THE BRYOPHYTES 421 
special buds-called gemma which, upon being detached, may give 
rise directly to a new gametophyte. This is the vegetative 
method of reproduction. 
Marchantia is diecious for it produces two kinds of gameto- 
phytes, ope bearing antheridia (male) and another archegonia 
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Fic. 313.—Marchantia polymorpha. 1, Vertical section of one lobe of the disk 
of the archegonial receptacle, showing archegonia on lower surface, the group 
being surrounded by a laciniate perichaetium. 2a, 2a2, 3, 4, 5, 9, 10, Successive 
stages in the development of the archegonium. 6, 7, 8, Transverse sections of the 
same. 11, Mature archegonium with antherozoids attracted to mouth. 12, 
Transverse section of venter of mature archegonium. 13, Transverse section of 
neck of same, showing six cells. 14. Tuberculate rhizoid. 15, Transverse section 
of same. (From Small after Kny.) 
(female). There is no way of distinguishing one from the other 
until stalked structures or receptacles arise from the upper surface 
of the gametophyte. 
The antheridial receptacle consists of an erect stalk surmounted 
by a disk with an eight lobed edge. Embedded in numerous 
separate cavities of the upper region of the disk are the antheridia. 
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