I never saw anyone in Mali tie a rock to their breast!  But I did see many
women whose breasts were so long they could easily be thrown over the
shoulder or under the arm to feed a baby tied on the back.  One of the
reasons, IMHO, women in many African societies have such pendulous breasts
is because of the very practice of carrying the child on their back.  Most
use a simple piece of cloth to hold baby on.  They bend over, baby is placed
on their backs, and the piece of cloth (imagine a beach towel, but thinner
material), is positioned over baby, so the ends hang down on each side, to
mom's front.  Mom ties bottom ends of cloth in a TIGHT knot in front, below
her breasts, then tucks top ends of cloth in a TIGHT tuck, right over the
tops of her breasts.  Imagine putting a bath towel around yourself after
your bath.  Most Americans tuck the outer edge IN, and then it slips and
falls off when you run to answer the phone.  Instead, try overlapping the
ends and then folding the top part OUT and down.  You'll find that it holds
much better, and actually gets tighter when you inhale, rather than looser.
This is how women in Mali wear their babies when they have to travel
somewhere, or need to work (hoeing the field, pounding millet, drawing water
from the well) and must have baby safe and out of the way.  This steady
constant presssure on the breasts smushes them down.  The milk ducts must
just grow gradually in response, as I've seen women with their "breasts"
down at the end of a long ropy length of tissue.  Obviously the child is
getting milk.  One little girl even used to walk around holding the "breast"
and nursing, while her mother sat on a stool cooking.

Katherine A. Dettwyler, Ph.D.
Texas A&M University