DR. 8. O. LINDBERG ON ZOOPSIS. 197 
as in the Bryinee: in these latter, however, the protonema * 
nurse produces several new plants and is much more branched. 
The stem is narrow, terete, and normally foliate, or broad, flattened, 
and bearing leaves on its underside, in the former sometimes 
covered with a layer, or layers, of larger cells of epidermis not un- 
like what is seen in Sphagnacee, in the latter very often showing 
within many large air-holes and numerous stomata in its upper- 
side. The leaves are most multiform, and of more diverse kinds 
than in Bryinee, as nearly all Liverworts bear true vegetative 
leaves, amphigastria, bracts, and colesule ; they are fixed on the 
stem longitudinally or transversely with all possible intermediate 
angles of adhesion; sometimes they are alternate, sometimes op- 
posite and connate with each other and with the interjacent am- 
phigastrium ; in form both they and the amphigastria are most 
variable, from reniform, or round and entire, to penicilliform, and 
dissect in fine thread-like segments; moreover the leaves are 
often furnished with one or several ventral lobes, subulate to pouch- 
like; these are formed by only one layer of cells, and want all trace 
of the nerve of mosses T. What has been said about the leaves is 
also applicable to the female and male bracts. The pistillidia 
(archegonia) are fixed on the top of a usually very short branch 
growing out from the axil of an amphigastrium, or on the top of 
the stem itself and of the secondary or tertiary branches (inno- 
vations) from axils of true vegetative leaves. As far as I know, 
no paraphyses have been found in the female inflorescence, except 
in some thalamomitrious forms. The fruit is enveloped by a 
proper pouch as long as it is unripe, after maturity the seta be- 
gins to grow out and becomes elongated ; the covering pouch is 
formed by the cellular tissue around the original central cell 
(calyptra gynomitriea), or by the excavate receptacle of the female 
‘inflorescence (e. thalamomitriea). The inside of the fruit, when 
its wall is cleft into valves, shows beautiful annular cells; the 
valves are usually four, straight, or seldom twisted, but some- 
times only one (Monoelea), or two (Anthocerotacez), or more than 
* The prothallium of ferns is, in physiological respects, an organ widely dif- 
ferent from the protonema of Livermosses and Mosses, andit may, from bearing 
the organs of generation, be called gamothallium. "M 
+ In the base of the leaves of Nardia revoluta, from Dovrefjeld, in Norway, I 
have observed that the cells in the middle are arranged in two layers. The obscure 
nerve in the leaves of Diplophyllum albicans is formed by only one layer of 
cells, just as the nerve in the female bracts of Hypopterygium japonicum. 
