MOSSES AND LIVERWORTS 109 
the sporophyte in Riccia is very simple, recalling that 
of Coleochete (Fig. 10, C) among the algz, and there 
is no difficulty in understanding how a sporophyte of 
the type of that in Riccia may have originated from 
that of Coleochate. 
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Fic. 28 (Development of the sporophyte in Hepaticew).— A, young, em- 
bryo-sporophyte of Targionia ; 1, 11, the first division walls in the fertil- 
ized egg; B, longitudinal section of the young sporophyte of Riccia, in- 
cluded within the archegonium, ar; all of the cells, except a single 
peripheral layer, produce spores ; C, longitudinal section of the young 
sporophyte of Sphzrocarpus; only the upper part produces spores, the 
lower half forming an organ of absorption, the foot, f; D, a similar 
section of the embryo of Anthoceros; the nucleated cells represent 
the archesporium or sporogenous tissue; E, cross-section of an older 
sporophyte of Anthoceros, showing the small amount of sporogenous 
tissue, sp; F, section through a spore-tetrad of Fossombronia longiseta ; 
only three of the four spores show; G,a ripe spore of the same species ; 
H, an elater. 
The first result of fertilization is the formation of a 
cellulose membrane about the egg, which thus is trans- 
formed into a spore directly comparable to the resting- 
spore of such an alga as CEdogonium. Here, however, 
instead of remaining at rest for a long period, it ger- 
minates at once. It first divides by a transverse wall 
