CONFORMITY TO TYPE 267 



an important difficulty to be overcome, and one upon 

 which considerable time has been spent, is the appearance 

 in the offspring of peculiarities not found in his parents, 

 though present in his earlier forbears. Light upon this 

 obscure subject is found in the thoughtful and important 

 work of -Gregor Johann Mendel, an Austrian botanist, 

 who for a number of years studied the phenomena of 

 hybridity among certain peas. His writings, being 

 published in an obscure journal, were overlooked partly 

 for that reason and partly because they appeared in 

 1866 when Darwin was impressing the whole world 

 with his plausible theory of the "Origin of Species by 

 Natural Selection" which so changed scientific thought 

 as to make experiments upon hybridity appear futile. 



Line of succession of 

 individuals. 



-y Line of here- 

 ditary trans- 

 mission. 



FIG. 100. Heredity of germ cells and somatic cells. G, Germ cells; S, somatic 

 cells. (Lock.) 



The writing was discovered in 1900 by de Vries, who 

 called attention to its great importance, excited interest 

 in Mendel's problems, and aroused such enthusiasm 

 among scientists generally that the paper was translated 

 and republished with an introductory note by W. 

 Bateson in the Journal of the Royal Horticultural Society 

 of London, Vol. XXIV, 1901-02. 



In considering Mendel's work it must not be forgotten 

 that it is a study of hybrid characters and that in conse- 

 quence all that was found need not apply to normal repro- 

 duction. But on the other hand, the study of hybrids, 

 the striking dissimilarities of whose parents are combined 

 in the offspring, enables us to trace given characters 

 with ease because of their conspicuousness. It is the 



