414 The Ohio Journal of Science [Vol. XIX, No. 7, 



kins or bisporangiate catkins on a plant. One individual, how- 

 ever, had a considerable proportion of carpellate or fruiting 

 catkins and produced considerable seed. Still it was prevailingly 

 staminate. ' 



In most cases, the carpellate catkins were staminate below 

 and became carpellate at the outer end, usually at or somewhat 

 above the middle. The axis of such catkins changed from the 

 staminate state to the carpellate state. The staminate flowers 

 below were normal for the species and the carpellate flowers 

 near the tip appeared normal and finally, discharged mature 

 seed in the usual manner. But on the transition zone, between 

 the staminate and carpellate parts, the axis seemed to be neu- 

 tral in regard to sex and here bisporangiate flowers were fre- 

 quently present, the same as is commonly observed in normal 

 monecious inflorescences where one part is staminate and the 

 other carpellate. In the neutral zone abnormal flowers were 

 very frequent. In some cases structures developed which were 

 partly staminate and partly carpellate. Or a stamen would 

 have some carpellate characteristics or a gynecium take on some 

 of the peculiarities of a stamen. 



The development of organs in such transition zones is very 

 interesting, since it indicates that the differential sexual state 

 is not sufficiently strong in one direction or the other to make 

 the factors which control the expression of one or the other set 

 of organs entirely latent or entirely active. In consequence of 

 the lack of such control, there is an attempt, so to speak, to 

 develop both male and female characters in an organ which 

 phylogenetically, and normally in its ontogeny, is purely male 

 or purely female in expression. The reversal of the sexual state 

 in the middle of the catkins is not abrupt but there is a gradual 

 change in the tissues from one condition to the other. It is a 

 quantitative change; and thus it necessarily follows that the 

 characters developed through the activity of the hereditary 

 factors are also quantitative in respect to maleness and female- 

 ness. In these catkins the reversal of sex is from male to female 

 as in the inflorescence of Zizania aquatica L. In other plants 

 like Tripsacum dactyloides L. it is just the opposite. 



The conclusion from the evidence presented above seems to 

 be inevitable, that sex expressed as maleness or femaleness is 

 not an irreversible, Mendelian, hereditary character, dependent 

 on the presence of a single hereditary factor or group of factors, 

 but is a physiological state or condition which influences the 



