Abstract
1. The action of excess of retinol on chick limb-bone rudiments cultured in chemically defined media has been investigated. 2. After 6 days in vitro, the hexosamine and hydroxyproline contents of the retinol-treated rudiments were much less than those of their paired controls. 3. Synthesis of these compounds, however, was not correspondingly decreased. 4. The control rudiments released hexosamine- and hydroxyproline-containing materials into the culture medium; a greater proportion of the hexosamine and hydroxyproline synthesized was liberated from the retinol-treated than from the control rudiments. 5. Although hydrocortisone in physiological concentrations prevented excessive hydration of the rudiments in culture, it did not significantly inhibit the changes induced by excess of retinol.