156 BOTANICAL GAZETTE [OCTOBER 
(3) vertical wall formation occurs in these four cells, with the ex- 
ception, commonly, of the basal cell; (4) oblique walls may occur 
in any part of the embryo, and are not uncommonly to be found in 
the apical region where they may form a triangular apical cell, 
functional in the cutting off of a few segments; (5) the foot and 
stalk are probably derived from the hypobasal cell, the epibasal 
cell giving rise to the capsule, although it may conceivably make 
some contribution to the stalk as well; (6) the basal cell of the 
row of four varies in its contribution to the tissue of the foot, at 
times apparently remaining undivided, in which case the remainder 
of the foot and the stalk is derived from its sister cell. 
4. The variations in the early embryo support. the view that 
Reboulia is a plastic form, and as such may occupy a genetic position 
among the Hepaticae. 
JuntATA COLLEGE 
Hontincpon, Pa. 
LITERATURE CITED 
1. CAMPBELL, D. H., Mosses and ferns, 3d ed. New York. 
2. CAVERS, F., On die structure and iesag of Fegatella conica. gre Botany 
18:87-120. oe. 6,7. figs. 28-31. 190. 
3. ———, Notes on Yorkshire She III. Reboulia hemisphaerica (L.) 
Raddi. Naturalist 1904:242-250. pil. 8. figs. 2-6 
e interrelationships of the Serie, New Phytol. Reprint 
no. 4. \Conbidilan: IQIl. 
Crapp, GRACE L., The life history of Aneura pinguis. Bor. GAZ. 54:177- 
193. pls. Q-12. 1912. 
. Dupter, A. W., The antheridium and male receptacle of Reboulia hemi- 
sphaerica. Amer. Jour. Bot. 9:285-295. pl. 14. figs. 24. 1922. 
. Duranp, E. J., The development of the sex organs and sporogonium of 
Marchantia polymorpha. Bull. Torr. Bot. Club 35:321-335. pls. 21-25: 
i 
an 
a 
1908. : 
8. GARBER, JOHN F., The life pind of Ricciocarpus natans. Bot. GAZ. 
37:161-177. pls. 0, 10. figs. 4. 
9. Haupt, A. W., The eons i se sex organs of Reboulia hemis phaerica. 
Bot. Gaz. 71: me —74. figs. 21. 1921. 
, Embryogeny and sporogenesis in Reboulia hemisphaerica. BOT. 
GAZ. 71:446-453. pl. 33. figs. II. 1921. 
11. Hormeister, W., On the germination, development, and fructification of 
the higher Cryptogamia. Eng. trans. by F. Curry. London. 1862. 
