STRUCTURE AND DEVELOPMENT OF DENDROCEROS. 467 
On the Structure and Development of Dendroceros, Nees. By 
Doveras Hoventron CAMPBELL, F.M.L.S., Professor of 
Botany, Stanford University, California. 
(Prates 21 & 22.) 
[ Read 21st April, 1898.] 
Tar Anthocerotacex stand very much alone, and their affinities 
with the other Archegoniates have given rise to much discussion. 
All the members of the order agree closely in the character of 
the sexual organs and sporophyte, which differ much from those 
of the other Hepatice, and the single chromatophore in each cell 
of the thallus is a peculiarity which they share with no other 
Museinez, but in which they rather resemble certain Alge. 
There are three well-marked genera of the Anthocerotacee 
which, while differing from each other in certain minor par- 
ticulars, are obviously closely related among themselves, but 
show no very clear evidences of relationship with any other 
Hepatice. These genera are Notothylas, Sulliv., Dendroceros, 
Nees, and Anthoceros, Mich. The latter genus includes the 
greater number of species and is widely distributed throughout 
temperate and tropical regions ; Notothylas, with a much smaller 
number of species, seems to belong mainly to the temperate zones; 
while Dendroceros is exclusively tropical in its range. 
Anthoceros, being widely distributed in Europe, has been the 
subject of repeated investigations; and Notothylas has been 
studied by Leitgeb *, to whose researches on the Liverworts 
80 much of our present knowledge of these plants is due. - More 
reently the development of this plant has been studied by 
Mottier +, and the present writer has considered this genus as 
vellas Anthocerosin a recent worki. Practically the only account 
of Dendroceros which is in any way complete is that given by 
Leitgeb in the work already referred to. While this observer was 
able to make out an amount of detail which is really astonishing 
considering that he had herbarium-material only at his disposal, 
Which comprised little except mature plants, there were a 
number of important points which his imperfect material obliged 
* H. Leitgeb, Untersuchungen über die Lebermoose, Heft 5. — 
t D.M. Mottier, “ Contributions to the Life-History of Notothylas,” Annals of 
i y, viii. Dec. 1894. 
ił D. H. Campbell, Structure and Development of 
Macmillan, 1895. 
LINN. JOURN.—BOTANY, VOL. XXXIII. 
Mosses and Ferns : 
2M 
