No. II.] THE BRYOPHYTES OF CONNECTICUT. 23 
three longitudinal rows. The leaves vary in form from linear 
to orbicular, and, although they are sometimes toothed or 
even ciliate on the margins, they are never deeply lobed or 
divided as in some of the Jungermanniacee. Except for the 
midrib, which may or may not be present, the leaves very 
rarely show any differentiation in their cells. In prostrate 
species the plants sometimes acquire a dorsi-ventral appearance, 
and a slight differentiation in the leaves is occasionally to be 
observed. These peculiarities, however, are never so clearly 
marked as in the Jungermanniacee, and there is little danger 
of confusing the True Mosses with the Scale Mosses. The 
branching in the Bryales is always of the monopodial type, and 
is often- distinctly pinnate. In the lower forms the stem 
presents a simple and uniform structure, but in some of the 
higher genera it shows a distinct cell differentiation into 
storage, strengthening, and conducting tissues, and the same 
is sometimes true of the midribs of the leaves. 
In the majority of cases the sporophyte shows a distinct 
foot, a firm stalk, which early becomes elongated, and a highly 
complex capstile. The calyptra at first keeps pace with the 
lengthening sporophyte but soon stops growing and becomes 
ruptured. In nearly every case the line of rupture is near the 
base, and the calyptra is carried up on the tip of the sporophyte. 
As the capsule gradually enlarges, the calyptra, which is now 
cut off from its source of food-supply, dries up and splits in 
one or more places, so that it frequently falls away long before 
the spores are mature. The spore cavity occupies a relatively 
small space in an immature capsule, and is in the form of a 
hollow cylinder open at both ends, differing in this respect 
from all the preceding Bryophytes. It encloses a*massive 
columella, and is bounded by a thick wall, which, in most 
species, represents an efficient photosynthetic tissue. The 
outer cell layer of the wall forms an epidermis with stomata, 
the latter being usually restricted to the base of the capsule. 
The green cells are usually arranged in two more or less 
definite layers, one surrounding the spore cavity and the other 
lining the epidermis. These two layers are separated by a’ 
large air space in the form of a hollow cylinder. Stretching 
across the air space from one green layer to the other are 
