124 GENETICS 



by the newly published epoch-making work of Charles 

 Darwin. 



Mendel died in 1884, and his work slumbered on 

 until it was independently discovered almost simul- 

 taneously by three botanists whose researches had 

 been leading up to conclusions very much like his 

 own. These three men were de Vries of Holland, 

 von Tschermak of Austria, and Correns of Germany. 

 Their papers were published only a few months apart 

 in 1900 and were closely followed by important 

 papers from Bateson in England and Davenport 

 and Castle in America, with a rapidly increasing 

 number from other biologists the world over. To- 

 day the literature upon this subject has grown to 

 be very large, and the end is by no means yet in 

 sight. 



Concerning Mendel, Castle has well said: "Mendel 

 had an analytical mind of the first order which en- 

 abled him to plan and carry through successfully 

 the most original and instructive series of studies 

 in heredity ever executed." 



4. MENDEL'S EXPERIMENTS ON GARDEN PEAS 



What Mendel did was to hybridize certain varie- 

 ties of garden peas and keep an exact record of all 

 the progeny, in itself a simple process but one that 

 had never been faithfully carried out by any one. 



Before examining Mendel's results it may be well 

 to state the difference between normal and artificial 

 self-fertilization. Self-fertilization occurs when from 

 the pollen and ovule of the same flower are derived 



