1908] BARNES & LAND—CUPULE OF MARCHANTIA 405 
bors to outgrow them, so that they can soon be located by the depres- 
sion of the surface, as well as by their form and size (p, fig. 3). The 
depression, however, is not always well marked at this stage (cf. 
g. 5). The contents, too, are sometimes distinctive, a glandular 
appearance being not infrequently noticeable; but as all the cells 
thereabouts are rich in protoplasm, this feature is not very striking. 
The next step in development is the prolongation of one or more 
C/I 
Fic. 7-—Two gemmiparous cells Fic. 8.—Further elongation and first 
“longated; I, young air chambers; #, ¢, division of gemmiparous cells (p, p); inf 
MS 0 fig. 2. longitudinal division; w, rim cells. 
Of the gemmiparous cells into papillae (f, jigs. 5, ©); and simultane- 
Cusly the further upgrowth of the cells at the rim of the depression, 
and first on the posterior margin (w, figs. 4, 5, 6). The freé ends of 
the Papillose extensions quickly enlarge (figs. 7, 8) and doubtless 
“ecrete some of the mucus in which the whole apical region is envel- 
ped. Certain of the cells that form the rim divide obliquely (w, 
figs. 4, 8). Probably the cells thus cut off are the primordia of the 
thin lobes, which are so marked a feature of the mature cupule; for 
*ven in this early condition the rim becomes scallo — 
After some further extension and enlargement, the —e 
