Campbell. — Studies on some Javanese Anthocerotaceae. I. 479 
sporogenous tissue does not extend to the base of the capsule, but there 
is a clearly defined basal zone where it is absent. In Megaceros , on the 
contrary, the sporogenous layer can be traced to the line dividing the foot 
from the capsule. In this respect Megaceros exactly resembles Dendroceros 
(Campbell, loc. cit., Fig. 79). As in all the other Anthocerotaceae the 
sporogenous layer arises from a series of periclinal walls in the amphithecium, 
and there is thus formed a single layer of cells investing the columella 
(Figs. 43-5). These do not form simultaneously (see Fig. 43), but very 
soon the sporogenous layer is complete and is then seen to extend to the 
base of the capsule. 
The columella of the young embryo seen in cross section forms a 
nearly regular square of four cells. Subsequently, these are further divided 
(Fig. 45 b), and in the older sporophyte there may be sixteen cells arranged 
in regular quadrant fashion, or not infrequently (Fig. 58) there may be 
further divisions in some of the cells. This also recalls the larger species 
of Dendroceros. In longitudinal sections there usually appear four rows 
of cells in the columella except toward the apex, where the columella 
becomes narrow, this being especially marked in M. Tjibodensis , where 
it tapers to a point (Fig. 52). 
While in the early development of the embryo and in the details 
of the adult sporogonium Megaceros most nearly resembles Dendroceros , 
the sporogenous tissue is much more extensive and may best be compared 
with that of Notothylas. In Dendroceros and in some species of Anthoceros 
the sporogenous layer remains simple throughout nearly its whole extent. 
In the larger species of Anthoceros , e. g. A. fusiformis , it becomes double, 
while in Notothylas it is three to four cells thick, occupying relatively 
a very much larger part of the sporophyte. In the extent of the sporo- 
genous tissue Megaceros (Figs. 54, 57) is to some extent intermediate 
between Anthoceros and Notothylas. When the divisions are complete 
it is three to four cells in thickness, but the cells are smaller than in 
Notothylas , and hence the mass of sporogenous tissue is relatively less ; but 
it is very decidedly greater than in any species of Anthoceros that has yet 
been studied. 
While in Anthoceros the portion of the sporogenous layer above 
the apex of the columella has the same thickness as that at the sides, there 
is in Megaceros the development of a considerable amount of sporogenous 
tissue in the amphithecial cells lying above the layer in contact with the 
columella (Figs. 53, 56). This is especially conspicuous in M. Tjibodensis , 
where it is quite as marked as it is in Notothylas. A trace of this increase 
of the sporogenous tissue at the apex of the sporogonium is also seen 
in Dendroceros , but it is very much less marked. The development of 
sterile tissue in the apical region of the sporogonium of Megaceros is also 
greater than in the other genera. 
