36 HETEROSTYLED DIMORPHIC PLANTS. Chap. 1. 



flowers from each lot were measured, but there was no 

 sensible difference between them in size. Nine long- 

 styled and eight short-styled plants growing together 

 in a state of nature were marked, and their capsules 

 collected after they had been naturally fertilised; and 

 the seeds from the short-styled weighed exactly twice 

 as much as those from an equal number of long-styled 

 plants. So that the primrose resembles the cowslip in 

 the short-styled plants, being the more productive of 

 the two forms. The results of my trials on the fer- 

 tility of the two forms, when legitimately and illegiti- 

 mately fertilised, are given in the following table : 







Table 9. 



Primula 



vulgar 



is. 







Nature of Union. 



Number 



of 



Flowere 



fertilised. 



Number of 

 good Cap- 

 sules i ro- 

 duced. 



Maximum 



Number of 



Seeds in any 



one Capsule. 



Minimum 



Number of 



Seeds in any 



oneCapsule. 



i 



Average 



Number of 



Seeds per 



Capsule. 



Long-styled form, bypol- ] 

 len from short-styled. > 

 Legitimate union . . J 



12 



n 



77 



47 



66.9 



Long-styled form, by ] 

 own-form pollen. 11- > 

 legitimate union . . j 



21 



14 



66 



• 



30 



52.2 



Short-styled form, by 1 

 pollen from long- 

 styled. Legitimate [ 



8 



7 



75 



48 



65.0 



Short-styled form, by ] 

 own-form pollen. 11- > 

 legitimate union . . J 



■ 



18 



* 



7 



43 



5 



18.8* 



The two legitimate \ 

 unions together . . J 



20 



18 



77 



47 



66.0 



The two illegitimate '{ 

 unions together . . j 



39 



21 



66 



5 



35.5* 



* This average is perhaps rather too low. 



•We may infer from this table that the fertility of 

 the two illegitimate unions taken together, is to that of 





■. -«:; 





