108 A Defence of Mendel's 



The only conclusion which most readers could draw 

 from this abstract and indeed from the article it epitom- 

 izes, is that Mendel's discovery so far from being of 

 paramount importance, rests on a basis which Professor 

 Weldon has shown to be insecure, and that an error has 

 come in through disregard of the law of Ancestral Heredity. 

 On examining the paper it is perfectly true that Professor 

 Weldon is careful nowhere directly to question Mendel's 

 facts or his interpretation of them, for which indeed in 

 some places he even expresses a mild enthusiasm, but there 

 is no mistaking the general purpose of the paper. It must 

 inevitably produce the impression that the importance of 

 the work has been greatly exaggerated and that supporters 

 of current views on Ancestry may reassure themselves. 

 That this is Professor Weldon's own conclusion in the 

 matter is obvious. After close study of his article it is 

 evident to me that Professor Weldon's criticism is baseless 

 and for the most part irrelevant, and I am strong in the 

 conviction that the cause which will sustain damage from 

 this debate is not that of Mendel. 



I. THE MENDELIAN PRINCIPLE OF PURITY OF GERM- CELLS 



AND THE LAWS OF HEREDITY BASED ON ANCESTRY. 



Professor Weldon's article is entitled "Mendel's Laws 

 of Alternative Inheritance in Peas." This title expresses 

 the scope of Mendel's work and discovery none too 

 precisely and even exposes him to distinct miscon- 

 ception. 



To begin with, it says both too little and too much. 

 Mendel did certainly determine Laws of Inheritance in 



