During pregnancy the breasts increase in size, WOW you say. This isn't for your 'tit'illation. The blood supply increases, the network of veins become more apparent, all in preparation for the onslaught of mothers liquid gold. All mammalian milk is species specific and we are after all, mammals. Even though some of us think we're God like.
Human milk is a very precious commodity.
No more precious than any other milk meant to feed it's infant, but over the years human breast-feeding has been left out in the cold and given bad press. During the turn of the century the medical profession got all scientific and obsessed with numbers. Victorian breasts had to be hidden away. Breast-feeding became a rather vulgar occupation, especially in the upper classes. Breasts belonged to men in the bedroom ensconced in a pretty d colletage and not for babies as nature intended.