Phenomena of Inheritance 



79 



Statistical vs. Physiological Methods. One of the chief aims 

 and results of statistical studies is to eliminate individual peculiari- 

 ties and to obtain general and average results. Such work may 

 be of great importance in the study of heredity, especially where 

 questions of the occurrence or distribution of particular phenomena 

 are concerned; but the causes of heredity are individual and 



63 



FIG. 25. SCHEME TO ILLUSTRATE GALTON'S "LAW OF FILIAL REGRESSION" 

 as shown in the stature of parents and children. The mean height of 

 all parents is shown by the dotted line between 68 and 69 inches. The 

 circles through which the diagonal line runs represent the heights of 

 graded groups of parents and the arrow heads indicate the average heights 

 of their children. The offspring of undersized parents are taller and of 

 oversized parents are shorter than their respective parents. (After 

 Walter.) 



