The Royal Society read part of Letter L-157 about the role of eggs and male sperm in a female dog

June 20, 1685

Birch, History, vol IV, p. 383, 10 June 1685 (O.S.) in London:

Part of a letter of Mr. LEEWENHOECK, dated March 30, 1685, was read, containing some curious observations about the manner of generation from an animal, and not an egg; the crooked shape and stiffness of the Fallopian tubes in a bitch, rendering them incapable of giving a passage to eggs; his finding the animals of male seed in several parts of the cornua of a bitch, that had been lately limed; with a description of the uterus. The rest of the letter was deferred till the next meeting.