244 Poult on . — The S time here and Life-history of 
down into the cavity. They are very abundant, and may be recognized at 
an early stage in the development of the perithecium. The periphyses are 
multicellular and contain granular protoplasm (Fig. 13). A channel is now 
formed from the apex of the cone through the thalline covering so that an 
ostiole is formed. Fuisting finds that the ostiole is formed in a lysigenetic 
manner in Ver rue aria} 
The periphyses now line the upper part of the perithecium as a fringe 
and eventually extend through the ostiole (PL XIV, Fig. 14). 
From the hyphae forming the floor and sides of the perithecium the 
asci are developed. Each ascus is a transparent, colourless sac containing 
very granular protoplasm (Fig. 14). 
The contents become vacuolate and subsequently divide into eight por- 
tions, each of which becomes rounded off and invested with a cell wall. 
The spores are colourless and spindle-shaped (PL XIII, Fig. 1 5). They 
contain granular protoplasm in which a large quantity of oil occurs. The 
application of osmic acid or alkanin solution will show that the oil is 
diffused in the general cytoplasm, and frequently forms one or more large 
refractive granules also (Fig. 16). 
The spores are 12-16 ju, long by 5-7 \x broad when in the ascus, and 
they are invariably unicellular. After their liberation a septum appears in 
the broadest portion, so that the spores become bicellular. 
The spores usually germinate in the bicellular condition, although 
aseptate spores have occasionally been observed germinating. A colourless 
germ-tube is protruded from one or both extremities of the spore (Fig. 17, s). 
This usually becomes divided by transverse septa, and eventually branches. 
A number of germinating spores were kept under observation for two to 
three weeks. The spores were at first aseptate, but after a short time 
a septum appeared in most of the spores. A little later two more septa 
were formed, one in each half of the originally bilocular spore. At the same 
time the spores increased in size considerably. Their dimensions are 21-24 /x 
x 9-10 \x in this condition. In many cases germ tubes were put out from 
each locule of the spore (Fig. 17,^). All stages between aseptate and 
3-septate conditions were observed. Quadrilocular spores often occur in 
nature some time after their liberation from the ascus. 
Spores are frequently found germinating singly upon the surface of the 
thallus. A large number of spores, however, germinate while still in the 
perithecium and the resulting hyphae branch profusely. A closely inter- 
weaving mass of hyphal threads is thus formed (Fig. 18). This mass of 
hyphae and spores projects through the ostiole and is visible to the naked 
eye as a small white speck (the ‘ nucleus ’ of lichenologists). It is eventually 
expelled through the ostiole and floats freely in the water. 
The tendency of the ascospores to germinate en masse while still in the 
1 Bot. Ztg., 1868, pp. 369, 641. 
