324 PLANT HYBRIDIZATION BEFORE MENDEL 



for publication first, March 14, 1900, yet the brief two-page 

 article in French in the Comptes Rendus, dated March 26, 1900, 

 was the first actually to appear. 



In the Comptes Rendus article, no mention is made of Men- 

 del's paper, but the author's own results are given. In the article 

 in the Berichte, however, Mendel's paper is discussed, and the 

 author's own results in harmony therewith are given in detail. 



Following are abstracts of the three principal papers of De 

 Vries concerned with the Mendelian discovery: ' 



a. De Vries ^ Hugo. 



Sur la loi de disjonction des hybrides. 



Comptes Rendus, T. 130, pp. 845-7, 1900- (lb.) 

 The author cites from his Intracellular Pangenesis, 1889, the 

 principle enunciated that the 



". . . specific characters of organisms are composed of very distinct units. 

 One is able to study experimentally these units, either in the phenomena 

 of variability, of mutability, or by the production of hybrids. In the lat- 

 ter case, one chooses by preference hybrids whose parents are not dis- 

 tinguished among themselves except by a single character (mono-hybrids), 

 or by a small number of characters, well delimited, and from which one 

 does not consider but one or two of these units, while leaving the others 

 to one side." {ib., p. 845.) 



"Ordinarily hybrids are described as participating at the same time in 

 the characters of the father and of the mother. In my opinion one ought 

 to admit, in order to understand this fact, that the hybrids have, 

 some of them, the simple characters of the father, and others characters 

 equally simple of the mother. But when the father and the mother are 

 not distinguished except in a single point, the hybrid could not hold 

 the mean between thern ; because the simple character should be consid- 

 ered as a non-divisible unit." {ib., p. 845.) 



"The hybrid shows always the character of one of the two parents, 

 and that always in all its force ; never is the character of one parent, 

 which to the other is lacking, found reduced by half." {ib., p. 845.) 



"Ordinarily," De Vries comments, "it is the character of the species 

 which supervenes over that of the variety, or the older character over 

 the younger. . . . But," he adds, "I have observed diverse exceptions to 

 these rules." {ib., p. 845.) 



De Vries then adds : 



"In the hybrid, the simple differentiating character of one of the par- 

 ents is then visible or dominant ; while the antagonistic character is in a 

 latent or recessive state." {ib., p. 845.) 



"The antagonistic characters remain ordinarily combined during the 

 vegetative life, these dominant, the others latent. But in the generation 

 period they are disjoined. Each grain of pollen and each oosphere re- 

 ceives but one of the two." {ib., p. 845.) 



