In the strange intermingling of sacred allegory with something much more visceral, even secular, that is at work in the description of the twins' birth, the twisting of normal temporal sequence, having the babes suck seemingly at once before and after they're born, seems crucial. It makes me think of that most peculiar and plangent example of (I think) hyperbaton, when Venus and Diana, not waking Chrysogenee out of her "heavy swowne," together agreed "from her loving side the tender babes to take" -- where the love Chrysogenee will never show to the children she never sees is lent to her body (here merest "side"!) at the very moment she loses them. Ken