1922] SINNOTT—FRUIT SHAPE IOI 
study of the F, in a number of crosses involving differences in fruit 
shape shows that a distinct bimodal curve is present, thus suggesting 
a segregation something like that here reported in squashes. In 
many other shape crosses studied by this investigator, however, the 
F, showed a wide range of shapes with no clear cut segregation of 
LJ = Disc 
MB = Spuere 
or ee yO ae a a a NS 1 ee EO a8 
LENGTH 
YY 
iS Wow Be tS lee RAN a0. Ab ab: 23 24 35 
WIDTH 
Fic. 3.—Length and width of F, fruits, pedigree 19 
types, thus suggesting the operation of a larger number of factors. 
EMERSON’s? work with squashes also shows a great increase in the 
variability of shape in the F, and (apparently) no clear cut segrega- 
tion. The parental types used by EMERSON, however, were not 
inbred homozygous strains. 
It is assumed that in the present case such things as “‘shape fac- 
tors” exist in the germ plasm and are operative. It may be objected 
* Emerson, R. A., The inheritance of sizes and shapes in plants. Amer. Nat, 
44:739-746. IgIo. 
