322 EVOLUTION, GENETICS, AND EUGENICS 



Mendel was not by any means the first hybridizer. Plant hybrid- 

 ization had attracted the attention especially of botanists for a century 

 or more before Mendel made his discoveries. Several of his prede- 

 cessors barely missed making essentially the same discovery that has 

 made Mendel famous. Had they been as systematic in their records 

 and as exact in their methods, they could hardly have failed to find 

 what Mendel found. 



The pioneer plant-hybridizer was Joseph Kolreiiter (1763). He 

 appears to have been the first to establish the fact of sexual reproduc- 

 tion in plants by demonstrating that hybrids inherit equally from both 

 seed plant and pollen plant. He claimed that most hybrids are in- 

 termediate between the two parents with regard to most of the parts, 

 a finding which is in contrast with Mendel's results. He failed to note 

 the phenomenon of the regular sphtting of hybrids, which constitutes 

 the most significant feature of Mendel's discovery. Two Enghsh 

 hybridizers, Thomas Knight (1799) and John Goss (1822), and especial- 

 ly the Frenchman Naudin (1862), barely missed stating the same laws 

 that Mendel did a few years later. Naudin recognized that the 

 hereditary characteristics of the parents are contained in the pollen 

 and ovules and that when fertilization takes place both parental char- 

 acters are united in the hybrid. He also thought that the opposed 

 parental potentialities may segregate in the germ cells of the hybrid 

 plant, an idea which seems to have been adopted by Mendel. Naudin 

 also anticipated Mendel's "unit-character" conception, for he believed 

 that segregation did not apply to all the features of a species at once, 

 but was confined to single potentialities. It would seem, then, that 

 Mendel, like Darwin, was not the sole discoverer of a great funda- 

 mental principle, but added the final touch of accuracy and clearness to 

 results already rather vaguely understood. 



