422 PHARMACEUTICAL BOTANY . 
The archegonial receptacles consist of a stalk surmounted by an 
umbrella-shaped disk with about nine somewhat pendant rays. 
On the lower surface of the disk the archegonia arise as flask- 
shaped structures which hang downward. 
The anthertdia are somewhat oval and consist of a wall of sterile 
cells surrounding a mass of sperm mother cells. The latter give rise 
to the sperms or antherozoids which are biciliate. 
The archegonia are flask-shaped structures, each of which 
possesses a basal bulbous part called the venter and an elongated 
tubular part termed the neck. The flask has an outer layer of 
stertle cells and a central axial row of cells which from the base of 
the venter upward are the egg cell, ventral canal cell and neck canal 
cells. As the archegonium matures, the horizontal walls of the 
canal cells are dissolved by an enzyme and the contents of the - 
cells are transformed into a mucilaginous mass. During wet 
weather the upper portion of the wall of the mature antheridium 
bursts open and the biciliate sperms are liberated in a mucilagi- 
nous mass. Attracted by the substances then issuing from the 
mouths of the archegonia, they swim toward them and usually a 
number pass down the neck of the canal of each archegonium 
and gather around the egg. One of them unites with the egg 
fertilizing it and forming an oospore. The act of fertilization 
concludes the gametophyte generation. 
form a spherical mass of cells which in time become differentiated 
to form a sporophyte or asexual plant which consists of (1) a basal 
foot which attaches the sporophyte to the base of the archegonium 
and absorbs nutrient substances in solution from it, (2) a short 
stalk which gradually lengthens and (3) a capsule composed of an 
outer layer of sterile cells enclosing spores and slender, elongated 
cells called elaters. : 
Upon the rupture of the wall of the capsule the spores are 
discharged, being aided in their dispersal by the elaters found 
among the spores which, being hygroscopic and with spirally 
thickened walls, bend and twist, giving force to the process of 
spore distribution. Each spore, upon absorbing water, may 
develop into a gametophyte. 
