Abstract
1. The results of a study of the characteristics of the vessels found in forty-six human femoral heads during the growth period are described.
2. Of the three different sources of blood entering the human adult femoral head it was found that from birth to about three to four years the vessels of the ligamentum teres do not contribute to the nourishment of the head.
3. After the fourth year the metaphysial vessels decrease in importance until they finally disappear, leaving the head with only one source of blood through the lateral epiphysial vessels; the ligamentum teres is not yet contributing to the circulation of the head.
4. After about eight or nine years it was found that the vessels of the ligamentum teres contribute to the blood supply of the head while the metaphysial blood flow is still arrested.
5. Finally, at puberty, after a period of activity of the metaphysial vessels, epiphysial fusion takes place, bringing together the three sources of blood characteristic of the adult.
