The findings in a correlated angiographic and histological study of eighty-one selected femoral heads obtained from cadavera ranging from thirteen to eighty years of age are reported. Three groups of arteries were demonstrated: upper and lower capital and ligamental arteries. Anastomoses of the upper and lower capital arteries formed the superoinferior arch in fifty-five of the eighty-one specimens; ligamental arteries were visualized in twenty-eight specimens; superoligamental arches, in twelve, and superoinferoligamental arches, in fourteen.

There was no correlation between the occurrence of the arches and age or race, but there was a significant correlation between the presence of the superoinferior arch and the female sex, the arch being found in twenty-eight of thirty-three female cadavera and in only two of forty-eight male cadavera.

The histological studies of the site of attachment of the ligamentum teres revealed arteries in every specimen. However, in approximately two-thirds of them, these arteries were 200 micrometers in diameter or less and did not fill with radiopaque material; in the other third the vessels ranged from 201 to 511 micrometers in diameter and did fill with the injection medium. These larger vessels anastomose with the arterial network within the femoral head and contribute to its blood supply.