Continuing to quote from the passage I began yesterday…

In a normal act of generation the father has no creative function. A microscopic particle of matter from his body, and a microscopic particle from the woman’s body, meet. And with that there passes the color of his hair, and the hanging lower lip of her grandfather, and the form of humanity in all its complexity of bones, sinews, nerves, liver, and heart, and the form of those prehuman organisms which the embryo will recapitulate in the womb. Behind every spermatozoon lies the whole history of the universe: locked within it lies no inconsiderable part of the world’s future. The weight or drive behind it is the momentum of the whole interlocked event which we call Nature up-to-date. And we know now that the “laws of Nature” cannot supply that momentum. If we believe that God created Nature, that momentum comes from Him. The human father is merely an instrument, a carrier, often an unwilling carrier, always simply the last in a long line of carriers – a line that stretches back far beyond his ancestors into prehuman and preorganic deserts of time, back to the creation of matter itself. That line is in God’s hand. It is the instrument by which He normally creates a man. For He is the reality behind both Genius and Venus; no woman ever conceived a child, no mare a foal, without Him.

~ C.S. Lewis The Joyful Christian, pg 57[emphasis added]