HEREDITY 



517 



5. Differences in color of unripe pods, light green, dark 

 green, or vividly yellow. 



6. Differences in position of flowers, whether axial or 

 terminal ; that is, whether distributed along the main stem or 

 bunched at the top in a " false umbel." 



7. Differences in length of the stem, varying from 9 inches 

 to 6 or 7 feet. 



It is perfectly easy to see that many of these characters would 

 be dominant over others, the less noticeable being "lost" to 

 view in the hybrid forms. For example, dark green would be 

 dominant over light green and over most shades of yellow ; long 

 stems over short ones ; and dark colors generally over light ones. 



The preponderance of the dominant character over the reces- 

 sive is so pronounced as to lead Mendel to remark that fre- 

 quently " one of the parental characters was so preponderant 

 that it was difficult or quite impossible to detect the other in 

 the hybrid." In each of the seven crosses of peas, he adds, 

 " The hybrid character resembles that of one of the parent 

 forms so closely that the other either escapes observation com- 

 pletely or cannot be detected with certainty." 1 Of the charac- 

 ters used, the following were found to be dominant : 2 



1. The round or roundish form of seed. 



2. The yellow coloring of the endosperm. 



3. The gray, gray-brown, or leather-brown color in the seed 

 coat. 



4. The inflated over the constricted pod. 



5. The green color in the unripe pod. 



6. The distribution of flowers along the stem. 



7. The greater length of stem. In respect to this point the 

 investigator remarks that stems I foot long crossed with stems 

 6 feet long gave rise to stems from 6 feet to *j\ feet long. 



The first, or hybrid, generation. Because of the overpowering 

 influence of the dominant characters, the "hybrid," or cross, 

 could not commonly be distinguished from the "pure" parent 

 possessing the dominant character. This agrees with the experi- 

 ence of breeders generally. 



1 Bateson, Mendel's Principles of Heredity, p. 49. 



2 Ibid. p. 50. 



