A Genetic Study of Plant Height in Phaseolus Vulgaris. 31 
growth habit, the definite segregation in F2 into indeterminate 
and determinate habit with a ratio approaching 3:1, and the 
typical Mendehan behavior in F3 and later generations of both 
the dominant and recessive characters. Since the publication of 
that paper, a large number of crosses between pole and bush 
beans have been grown, but, since these crosses were made pri- 
marily for the study of other characters, definite records of habit 
of growth for F2 have been made in only a comparatively few 
cases. 
Including the records reported in my former paper, I have 
g 'own in all 948 Fi plants of crosses between pole and bush beans. 
Without exception these have been all indeterminate in habit 
of growth. 1 As parents of these crosses there have been employed 
101 distinct races or strains, 58 of which were bush beans and 43 
pole beans. Of the rather large number of Fi plants, progenies 
of which have been grown, positive records are available of the 
offspring of only 32 plants of 16 distinct crosses. From these 
there were produced in F2 1,104 plants, of which 832 were indeter- 
minate and 272 determinate in growth, a ratio of 3.01:0.99, a 
variation from expectation well within the probable error for 
the numbers observed. Of the many F2 bush plants tested in 
F3, accurate records of only 23 are available. All of these were 
found to be constant for determinate growth habit, having pro- 
duced 588 bush and no pole beans in F3. Likewise 24 F2 pole 
beans are known to have bred true, having produced 686 pole 
and no bush beans in F3. Again 40 F2 pole beans segregated into 
pole and bush beans in F3. The F3 progenies of these heterozyg- 
ous F2 pole beans totaled 1,259 plants. In most of these cases, 
however, my notes indicate merely the fact of segregation without 
exact records of the number of plants of the two classes. 
It can be said then, by way of conclusion, that in Phaseolus vul- 
garis indeterminate and determinate habits of growth constitute 
a simple Mendelian character pair with indeterminate habit 
completely dominant. 
INHERITANCE OF NUMBER OF INTERNODES. 
While it is obviously true that habit of growth is an important 
factor in determining ultimate height in bean plants, it is one of 
the few size factors that can be definitely recognized and that 
can, therefore, be given separate treatment. In many crosses 
the parents of which differ greatly in height, growth habit can 
1 Since these records are merely confirmatory of the results previously 
reported in detail (Emerson 1904), it is thought sufficient to give only the 
summaries here. 
