40 EVOLUTION, GENETICS, AND EUGENICS 



himself, both before and since, has seemed to regard it as of minor 

 importance. He called this the 'law of splitting of hybrids.' The same 

 law, it is claimed, was independently discovered about the same time 

 by two other botanists, Correns in Germany, and Tschermak in 

 Austria. Further, historical investigations made by De Vries showed 

 that the same law had been discovered and clearly stated many years 

 previously by an obscure naturalist of Briinn, Austria, named Gregor 

 Mendel, and we have now come to call this law by his name, Mendel's 

 Law. Mendel was so little known when his discovery was published 

 that it attracted little attention from scientists and was soon forgotten, 

 only to be unearthed and duly honored years after the death of its 

 author. Had Mendel lived forty years later than he did, he would 

 doubtless have been a devotee of biometry, for he had a mathematical 

 type of mind and his discovery of a law of hybridization was due to the 

 fact that he applied to his biological studies methods of numerical 

 exactness which he had learned from algebra and physics. In biology 

 he was an amateur, being a teacher of the physical and natural sciences 

 in a monastic school at Briinn. Later he became head of the 

 monastery and gave up scientific work, partly because of other duties, 

 partly because of failing eyesight." 



There had been plant-hybridizers before Mendel, but their lack 

 of exactness in technique had prevented them from discovering the 

 law of segregation or splitting of hybrids. 



Joseph Gottlieb Kolreuter (1733-1806), who really belonged to the 

 period of Lamarck, barely missed making the discovery that was 

 afterward made by Mendel. The salient features of his work are 

 according to Castle: 1 



" 1. Kolreuter established the occurrence of sexual reproduction in 

 plants by showing that hybrid offspring inherit equally from the 

 pollen plant and the seed plant. 



"2. He showed that hybrids are commonly intermediate between 

 their parents in nearly all characters observed, such for example as 

 size and shape of parts. 



"3. Many hybrids are partially or wholly sterile, especially when 

 the parents are very dissimilar (belong to widely distinct species). 

 Such hybrids often exceed either parent in size and vigor of growth. 



"4. Kolreuter did not observe the regular splitting of hybrids 

 which Mendel and De Vries record, but some of bis successors did, 

 particularly Thomas Knight (1799) and John Goss (1822) in England, 



1 Op. cit., p. 86. 



