376 REPRODUCTIVE ORGANS OF HEPATICACEA. 
contained a number of small sperm-cells; and their walls are 
usually formed of a double layer of cells. When ripe the an- 
theridium bursts and discharges its contents; the sperm-cells 
also burst, and each emits a single antherozoid, in the form of a 
spirai thread with two or three coils, somewhat like those of 
Chara (fig. 857). 
The archegonia or female organs, like the antheridia, are 
differently arranged in different genera ; thus in Riccia they are 
imbedded in the substance of the frond, while in Jungermannia 
and Marchantia (fig. 832) they are imbedded in the undér sur- 
Fic. 832. Fie. 833. Fic. 834. 
Hy 
\ i P 
fo it 
\ WR  X 
; 
x 
XN 
NSS y 
WS 
Wo . 4 
Fig. 832. A portion of the thallus orthalloidstem 
of Marchantia polymorpha. r. Receptacle sup- 
ported on a stalk, s, On the under surface of 
the receptacle the archegonia are imbedded. 
— Fig. 833. Arehegonium of Marchantia. 
b. Perigone, open at its apex and surrounding 
an inner cellular case or epigone. c,c. Para- 
physes.—Fig. 834. Elaters, e, of Marchantic. 
s, s. Spores. 
face of the receptacles, 7, which are elevated above the thallus 
on stalks, s. They are usually small flask-shaped bodies, each of 
which consists of a cellular case or epigone (fig. 833), having a 
canal in its upper elongated portion which leads to a cavity, at 
the bottom of which a single free cell, called the germ or em- 
bryonal cell, is developed. The yerm-cell is doubtless fertilised, 
as in Ferns and Mosses, by the passage of the antherozoids down 
the canal until they come in contact withit. The fully-developed 
archegonia, like those of Mosses, have also at times an additional 
covering surrounding the epigone, called the perigone, which 
frequently grows up so as to form a.sort of cup-shaped covering 
