DR. 8. 0. LINDBERG ON ZOOPSIS. 193 
rotec, all three so very distinct in their development, vegetative 
and fructificative organs, that we must regard them all as proper 
families. 
The calyptra, that most peculiar organ of Mosses and Liverworts 
(plante calyptrate), must be considered separately in these three 
orders. In Anthocerotacee it must, of course, be absent, because 
in them the oogonium (central cell) lies in a small concavity of 
the thallus, and is quite naked, wanting the usual cover of cells, 
and sheltered only by the walls of the cavity of the thallus itself. 
And, indeed, the Anthocerotacee are, of Muscinee, the only ones 
which possess no veil at all. 
In Marchantiacee (Marchantiese and Ricciem) the calyptra is 
formed in the usual way by the enlarged cellular cover (at the 
top narrowed into a perforated style and stigma) around the cen- 
tral cell of the germen, which cover shelters the theca during its 
development from cold and drought. In Marchantiacee we thus 
find that the calyptra always preexists in the unimpregnated 
pistillidium (archegonium), and is the organ which I will call 
gynomitrious (from yvví, pistillum, and purpioy, calyptra). But in 
Jungermanniacee we see two different forms of cover for the in- 
creasing theca, one of which is the usual calyptra gynomitriea, the 
other an excavation in the very rachis of the female inflorescence 
(calyptra thalamomitriea). As the former is well understood and 
already mentioned above, I have now only to explain the latter. 
We will, for this purpose, select a good example, e. g. the develop- 
ment of the fruit in Zrichocolea tomentella (Ehrh.), Dum. 
In this Liverwort the young perichetium is acrogynous; and 
under it, from the uppermost axils of the true leaves, the stem is 
: elongated by an innovation from each side, rarely by only one, in 
which case the perichetium seems to be axillary and lateral; but 
really it is what is named inflorescentia oppositifolia in higher 
plants. The perichztium is at first small and short, everywhere 
covered by a felt of small bracts, filiform, branched, and intricate, 
like some Cladophore, without any constant position, size, or form ; 
also the top of it, which is somewhat convex, possesses a pretty 
dense tomentum of such, but smaller, conferva-like bracts ( para- 
Physes!). Among them are fixed on the top of the rachis or re- 
ceptacle an unusually large number of pistilidia of different 
degrees of ripeness, the central of which are most mature. When 
one of these has been impregnated, not only its central cell in- 
creases in size, but also the very rachis itself (“ubi irritutio, 
LINN. JOURN.—BOTANY, VOL. XIII. o 
