On the Sporogonium of Notothylas. 
BY 
WILLIAM H. LANG, M.B., D.Sc. 
Botanical Department , University of Glasgow. 
With Plate XXI. 
T HE only indication of direct relationship between the Anthocerotaceae 
and any other group of Liverworts has been afforded by Leitgeb’s 1 
study of the sporogonium of Notothylas. This extended and careful investi- 
gation was carried out with special thoroughness so far as the material of 
a number of species allowed, and Leitgeb’s observations must be given full 
consideration, even if regarded as insufficient to support the view of a genetic 
connexion between the Anthocerotaceae and the Jungermanniaceae, which 
he only put forward tentatively. Recent researches on satisfactory material 
of Notothylas orbicularis have shown that the well developed columella of 
this species is not (as Leitgeb had suggested was the case throughout the 
genus) due to secondary differentiation within the sporogenous tissue, but 
is defined by the first periclinal divisions in the embryo, as in other Antho- 
cerotaceae. The lack of agreement between the facts of development in 
this species and the conclusions of Leitgeb leaves us in a state of un- 
certainty on a number of points which can only be cleared up by the 
reinvestigation of other species. The present paper is a contribution 
towards this. 
A brief outline of the progress of investigation and opinion on the 
subject will serve to make the points at issue clear. Notothylas as founded 
by Sullivant 2 was described as having a columella in its small capsule. 
Shortly afterwards another form was found by Milde 3 in Germany, and, 
mainly on the absence of a columella, was placed by him in a new genus as 
Chamaeceros fertilis . Gottsche 4 in 1858 critically discussed the question 
and collected and grouped the known species. He found that many capsules 
of Milde’s plant possessed a columella, and did not regard it as even specifi- 
1 Untersuchung fiber die Lebermoose, Heft v, 1879. 
2 Musci and Hepaticae of the United States, East of the Mississippi River. New York, 1856. 
3 Nova Acta, xxvi, 1856, p. 167. ' 4 Bot. Zeit., 1858, Beilage. 
[Annals of Botany, Vol. XXI. No. LXXXII. April, 1907.] 
