40 READINGS IN 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 (1783-1806), 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, 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 his successors did, 
particularly Thomas Knight (1799) and John Goss (1822) in England, 
1 Op. cit., p. 86. 
