1908] BARNES & LAND—CUPULE OF MARCHANTIA 407 
gemmiparous cells, so that each basal cell ultimately becomes the 
center of a group. 
As the primordium of a cupule grows older, the number of gemmip- 
arous cells forming its floor is increased by longitudinal (anticlinal) 
divisions (j, figs. 8, 9). The new floor cells so produced grow into 
Fic. 11 
Fics. 11, 12,—Further development of gemma cell (now triple) 
and rim (w). 
Thus the gemmiparous 
Papillae and soon produce gemma cells. 
linal division of the prim- 
area is increased in two ways: by the antic 
Ordial cells, and by a scailak aiien of basal cells that have borne 
Or are bearing gemmae. ‘The tissues adjacent grow rapidly, leaving 
the floor of the cupule soon far below the general surface (fg. 12), 
and the rim continues to outgrow the developing gemmat uae - 
embedded in mucus. The antero-posterior diameter of the young 
