SEXUALITY IN PLANTS 251 



sub-andrcecious male (that is, a male with non-functional 

 ovaries) when crossed with a pure female gives approximately 

 equal numbers of females and sub-androecious males. It is 

 interesting to note that the sex ratio in i*. Rcemeri depends on 

 both male and female plants. On examining Mr Newton's 

 results in Silene Otites I found that females as well as males 

 influence the sex ratio of the progeny, since different females 



TABLE I 



The Progeny of Crosses using One Male Parent in Silene Otites 

 Constructed from Data of W. C. F. Newton 



P equals Silene pseudoiites, O equals S. Otites, U equals S. umbellata. 



when crossed with the same male gave different sex ratios 

 (Table I). Also there are indications that females of a similar 

 origin give similar sex ratios when crossed to one male, whereas 

 females of dissimilar origin give dissimilar sex ratios. In truly 

 dioecious species of plants, females may influence the sex ratio 

 by bringing in lethal factors. In sub-dioecious species the female 

 seems to have a more determinant control on the sex ratio. 

 This is analogous to the conditions in some polyoecious species, 

 such as Plantago lanceolata (Correns), where similar females 



