THE 
HEW PHYTOhOGIST. 
Vol. IX., No. io. 
December, 1910. 
[Published December 30th]. 
THE INTER-RELATIONSHIPS OF THE BRYOPHYTA, 
By F. Cavers, D.Sc. 
V. ANTHOCEROTALES. 
T N Schiffner’s account of this family in Engler and Prantl (32), 
three genera are distinguished : Anthocevos (cosmopolitan, 
with 79 species), Dendvoceros (tropical, with 15 species), and Noto- 
thylas (temperate and tropical, with 9 species.) At the present 
time, the number of species described stands at about 120, 
all growing on damp soil with the exception of a few Anthocevos 
species, which occur on decaying wood, and of all the Dendvoceros 
species, which are epiphytic on the stems and even on the living 
leaves of tropical trees. 
In most species of Anthocevos the thallus is, as in the widely 
distributed A. Icevis , several cells thick at the middle and thins out 
to a single layer at the margin, where there are numerous growing 
points each occupying a notch. The apical growth can usually be 
referred to a single initial cell, from which segments are cut off 
above, below, and on either side. The further divisions of the 
segments are very regular; each upper and lower segment divides 
first into an inner and an outer cell, the inner cells derived from 
both segments giving rise to the central tissue of the thallus, while 
the sexual organs on the upper side and the rhizoids and Nostoc- 
cavities on the lower are derived from the outer cells of the 
segments. The thallus branches repeatedly and rapidly, and often 
in such a regularly dichotomous manner as to form a more or less 
regular disc, or rosette, of circular outline. When branching is 
about to occur, the apical cell divides so as to form a row of cells 
lying side by side, and the middle cells then grow out and form a 
projection (“ middle lobe ”) separating the two new growing-points. 
