102 UNIVERSAL EVOLUTION 



bination of characters desired, in an ideal type, and 

 can with considerable confidence estimate the number 

 of plants it will be necessary to grow, to get this com- 

 bination. " 



The great importance of this, in breeding varieties 

 of grass and vegetables, for the use of man, and in 

 determining the cause of variation in all organisms, is 

 apparent from the statement itself. Mendel died in 

 1884 without knowing that his name has been immor- 

 talized, in that given to the principle, Mendelism. 

 and has been attached to a discovery that will revolu- 

 tionize the ideas before held, as to causes and times of 

 appearance of variations in heredity. The principles, 

 he discovered, were rediscovered in 1900 by De Vries. 



The hybird, resulting from the crossing first made by 

 Mendel, although showing only the characteristics, of 

 one of the parents the dominant, yet contained, also 

 the other, invisible the recessive. Both characters 

 are present within all the seeds. Castle, Davenport 

 and others, experimented with animals. These tend 

 to support the principle, and make it into a law. It is 

 of great importance to establish a principle that germ 

 cells remain pure however mixed, and transmitted, and 

 that, as long as they are transmitted, their type of 

 organism, from which they first came, will continue to 

 live. The names of Weissman and Mendel stand high 

 in the theories of heredity. 



With plants, and a few animal forms, self fertil- 

 ization is frequent. But there is no exclusive ap- 

 paratus w r hich prevents an occasional cross. In case 

 of plants, their fixed locations necessitate a means of self 

 fertilization. But being exposed to winds, and other 

 natural mediums, for conveying pollen, an occasional 

 cross occurs. These crosses are the probable source 



