Evans . — Branching in the Leafy Hepaticae . 
ii 
underleaf, one at the apex and the others on the lateral teeth or in a corre- 
sponding position on the sides. 
The leaf at the base of a branch shows its incomplete character by 
being undivided ; its line of attachment extends until it almost meets the 
first underleaf, very much as in Frullania. In the figure only the apex and 
a portion of the base are visible. The first underleaf differs from ordinary 
underleaves in being distinctly bilobed, thus bearing a marked resemblance 
to a normal leaf arising from a lateral segment. It betrays its true nature, 
however, by the presence of a papilla at the apex of each lobe. The second 
underleaf of the branch is normal in form and position, and the other leaves 
show no striking peculiarities. 
Lophocolea . — In this genus the leaves are distinctly succubous, and the 
underleaves are well developed, although relatively smaller than in Plenro - 
Fig. 14. Lophocolea heterophylla. Stafford, 
Connecticut (G. E. Nichols), x 27. 
Fig. 13. Pleuroclada albescens. Valais Alps, 
Switzerland (F. Camus), x 40. 
clada albescens . The branching is largely intercalary, but terminal branches 
of th e. Fndlania type are not unusual. The plant chosen to represent this 
type of branching is a small and juvenile form of L . heterophylla , an 
exceedingly common species throughout Europe, Asia, and North America. 
In the portion of the plant shown in Fig. 14 it will be seen that the leaves 
are bifid and that the linderleaves are either deeply bifid or quadrifid. The 
leaf which belongs to the same segment as the branch does not lie over the 
angle between the branch and the axis as in the species previously considered. 
It is situated instead below the branch, although its line of attachment 
extends nearly or quite to the base. The leaf is nearly as broad in the 
basal portion as normal leaves, but is undivided, the apex being sharply 
acuminate. The first underleaf of the branch is normal in position, and is 
often larger and more complex than the second underleaf. The first leaf 
is small but bifid, and is completely covered over by the leaves of the 
