446 BOTANICAL GAZETTE [JUNE 
rather to show that these organs not only may not protrude but 
that the cover cells may actually be depressed. Several antheridia 
much larger than this were observed. The sperm cells, while 
perfectly normal in appearance, are considerably larger than those 
developed under the.usual conditions. 
Imbedded antheridia were not found on the prothallia showing 
an unusual origin of the egg cells. In the case of the archegonia, 
the most frequent deviation from the normal gave two egg and 
two ventral canal cells lying in the plane of the longer axis of the 
archegonium (fig. 15). There is little doubt in this case that the 
more deeply imbedded egg and ventral canal cell were derived 
from the basal cell of the young archegonium. Ordinarily this 
cell contributes to the formation of the venter of the archegonium. 
In several instances the basal cell contained a beautiful, spherical 
mass of dense cytoplasm with a large nucleus, presenting the 
appearance of a large central cell before its division to form the 
ventral canal cell and the egg cell (fig. 14). The preparations 
studied showed egg cells that were unquestionably derived from 
other cells of the venter, but in these instances the sections were cut 
at such an angle as to render the figures unfavorable for reproduc- 
tion. 
There is no evidence that these deep-seated eggs or the imbedded 
antheridia were developed in response to dryness, as was the case 
in Miss Biack’s material. The two prothallia containing each 
seven or eight abnormal antheridia and the three prothallia show’ 
ing several deep-seated eggs occurred in cultures from which sed 
large amount of material was put up, and no other prothallia 
showed any deviation from the normal. Of course the fact esau 
that these particular prothallia may have been in positions ' 
especial exposure, but, considering the method of culturing the 
prothallia, this is not probable. : 
I shall not enter into a prolonged discussion of the significance 
of these structures, since this has been so recently and so ably 
done by Miss Brack. I wish simply to emphasize the point 
which she makes regarding the bearing of these phenomena on the 
question of the determination of sex in monoecious prothallia, | 
on the problem of vegetative fusion as described by recent writers: 
