170 HETEROSTYLED TKIMORPHIC PLANTS. CIIAP. IV. 



form, the stigmas pass out between the filaments of 

 the longest stamens (as in the short-styled form of 

 Linum); and they stand rather nearer to the upper 

 anthers than to the lower ones. In the short-sty Isd 



fc? it. 



Long-styled. Mid-styled. Sbort-.-tyled. 



OXALIS SPECIOSA (with the petals removed). 



S S S, stigmas. The Jotted lines with arrows show which pollen mast 

 be carried to the stigmas for legitimate fertilisation. 



form, the stigmas also pass out between the filaments 

 nearly on a level with the tips of the sepals. The 

 anthers in this latter form and in the mid-styled rise 

 to the same height as the corresponding stigmas in the 

 other two forms. 



Oxalis Valdiviana. This species, an inhabitant of 

 the west coast of South America, bears yellow flowers. 

 Hildebrand states that the stigmas of the three forms 

 do not differ in any marked manner, but that the pistil 

 of the short-styled form alone is destitute of hairs. 

 The diameters of the pollen-grains are as follows : 



Divisions of the 



Micrometer. 



trom the longest stamens of short-styled . . . . 8 to 9 

 mid-length .... 7 8 



longest stamens of mid-styled .... 8 

 shortest .... 6 



mid-length stamens of long-styled ... 7 

 shortest . . 



