ES BOTANICAL GAZETTE [JANUARY 
In the great majority of cases only one archegonium is formed 
from a single segment of each apical cell, and usually the egg of 
each develops a sporophyte. In one case, however, 2 archegonia — 
were observed which had developed from segments of. the same 
apical cell. This indicates a reversion to a condition as seen in 
Marchantia, which from the standpoint of number of archegonia 
is very primitive. The tendency 
to reduce the number of arche- 
gonia among the Marchantiales 
reaches its highest expression in 
forms like Reboulia. Cavers has 
also reported that in Reboulia occa- 
sionally 2 archegonia may be pro- 
duced in the same receptacle notch. 
The apical cells of the female 
receptacle are checked by the for- 
mation of the archegonia and soon 
become lost. The lobes which de- 
velop between the archegonia grow 
entirely by intercalary divisions. 
Slender filaments arise below 
each archegonium, and grow to a 
considerable length. The filaments 
become quite numerous in each re- 
ceptacle notch, and persist until 
the spores are shed. ‘They are 
probably protective in function. 
Fic. 21-—Venter of mature arch- The mature egg is oval and con- 
egonium showing egg ready for z : 
fertilization, 660. tains many plastids and several 
large oil globules (fig. 21). These 
oil drops are much larger than those found in the cells of the 
thallus, and they persist in the early stages of the embryo. The 
mature egg does not develop a cellulose wall until after fertilization. 
The number of lobes developed by the mature female receptacle 
corresponds with the number of growing points organized in the 
young receptacle. The lobes are not conspicuous. In their 
paper Cu. and R. Dovurn distinguish very carefully between the 
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