486 



Plant Physiology 



297. Tomato characters. To accord with Mendelian 

 results every plant may be regarded as made up of a cer- 



FIG. 138. Hybridization of tomatoes: parental types (top row), Honor 

 Bright and Yellow Pear ; F! generation (2d row) quite uniform ; F 

 generation (3d and 4th rows) showing segregation. [Photograph by 

 H. L. Price.] 



tain number of unit characters, which may be contrasted 

 in different forms or varieties. Price and Drinkard have 

 determined thirteen such alternative character pairs 



