24 THE THEORY OF EVOLUTION 



normal manner in which new species originate in 

 nature and that the struggle for existence is not so 

 much between individuals as a competition between 

 mutants or incipient species. 



Interesting and important as the mutation theory 

 undoubtedly is, it offers no explanation of the phe- 

 nomena, for the cause of such sudden changes re- 

 mains a complete mystery. The seat of the change, 

 it can hardly be questioned, must be sought in the 

 germ-plasm of one or both parents, but we have not 

 the least inkling of how such modification is brought 

 about. 



Finally, should be mentioned the work of Johann 

 Gregor Mendel (1822-1882) an Austrian monk, who 

 made experiments in crossing different varieties of 

 peas and subjected his results to a mathematical 

 analysis. His paper was published in 1866 and at- 

 tracted no attention, but long after his death it was 

 rediscovered, his results having been independently 

 and almost simultaneously attained by three botan- 

 ists, who published them in 1900, de Vries, von 

 Tschermak in Austria and Correns in Germany. It 

 is pathetic to contrast the complete neglect with 

 which Mendel was treated during his lifetime with 

 the honour which is paid to him now. His work has 

 been developed into a new branch of biological 

 science, called 'Genetics," an exact analysis of the 

 mechanism of heredity, and will be more fully dealt 

 with in the last lecture of the course. Mendel's name 

 is mentioned here merely to complete the list of those 



