Anacrogynous J ungermanniales. 203 
divisions next occur which cut off four axial rows of cells (the 
endothecium) from a layer of outer cells (the amphithecium). The 
further development of the Aneura capsule, from this stage onwards, 
has been well described by Goebel (23) and by Bower (4). The 
amphithecium gives rise to the capsule-wall, which at a very early 
stage becomes two-layered and remains so throughout its develop¬ 
ment ; the whole of the rest of the capsule is derived from the four 
primary endothecial cells. The tissue formed by the early divisions 
of the endothecium is uniform, but this tissue soon becomes 
differentiated into two portions, which Goebel characterises as 
“independent meristems.” The peripheral cells, forming a U- 
shaped layer or band in a longitudinal section of the capsule, divide 
rapidly and contain dense protoplasm, with chloroplasts but no 
starch ; the central cells, continuous above with the apical portion 
of the capsule-wall, undergo relatively few divisions, are more 
transparent and contain starch, but no chlorophyll. As Bower has 
clearly shown, the cells produced by the inner portion of the peri¬ 
pheral band, as development proceeds, assume the characters of the 
central cell-group, so that the latter becomes more extensive, and 
the densely-staining peripheral region becomes reduced to a thin 
peripheral fringe around the sides and base of the large central 
tissue. The peripheral fringe, which produces the spores and free 
elaters and to which the term archesporium might therefore be 
restricted, now begins to grow actively and becomes more sharply 
marked off from the sterile columella, which hangs downwards into 
the cavity of the capsule. As the development of the capsule 
proceeds, the size of the sterile columella, as compared with the 
capsule as a whole, diminishes, so that in a ripe capsule of A.pinguis 
the columella extends only about one-third the distance from apex 
to base of the capsule. The columella probably serves to nourish 
the fertile tissue during the early development of the capsule, since 
its cells contain starch, but as the capsule ripens the starch 
disappears from this sterile tissue and the cells become elongated 
and acquire ring-like fibrous thickenings. Ordinary free elaters, 
pointed at each end, are developed amongst the spores, but from 
the surface of the columella (which is also termed the “elatero- 
phore ”) there grow out elater-like cells (“ fixed elaters ”) which 
project into the mass of spores and free elaters. 
When the capsule is pushed up through the calyptra by the 
elongation of the seta, the capsule-wall and also the columella or 
“ elaterophore ” split into four parts, along lines of thin-walled cells 
