In plants with multinucleate cells, such as Albugo, Peronospora and Vaucheria, it is usually a uninucleate cell differentiated by separation of the nuclei from a multinucleate cell, but in Albugo bliti it is multinucleate, and in Sphaero plea it may contain more than one nucleus.
Even in the multinucleate oosphere of Albugo bliti the nuclei fuse in pairs; and in the oospheres of Sp/zaero plea, which may contain more than one nucleus, the egg nucleus is formed by the fusion of one only of these with the spermatozoid nucleus (Klebahn).
In Cystopus Bliti the oosphere contains numerous nuclei, and all the male nuclei from the antheridium pass into it, the male and female nuclei then fusing in pairs.
Between Cystopus Bliti on the one hand and Pythium de Baryanum on the other a number of cytologically intermediate forms are known.
(1900); Stevens, "The Compound Oosphere of Albugo Bliti," Bot.