302 BOTANICAL GAZETTE [May 
ecologically equivalent, with the possible exception of Archidium 
which seems to be a degenerate type rather than rudimentary. 
The basal type among Musci seems to be that of Sphagnum, 
which connects closely with the type of Anthoceros among Hepat- 
ice. In mosses the most important improvement over Hepatica, 
in the embryogeny, is the early differentiation of at least the 
distal cell of the embryo as an apical cell, while in some cases 
the proximal cell also accepts this character and organizes the 
foot by apical segmentations. In Hepatice the distal apical 
cell is the only apical cell developed, and this does not undergo 
improvement beyond the hemispherical type, so that apical 
growth in the hepatic embryo is limited. 
Embryogeny of Riccia.— Early researches upon the embryogeny 
of Riccia glauca were conducted by Hofmeister,’ whose account 
however, was quite imperfect. His figure (/. ¢. pl. 10 fi: 9) 
shows a rather abnormally inclined basal wall. Our exact know! 
edge of the early stages in this embryog 
eny are due to Kienitz-Gerloff,’ who cor 
rected the errors in the original account 
of Hofmeister and figured the early stages 
B B (2. c. pl. 3) from the primitive ag instal 
tion to the specialization of ano 
and endothecium. Leitgeb* or 
the embryogeny of this plant and Bk 
Fic. 1.—Embryo of Riccia. CZ. Co Pl. Bi Jig: 8) 6 early ie aly 
: embryogeny with the normal slig' : : 
inclined basal wall. The accompanying figure (78: Z - 
resents diagrammatically the early stages of the Riccia em 5 
eny as determined by Hofmeister and Kienitz-Gerlof rche- 
first wall is approximately transverse to the axis ” Bo ual 
gone. Succeeding walls divide the embryo into mel 
"Vergleich. Unters. 47. 1851, 
* Vergleich. Unters. iiber die Entwickelungsgesch. 
Bot. Zeit. 32: 166. 18 
3Unters. iiber Lebermoos. 4:22. 1879. 
: jum. 
des Lebermoos-Sporoso™ 
