224 GENERAL BIOLOGY 



has chiefly served to reveal the immensity of the 

 fields that yet remain to be explored. 



The beginning of this line of work we owe to the 

 efforts of a monk named Mendel, who worked in 

 the cloister garden of his monastery at Briinn 

 (Austria), in the middle of the last century. The 

 results of his experiments were published shortly 

 after the publication of Darwin's famous " Origin of 

 Species," and were so completely eclipsed by the 

 controversies arising out of that famous hypothesis, 

 that they were buried in obscurity, until the facts 

 were rediscovered at the beginning of the present 

 century. 



The material that Mendel worked with was the 

 common garden pea, which affords a number of 

 diverse and easily recognized characters, such as 

 the habit of the plant, the color of the flower and of 

 the seed, the nature of the seed-coat, etc. When 

 Mendel crossed (hybridized) peas that differed with 

 respect to these characters, he found that such 

 characters behaved as independent units. Thus, 

 in his first and classic experiment, two strains of 

 peas were crossed, a tall and a dwarf. The matured 

 seeds of this cross were saved and planted. The 

 plants that grew from them were all tall. It made 

 no difference whether pollen of the dwarf were used 

 on the stigma of the tall, or vice versa, the result 

 was always the apparent extinction of the dwarf 

 characters, the plants were all tall. When, how- 

 ever, the flowers of these tall (hybrid) peas were self- 

 fertilized and the matured seeds planted, the resulting 



