Campbell.— Studies on some Javanese A nthocerotaceae. /. 475 
lies. The cells adjoining the mother-cell of the antheridium withdraw 
slightly from it, apparently owing to a mucilagenous degeneration of the 
inner layers of the cell walls. This mucilage forms a strongly staining 
substance outlining the young antheridia in stained sections, and with the 
growth of the tissue near it the chamber rapidly enlarges and becomes very 
conspicuous (Figs. 24, 25). 
In the youngest stage that could be recognized (Fig. 23) the mother- 
cell had divided into a small basal cell and a large terminal one. Whether 
this division always occurs is doubtful, but usually traces of the basal cell 
could be made out in the younger antheridia (Fig. 24 b). The first wall in 
the antheridium itself is longitudinal (Fig. 24), and this is probably in most 
cases at least followed by a second longitudinal wall intersecting the first. 
Following this, transverse walls arise that separate the pedicel from the 
upper portion. There next arise periclinal walls in each of the upper 
segments, by which the inner cells that develop into the sperm cells are 
separated from a single layer of parietal cells. Each of the latter finally 
develops a conspicuous chromatophore, as in other cases. The further 
divisions in the central cells follow with a good deal of regularity, and the 
limits of the early cell divisions are evident, even in the nearly ripe 
antheridium where the mass of almost cubical spermatocytes is divided 
into blocks corresponding to the early divisions of the central cell, 
a phenomenon which is of common occurrence in many other Bryophytes. 
The small size of the spermatozoids makes them unfavourable subjects for 
study of spermatogenesis, and no attempt was made to follow out the 
details. In the adult antheridia the slender curved body of the sperma- 
tozoid can be readily seen, but the blepharoplast, which is presumably 
present, could not be seen. Free spermatozoids were found to resemble 
those of ordinary Bryophytes, having the usual two cilia, but beyond 
demonstrating this point no further study was made of them. 
The two species studied differed a good deal in the form of the 
antheridia. In M. Tjibodensis (Fig. 31) the mature antheridium is nearly 
globular, and has a short stalk inserted near the centre of the floor of the 
antheridial chamber. In M. Salakensis the insertion of the pedicel is 
toward the front of the antheridial chamber, not infrequently actually on 
the anterior wall of the cavity, and the antheridium lies almost horizontal, 
as it does in Dendroceros (Fig. 29). The pedicel is much longer than in 
M. Tjibodensis , and strongly bent, in this respect also resembling Den- 
droceros, although it never reaches the extreme length found in the 
antheridium of the latter. The pedicel in both species examined has 
ordinarily four rows of cells, but it is possible that sometimes, as is usually 
the case in Dendroceros, there may be only two rows. Rarely two 
antheridia occur in a single chamber. 
Leitgeb (loc. cit., p. 19) has called attention to the occasional occur- 
M m 2 
