818 QUARTERLY CHRONICLE OF MICROSUOPICAL SCIENCE. 
an alternation of generations of the type of that met with in 
the sporocarp of Muscinee. And we may have every grade 
of development, from the simplest case, in which the sporo- 
carp appears as a mere appendage of the parent plant, of 
inconsiderable dimensions, to the most extreme condition in 
the other direction, in which the sporocarp is capable of inde- 
pendent growth, and therefore represents a second generation 
which is entirely distinct. 
The sporocarp also differs essentially from the oospore, in 
the fact that cells contribute to its formation which have not 
been directly influenced by fertilisation, and that in con- 
sequence the part of the fruit which produces the spores is 
surrounded by what—for want of a more convenient term— 
we may call the pericarp, in which no spores are developed, 
and which serves as a mere protective investment, or is sub- 
sequently draw upon for purposes of nutrition. 
In Phycomyces, which belong to the Zygosporea, it is note- 
worthy that there is a kind of anticipation of the develop- 
ment of a protective investment to the zygospore. 
CoLrocH HTE#.—In Coleochete the carpogonium (hitherto 
considered an oogonium) consists of a single cell tapering 
into a long slender canal open at the apex (fig. 12, a). Fer- 
tilization is effected by motile antherozoids (fig. 12, m), as 
the result of which the protoplasm contained in the basal 
portion surrounds itself with a firm cell-wall. Except in 
the presence of the long canal, there is nothing here which 
differs essentially from the mode of formation of the oospore 
in Vaucheria and Cidogonium. The essentiai difference 
consists in the fact that the apparent oospore grows after 
fertilization very considerably, and the cells adjacent to 
the female organs are stimulated into growth, and surround 
the fertilised female cell with a pericarp (Fig. 12,6). A 
sporocarp is thus formed, the central cell of which de- 
velops a mass of tissue, the whole of the cells of which 
produce zoospores, each of which is capable of giving rise 
to a plant similar to the original parent. Here we have 
the essential features of the oospore combined with the es- 
sential features of the sporocarp. ‘The zoospores developed 
from the central cell must be regarded as members of a 
second generation, homologous with the spores of a moss.! 
FroripeE#.—In Nemalion the carpogonium consists of a 
single cell, which is thick below and elongated above into a 
1 Braun (1851) regarded the formation of the “‘ pericarp ” in Coleochete 
as a species of conjugation analogous to what takes place in Saprolegniece ; 
‘Rejuv.’ (Ray Soc., p. 298). Pringsheim (1860) made out the true nature 
of its development (‘Jalrb.,’ vol. ii). 
