338 PRACTICAL COURSE IN BOTANY 
upper part, the neck, which is perforated by the neck canal, 
ca. The venter contains the egg cell, 0, and the ventral canal 
cell, vc. The neck canal is filled with small cells which, 
at maturity, dissolve into a mucilaginous substance that 
swells on being wet and discharges itself through the top 
of the neck, leaving an open passage to the venter, where 
the egg cell is ready to be ferti- 
lized. 
Make a drawing of the section as 
seen under the microscope, labeling 
all the parts. 
392. Fertilization. — In the liver- 
worts, and in cryptogams generally, 
this process has to take place under 
water, as the antherozoids are motile 
only in a liquid, but the amount re- 
quired is so small that a few drops 
of rain or dew will enable them to 
make their journey to the archego- 
nium. The mucilaginous substances 
discharged from the neck canal at- 
tract them to the mouth of the open- 
Fras. 480, 481.—480, young ing, one or more of them penetrates 
SrChPEOnIET OF -M. polymer. 46 ihe egg cell, and fertilization is ac- 
pha; v, ventral portion; 0, egg 
cell; 2c, ventral canal andcells; complished. Do you see any anal- 
ca, neck canal with cells; 481, : : 
the same ready for fertilization O8l€S between this and the same 
after discharge of the mucilagi- function among flowering plants? 
: (250, 251.) 
393. The spore case. — After fertilization the egg becomes 
an odspore, capable of producing a new plant. Instead, 
however, of separating from the mother plant and giving 
rise to an independent growth, it germinates within the ar- 
chegonium and produces there a small, stalked body, called 
a sporogonium, or sporophyte, which at length ripens into 
a spore case, as shown at f, Fig. 479. At maturity this 
capsule-like sporophyte ruptures at the apex, and discharges 
