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most by the use of a lens. In addition to these characters, 
the capsule or the receptacle which bears the spores, or 
reproductive bodies, usually splits into four valves when 
full-grown and the spores themselves are accompanied by 
spiral threads called elaters. The favorite habitat of 
hepatics is wet places, and mountains continually steeped 
in clouds yield a surprising variety of forms. Closely re- 
lated to the hepatics, and commonly included with them, 
is the group Anthocerotes; these plants may, however, be 
distinguished by the presence of a central axis or column 
(columella) in the capsule, and there are several other im- 
portant structural differences in their tissues. 
e mosses (cases 41 to 48) follow the hepatics in order 
of development and complexity; they differ from them, 
however, in many respects. The stem and leaves have 
more differentiated tissues, and the leaves usually have a 
midvein. ‘The moss capsule generally opens by a lid under 
which there are commonly appendages to aid in scattering 
the spores, which in this case are not accompanied by 
spiral threads as they are in the hepatics. The mosses 
fall into three primary groups: First the ‘‘peat-mosses”’ 
(Sphagnum), which differ from the rest of the mosses in 
the development of the tissue-structure of the capsule and 
in the spores; they grow in swamps and other wet places, 
and their accumulation forms peat. The ‘‘black mosses” 
(Andreaea) differ from both of the other groups in the 
valvular capsule; they grow on dry rocks. The true mosses 
vary exceedingly in size and aspect. An examination of 
the specimens in the exhibition cases will convey to the 
mind a better idea of this group than may be gained from 
a description. They grow under all kinds of conditions 
from dry rocks to deep water. Many of the kinds grow on 
almost any kind of rock, earth, or bark of trees, while 
certain ones are more particular as to their habitat. Some 
will thrive only on limestone, which they often gradually 
disintegrate and partially preserve in the masses of closely 
set plants as a calcareous tufa; other species prefer ground 
