The Sex Life of the Polyp (1928)

Dr. Benchley is addressing the Ladies Club on the subject of the reproductive habits of the polyp, a small aquatic organism. Although he is not able to display his live specimens, he has prepared a series of pictures of his subjects. He explains that the subject is made more complicated by the fact that polyps are able to change their sex from time to time. Then he presents some of the pictures of his specimens and the experiments that he has done with them. (IMDb)