1894. ] The Evolution of the Hepatice. 359 
come finally to the group in which their development has 
looked toward something higher in the plant world. If the 
Marchantiales have elaborated the thallus at the expense of 
other parts, and the Jungermaniales have developed leafy 
axes and exhausted their energies in the elaboration of beauty 
and intricacy of foliar development, the Anthocerotales have 
ound a more important line in which to differentiate, namely, 
the development of the sporogone. And while it has resulted 
in small returns when considered from a hepatic standpoint, 
the results otherwise are commensurate with the whole range 
of higher plants from mosses to Composite 
In the Anthocerotales, the thallus has undergone only a 
slight differentiation from the primitive type; the sporogone, 
however, develops into a fleshy structure that frequently re- 
quires stomata for its transpiration processes. The capsule 
is necessarily a somewhat permanent structure and unlike all 
other bryophytes, develops its. spores continuously from above 
ownward, 
The ancestors of Anthoceros and Notothylas on the one 
hand, and the Musci on the other, were doubtless the same, 
and the line of separation between them probably commenced 
at an early day, since the elaboration of genera and species 
1s no less marked in the Musci than in the foliaceous Hepat- 
ice. 
It has further become evident that the line of development 
n. A reorganization becomes necessary as $ 
maining bryophytes can be properly co-ordinated. 
€ can then summarize the relations of the Hepatic®. 
6 ' - The group is not of recent origin. This is shown cet 
ly from the wide-spread geographic distribution of its ma 
