218 . - BOTANICAL GAZETTE ‘  [warcH 
_from one state to the other without any reference to chromosome 
segregation or combination which are the ordinary causes of 
Mendelian phenomena. 
10. Sex is subject to experimental control in the individual 
in such dimorphic, dioecious species as hemp, and such control can 
be exercised in various ways by changing the ordinary factors of 
environment, and, therefore, presumably also by chemical and 
physical stimuli of various kinds. 
Oxu10 STATE UNIVERSITY 
CoLumBus, OHIO 
LITERATURE CITED 
i Davey, A. J., and Grsson, C. M., Note on the distribution of sexes in 
M 
1917. 
2. PRICHARD, F. J., ee of sexin hemp. Jour. Heredity 7: 325-329. 1916. 
3. SCHAFFNER, JOHN H., The expression of sexual dimorphism in heterosporous 
conga br a dat. Sci. 18: 101-125. 191 
4. get of the dioecious denice} in Morus alba and Salix 
sitoglaiouaal: hio Jour. Sci. 19: 409-416. 1919. 
—, C sar reversal of sex in deceit. Science N.S. 50: 311-312. 
1919. 
6. Stout, A. B., Intersexes in Plantago lanceolata. Bot. Gaz. 68: 109-1 33« 
1919. 
7. YAMPOLSKY, ae B con ttem of sex in Mercurialis annua. Amer. 
Jour. Bot. 6:410-— 1gIQ. 
, ox interradation in the flowers of Mercurialis annua. Amer. 
Jour. Bot. 7:95-100. 1920 
8. 
EXPLANATION OF PLATE XI 
All the figures are slightly magnified 
Fic. 1—Normal staminate flower from staminate plant just before 
dehiscence of anthers. 
Fic. 2.—Normal carpellate flower from carpellate plant; perianth is 
sheath with oblique limb; sheath or calyx cut open to expose ovulary 
Fic. 3.—Nearly perfect carpellate flower from base of staminate inflores- 
cence on staminate plant; 4 sepals fused together; side of calyx torn open to 
se ovulary; in staminate plants usually most perfect carpellate flowers 
develop first. 
. 1G. 4.—Stamen with stigma; from staminate plant. 
5.—Ovulary from carpellate plant with stamen growing from one 
side; go oa is flat on side from which anther projects. 
