PARASITIC FUNGI AND MOULDS. 27 
produced in the yellow balls correspond with those 
which issue from the asci developed on the sclerotis; 
these are endogenous spores. 
Many of the parasitic fungi belonging to the genera 
Erysiphe, Spheria, Sordaria, Penicillium, etc., pre- 
sent a similar mode of vegetation, and affect a large 
number of plants. Such is the Oidiwm of the vine 
(Erysiphe Tuckert) to which we shall presently revert. 
IV. Oomycetes, MucoRINE&, OR MOULDS, PROPERLY 
SO CALLED; PERONOSPOREE; THE PoTaTo-FuNGUS. 
In all the parasitic fungi of which we have hitherto 
spoken there is no sexual reproduction analogous to 
that of the higher plants; there are no male and female 
organs comparable to the stamens and pistil. This 
sexual reproduction exists in the oomycetes, although 
only in a very elementary form. In 
addition to the ordinary spores which 
we have noticed in other fungi, there 
are others termed oospores, which are 
formed by the fusion of the originally 
distinct contents of two different 
cells. In the family of the mucorinez, 
which includes most of the fungi 
commonly called moulds (Fig. 14),  Gog's excrement (mag. 
the two cells of which the contents ™"*” 
are fused together are similar. In the peronosporex, 
however, which includes the potato-fungus, one of the 
