Chap. 20 



THE PHYSICAL BASIS OF HEREDITY 



389 



Beginning of Genetics 



The science of genetics has had a lifetime of about fifty years, marked by 

 an extraordinary advance in knowledge and usefulness. From its beginning 

 workers in this field have used precise methods, analysis, experiments upon 

 large numbers of individuals, and meticulous records. The present knowledge 

 of heredity rests upon the discovery that the characters of an organism 

 are inherited independently of each other and not blended together. The 

 discoverer. Father Gregor Mendel, was a gardener, beekeeper, and priest 

 who was interested in flowers, their pollination and the part taken in it 

 by the bees, not only bees in general but the particular varieties that he 

 secured by selecting and cross breeding them (Fig. 20.1). All of his work 

 was illumined by enthusiasm and enjoyment. The flowers were lively and 

 special to him; the fuchsia was his favorite. He finally selected garden peas 

 for his main experiments because they were easy to raise and cross pollinate, 

 and he was especially interested in their inheritance of size and form. So 

 it came about that for his far-reaching work, his material was mainly garden 

 peas grown in a small plot near his monastery. Mendel's enthusiasm was 



Fig. 20.1. The garden in the Koniginkloster in Brunn where Gregor Mendel 

 (1822-1884) carried on his experiments ( 1856-1864). Those experiments were the 

 foundations of genetics, the science of the gene, the unit of inheritance. (Photo- 

 graph by Hugo litis. Courtesy, Sinnott, Dunn, and Dobzhansky: Principles of 

 Genetics, ed. 4. New York, McGraw-Hill Book Co., 1950.) 



