iqiq] stout— intersexes 131 



The development of perfect flowers in hermaphrodites shows 

 that male and female organs may originate side by side. That 

 stamens and pistils exhibit diflferences in nutritive and metaboHc 

 activities is obvious, most marked of which perhaps is the tempo- 

 rary nature of the stamens and the more permanent and vegeta- 

 tive nature of the ovary portion of the pistil. The life processes 

 of the two develop along somewhat different hnes, as the structure 

 and physiology of the respective spores, gametophytes, and sex 

 cells fully indicate. Such organic specificity is well known fre- 

 quently to involve specific differences in chemical organization. 

 This, however, is not indicative that the essential nature of fertili- 

 zation processes is dependent on such differences. 



There seems to be no exception to the rule that in perfect 

 flowers the male organs constitute an outer and lower whorl, 

 the primary anlagen of which are laid down slightly ahead of 

 those for the female. Such a general mode of development it 

 would seem must have special significance in respect to sex dif- 

 ferentiation. Such conditions, however, are adaptive both to 

 immediate and to more remote function of the parts involved. 

 When conditions in monoecious forms are reviewed it is to be 

 noted that when grouped in spikes and catkins the staminate 

 flowers are as a rule about the pistillate, either when both are 

 in a same catkin or when they are in different catkins. Here, 

 however, direct adaptations for facilitating pollination are in 

 evidence. 



The phenomena of intersexuality in plants and animals indi- 

 cate clearly that neither hermaphroditism nor dioecism are fixed 

 conditions for species or for individuals as such. Maleness and 

 femaleness are subject to much lability; they are even reversible; 

 the physical and chemical substances involved are subject to 

 modification in ontogeny. The factors in sex determination for 

 the individual as a whole or for individual sex organs are highly 

 variable. Such conditions give support to a metabolic and epi- 

 genetic theory of sex in so far as the nature of sex is revealed in 

 the morphological dift"erentiation of sex organs. 



New York Botanical Garden 

 New York 



