9^ Appendix III 



constitution of their average offspring, Nor 

 is this inheritance confined to man alone, for 

 we find almost the same hereditary intensity 

 in other forms of life, from dog to water-flea. 

 Fraternal relationships are equally strong! 

 Thus, if we consider the cephalic index, the 

 ratio of breadth to length of skull, we find 

 the slope of the ' regression line ' in the case 

 of parental relationships to be -4 to -5, while 

 in the case of fraternal it is -5 to '6. 



Now progress does not depend solely on 

 physique, but also on ' psychique.' But if we 

 turn to the consideration of the inheritance of 

 psychical characters, we see the same results. 



The line which represents the resemblance 

 of brothers in ability has a slope which again 

 approximates to the mean -5, and a like 

 result is also shown in plotting the inheri- 

 tance of shyness or temper. 



Fraternal resemblances have the same in- 

 tensity for physical and psychical characters. 

 From wide observations, then, we are led to 

 this general statement : Inheritance in masses 

 of men is the same as in other forms of life, 

 and this inheritance covers both physical and 

 psychical characters. We do not know what 

 is the best type of man for the society of the 

 future, but we do know that no society can , 

 exist in which health, sanity, and intellectual 

 ability are not fully represented. We know J 

 also that health, sanity, conscientiousness and ' 

 ability are inherited characters. If you breed 



