i6 



iii. TJic PJicnomaia of Heredity. 



(See Darwin, Animals and Plants under Domestication, Chap- 

 ters XII, XIII, and XIV; Galton, Natural Inheritance; 

 Delac.e, Heredite, pp. 186-260.) 



The force of heredity. 



Pedigrees of domestic animals. 

 Inheritance of saltatory variations. 

 Variability itself a variation that is often 

 strongly inherited. 



Capriciousness of heredity. 



Non-inheritance due to opposing conditions. 



Fixedness of character apparently not due to 

 antiquity of inheritance. 



Inheritance at corresponding periods of life. 



Particulate inheritance (Galton, p. 7). 

 Heritages that blend. 



Stature : (Galton, p. 83). 



Not affected by marriage selection. 



Not affected by diversity of parents. 



" The mid-parent." 



"Mid-stature of population," about 68.4 

 inches = /'. 



Filial regression (pp. 95-97). 



Mlial deviation from /-* : to the mid-pa- 

 rental deviation : : 2:3. 



On the other hand, — Mid-parental devi- 

 ation from /"* : Filial deviation : : i : 3 

 (See Table 1 1 ). 



Galton's law of regression : " The devia- 

 tion of sons from /' is on the average 

 equal to 1-3 of the deviation of the pa- 

 rent from /' and in the same direction." 

 (When in one parent D = o.) 



