PRACTICAL LAWS OF LIFE 



337 



to realize what Mendel has done for the world. As Walter sums up the 

 case : '* Thus in a few generations of properly directed crosses there 

 can be obtained combinations of characters united in one strain that 

 formerly were never obtained at all or were only hit upon by merest 

 chance at long intervals. Herein lies the scientific control of heredity 

 which the trinity of Mendelian principles, namely, independent unit 

 characters, segregation, and dominance, has placed in human hands." l 



Historical. Mendel presented the re- 

 sults of his era-making experiments 

 before the Natural History Society in 

 Briinn early in 1865, and they were 

 published in the Proceedings in 1866. 

 Neither the reading nor the publication 

 caused a ripple of interest. No one un- 

 derstood its significance. Had Darwin 

 learned of Mendel's law in 1865, the 

 history of human science, philosophy, 

 and even religion might have been 

 pushed forward fifty years. Mendel died 

 January 6, 1884, bitterly disappointed 

 that no one could be found to share his 

 vision, and his discovery slumbered for 

 sixteen years longer. 



In 1900, three men, working independ- 

 ently, rediscovered Mendel's law almost 

 at the same time. These were De Vries 

 in Holland, Correns in Germany, and 



Tscherrnak in Austria. The time was ripe for its appreciation, and it 

 immediately transformed the subject and, from a matter of abstract 

 disquisitions, made heredity the most intensely practical concern of the 

 experimental breeding plot and pen, of the hunt for variations in nature, 

 and of even sociological analyses and surveys. " The practical breeder 

 of animals or plants, basing his methods on a determination of the 

 Mendelian units and their properties, will in many of his operations 

 be able to proceed with confidence and rapidity. Lastly, those who as 

 evolutionists or sociologists are striving for wider views of the past or 

 of the future of living things may by the use of Mendelian analysis 

 attain to a new and as yet limitless horizon." 2 



FIG. 165. Diagram illustrating 



relation of germ plasm (straight 



lines) to somatoplasm (circles) 



in bisexual reproduction 



1 Walter, Genetics, p. 144. 



2 Bateson, Mendel's Principles of Heredity, 1909, p. 17. 



