Demonstration of the intermediate cells of Billingham and Medawar in the epidermis of Macaca mulatta and rhesus monkey.

The digest of the pure epidermis preparation from Macaca mulatta demonstrated three types of dendritic cells i.e. (1) dopa-positive melanocytes, (2) dopa-negative Langerhans' cells and (3) weakly dopa-positive intermediate cells of Billingham and Medawar. The last type of cell was found to have characteristics being intermediate between those of the melanocytes and of the Langerhans' cell. A similar digest prepared from the epidermis of the rhesus monkey demonstrated isomorphous dendritic cells which were all dopa-negative. Here also the intermediate cells of Billingham and Medawar with characteristics intermediate between those of the melanocytes and of the Langerhans' cells were identified.