CARPOPHYTA. 167 
tically. These protophytes, which 
live in the midst of the moist tis- 
sues of the lichens, were until re- #% 
cently supposed to be parts of the 
lichen itself, and were called go- 
nidia, a term which it is still con- 
venient to use. A few lichens are 
parasitic in this way upon plants a 
little higher than protophytes. 
351. The spores of lichens are 
produced in sacs, which are either 
in discs (similar to those of Cup- 
fungi) or in cavities (similar to 
these of the Black Fungi). In 
many common species the spore- 
bearing discs (called apothecia) 
are large and readily seen (Fig. 90, 
A and B), while in others they are 
small and not easily made out. In 
other species the spore-sacs are im- 
Fie. 91. 
Fie. 91.—Gonidia of different Lich showing 
PAN 
e 
Fig. 92. 
attach it of the parasitic 
filaments: several are dividing. All highly magnified. 
Fie. 92.—A vertical section of a common Lichen (Physcia stellaris) through a 
fruit-dise, showing spore-sacs at th, intermingled with slender filaments (para- 
hyses), ¢; gonidia at g, g’; cm, the interlacing branching filaments, becoming 
harder and denseratccandh, Much magnified, 
