STRUCTURE AND DEVELOPMENT OF DENDROCEROS. 477 
these. The archesporium can be traced to the boundary between 
the foot and capsule, and resembles in this particular Notothylas 
rather than Anthoceros. 
6. The division of the archesporial cells into sporogenous and 
sterile ones is less regular than in either of the other genera, and 
the primary archesporial cells may be transformed directly into 
sporogenous ones without any further divisions. The elaters are 
composed of two or more cells and have a thickened spiral band. 
7. In D. Breutelii the spores remain undivided, but in 
D. crispus(?) they germinate within the capsule and are dis- 
charged as multicellular bodies. All the spores of a tetrad 
develop normally, and there is no abortion of a part of them, as 
described by Leitgeb for D. cichoraceus. 
8. Leitgeb's statement as to the absence of stomata from the 
capsule was confirmed. 
Dendroceros is unquestionably closely related to Anthoceros, 
from which it differs principally in the form of the thallus and the 
less highly developed sporophyte. Leitgeb * concludes that the 
division of the genus Anthoceros which includes A. vincentianus, 
A. giganteus, and others is perhaps more nearly related to Den- 
droceros than to the other species of Anthoceros, and suggests a 
separation of this section as a distinct genus. These forms 
have no stomata upon the capsule, and possess spiral elaters 
like those of Dendroceros. A careful comparison of these 
with Dendroceros would be interesting, to see how far they 
agree in other respects with it. Leitgeb cites one species, 
probably A. vincentianus, which has a solitary antheridium ; and 
à comparison of the apical cell and archegonium might throw 
light upon the relation of these forms to Dendroceros. 
In the form of the archegonium, as well the early stages of 
the embryo, Dendroceros is fairly intermediate between Noto- 
thylas and Anthoceros. Whether the type of thalius found in 
Dendroceros is more primitive than that of Anthoceros would 
be hard to say, as both forms occur among the other primitive 
Hepatics, 
* Leitgeb, Unters, über Lebermoose, Heft 5, p. 27. 
