Anacrogynous Jungermanniales. 217 
vegetative structure, having similar leaves, iVos/oc-appendages, 
amphigastria, and antheridia, but its sporogonia have not been 
discovered. Two kinds of gemmae are produced, according to 
Schiffner (56) ; some are lens-shaped, others spherical, and both 
kinds are produced in crescent-like receptacles resembling those 
of Lunularia. The archegonia are developed in receptacles exactly 
like those containing the gemmae, the latter being produced on the 
sterile female plants ; sometimes, in fact, the archegonia occur in 
groups in the gemma-receptacles themselves. It seems probable 
that in both Blasia and Cavicularia we have an example of the 
replacement of spore-production by asexual propagation; Blasia 
is more often found with gemma flasks than with fruits, and 
apparently in Cavicularia fruits are very rarely formed and have 
not yet been discovered. 
In Fossombronia, which is the largest genus of Codoniacete, 
having nearly fifty species, the plant has the same general habit as 
that of Noteroclada, but the stem is broader, and sometimes the 
leaves are no more sharply marked off from it than in the case of 
Blasia. There are small ventral scales near the growing point (33), 
serving for the protection of the latter and soon perishing ; the 
underside of the stem bears numerous rhizoids, which usually have 
a characteristic deep reddish-violet colour. In some species, e.g., F. 
longiseta —recently described in detail by Humphrey (35)—the 
stem is thickened to form a tuber in which food is stored ; while 
in F. tuberifera —discovered by Goebel (17)—the plant periodically 
grows down into the soil, the leaves becoming greatly reduced in 
size and the end of the stem swelling to form a tuber which passes 
through a resting stage and afterwards resuming growth to form 
an ordinary leafy shoot. The antheridia are scattered singly over 
the stem, close to the leaf-bases, and are sometimes protected by a 
scale growing from the stem tissue immediately behind the antheri- 
dium. The archegonia are developed in small groups, on the 
middle or sides of the stem; after fertilisation an envelope 
(perianth) arises, as in Noteroclada, as a ring-like outgrowth from 
the stem tissue surrounding the group. The capsule-wall has an 
outer layer of unthickened cells and an inner layer of cells bearing 
thick half-ring fibres, often very irregularly arranged. The elaters 
are short and there are usually no fixed elaters, or very few, at the 
base of the capsule. Sometimes the ripe capsule dehisces by four 
valves, but more often the upper portion of the wall breaks up into 
irregular plates which are thrown off, leaving the mass of spores 
and elaters held in the saucer-like lower portion of the wall. 
