A.E. Popham, The Drawings of Leonardo da Vinci (London: Random House, 1946), 248.
Drawing of a a developing human in a womb. I have stated before that it seems like da Vinci is designing a human, but here he quite literally is. Along with the smaller drawings around the womb, he provides an extreme amount of detail. The veins and other parts of the womb are also in exact places, and similar to the other drawings he presents the layers of the subject.