Campbell.—Studies on some East Indian Hcpaticae . 331 
cliffs in which are excavated the Bidi Caves, not far from Ban, in Sarawak. 
At Bau other specimens were collected growing on the ground close to 
outcrops of limestone. These specimens were fertile, that is, they bore both 
male and female receptacles ; but no sporophytes could be found. The 
substratum where these fertile plants were growing was much moister than 
the heaps of soft lime-dust upon which the plants first collected were 
growing, and this probably accounts for their greater luxuriance and the 
development of receptacles. 
The sterile plant (PI. VIII, Fig. 1, a) is a delicate ribbon-like thallus with 
a faint midrib. In colour it resembles D. trichocephala , a dull olivaceous 
green, but is very much smaller than that species—or indeed than any other 
species of Dumortiera. The largest sterile specimens measured barely 
5 mm. in breadth, while some of the larger forms of D. trichocephala may 
be more than five times as wide (see Text-fig. i, A). 
The fertile plant (PI. VIII, Fig. 1, B-D, Fig. 2) differs so much in 
appearance from the sterile one that it was not at first recognized as the 
same species. The fertile branches are deeply lobed, so that they look as 
if there was a row of leaves on either side. Corresponding to each pair of 
lobes is a receptacle, sometimes five or six of these being formed in 
succession. Both male and female receptacles occur in the series, the first- 
formed one being usually, at least, male. It is not always possible to 
determine by a superficial examination whether the receptacle is male or 
female, but the former is usually more distinctly lobed than the female. 
So far as could be determined from the material at hand, both male and 
female receptacles are sessile; but as no sporophytes could be found, 
although both archegonia and antheridia were abundant, it may be that 
after fertilization the female receptacle develops a pedicel as in the other 
species of Dumortiera . 
It was supposed when the specimens were collected that the receptacles 
were really dorsal outgrowths of the thallus ; but further examination 
showed them to be really terminal structures, as in most other Marchan- 
tiaceae. Each receptacle terminates a shoot, and all except the first-formed 
one are borne on short adventitious branches which arise on the ventral side 
of the next younger shoot, near the apex. These short heart-shaped shoots, 
each bearing a receptacle at the apex, and closely linked together, give the 
series the appearance of a single leafy shoot, with a receptacle corresponding 
to each pair of leaves. Goebel 1 has noted the same phenomenon, though less 
marked, in the peculiar genus Monoselenium ; and it is possible that when 
the sporophyte of D. calcicola is found it may show that this plant is more 
nearly related to Monoselenium than it is to Dumortiera. It may be said, 
however, that sometimes in D. trichocephala similar adventitious branches 
are found (Text-fig. 2, b). 
1 Goebel, K.: Archegoniatenstudien, XIII. Flora, vol. cl, 1910, pp. 43-97. 
