1922] SINNOTT—FRUIT SHAPE 97 
coming from the crosses where the flattest disc was used being 
noticeably flatter than those coming from the crosses where the - 
thickest disc was used. 
TABLE I 
FRUIT SHAPE IN F, OF THREE CROSSES OF DISC XSPHERE 
Pedigree Disc Sphere 
es Ute Ge viene ott pee es fC 83 18 
Dare ee ee et 79 29 
EQ ura SE ek varus ee ness 41 13 
otal) i) aa eee 203 60 
PAPECHAMON. 350 ese. 197 66 
To bring out more clearly the various shape differences, a study 
of the relative sizes of the two major dimensions, width and length, 
as represented by an index, is useful. This shape index for a given 
fruit is its width (the dimension at right angles to the fruit axis) 
divided by its length or thickness (dimension parallel to the fruit 
axis). The means for the shape index of parents, the F,, and the two 
extracted types in the F, for the three pedigrees, are set forth in 
table II. The frequency distribution of the individuals in the three 
pedigrees with respect to this shape index is also given in fig. 2. 
TABLE Il 
MEANS FOR FRUIT SHAPE INDEX (WIDTH+ LENGTH) IN THE FOUR PURE LINES STUDIED, 
IN F', AND THE TWO TYPES SEGREGATING IN F2, FOR THE THREE PEDIGREES; FIG 
PARENTHESES ARE INDICES EXPECTED ON BASIS OF TWO-FACTOR HYPOTHESIS 
| 
Disc SPHERE 
Pure Oxser- | Expec- OxssER- | EXPEC- 
LINES | VATION | TATION F VATION | TATION Fs 
r- | Expec- | Obser- | Expec- 
vation | tation | vation | tation 
| 
103 (sphere) .| 0.97 |...... 
15 (disc)....) 2.48 | (2.47) 15...| 2.50 | (2.47) 15. ..| 2.51 | (2.47)| 0.86 | (0.97) 
1 (disc)... .| 2.50 |(2.72)| 1...| 2.01 | (2.72) ..| 2.61 |(2.66)| 1.20 | (1.16) 
19 (disc)... .| 3.28 | (3.22)] 19...| 3.34 | (3-22) o ..| 2.94 |(3-03)| 1.50 | (1.53) 
Records for a comparatively small number of individuals of the 
four pure types are here presented, since only a few plants are grown 
of each of the various pure lines in any one year. The F, generations 
were also small, but the F, generations were considerably larger. 
Cultures involving much greater numbers are now being grown. 
