Chapter V
Animals and Babies
All the animals that start their lives in the bodies of their mothers grow from eggs in the same way that you did. Some of the animals take more time to do this than you needed. Most of them take less time.
A baby spends nine months in the body of its mother. An elephant spends twenty months there and a mouse spends twenty days. A horse needs a little more than eleven months in which to get ready to be born and a rabbit needs only one month. But the rabbit and the horse and the mouse and the elephant all grow up in the bodies of their mothers just as babies do, and they are born just as babies are born.
Usually babies grow one at a time. Now and then two babies—twins—will grow in the body of the mother and once in a long, long while