THE FORMAT[ON OF SPORES IN LICHENS AND FUNGI. 
97 
In the P ijreiiomycetes the ascus contains equally a nucleus, which 
is replaced by eight spores arising simultaneously, but destitute of 
nuclei. 
M. Sachs notices an analogous fact in Peziza convexula. In the 
upper part of the ascus the protoplasm is accumulated in part 
around eight points, or ellipsoid masses. At first each of these 
masses is composed of a protoplasm, coarsely granulose, and sur- 
rounded by a clear aureole. Later, this aureole disappears, and 
each spore is well defined ; its substance becomes more finely 
granular and clearer, whilst in its focus { foyer) a vacuole is formecl, 
that is to say, a transparent drop of liquid. Eventually each spore 
becomes surrounded with a solid membrane, the vacuole disappears, 
and in the centre there is a large drop of very refractive oil, sur- 
rounded with numerous smaller drops of the same nature. 
M. de Bary says, in another place, that whether the ascus con- 
tains less than eight spores, or a much greater number, fifty or 
more, these spores are always formed simultaneously. In the asci 
of Tiiber we see at first a round globule of protoplasm, excentri- 
cally placed and coloured yellow by iodine, and around this proto- 
plasm a parietal epiplasm, which is coloured of a red -brown by 
iodine. It is in this round mass of protoplasm that the spores 
arise. In reality, in its interior, one to three round cellules are 
formed, of the size of -3^ to ’^ery vaguely limited, and 
only defined from the rest of the protoplasm by their feebler trans- 
parence. 
Nevertheless, they quickly increase in size considerably, become 
clearly defined, and snrrounded'by a solid membrane. During the 
production of these primary spores, the outlines of other new ones 
are frequently seen, and before maturity the ascus contains many 
spores, all of which are in the same state of development. At 
this epoch of maturity only, the younger spores arrive at the same 
degree of perfectness as the older ones. We do not see any nucleus 
appear, either in the ascus before the formation of the spores, 
or in the spores themselves, whatever be their age. 
An analogous phenomenon occurs in Elaphomyces granulatus. 
But here the protoplasm is arranged under the form of a thin 
parietal layer around one or more large vacuoles, so that the 
spores are produced near the wall of the ascus. 
According to the observations of M. de Bary, the formation of 
the spores in Lichens, is, in all their phases, precisely similar to the 
genesis of the spores of the Ascomyceti ; this is proved especially by 
this, that we are able, at least in certain cases, to observe in the asci 
the existence of a primary nucleus before the formation of spores. 
According to my own special researches in Physcia ciliarh 
(L.), the primitive nucleus really exists, and is found in the upper 
portion of the claviform ascus before the production of the spores. 
The ascus is filled with a protoplasm nearly uniform in density, 
and possesses a thick and very turgescent wall. The nucleus is 
