THE BIOMETRIC STUDY OF HEREDITY 41 



should now be sending their observations to the 

 biometricians for analysis and criticism. The readers 

 of the British Medical Journal have greatly profiled 

 by the publication therein of various papers by Pro- 

 fessor Karl Pearson, dealing with such diverse mat- 

 ters as the inheritance of insanity and the value of 

 anti-typhoid inoculation. It is now becoming evi- 

 dent to all thoughtful students that no quantitative 

 or statistical observations, whether dealing with 

 heredity or any other subject, can be regarded as 

 complete until they have been submitted to expert 

 mathematical criticism. There is no questioning the 

 dictum of Kant, that the completeness and validity 

 of any objective science is proportioned to the degree 

 in which it is informed with mathematics. Some- 

 times, when the student wants a laugh, he tries to 

 picture the results of submitting the crude and ludi- 

 crous arguments for and against " Fiscal Reform," to 

 the criticism of the mathematician. But "let that 

 pass." 



Ignoring for the nonce the critical and corrective 

 services of biometry, we may note the chief of those 

 constructive efforts which already stand to the per- 

 manent credit of its youth. The tirst of these is now 

 known as " Galton's Law." Many years ago Mr. 

 Galton devoted himself to the exact study of "human 

 faculty " in relation to heredity ; and also to the study 

 of the inheritance of physical characters in certain of 

 the lower animals. He collected and analysed an 

 enormous number of data as to health, eye-colour, 

 stature, and artistic faculty in several generations of 

 some hundred and (ifty distinct famihes. Later he 

 was able to study the records of the colours of a 



