10 BOTANICAL GAZETTE [JULY 
THE CAPSULE. 
In the terminal segments of the sporocarp, which form the 
capsule, the number of primary divisions is seven, as we have 
seen. Ofthese the six sections immediately divide up to form 
the three meristem layers, while the marginal cells, or at least : 
pair of these on each side, do not (figs. 79, 22). There are fo 
ultimate marginal cells in each segment arising from the divisio 
of each of the two quaternary marginal cells by a transverse 
anticline (fig. zg). On each side of the capsule we find tha 
two of these cells, in different but successive segments, becom 
considerably larger than their fellows (fig. 74), and each finally | 
gives rise to the sporangia of one of the four sori. In several 
cases these sporangial marginal cells, as we may call them, 
seemed to be the upper ones of the segments, as in the case 
figured ( fig. 14), but the material at hand of this stage was not 
sufficient to allow me to determine whether this is always true. 
Neither can I assert positively that all of the sporangia of 
sorus come from one marginal cell, but the evidence obtained 
such that I feel practically satisfied that further study will sho’ 
this to be the case. The essential thing, however, and of 
which is quite certain, is that the sporangia come from marg} 
cells, in'a way that we shall find to be similar to that found 
Marsilia, though differing in some details. 
In describing further the development of the various $ 
tures of the capsule, we shall find it best to take them up sep 
rately, and may conveniently begin with the wall develop‘ 
_ from the protodermal layer. Soon after apical growth ceases 
the young sporocarp, the portion near the tip, that is the regi 
including the four sporangial marginal cells, begins to swell 
ventrally and laterally to form the globular capsule ( Sigs. 
to a circinate coiling of the young sporocarp is seen at anyt ti 
but growth soon becomes more rapid on the lower side of 
ventral protuberance and the original apex is thus push 
