6 Pre-Mendelian Writmgs [ch, 



recognized. In 1897 he definitely enunciated his now 

 famous *' Law " of heredity, which declared that to the total 

 heritage of the offspring the parents on an average contribute 

 \, the grandparents \, and the great-grandparents -J-, and so 

 on, the total heritage being taken as unity. To this 

 conclusion he had been led by several series of data, but 

 the evidence upon which he especially relied was that of 

 the pedigrees of Basset Hounds furnished him by the late 

 Sir Everett Millais. In that instance the character con- 

 sidered was the presence or absence of black in addition to 

 yellow and white. The colours were spoken of as tri-colour 

 and non-tri-colour, and the truth of the law was tested by 

 the average numbers of the respective colours which resulted 

 from the various matings of dogs of known ancestral 

 composition. These numbers corresponded so well with 

 the expectations given by the law as to leave no reasonable 

 doubt that the results of calculation were in general har- 

 mony with natural fact. 



There are features in this important case which need 

 special consideration, and to these I will return. Meanwhile 

 we may note that though there was admittedly a statistical 

 accord between Galton's theory and some facts of heredity, 

 yet no one familiar with breeding or even with the literature 

 of breeding could possibly accept that theory as a literal or 

 adequate presentation of the facts. Galton himself in pro- 

 mulgating it made some reservations ; but in the practice of 

 breeding, so many classes of unconformable phenomena 

 were already known, that while recognizing the value of his 

 achievement, we could not from the first regard it as more 

 than an adumbration of the truth. As we now know, 

 Galton's method failed for want of analysis. His formula 

 should in all probability be looked upon rather as an 

 occasional consequence of the actual laws of heredity than 

 in any proper sense one of those laws. 



Of the so-called investigations of heredity pursued by 

 extensions of Galton's non-analytical method and promoted 

 by Professor Pearson and the English Biometrical school 

 it is now scarcely necessary to speak. That such work 

 may ultimately contribute to the development of statistical 

 theory cannot be denied, but as applied to the problems of 

 heredity the effort has resulted only in the concealment of 



