1898] ORIENTATION OF THE PLANT EGG 307 
of the Anthoceros capsule capable of evolutional modification 
into the capsule of Sphagnum on the one hand, or the strobilus 
of Phylloglossum on the other, is prefigured to a degree in the 
egg. That the basal wall should not be the first wall formed is 
apparently a peculiarity not confined to this genus of plants, 
for in fern embryogeny the same irregularity has been noted. 
From the further development of the segments it is quite clear 
that the vertical wall first formed is by no means basal, as it is 
in Pilularia, and the only explanation at all satisfactory is the 
one given here, that it is in reality median or transverse. 
Embryogeny of the Jungermanniacee.—In this important family 
of Hepatice there is no new type developed. Strong distal- 
proximal specialization is universal, and the base of the cap- 
‘ular tract is converted into a sterilized stalk, so that the eleva- 
tion of the sporogenous area is brought abovt by an organ 
derived from the epibasal hemisphere, rather than from the 
hypobasal, as in Spherocarpus. In Marchantiacee, as is well 
known, the elevation of the sporogenous area is a function not 
of any sporophytic organ, but principally of the archegoniophore 
stalk which elongates, carrying up into the air the circle of 
attached Sporogonia. In Fossombronia, Pellia, Frullania, Lejeu- 
Ma, and the other Jungermanniaceez the embryogeny is of essen- 
ry the type described for Spherocarpus. An additional 
‘longation of the sporophyte is provided for in the manner 
“scribed, but in general the diagram of the Spharocarpus 
ye would suffice for that of any of the others, as for any 
OSs, 
‘ Comparison of bryophytic types of orientation and segmentation.— 
on at the figures will show that there is really but one 
thes . “$8 Orientation represented in this group. In Riccia 
e120 shar p differentiation between the epibasal and hypo- 
Ih hemispheres so far as concerns their further ee. 
lized, higher genera the hypobasal segment 1s invariably s @ 
dey \ while the epibasal hemisphere is wholly des we 
> fet into a capsular body, maturing spores with or wit 
