Io THE MICROSCOPICAL NEWS, 
leafy stems as lateral buds, but in the Phascacez, Pottia, and 
Physcomitrium, the protonema remains even after the capsule has 
been developed, and all the stages of development are present 
simultaneously. ; 
The formation of the protonema, as well as the structure of the 
capsule, differs from the typical Mosses in the Sphagnacee, 5S. 
acutifolium, Fig. 12; Andrezacee, and Tetraphidee, TZ’ pelluada, 
Fig. 13, and consists, when growing upon a firm substratum, of 
a flatly expanded plate of tissue. In Andreza, according to Kuhn, 
the contents of the spore divide, while still within the closed exo- 
spore, into four or more cells, and a tissue is thus formed similar 
to that produced in the spores of some Hepaticez, as Radula and 
Frullania. 
The Moss stems are developed from buds, which arise as lateral 
branches upon the protonemal filaments, and never at the end of 
them. 
Fig. 11. 
From observations made by Shuck and Miller, the principal 
filaments of the protonema and the larger rhizoids are considered 
by Sachs to be very rudimentary, much-elongated Moss stems, as 
the oblique septa formed in the elongated apical cells are regularly 
inclined spirally in three or more directions; just in the same 
manner as the principal walls of the segments of the trilateral 
apical wall of the Moss stem. These walls do not, however, inter- 
sect, as in the stem, since the segments are so long. 
Each segment is capable of forming a protuberance immediately 
behind the front wall, which becomes shut off by the foliar wall, 
and after elongation is again divided into two cells by a basal wall 
as in the segments of the stem ; the upper of these cells corres- 
ponds to the mother cell of the leaf, while the above developes a 
lateral branch as in the case of the Moss-stem. Fig. 11. 
The position of the walls of these cells is precisely similar to 
that of the corresponding walls of the stem, the protonema differ- 
ing from the stem simply in the distance of one segment from the 
other, so that a Moss-stem is a protonemal filament with more 
