i IO 
F. Cavers. 
the archegonia and the developing sporogonia. In Ricciaceae each 
archegonium is simply sunk in a cavity of the thallus; in the 
Marchantiaceae they are carried up on stalked archegoniophores, 
besides being protected, singly or in groups, by involucres; while in 
Monoclea Forsteri. 
Fig. 17. A.—Longitudinal section through a receptacle containing a half- 
ripe sporogonium, covered by the calyptra, on the sides of which, towards the 
base, are borne the unfertilised archegonia and some of the mucilage-hairs. 
X35. B., C., D.—Young sporogonia in longitudinal section. x90. E.—Part 
of the capsule-wall in surface view (outer surface), showing the ends of the 
fibrous thickenings on the vertical walls of the cells. x200. F.— Part of the 
capsule-wall in transverse section. x200. G.—A cell of the capsule-wall, 
from a longitudinal section of the capsule, showing the two sets of fibres 
crossing each other on the cell-wall. x200. H. —Spore in section and part 
of an elater in surface view, x 700. 
the three intermediate families they are developed in groups on the 
free surface of the thallus and are protected by the hood-like 
outgrowth of the surrounding tissue. 
