328 PLANT HYBRIDIZATION BEFORE MENDEL 



"My experiments," he says, "have led me to the following principles : 



1. "O/ the two antagonistic characters, the hybrid carries only the one 

 and, indeed, in complete expression. It is accordingly in this point not 

 to be distinguished from one of the two parents. Intermediates do not 

 occur. 



2. "0/2 the formation of the pollen and egg cells the two antagonistic 

 characters separate. They follow accordingly, in the majority of cases, 

 simple laws of probability. These two principles, in the most essential 

 points, have already been propounded a long time since by Mendel, for 

 a special case (peas). They passed, however, again into oblivion, and 

 were misunderstood. They obtain generally according to my experiments, 

 for true hybrids. 



"The lack of intermediates, between any two simple antagonistic char- 

 acters in the hybrids, is perhaps the best proof that such characters are 

 indeed delimited units, (la, pp. 84-5.) 



"That polyhybrids so often represent intermediate forms, rests mani- 

 festly upon the fact that they have inherited a part of their characters 

 from the father, another part from the mother. With monohybrids, such, 

 however, is not possible. 



"of the two antagonistic characters, that visible in the hybrid is the 

 dominating, the latent is the recessive." {ih., p. 85.) 



In regard to Mendel's paper, De Vries remarks further in a 



footnote (la, p. 85) : 



"This important treatise Is so seldom cited, that I myself for the first 

 time came to know about it after I had closed the majority of my ex- 

 periments, and had derived therefrom the principles contributed in the 

 text." 



The italics are Inserted, In order to call more definite attention 

 to this very important fact. In view of the almost parallel nature 

 of the conclusions of De Vries with those arrived at bv Mendel 

 himself. 



In the following section of his paper, De Vries goes on to 

 state (p. 85) : 



"in the hybrid, the two antagonistic characters lie near one another as 

 primordia. In vegetative life only, the dominating one is ordinarily visi- 

 ble. Exceptions are seldom." {ib., p. 86.) 



As such De Vries cites the case of Veronica longifolia (blue) 

 X V' longifolia {alba\ in which Inflorescences occur, the flowers 

 of which are white on the one side, and blue on the other. Such 

 cases De Vries calls sectional splittings (sectionale Spaltungen). 



Continuing, it is stated as to the primordia of the antagonistic 



characters : 



"On the formation of the pollen grains and egg cells, they separate. 

 The individual pairs of antagonistic characters behave at that time inde- 

 pendently of one another." 



From this separation results the law : 



