492 
The Ohio Naturalist. 
[Vol. XV, No. 6, 
3. From an examination of all available data upon the 
inheritance of fruit-size in the F-l generation, it appears that, 
when two varieties are crossed which differ widely in fruit-size 
(the size of fruit of one parent being probably about two, three or 
more times the size of fruit of the other parent), the F-l fruit-size 
will be nearer to the geometrical than the arithmetical mean; but, 
when two parents similar in fruit-size are crossed, the size of fruits 
of the offspring will approach more nearly to the arithmetical 
than to the geometrical mean. 
4. The average fruit-size of the F-2 generation docs not 
exceed and is even slightly less than the average fruit-size of the 
F-l generation. The segregation of size factors and the incomplete 
dominance of the small size factors of the red currant parent may 
be explained by the assumption of at least four size factors. If 
no parental sizes can be ever obtained, there may be more than 
multiple factors involved. 
5. The fruits of the F-2 and F-3 generations agree fairly well 
with respect to variability and average generation size. The F-4 
fruits show diminished variability and size. 
6. This paper deals only with the inheritance of size in the 
currant-pear tomato cross. Conclusions as to how far the results 
obtained may be applied to the inheritance of size in crosses 
between other species and varieties must be left to the accumula¬ 
tion of further data. 
1. Belling, John. Velvet Beans crossed with Lyon Beans. Ann. Rpt. 
Florida Agr. Exp. Sta. 1910: 79-92. 
2. Second Generation of the Cross between Velvet and 
Lyon Beans. Ann. Rpt. Florida Agr. Exp. Sta. 1911: 82-103. 
3. Bruce, A. B. The Golden Mean. Science N. S. 40: 59. 
4. Heredite des caraters quantitatifs, (4 Conf.-int. Gcne- 
tique Paris 1911 4pp.) 
5. Castle, W. E. Heredity in Relation to Evolution and Animal Breed¬ 
ing. 1911. 
0. Pure Lines and Selection. Jour. Hered. Vol. 5. 1914. 
7 . The Inconstancy of Unit Characters. Amer. Nat. 
46: 352-362. 1912. 
8 . Studies of Inheritance in Rabbits. Car. Inst. Wash. 
Pub. 114: 5-70. 1909. 
9. Collins, G. N. The Value of First Generation Hvbrids in Corn. Bu. 
P. Ind. 191. 1910. 
10. De Vries, Hugo. Plant Breeding. 1907. 
11 . The Principles of the Theory of Mutation. Science. 
N. S. 40: 74-88. 1914. 
12. East, E. M. The Genotype Hypothesis and Hybridization. Am. 
Nat. 45: 160-174. 1911. 
13 . Inheritance of Flower Size in Crosses between Species 
of Nicotiana. Bot. Gaz. 55. 1913. 
14 . A Mendelian Interpretation of Variation that is Ap¬ 
parently Continuous. Am. Nat. 44: 65-82. 1910. 
15. East, E. M. and Hayes, H. K. Inheritance in Maize. Con. Agr. 
Exp. Sta. 167. 
