Breastfeeding social reactions in the English-speaking world. It is possible for a mother to continue breastfeeding an older sibling while also breastfeeding a new baby; this is called "tandem nursing". During the late stages of pregnancy, the milk changes to colostrum. While some children continue to breastfeed even with this change, others may wean. Most mothers can produce enough milk for tandem nursing, but the new baby should be nursed first for at least the first few days after delivery to ensure that it receives enough colostrum. Breastfeeding triplets or larger broods is a challenge given babies' varying appetites. Breasts can
Mathematics, Form and Function Mathematics, Form and Function Mathematics, Form and Function is a survey of the whole of mathematics, including its origins and deep structure, by the American mathematician Saunders Mac Lane. Throughout his book, and especially in chapter I.11, Mac Lane informally discusses how mathematics is grounded in more ordinary concrete and abstract human activities. The following table is adapted from one given on p. 35 of Mac Lane (1986). The rows are very roughly ordered from most to least fundamental. For a bullet list that can be compared and contrasted with this table, see section 3 of "Where Mathematics Comes From".