Preface xi 



built of statistical data, as Mendel knew long ago ; 

 but, as he also perceived, the ground must be pre- 

 pared by specific experiment. The phenomena of 

 heredity and variation are specific, and give loose and 

 deceptive answers to any but specific questions. That 

 is where our exact science will begin. Otherwise we 

 may one day see those huge foundations of "biometry'' 

 in ruins. 



But Professor Weldon, by coincidence a vehement 

 preacher of precision, in his haste to annul this first 

 positive achievement of the precise method, dispenses 

 for the moment even with those unpretending forms 

 of precision which conventional naturalists have use- 

 fully practised. His essay is a strange symptom of 

 our present state. The facts of variation and heredity 

 are known to so few that anything passes for evidence ; 

 and if only a statement, or especially a conclusion, be 

 negative, neither surprise nor suspicion are aroused. 

 An author dealing in this fashion with subjects com- 

 monly studied, of which the literature is familiar and 

 frequently verified, would meet with scant respect. 

 The reader who has the patience to examine Professor 

 Weldon's array of objections will find that almost all 

 are dispelled by no more elaborate process than a 

 reference to the original records. 



With sorrow I find such an article sent out to 

 the world by a Journal bearing, in any association, 



