ARCHEGONIUM AND SPOROPHYTE OF TREUBIA INSIGNIS 263 
The shoot branches monopodially, but neither Goebel nor Griin 
determined exactly the origin of the lateral branches, nor their rela- 
tion, if any, to the leaves. The plant may reach a length of 16 cm. 
with an extreme breadth of 2.5 cm. 
Although the general aspect of the plant is that of a very large 
acrogynous leafy liverwort, in the position of the archegonia and 
sporophyte, it is distinctly anacrogynous, i. e., the apical cell of the 
shoot is not transformed into an archegonium. Unlike most of the 
Anacrogynae, e. g., Pellia, Morkia, Pallavicinia, etc., the archegonia 
do not arise in the median plane of the shoot but are formed in lateral 
groups subtended by the scales at the base of the leaves. Goebel 
compares their position to that in Fossombronia, where the archegonia 
are also lateral in position; but in the latter the archegonia are formed 
singly and not in groups, and instead of being protected by a distinct 
scale are covered only by the inrolled margin of the young leaf. 
Goebel showed that the growth of the shoot is due to a three-sided 
pyramidal apical cell, very much like that of the typical Acrogynae, 
and his statement has been verified by Griin. As in most leafy liver- 
worts the ventral face of the apical cell is smaller than the two dorsal 
lateral faces. From the latter, segments are cut off, each of which 
gives rise to a leaf, but no trace of leaves (amphigastria) are produced 
from the ventral segments. 
The leaves are very large, and, except for the extreme margin, are 
composed of several layers of cells. From the ventral side of the leaf 
is developed a wing-like outgrowth which extends for a short distance 
along the ventral surface of the axis. On this wing are developed 
many mucilage-secreting papillae which exude great quantities of a 
colorless slime. Goebel suggests that the abundance of these secreting 
organs on the leaves accounts for the absence of the secretory hairs 
or scales that are so commonly found on the ventral surface of the 
apical region in most thallose liverworts. These secretory papillae 
may be single cells, or they may be stalked organs. The mucilaginous 
secretion fills a shallow furrow which occupies the ventral side of the 
midrib, and within this furrow are numerous short rhizoids. Goebel' 
found in some of the cells of the thallus oil-bodies much like those 
occurring in the Marchantiales. Similar, but smaller oil-bodies occur 
also in many other liveiworts. 
There is always present an endophytic fungus which is very 
abundant in the ventral region of the shoot, and mainly confined to a 
