Figure 295 from Chapter 11 (Melanin Pigment) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Formative stages of melanosome development are apparent in this example from a human fetus. In these early stages, the melanosome is limited by a membrane, and contains a highly organized internal of longitudinal stands, or concentric lamellae that have a regular 10 nm periodicity. As melanization proceeds, this protein framework becomes obscured by the accumulation of melanin polymer. Image by Aiden Breathnach. A PDF copy of the accompanying chapter is available on the ASCB's BioEDUCATE website.