veeery interesting, thankyou.

What on earth can it be about big rocks that gets you pregnant*. The witches stone doesn't look particularly phallic and pointy, then you could understand a bit more. And why not other stones / rock art? More scouring about required. but these things aren't written down are they. and they're not really the sort of thing to be communicated to respectable gentleman antiquarians, too delicate / or should that be, too earthy a subject.

*yes yes they don't really (presumably).