300 



FOUNDATIONS OF BIOLOGY 



shots from the bull's-eye in a shooting match. Therefore the 

 variations with respect to a given character very closely ap- 



Pure Line 



FIG. 153. Diagram to illustrate a population of beans and its five compo- 

 nent pure lines. The beans are assorted according to weight. Tubes containing 

 beans of the same weight are placed in the same vertical row. The population 

 represents the quart of beans discussed in the text. (From Walter, after 

 Johannsen.) 



proximate the expectation from the mathematical theory of 

 probability, or chance, and the reasonable conclusion is that 

 the FLUCTUATIONS are a resultant of a large number of factors 



