310 BOTANICAL GAZETTE [May¥ 
to Farmers who has carefully investigated the first segmenta- 
tions. The archegones are situated upon the lower side of the 
rather thick and massive prothallium. The eggs segment bya 
transverse basal wall followed by a median. Unlike the egg of 
Marchantia this egg of Angiopteris retains its original orientation 
with reference to the horizon, although the archegone is dis- 
placed, for protection, to the lower surface of the prothallium. 
The epibasal hemisphere is directed upward, hence away from 
the neck of the archegone, and the egg must be conceived to 
have rotated in the reverse direction to the archegone as it 
passed from the original dorsal position, as in Anthoceros, to the 
ventral position generally characteristic of the ferns. Fig. 6 
shows the position of the egg and its 
segments in the inverted archegone, and 
should be compared with fig. 3, that of 
Marchantia, where the inversion ae 
place during ontogeny and the egg 's not 
rotated. In Angiopteris and the other 
Marattiace which have been studied, this 
inversion does not take place ag io March- 
Fic. 6.—Embryo of antia, during oe ni af were 8 
Angiopteris. thallium, but has evidently resulte 12 
a slow adaptation. Opportunity is . 
been given for the egg to change its position from = 
time as the slight inclination of the archegone made — 
if it was to retain its normal position with reference to ee 
face of the substratum. Consequently the Angiopteris cnet 
and cotyledon bore through the prothallium, and ous 
to independent illumination and the plant develops Jett ym 
a sufficient distance above the substratum to insure spore 
tribution, 
-; plant has 
Embryogeny of Isoetes-——The embryogeny . OL ia of 
been studied by a number of observers of differen d the prope! 
ability, but, it seems to the writer, has never recelve = 
: 265. 189 
*5On the embryogeny of Angiopteris evecta. Ann. of Bot. 6: 265 
