to get down to fundamentals. 



REFERENCES 



CowDRY, E. V. (Editor) 1924. General Cytology. Univ. Chicago Press. A 



cooperative book written by 13 authors. General principles underlying 

 cellular structure and function. 

 CowDRY, E. V. (Editor) 1928. Special Cytology. N. Y., Hoeber. A cooperative 



book written by 35 authors. Special activities of the cell in health and 



disease. 

 Sharp, G. L. 1927 Introduction to Cytology. Ed. 2., N. Y. McGraw Hill. 



Written chiefly from the. botanical point of view. 

 Wilson, E. B. 1925. The Cell in Development and Inheritance. Ed. 3., N. Y., 



Macmillan. 



