8 .CRYPTOGAMIA ANTARCTICA. [Auckland and 
They are roundish, on pedicels as long or longer than themselves, generally solitary in the axils of the Perigonial 
leaves, which are somewhat ventricose at the base, but not otherwise different from those of the stems, 
The anatomy of the theca of Sphagnum is very peculiar. What appears the columella does not extend, as in other 
genera, to the summit of the theca, but is a continuation of the seminal sac, ascending from the bottom of the theca, 
and forms a portion of the same membrane which also lines the under surface of the operculum, passing completely 
across the stoma, as shewn in Plate LVII. fig. VL, where the central figure is drawn from a sketch and section pre- 
pared by Mr. Wilson. 
This curious structure of the seminal sac is quite different from what obtains in most genera of mosses, and 
appears to have been misunderstood by Arnott and Greville, in whose excellent essays upon the ‘ Genera of Mosses,’ 
the columella is described as sinking, along with its opercular membrane, so low, as to assume the appearance of a 
tympanum, stretched across the interior of the theca, a little below its base (Wern. Trans. vol. iv. p.131.); their figure 
however does not represent the columella bearing any residua of the opercular. membrane, but merely having the base 
of the seminal sac drawn up into the axis of the theca in the form of a cone, which is its true origin. The more 
striking peculiarities of the sporular sac of Sphagnum are these ; 1st. its forming a bag or cyst without any orifice : 
2nd, in the drawing up of the base of this bag into the axis of the theca, but not so far as to reach the level of the 
stoma, nor consequently the upper surface, or that opposite the base, which remains entire and stretched across the 
stoma. Ifthe columella were carried up to the same height as in other mosses, an obliteration of the upper part of 
the sporular membrane would be caused by the perforation of the latter, (if we regard the metula as a portion of the 
columella), or else there would ensue a mutual cohesion of the membranes of columella and sac. 
Sphagnum may be considered to possess the simplest form of sporular sac, the dehiscence of Ue is probably 
caused by a removal of the upper portion in the same plane as the stoma and parallel to the operculum, The next 
stage of development of this organ is, perhaps; presented in some astomatous mosses; 7 vitia*, for instance, a per- 
pendicular section of the theca in which genus exhibits the seminal sac in the form of a vertically elongated ring, 
supported in the axis of the theca by the corculum of the columella. The latter passes uninterruptedly from the 
apex of the seta to the top of the persistent operculum, thus apparently perforating the sac, by whose inflected walls 
it is lined for the greater part of its length. In this case, dehiscence and the escape of the sporules may be supposed 
* In the young state of Voitia hyperborea, of which (through the kindness of Sir James Ross), I have exa- 
mined many thecze, there is a communication between the seminal sac and the lining of the walls of the theca (thecal 
membrane), by means of conferva-like filaments such as are seen in most other mosses. Tracing the different 
membranes upwards, from the apex of the theca, I was led to believe that the same tissue formed the thecal mem- 
brane, the conferva-like filaments, and the corculum of the columella; and further, the immediate communication 
between all the surfaces of the seminal sac and the walls of the theca afforded room for a conjecture, that the latter 
“were immediately concerned in the development of the sporules, especially as before the separation of the spores 
both the thecal membranes and filaments were full of a grumous fluid, which afterwards disappears. If such a view 
be correct, the internal structure of the theca of Voitia is very simple, and consists, Ist, of stout cells forming the 
external walls ; 2nd, of a fine tissue, not only lining the former and .sending filaments to the opposite walls of the 
seminal sac, but, becoming more condensed at the base and apex of the cavity of the theca, it ascends in its axis and 
meets the descending portion in the hollow of the columella, over whose surfaces they both ramify; and 3rd, of a 
vertically elongated ring (the seminal sac) through whose centre this second membrane passes. Mr. Wilson (to 
whom I am indebted for my knowledge of the structure of both theca and cellular tissue of Sphagnum), has not been 
able, from the want of specimens, to confirm this view of the structure of Voitia; he, however, informs me, that 
* the existence of such a connecting tissue is only analogous to what is found in Gymnostomum pyriforme, whose 
sporular sac is connected with the base of the theca by a bundle of filaments ;” he also adds, that “in many Poly- 
tricha there is a distinct, almost woody, central axis to the columella, with filaments intervening betwixt it and the 
winged folds of the sporular sac which forms the outer part of the columella."—J. D. H. 
KC PERPE 
— s 
Camph 
to take pl 
from the | 
have seen | 
The 1 
mere modi 
tends to coi 
sic), ascend 
mouth of a i 
After a time, 
egress to the 
Mr, Vale 
in several res 
tubes, runnin 
tion of a leaf 
latter are deri 
Tle cells 
hering to their 
and branched. 
its surface to tl 
dificulty of de 
aware of, been a 
pressure of the 1 
The pores, 
is preserved, are 
face of the leaf, | 
leaf itself is per 
where the spire 
whence probabl 
greatly in size, û 
truncated cone; 
ened, as describe 
and each perfora 
by far most nune 
de due to the nat 
intercellular tubes 
continue reservoir 
their moisture, 
Until the de 
served the desilie 
together in fours, 
Species the surfa 
10t Wholly absen 
low the Orifice o 
Pare LY] 
ftom centre of th 
