ids in _Vaucheria_, have their movements
assisted by a long cilium. It is presumable that here, as in the
Algae, the spermatozoids introduce themselves into the cavity of
the oogonium, and unite with the gonospheres.

Amongst obscure and doubtful bodies are those described by Pringsheim,
which have their origin in thick filaments or tubes, similar to those
which form the zoosporangia, and represent so many distinct little
masses of plasma within an homogeneous parietal ganglion. The contour
of these plastic masses is soon delineated in a more precise manner.
We see in their interior some homogeneous granules, which are at first
globose, then oval, and finally travel to the enlarged and ampullaeform
extremity of the generating tube. There they become rounded or oval
cells covered with cellulose, and emit from their surface one or
several cylindrical processes, which elongate towards the wall of the
conceptacle, and pierce it, without, however, ever projecting very far
beyond it. At the same time the lacunose protoplasm of each cell
becomes divided into a number of corpuscles, which escape by the open
extremity of the cylindrical neck. They resemble in their organization
and agility the spermatozoids of _Achlya dioica_. They soon become
motionless in water, and do not germinate. During the development of
these organs, the protoplasm of the utricle which contains them offers
at first completely normal characteristics, and disappears entirely by
degrees as they increase. De Bary and Pringsheim believe that these
organs constitute the antheridia of the species of _Saprolegnia_ to
which they belong.

The oospores of the _Saprolegniae_, when arrived at maturity, possess a
tolerably thick double integument, consisting of an epispore and an
endospore. After a considerable time of repose they give rise to
tubular or vesicular germs, which, without being much elongated,
produce zoospores.[H]

De Bary has claimed for the oogonia in _Cystopus_ and _Peronospora_ a
kind of fecundation which deserves mention here.[I] These same fruits,
he says, which owe their origin to sexual organs, should bear the
names of _oogonia_ and _antheridia_, according to the terminology
proposed by Pringsheim for analogous organs in the Algae. The formation
of the oogonia, or female organs, commences by the terminal or
interstitial swelling of the tubes of the mycelium, which increase and
take the form of large spherical or oboval cells, and which separa