asure expelled from the mouth of the
perithecia, as is evident in species with large dark sporidia, such as
exist in the genera _Hypoxylon_, _Melanconis_, and _Massaria_. In
these genera the sporidia, on maturity, may be observed blackening the
matrix round the mouths of the perithecia. As moisture has an evident
effect in producing an expulsion of sporidia by swelling the
gelatinous nucleus, it may be assumed that this is one of the causes
of expulsion, and therefore of aids to dissemination. When _Sphaeriae_
are submitted to extra moisture, either by placing the twig which
bears them on damp sand, or dipping one end in a vessel of water, the
sporidia will exude and form a gelatinous bead at the orifice. There
may be other methods, and possibly the successive production of new
asci may also be one, and the increase in bulk by growth of the
sporidia another; but of this the evidence is scanty.

Finally, OOGONIA may be mentioned as occurring in such genera as
_Peronospora_ amongst moulds, _Cystopus_ amongst Uredines, and the
_Saprolegniaceae_ amongst the _Physomycetes_. The zoospores being
furnished with vibratile cilia, are for some time active, and need
only water in which to disseminate themselves, and this is furnished
by rain.

We have briefly indicated the characteristics of some of the more
important types of spores to be found in fungi, and some of the
modes by which it is known, or presumed, that their dissemination
takes place. In this summary we have been compelled to rest content
with suggestions, since an exhaustive essay would have occupied
considerable space. The variability in the fruit of fungi, in so far
as we have failed to demonstrate, will be found exhibited in the
illustrated works devoted more especially to the minute species.[F]

[A] Cunningham, in "Ninth Annual Report of the Sanitary Commissioner
with the Government of India." Calcutta, 1872.

[B] See "Corda Icones," tab. 2.

[C] Corda, "Icones Fungorum," vol. vi. Prague.

[D] Tulasne, "Fungi Hypogaei." Paris.

[E] Winter, "Die Deutschen Sordarien" (1873).

[F] Corda, "Icones Fungorum," 6 vols. (1837-1842); Sturm,
"Deutschlands Flora," Pilze (1841); Tulasne, "Selecta Fungorum
Carpologia;" Bischoff, "Kryptogamenkunde" (1860); Corda,
"Anleitung zum Studium der Mykologie" (1842); Fresenius,
"Beitraege zur Mykologie" (1850); Nees Ton Esenbeck, "Das System
der Pilze" (1816); Bonorde