File:EB1911 Fungi - fertilization and development of the perithecium.jpg

DescriptionEB1911 Fungi - fertilization and development of the perithecium.jpg	English: Sphaerotheca castagnei: fertilization and development of the perithecium.
Date	published 1911
Source	Encyclopædia Britannica (11th ed.), v. 11, 1911, “Fungi,” fig. 9, p. 339.
Author	From Strasburger’s Lehrbuch der Botanik. After Harper.
Permission (Reusing this file)	Public domainPublic domainfalsefalse This image comes from the 13th edition of the Encyclopædia Britannica or earlier. The copyrights for that book have expired in the United States because the book was first published in the US with the publication occurring before January 1, 1929. As such, this image is in the public domain in the United States.

1, Oogonium (og) with the antheridial branch (az) applied to its surface

2, Separation of antheridium (an).

3, Passage of the antheridial nucleus towards that of the oogonium.

4, Union of the nuclei.

5, Fertilized oogonium surrounded by two layers of hyphae derived from the stalk-cell (st).

6, The multicellular ascogonium derived by division from the oogonium; the terminal cell with the two nuclei (as) gives rise to the ascus.