154 BOTANICAL GAZETTE [OCTOBER 
basal portion of the embryo would seem to warrant the writer’s 
interpretation. 
While it may be probable that the future sporogenous tissue is 
cut off from the capsule wall by the first periclinal walls which form 
in this portion of the embryo, it does not show differential staining 
until later, when the physiological differentiation becomes evident, 
as shown in the more massive 
EIS Glo\ capsule (fig. 46) of the winter 
GE olojop condition. Cavers (4) holds 
to the view that “‘the capsule 
. wall in Marchantiales is not 
>. differentiated until a rela- 
o\ tively late stage; that is, the 
separation of the archespo- 
rium is not determined by the 
first periclinal divisions in the 
young capsule.” Further de- 
velopment takes place the 
succeeding spring, with the 
sporophyte reaching ma- 
turity, in this latitude from 
the middle of May to the 
middle of June. The writer 
: has not made a careful study 
Fics. 42-47.—Figs. 42-44, transverse : ? 
sections of embryos showing first periclinal of sporogenesis, Haupr's 
walls; fig. 45, longitudinal section of young Paper giving an account of 
embryo late in November (note prominent the features in detail. 
basal cell); fig. 46, embryo in winter con- 
dition; 350; fig. 47, base of embryo in Calyptra and involucre 
winter condition (large basal cell quite con- 
spicuous). The calyptra grows apace 
as the embryo develops, be- 
coming several layered and relatively somewhat massive. The 
longitudinal axis of both embryo and calyptra becomes more and 
more vertical, until finally it is practically perpendicular to the 
substratum, with the neck of the archegonium hanging downward. 
The calyptra incloses the sporophyte until spring, when the rapid 
growth of the latter breaks through the slower growing calyptra 
