1 9 1 q] sto UT—IN TERSEXES 1 1 7 



INTERSEXES WITH FLOWERS UNIFORM 



No. II (figs. II, 12, 50). — The relative lengths of pistils and 

 stamens in the flowers of this plant are quite as in the first form. 

 The general appearance of the spikes in full bloom is quite similar 

 (fig. 50), but the anthers are noticeably smaller and more narrow, 

 and they are sUghtly greenish-yellow in color. Many anthers do 

 not dehisce, and after 2 or 3 days they turn brown. A high per- 

 centage of pollen is impotent, but the size of the apparently good 

 grains ranges quite as for the first form. 



No. 13 (figs. 13, 14). — The stamens produced by this plant 

 are somewhat smaller than those of the first form. They are 

 slightly greenish-yellow, but are fully dehiscent. A large propor- 

 tion of pollen was impotent, but a few well formed grains as large 

 as the largest of the first form were found. Tests of pollen germi- 

 nation in 1 5-1, 15-3, and 15-5 sugar-agar media gave germination 

 in about 3 per cent of the grains. The tubes made a feeble growth 

 and the longest obtained measured only 0.08 mm. 



No. 15 (figs. 15, 17). — Pistils of this plant are normally longer 

 than the stamens when both are fully developed. The filaments 

 are only slightly shorter than in the first form; the anthers are 

 decidedly smaller, but all are white and fully dehiscent. A large 

 proportion of the pollen is impotent, but normal grains of large 

 size are abundant. The pistils produced by this plant were among 

 the longest observed on any plant, except for the abnormally 

 elongated pistils (fig. 56) which appear in plants under certain 

 conditions. 



No. 18 (figs. 18, 19). — The stamens and pistils in flowers of 

 this plant are of nearly equal length. Nearly half of the apical 

 portion of the stamens is composed of a sterile blade. The small 

 anther sacs, however, are well developed and fully dehiscent. 

 Scarcely a shriveled pollen grain was found, the grains being 

 very uniformly of large size and a high percentage of them being 

 viable. In this plant the amount of sterile tissue in stamens is 

 decidedly more than that seen in nos. i, 11-17, but there is better 

 development of such sporogenous tissue as is formed. 



No. 20 (figs. 20-22, 54). — At the time when the pistils were 

 receptive the flowers of this plant appeared as shown in fig 20, 



