24 HENRIK PRINTZ [1920 
the vegetative thallus, and above all the cell-divisions, are also 
differing and very characteristic.*) 
I have never found this species in dense and maeroscopically 
visible masses, but it has very often been found associated with åa 
liver-wort rather frequently occurring on the bark of various 
trees. Associated with these two organisms were also very 
frequently to be found Trentepohlia aurea f., and these three species 
seem to constilute a rather common plant-community on trunks in 
the environs of Durban. 
As to the structure of the vegetative filaments of this plant I have 
nothing particularly to add to the descriptions already given by 
the previous authors, especially De WirLpeman, 1.c., KARSTEN, I.c., and 
HarrorT, Notes on Trentepohlia in Journal de Botanique 1889 et 1890. 
ft forms rather large and richly, but very irregularly ramified 
filaments, without any difference in main ones and branches. 
Intercalary cell-divisions do not occur, but new cells always 
originate from apical or lateral protuberances of older cells in one, 
or sometimes in several places. Such a protuberanee is at first only 
a thin-walled wart or cylindric papilla, which gradually grows in 
size and becomes spherically inflated. As shown in the figures on pl. 
XIII, this protuberance, which is to form the new cell, reaches å 
comparatively considerable size before it is separated from the 
mother cell by a wail across the narrowing. Further it is å very 
conspicuous character in this species that the membranes are 
extremely thin and delicate. At least on my old material which 
has been dried and later on resoaked, they seem to be colour- 
less. Usually the membrane is smooth; only as a rare excep- 
tion I have observed that the membrane — just as in so many 
others of the subaérial algae mentioned — may be finely erenulate, 
either on the whole of the surface, or partially only (sample no. 
154). It may also be noticed that in the samples where the speci- 
mens of Physolinum monile oceur with crenulate membramnes, the 
same feature is also to be noticed in the other subaérial algae 
associated with it, e. g. Tr. aurea f. This indicates that the above 
1) Ina paper: Haörozrerig mar» meropieii pasBuTit BOZOPOCJIM Tren- 
tepohlia lagenifera Hip. (W3x ,,Bioxornueeraro Miypnada . Moskau, 1910) 
K. Meyer reports to have observed the gametes in Trentepohlia lageni- 
fera sometimes not being liberated from the mother membrane, but ger- 
minating there after surrounding themselves with a wall. The author, 
however, is scarcely right when designating these as aplanospores 
as they have arisen from gametes, unisexual protoplasmic bodies. The, 
aplanospores are, according to their origin, of an asexual nature, and 
must be regarded as reduced zoospores. If, however, the said repro- 
ductive organs should really turn out to be true aplanospores, this 
species is also to be referred to the genus Physolinum. It recalls, for 
the rest, not a little, Physolinum monile in the shape of the cells as 
well as in their inner structure and cell divisions. 
