I'm responding to the posting by Mary-Kay of Kittie's responses. The section I find of great interest is McNeilly's work on prolactin release and manufacture of milk as baby feeds. How does this fit in with Peter Hartmann's work on breast capacity, which was measured before and after a feed? I've seen the slides and heard the talk from Peter (several times actually - one advantage of being an Aussie!) and he's certainly pretty convincing. However, my own personal experience was different. My first baby (now 14 yrs) would only feed on one side at each feed - this was way before one sided feeding was advocated for oversupply, and I did have oversupply (he worked it out for himself - who says babies aren't smart). Once lactation was well established and the baby would indicate he wanted to feed I would feel my breasts to determine which one he was due on, however they both felt quite soft and if I got it wrong and put him on the most recently used breast the other breast would let-down and "fill" - felt very full and tense and I would have to quickly take him off the other side and put him on the correct side (BTW the one I erroneously put him on would not have any changes - no let down, no 'filling', no tenseness. For many years I would also tell mothers that, once their supply has settled down after the initial fullness that they would be able to feel their breasts and think 'there isn't a bottle full of milk in there' and there wouldn't be because it got made fresh as baby drank. Then along came Peter! Confused and still hot in Brisbane (alias Denise Fisher)