ORIGIN AND IMPROVEMENT OF FRUIT 335 



light on this question. When the data of Hedrick and 

 Anthony ^ are presented according to the formula 

 by Valleau, the following ratios are obtained: 



Table XCI 

 flower types and ratios obtained in grape crosses 



The apijearance of the large number of hermaphrodite 

 seedlings in these crosses is of great importance to grape- 

 growers, because it is possible to select seedlings which will 

 be self -fertile. 



In crosses made between varieties of another species, Vitis 

 rot imdi folia, Detjen - presents data which throw some light 

 on the first appearance of the hermaphrodite flower in a 

 dioecious species. This is epochal in southern grape-growing 

 because it had heretofore been necessary to grow unproduc- 

 tive male vines in vineyards in order to secure proper 

 pollination. His evidence is so clear cut on this point that 

 some of it will be included here in a condensed form for the 

 convenience of the student : 



1 Hedrick, U. P., and Anthony, R. D. Inheritance of certain char- 

 acters of grapes. Jour. Agr. Res. 4: 315-330. 1915; also N. Y. State 

 Agr. Exp. Sta. Bull. Tech. 45. Valleau, W. D. Inheritance of sex in 

 the grape. Amer. Nat. 50: 554-564. 1916. 



- Detjen, L. R. Inheritance of sex in Vitis rotundifolia. N. C. Agr. 

 Exp. Sta. Tech. BuU. 12. 1917. 



