398 
Mottier. — Contributions to the 
As was stated in the preceding pages, there is marked 
variation in the size of the sporogonia of Notothylas. 
Fig. 20 represents a longitudinal section of a young sporo- 
gonium, differing considerably from all others observed — of 
the same size — especially in regard to the foot, which seems 
to have developed very little. From the fact that it was in 
a very slender lobe of the thallus, and that its cells with 
small nuclei were relatively poor in protoplasm, it is possible 
that we have here a starved specimen. No other similar case 
was observed. 
From the history of development here observed it is evident 
that the columella of Notothylas (wherever it occurs) is of 
primary origin, and this, together with other parts of the 
sporogonium, agrees closely with Anthoceros. There is, there- 
fore, a closer relationship existing between this and the 
other genera of the Anthoceroteae than has been previously 
supposed. 
The Archegonium, 
The development of the archegonium was found to agree 
with the account of Janczewski and Leitgeb 1 . My prepara- 
tions, however, showed the various stages very beautifully, 
and a few of these will be figured for the purpose of com- 
parison (Figs. 22-24). In the mature organ, however, slight 
differences were noted. In both genera, the neck-cells of the 
archegonium are quite inseparable from those of the thallus ; 
but in younger stages, in Notothylas , some of the neck-cells 
could be easily distinguished from the adjacent cells of the 
thallus by their denser contents. Occasionally the neck 
projected slightly above the surface of the thallus. In 
Notothylas , the neck-canal-cells were always fewer in number 
than in Anthoceros , amounting to three, not including the cap 
(Deckelzelle of Leitgeb), in the former (Fig. 22) ; and five or 
six in the latter, but not exceeding six in any case observed. 
In this respect, Notothylas resembles more closely certain 
Loc. cit. pp. 20, 21. 
