Mendel's law of heredity and hoeticultuee. 



25 



reproductive cells. In view of recent experiments, however, we prefer 

 to regard it more simply. In common with Mendel we regard tallness, 

 for instance, as due to a definite germinal factor present in the tall 

 pea, but on the other hand we regard dwarf ness as simply due to the 

 ahsenee of the tall factor from the dwarf pea. 



Fig, 13. — Illustrating Mendel's conception of the germinal segrega- 

 tion OP the factors for "tallness" and " dwarfness " in Peas. 

 (Also illustrating the "presence and absence" method.) 



Thus in the presence of the tall factor the pea is tall, while in its 

 absence the pea is dwarf. 



Tallness appears to be dominant simply because it is present, and 

 in its absence the seemingly recessive character is manifested. We 



