X PREFACE 



connection with the figures in addition to this general 

 one. Professor Tennan has not only delivered the lec- 

 tures on the relation of heredity and environment in man 

 but has also written chapter 42 in entirety. It is to be 

 understood that the authors assume full responsibility 

 for the statements and views expressed in the text. 



L. L. B., H. H., E. G. M., G. J. P. 



Stanford Unimirsity, Cali>x)knia« 

 December, 1922. 



