A Genetic Study of Plant Height in Phaseolus Vulgaris. 23 
habits of growth of the two classes. Even the most vigorous 
bush bean cannot be expected ordinarily to reach a height, with 
its 4-8 internodes, that may ultimately be reached by even the 
smallest pole bean with its 15-20 internodes. If, however, length 
of particular internodes be taken as a measure of height, there is 
found in this respect no characteristic difference between the 
two classes of beans. Some races of bush beans have twice as 
long internodes as others and the same is true of distinct races of 
pole beans. Moreover, the internodes of some bush beans are 
Fig. 9.— (A) Very short bush bean, Triumph. (B) Very taU bush'bean, Tall- 
bush, resulting from a cross between a tall pole bean and a short bush 
bean. (C) Short pole bean, Snowflake. (D) Tall pole bean, July. 
