112 The Ohio Journal of Science [Vol. XVIII, No. 4, 



the carpellate flowers below and the staminate above on a 

 common scape, although the entire inflorescence may be 

 staminate or carpellate. There is not much difference in the 

 corresponding perianth segments, but there is a difference in 

 the receptacle. The staminate flower contains a half dozen 

 or so of vestigial carpels whose imperfection would hardly be 

 suspected unless compared with a normal carpel from a car- 

 pellate flower. The carpellate flower contains much more 

 reduced vestigial stamens. In general, one can not predict 

 which set of organs will be the more reduced in any given 

 species though it is generally true that the carpellate flower is 

 more apt to retain stamen structures than the staminate flower 

 is to retain vestiges of the gynecium. This agrees with our 

 notion that maleness in general is a more extreme condition 

 than femaleness, but there are many exceptions like Sagittaria. 

 As to the area involved in the dimorphic state, Sagittaria is 

 rather extreme in that the inflorescence is divided into definite 

 carpellate and staminate regions. However, there are many 

 species of plants in which the two types of flowers are inter- 

 mingled throughout the entire inflorescence. In the cocoanut, 

 Cocos nucifera L., the flowers are monosporangiate and 

 monecious. The diphorism of the flowers, which are situated 

 on the branches of a large inflorescence, is very great. (Figs. 

 8 and 9). Both flowers have distinct vestiges of the opposite 

 set of organs. The dimorphism extends out to the perianth. 

 The sepals of the staminate flower are small and short, while 

 those of the carpellate flower are large and cover the entire 

 bud. The petals of the staminate flower are narrow while those 

 of the carpellate flower are broad. Figures 8 and 9 are sketches 

 of unopened buds drawn to scale and show plainly how the 

 dimorphic condition is expressed in the tissues far beyond the 

 sporangia. It is interesting to note that the vestigial carpels of 

 the staminate flower are only slightly united, while those of the 

 carpellate flower are completely syncarpous. The inhibitory 

 staminate condition does not permit a complete union and a 

 more primitive condition, apocarpy, is expressed. In the 

 carpellate flower the stamen vestiges are small; however, one 

 occasionally finds flowers in which one or more stamens are 

 rather prominent. The writer discovered one case in which a 

 vestigial stamen had developed a nearly perfect anther and the 

 other five vestiges were larger than usual. 



