114 BOTANICAL GAZETTE [august 



whose pollen germinated most completely. Of 100.3 pollen grains 

 placed in 15-1 and 15-3 sugar-agar media, 147 grains (about 15 

 per cent) had failed to germinate at the end of 24 hours, and of 

 these about half were shrunken and hyaline. 



Data regarding the ability to produce seed are of interest in 

 bearing on the condition of femaleness in intersexes. This is a 

 point of particular interest in respect to plants classed as hermaph- 

 rodites. LuDWiG (19) reports that the reduction in stamens seen 

 in female plants of Plantago is associated with increased fruit- 

 fulness. I have made special observations on 3 plants of the first 

 form. In 191 6 all of these failed to set any seed to controlled self- 

 pollination. In 191 7 two of these failed to produce seed to free 

 open pollination ; the third plant was isolated with a pistillate plant. 

 Day after day pollen of the hermaphrodite was very generously 

 shaken over stigmas of both plants. The female plant produced an 

 abundance of seed, while not a seed developed on the other. It is 

 possible that physiological self- and cross-incompatibilities may 

 be operating here (Stout 25), but the various grades of impotence 

 and intersexuality seen in stamens of plants of this species suggest 

 that the failure to set seed when pollinated with viable pollen may 

 involve impotence of pistils. It is readily observed in the field 

 that many plants fail completely to set seed; although pistils are 

 present they may be incapable of functioning. Such plants clas- 

 sified as of first form are functionally male only. In the highly 

 developed stamens and impotent pistils these plants may be 

 considered as representing the extreme of maleness seen in this 

 species. Some first form plants, however, produce seed in abun- 

 dance. 



Second form hermaphrodite (figs. 4-6, 53). — Plants most 

 typical of this class, as thus designated by Bartlett (2), are 

 especially to be distinguished from the first form by the stamens, 

 which have shorter filaments and slender yellowish-green anthers. 

 In most cases the anthers do not dehisce. There is no excessive 

 development of sterile tissue in the stamens. Pollen grains are 

 numerous, but the largest are only about half the diameter of the 

 largest of the first form; but poor and shrunken grains appear 

 to be no more numerous. Attempts to germinate the pollen have 



