203 
Lang . — On the Sporogonium of Notothylas. 
which Leitgeb observed in some examples. But this does not appear to 
justify putting on one side the recorded cases in which the columella was 
thinner and less distinct, or the records of its complete absence in many 
sporogonia. Leitgeb found that in sections across the basal region of such 
capsules the centre was occupied by a uniform mass of sporogenous cells. 
This observation is independent of his explanation of the origin of the 
sporogenoiri tissue from the endothecium alone ; as based on few and 
possibly abnormal embryos this is open to doubt, though even here the 
facts he records are not to be lightly put aside. 
The study of the form of Notothylas to be described below appears 
not only to provide some additional facts, but to show how the conflicting 
statements* which from the foundation of the genus have been made as to 
the presence or absence of a columella, may be reconciled. My material 
was collected in the Singapore Botanic Gardens, and since it was in 
abundant fruit, the small supply preserved in spirit has sufficed for a fairly 
complete study of the development and structure of the sporogonium. 
The form in question has dark spores, which are muriculate on the 
convex face, and thus belongs to the section A can tho- Notothylas, and differs 
from the species of E u- Notothylas (including N. javanicus from the same 
geographical region), in which the spores are smooth. Specific differences 
fn the genus are slight and indefinite, and from published descriptions and 
figures this form at first seemed distinguishable from N. Breutelii. Com- 
parison with specimens from Cuba 1 showed, however, such close agreement 
in all definite features that there seems no ground for distinguishing the 
plant from Singapore even as a variety from N. Breutelii. This species, 
which was first described as Anthoceros Breutelii in the Synopsis Hepati- 
carum, has been examined with regard to the presence or absence of 
a columella by Gottsche, Milde, and Leitgeb. The material examined by 
the two former observers showed as a rule a well-marked columella, between 
which and the wall the elaters extended. Milde, however, believed the 
columella to ultimately disintegrate, since he sometimes found it intact, 
sometimes only larger or smaller fragments, while in other cases no trace 
of it was to be found but a short stump-like portion at the base of the 
capsule. He figures a very complete columella. Leitgeb found a more or 
less perfect columella in some sporogonia. In sections of the base of other 
capsules no sterile columella could be distinguished, and on the evidence 
afforded by several embryos he regarded the whole sporogenous mass as 
derived from the endothecium and the columella as differentiated within it. 
Thus this particular species illustrates the difficulty which has been experi- 
enced in the genus as a whole of attaining a clear statement of the facts of 
structure of the sporogonium. 
1 I am indebted to Professor Weiss for the opportunity of examining authentic specimens in the 
Herbarium of the Victoria University, Manchester. 
Q 
