104 Humphrey , — The Development of 
to the growth of the sporogonium above the involucre the capsule is 
already very dark-brown or black, and to all appearances the spores are 
ripe. 
The capsule bursts in a manner characteristic among the Junger- 
manniaceae, splitting irregularly into four valves which turn back, exposing 
the mass of spores and elaters. The development of the elaters parallels 
in rate that of the spores, the spiral thickening appearing at about the 
time of the differentiation of the spore-crests. In a few cases much 
deformed nuclei were observed in elaters, in which the double spiral 
band was very prominent, but in the fully mature elater all trace of such 
a structure seems obliterated. Judging from its appearance at different 
stages in the development of the elater it undergoes structural changes 
that render it incapable of differentiation by use of stains, and, though it 
may still be present in the mature elater, it is not recognizable from other 
bodies sometimes present upon the inner surface of the wall. The mature 
elater attains a length varying from 150 /x to nearly twice that length. 
The capsule-wall is normally bistratose, the cells of both layers 
commonly bearing incomplete annular-like thickenings, though, in the 
original description of the genus, these thickenings are described as 
occurring only in the cells of the inner layer. In the material used in the 
preparation of this paper the wall in many cases appeared as in Fig. 64, 
PI. VI, in which it is readily seen that the development of these bands 
is by no means as constant a character in the outer cells as in those 
of the inner layer, and might quite easily be overlooked. 
Viewed en face , these annular bands appear as in Fig. 63, PI. VI, and 
are by no means as regular as those described by Cavers 1 for Preissia 
commutata , Targionia hypophylla , and Monoclea Forsteri. The calyptra, 
previous to the ultimate elevation of the capsule, is very closely applied 
to it, in fact so closely does it fit over the capsule as to make it sometimes 
difficult to distinguish its individuality from the capsule-wall-cells them- 
selves. As soon as the seta begins to lengthen the calyptra ruptures, thus 
exposing the nearly ripe capsule. 
The foot, somewhat globular in form, attains a relatively greater size 
than the corresponding structure in Sphaerocarpus . Its basal outline 
is irregular, owing to the development of cells that project (Fig. 62, PI. VI) 
half or more of their diameter beyond the average limits of the foot. 
The cells of the foot, especially those in the basal portion, are very rich 
in granular protoplasm, each possessing a conspicuous nucleus as in 
Geothallus 2 . In all cases examined the foot gives evidence of a con- 
siderable growth and consequent compression of the proximate cells of the 
gametophyte. 
1 Cavers (’04), pp. 9, 33, 44. 2 Campbell (’96), ,p. 504. 
