Feb., 1922] SCHAFFNER — CONTROL OF THE SEXUAL STATE 
77 
the Arisaema rust. In the first habitat the plants are thriving. In both 
habitats and in both years there is an enormously greater number of stami- 
nate individuals than of monoecious individuals. 
Table 2. Arisaema Dracontium in the Field 
Habitat 
Monoecious Plants 
Staminate Plants 
Number 
Percentage 
Number 
Percentage 
L Rich, moist, open mixed wood, 1920 . 
9 
8 + 
97 
91 + 
n. The same in 1921 
125 
18 + 
568 
81 + 
III. Open pastured wood, 1920 
2 
4 + 
43 
95 + 
IV. The same in 192 1 
I 
3 + 
27 
96 + 
On May 28, 1920, a plot on the north side of the greenhouse was planted 
with several monoecious individuals and a considerable number of staminate 
individuals, the leaf surface and the roots being reduced. The intention 
was to give the plants an environment that would keep the staminate 
plants staminate and change the monoecious individuals to staminate 
individuals. In the spring of 192 1, three of the originally monoecious 
plants bloomed ; two were monoecious and one was pure staminate. Seven- 
teen of the originally staminate plants bore inflorescences, of which sixteen 
were pure staminate and one typically monoecious. This monoecious 
plant had changed from the staminate condition in spite of the fact that the 
nutritive supply was decreased. Presumably, its bud for the following 
year's shoot was already sufficiently developed to have its sex determined, or 
else it had a sufficient amount of the proper food supply stored in the corm 
to cause a reversal of sex notwithstanding the unfavorable treatment given. 
But the important result is that in A. Dracontium staminate individuals 
do reverse to monoecious individuals, and that monoecious individuals 
do change to staminate individuals. The conditions of sexuality are in 
general the same as in Jack-in-the-pulpit. Sex in the green-dragon is a 
condition and not dependent on homozygous and heterozygous hereditary 
factors. The general hereditary constitution is apparently such that when 
the female state is established in the incept of the monoecious inflorescence, 
the condition is not strong enough to continue through the entire develop- 
mental cycle; but after the bud has developed a zone of carpellate flowers, 
the sexual state is reversed, perhaps through senile changes of the cells, 
specific differentiations, or exhaustion of available food supply, and only 
staminate flowers are produced above. Arisaema Dracontium is, therefore, 
a species with decidedly male characteristics and can be compared with a 
similar condition in the gametophyte generation of Selaginella Kraussiana 
and other like species where, because of the small percentage of mega- 
sporophylls and megaspores produced, the female gametophytes are out- 
numbered to an extreme extent by the males; or it may be compared with 
such animals as the European cuckoo bird, which is said to produce about 
four males or even more to one female. 
