O. kurzii Zeller matured sex organs periodically about every 15 days when grown in culture. The complete life history of 15 sperms was observed, 2 of which were observed in the act of passage into the egg. This act is complete in 30 seconds, after the egg is reached, and may occur 2 minutes after escape from the antheridium. Unsuccessful sperms die inside or outside the oogonium within 4-18 hrs. Sperms were most abundant between midnight and 400 a.m. The sperm shows dorso-ventrality, and is not considered a "miniature zoospore" as suggested by earlier writers.