336 Campbell.—Studies on some East Indian Hepaticae. 
available for a study of the development of the sexual organs, and how far 
these may differ from those of Dumortiera remains to be seen. The adult 
archegonium, to judge from a small number of unfertilized archegonia that 
were seen (PL IX, Fig. 24), does not differ much from that of Dumor¬ 
tiera. The neck is straight, and in this respect it recalls D. velntina. As 
in Dumortiera , there is no special envelope or perianth about the archegonia, 
and the sporophyte, apart from the calyptra, is protected merely by the 
inrolled margin of the receptacle lobe, which forms a sort of pocket in which 
the sporophyte is quite concealed until it is ready to open. 
The tissues of the carpocephalum are less specialized than is usual 
among the Marchantiaceae, and in this respect Wiesnerella shows its rela¬ 
tionship to the still more reduced Dumortiera. The dorsal region of the 
receptacle contains numerous irregular air-chambers, but the stomata are 
poorly developed (PI. IX, Fig. 28) when compared with those of most 
Marchantiaceae, and there are few of them. 
In the older receptacles a peculiar phenomenon was noted, which also 
occurs in a less marked degree in Dumortiera. This is a great enlargement 
of the chromatophores in some of the interior cells (Pl. IX, Fig. 30). 
Fig. 29 shows a cell with chromatophores of the normal size for com¬ 
parison. What this hypertrophy of the chromatophores may signify is not 
clear. 
No young embryos were found, and it must for the present remain 
a question whether they are of the same type found in Dumortiera. The 
older sporophytes (Pl. IX, Figs. 23, 25) are quite similar to those of 
Dumortiera , but the foot is more clearly defined. As in Dumortiera , 
the seta becomes considerably elongated (PL IX, Figs. 13, 15), in this 
respect differing from most Marchantiaceae. 
The ripe spores are very different from those of Dumortiera. They 
are very much larger (60/x), and instead of the small papillae on the surface 
there are present very conspicuous wing-like ridges (PL IX, Fig. 27). 
Conclusion. 
It is pretty generally agreed that the most striking peculiarity of 
Dumortiera , i. e. the more or less complete obliteration of the air-chambers, 
is secondary and associated with the marked hygrophilous habit of most of 
the species. Of the species examined, D . velutina shows the least reduc¬ 
tion, for not only are the outlines of the air-chambers quite evident, but the 
characteristic assimilative tissue is present in the form of very numerous 
superficial papillate cells. In D. trichocephala , which is more strongly 
hygrophilous in its habit, the reduction of the air-chambers is much more 
complete, and in one Hawaiian species (assumed to be D. trichocephala ) the 
suppression is complete, as it is in the presumably related genus Mono¬ 
selenium. 
