196 DR. 8. O. LINDBERG ON ZOOPSIS. 
ance only with respect to the composition of families or orders, and 
their further subdivision into genera and species. 
Hepatice are superior to Bryinee chiefly by the following cha- 
racters :—The polymorphy of all their organs; the spore gives 
rise to only a single plant; their protonema is short, usually thick, 
and very little or not at all branched; even in Pellia we can 
hardly speak about such a nurse-stage, as the cells composing the 
spore are, excepting the root-cell, all stem-cells, by which struc- 
ture the spore of Pellia is near to the globule of the embryo, as 
we see it in Pyrolacee, Orchidee, &c. In some frondose forms, 
as in Pallavacinia Lyellii, Hymenophyton, &c., a fibro-vascular 
fascicle formed of distinct bast-like cells is present *; moreover 
some of them show several different kinds of spiral cells, and 
the leaves are often opposite and connate. In the true genus 
Marchantia we can easily observe a proper well-developed gamo- 
phyllous involuere; and most of them possess a peculiar organ 
(colesula) wanting in analogy to the perichetium of Bryinee. 
They are never synccious, but, for the most, dicecious. 
Besides these characters, we may consider the matter a little 
more completely. The germination of the Hepatice is very poly- 
morphous ; in Marchantiacee, Jungermanniacee frondose, and An- 
thocerotacec the protonema (i. e. the protonema of all the frondose 
Liverworts) is very short, nearly globular and bulbiform, and com- 
paratively very little differentiated from the young spore plant—in 
Frullania, Radula, and others a cellular disk, developing the new 
individual—in Jungermanniacee foliose with round and entire 
leaves, a little more elongate, thick, and seldom branched—but in J. 
foliose with lobed leaves, rather long, narrow, and branched, nearly 
* The narrow base (stipes) of the shoots of Hymenophyton flabellatum is upright, 
undivided and somewhat flat, with a central fibrovascular fascicle, which is broad 
and much flattened, like a ribbon, as in most of the ferns. In a transverse sec- 
tion the fascicle is seen to be formed in the middle by three or four layers of cells, 
but at the ends by four or six layers. It is well defined and easily separated 
from the parenchyma of the stem ; for we have only to seize it with the forceps 
and draw it out from its connexion with the latter tissue, just as we can do in 
the softer parts of the ferns; and its cells are, in the transverse section, very 
small, distinctly incrassate, and of a light-brown colour. The cells are very long 
and narrow, with acute ends, and are thus very like bast-cells, though the ends 
are not so long and acute as is usually tho case with the latter when normally 
developed. They show, too, extremely dense and fine spiral incrassations, and 
mostly break up when they are isolated (and especially towards their ends) into 
beautiful, broad, spiral bands. The central, but terete fascicle in Pallavacimia 
Lyellii is constructed nearly in the same way. 
