1919]  Evans,— Notes on New England Hepaticae,—XV_ 153 
5 
glistening appearance," which Macvicar! mentions and which often 
aids in their recognition. Sometimes a reddish pigmentation becomes 
manifest in the axes and leaves, and this may change the appearance 
of the plants completely. Since, however, a distinetly red plant 
often gives rise to new growths without pigmentation, the color can- 
not serve as a basis for distinguishing varieties. 
The branches seem to be invariably intercalary in character. They 
are given off by the lateral segments and take their origin just above 
the leaves, close to the ventral end of the line of attachment. What 
induces the formation of branches is not always clear, but the cessa- 
tion of growth in an axis seems often to stand in a direct causal rela- 
tion. This cessation may be due to injury or to the development of 
archegonia. In the latter case, especially in the absence of fertiliza- 
tion, branching is almost sure to occur. The branches sometimes 
arise at some distance behind the inflorescence, but are more likely 
to develop as subfloral innovations, either between the perianth and 
an innermost bract, or between two successive bracts. The basal 
leaves of a branch are very small but these are succeeded, under 
favorable conditions, by larger and larger leaves, the branch soon 
acquiring the appearance of the axis from which it sprang. Schiffner ? 
states that he has never seen stolons in N. hyalina, and most speci- 
mens seem indeed to be quite free from them. The species does not 
lack them completely, however, and they are sometimes produced 
in considerable abundance. Even a Bohemian specimen,’ determined 
by Schiffner himself, shows an occasional stolon, indicating that these 
structures are by no means confined to American material. The 
stolons are somewhat more slender than ordinary stems and tend to 
grow downward. Their leaves are exceedingly rudimentary, and no 
'ases have been observed where a stolon gave rise to a leafy shoot. 
The leaves of N. hyalina (Figs. 1, 2) are usually somewhat imbri- 
cated, and the lines of attachment are long and oblique, bending 
abruptly downward at their ventral ends. The leaves are suborbicular, 
the broadest part being just above the base; they are normally about 
1 mm. long and wide, but vary greatly, the extremes being usually 
between 0.75 mm. and 2 mm. The apex is broad and rounded or 
1 Student's Handb. British Hepatics 134. 1912. 
? Ann. Naturhist. Hofmus. Wien 23: 135. 1909. 
3 The label reads as follows: “Flora von Böhmen. Gegend von-Hohenfurth — Schwarz- 
waldburg, Wegbéschung, 680m. 1896. 2/9. lgt. et det. Schiffner."' 
