The families are organized by common location or common theme. The Ursa Major, Perseus, Hercules, and Orion families include mainly constellations in the general vicinity of those four constellations. The Zodiac family includes the traditional 12 Zodiac constellations. The Heavenly Waters family includes mostly constellations generally associated with water. The Bayer family includes southern constellations first introduced by Plancius and subsequently included in Johann Bayer's "Uranometria" in 1603. The La Caille family includes most of the constellations introduced by Lacaille in 1756 from stars charted during his observations at Cape Town.