CHAP. III. 
ALGACE^. 
273 
through the general mass of each plant, or collected in certain 
places which are more swollen than the rest of the stem, and 
sometimes resemble the pericarpia of perfect plants. 
Nothing which can be compared to male organs has yet 
been found in Algaceae ; but it is not impossible that matter, 
possessing the properties of pollen, may be mixed up with the 
spores, in the inside of the tubes or other bodies in which 
they are developed. The mode of propagation in Algaceae 
is extremely variable, but apparently always takes place by 
the formation of spores, either within the ordinary cells of the 
plant, or within sporangia of one kind or other. The Zyg- 
nemata have the curious attribute of forming their spores by 
the copulation of two contiguous branches. 
The terms used in speaking of the parts of these plants are 
the following : — 
1. Gongylus ; a round hard body, which falls off the mother 
plant, and produces a new individual : this is found in 
Fuci. W. 
2. Thallus ; the plant itself. 
3. Apothecia ; the cases in which the organs of reproduction 
are contained. 
4. Peridiolum, Fr. ; the membrane by which the sporules are 
immediately covered. 
5. Granida ; large sporules, contained in the centre of many 
Algaceae ; as in Gloionema of Greville. Crypt. FI, 6. 30. 
6. Pseudoperithecium ; ^ terms used by Fries to express such 
7. Pseudohymenium ; I- coverings of sporidia as resemble 
8. Pseudoperidium ; J in figure the parts named peri- 
thecium, hymenium, and peridium in other plants : see 
those terms. 
9. Sporidia ; granules which resemble sporules, but which 
are of a doubtful nature. It is in this sense that Fries 
declares that he uses the word: vide Plant, homonom. 
p. 294. They are also called Sporce. 
10. Phy comater ^ Fries; the gelatine in which the sporules of 
Byssaceae first vegetate. 
11. Vesiculce ; inflations of the thallus, filled with air, by 
means of which the plants are enabled to float. 
T 
