hee "s tructural i 2 Physiological Bossy, 
\ 
‘laterally on it, aré often several leaves of a somewhat dif- 
different genera, opens by means of a lid or operculum; less 
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vided with peculiar Namalls : ‘otherwise there is, as a ee 
no special epidermal tissue ey stomata, hairs, &c., even — is ae 
when this is found on the stem and reproductive organs. = 
There are never true roots; the nutriment being absorbed 
through root-hairs. At the apex of the stem, or growing 
ferent form to the rest, forming the perdgondum, a kind of 
envelope which protects the organs of reproduction growing es 
within it (Fig. 427, Iv.). ee 
The organs of reproduction at first altogether resemble 
those of the Hepatice ; but in the course of their develop- 
ment the following differences arise :—The archegonium of 
Mosses is ruptured by the young sforogonzum, and usually _ 
in such a way that the lower part remains as a sheath or 
vaginula, while the remainder is elevated in the form of a ee 
cap or calvptra, surmounting the capsular ‘fruit,’ the wx, 
theca, or sporangium ; and is finally carried away by the 
wind, rain, or other accident. Theaxis of the sporangium is 
occupied by a central column or columella, around which the ee 4 
unicellular spores are formed. In order to allow these to 5 
escape, the sporangium, which varies greatly in form in the 
often, in the Andrezeaceze (Fig. 429), by four longitudinal 
slits, or, in the Phascacee, irregularly. The opening re- 
sulting from the operculum being thrown off, is called the 
stoma ; its margin is either smooth (gymmnostomous), or Is 
furnished with two rows of cilia or teeth of beautiful form, =~ 
constituting together the perzstome (Fig. 430), the nature of __ ~ 
which furnishes a character for the classification. of the i i. 
genera. ‘The antheridia are usually in groups, and are sur- — ee 
rounded by an envelope of peculiar leaves, the perzgonium — a 3 
(Fig. 427 Iv.). Among the antheridia are filiform struc- Sm 
antheridia produce a number of extremely minute anthero- — ti | 
zoids (Figs. 427 v., 428)|. On germination the spore puts — a e 
tures—possibly abortive leaves—the paraphyses, [The ~% 
out first of all a pro-embryo, which is either filiform, when it 
