CHAP. IV. OXALIS SPECIOSA. . 175 



containing on an average 10*31 seeds; whilst 39 

 flowers fertilised illegitimately did not yield a single 

 capsule or seed. Therefore the fertility of the six 

 legitimate to that of the several illegitimate unions, 

 as judged both by the proportion of flowers which 

 yielded capsules and by the average number of con- 

 tained seeds, is as 100 to 0. 



Oxalis speciosa. This species,- which bears piiik 

 flowers, was introduced from the Cape of Good Hope. 

 A sketch of the reproductive organs of the three 

 forms (Fig. 11) has already been given. The stigma 

 of the long-styled form (with the papillae on its sur- 

 face included) is twice as large as that of the short- 

 styled, and that of the mid-styled intermediate in size. 

 The pollen-grains from the stamens in the three forms 

 are in their longer diameters as follows : 



Divisions of the 

 Micrometer. 



From the longest stamens of short-styled. . 15 to 16 



mid-length . 12 13 



longest stamens of mid-styled . 

 shortest . 



mid-length stamens of long-styled , 

 shortest 



16 



11 to 12 

 14 

 12 



Therefore the extreme difference in diameter is as 

 16 to 11, or as 100 to 69 ; but as the measurements 

 were taken at different times, they are probably only 

 approximately accurate. The results of my experiments 

 in fertilising the three forms are given in the following 

 table. 



