14 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 
until they are mature. The sporophyte is much simpler than 
in any of the other Bryophytes and consists of a spherical 
capsule only, which absorbs through its entire surface. The 
capsule contains nothing but spores, and these are at first 
enclosed by the capsule wall, consisting of a single layer of 
cells. As development advances, this wall gradually disap- 
pears, and the mature spores lie free within the calyptra. They 
are set free by the decay of the surrounding tissues of the 
gametophyte, and are dispersed largely through the agency 
of water. 
The Marchantiacez are all terrestrial, some of them grow- 
ing on shaded rocks or in their crevices and others on damp or 
wet earth. The thallus is more highly differentiated than 
in the Ricciacee, and in the larger species sometimes reaches 
a length of twenty centimeters or more and a width of ten 
millimeters. The branching is normally but not invariably by 
forking. The New England species are more or less peren- 
nial but some of them develop sporophytes during the first 
year. 
Except in a few genera which do not occur in the eastern 
United States, the archegonia are borne on modified branches 
or outgrowths of the thallus known as carpocephala. These’ 
consist of two parts, an apical discoid or conical expansion 
and a basal cylindrical stalk. Sooner or later the stalk elon- 
gates and carries the expansion, to which it is attached in a 
peltate manner, high up above the surface of the thallus. As 
the sporophytes mature, they extend horizontally from the 
margin of the expanded portion or else hang downward from 
its lower surface. They are more complex than in the Ric- 
ciacez and not only develop a capsule with a persistent wall but 
also a foot and a short stalk, although the line of demarcation 
between the two latter organs is not always clearly defined. 
The spore cavity contains not only the spores but also a large 
number of peculiar bodies known as elaters, each of which 
consists of a long and slender cell with a thin cell wall, 
strengthened on the inside by one or more spiral bands of 
thickening. When the spores become mature, the stalk 
elongates slightly, the calyptra is ruptured, and the wall bursts, 
either by means of irregular valves extending backward from 
the apex, or else by a circular line, which leaves the basal 
