78 
AMERICAN JOURNAL OF BOTANY 
[Vol. 9 
Conclusions 
The foregoing study shows that sex in Arisaema is dependent on a 
functional state and not on hereditary factors; that the sexual state is 
readily controllable and is reversible in either direction, the male to the 
female or the female to the male, and then back again; and that the di- 
morphism which appears in the inflorescences of these diploid organisms 
cannot be due to homozygous and heterozygous factors or chromosome 
constitutions. 
The condition of affairs found in Arisaema is in perfect agreement with 
that discovered by the writer in Cannabis sativa (5) and by Yampolsky in 
Mercurialis annua (7), which are very different types of plants and belong 
to different subclasses of a different class. The factorial hypothesis of 
sex cannot be entertained by botanists, and it is the writer's conviction 
that sex in the higher animals is no more determined by Mendelian factors 
than in plants and that chromosome differences where they exist are merely 
indicators of sex and not determiners. Chromosome differences may in- 
fluence the metabolism of the cell and thus influence the determination of 
sex, but it is possible to overcome this influence in the cell and to cause a 
reversal of the sexual state even in the presence of an allosome difference. 
In fact, the sexual state is commonly reversed in the somatic cells of animals 
through various external causes, as by the injection of proper hormones, 
removal of sex glands, etc. 
In nature, we see quite generally the existence of positive, negative, 
and neutral conditions, and the physicist is inclined to interpret these 
conditions in terms of positive and negative electricity. Whatever the 
fundamental cause of the positive and negative states of matter will be 
found to be, it will probably also give the clue to the nature and cause of the 
remarkable duality and dimorphism which we call sexuality and which is 
a characteristic of all plants and animals except the very lowest. 
LITERATURE CITED 
1. Atkinson, G. F. Experiments on the morphology of Arisaema triphyllum [Abstract]. 
Bot. Gaz. 25: 1 14. 1898. 
2. Gow, J. E. Observations on the morphology of the Aroids. Bot. Gaz. 56: 127-142. 
1913- 
3. Pickett, F. L. A contribution to our knowledge of Arisaema triphyllum. Mem. Torrey 
Bot. Club 16: 1-55. 1915. 
4. Schaffner, J. H. The expression of sexual dimorphism in heterosporous sporophytes. 
Ohio Jour. Sci. 18: 101-125. 1918. 
5. . Influence of environment on sexual expression in hemp. Bot. Gaz. 71: 197-219. 
1921. 
6. . Reversal of the sexual state in certain types of monoecious inflorescences. Ohio 
Jour. Sci. 21: 185-200. 1921. 
7. Yampolsky, C. Inheritance of sex in Mercurialis annua. Amer. Jour. Bot. 6: 410-442. 
1919. 
Columbus, Ohio 
