Vlll 



Preface 



the position from which he had started upon them. 

 He had begun as a pupil of the Biometric school 

 with a strong bias against the Mendelian theory. 

 He now worked his way, through difficulty and 

 depression, to a point from which he saw that the 

 contradiction between the two theories was only 

 apparent and was really due to a difference in the 

 point of view from which each party approached 

 the same facts. He defined his position, and cut 

 himself adrift from both schools in his contribution 

 to the debate on heredity at the meeting of the 

 British Association at Cambridge in 1904, 1 and in 

 two papers contributed to the Manchester Literary 

 and Philosophical Society, " On the Supposed An- 

 tagonism of Mendelian to Biometric Theories of 

 Heredity " (1905) and " On the Difference between 

 Physiological and Statistical Laws of Heredity " 

 (1906). 2 



He maintained this independent and critical 

 attitude all his life, and upon no man's work, 

 whether of description or interpretation, did he 

 keep a closer critical watch than upon his own. 

 " One's attitude as an investigator," he wrote, 

 " should be one of continual, unceasing and active 

 distrust of oneself." His later experiments with 

 mice, peas, fowls and rabbits were designed to test 

 the Mendelian hypothesis with absolutely no pre- 

 judgment of the case. After thirteen years of patient 

 investigation he could write in February, 1915, "I 

 consider the Mendelian principles to be still sub 

 judice ; and they are so attractive by reason of 

 their simplicity that they need to be under a very 



1 Vide infra, p. 162. * Vide infra, pp. 144 and 167. 



