Riehl's melanosis occurs among the Bantu in South Africa. The differential diagnosis of Riehl's melanosis in the Negro must include lichen planus, pellagra, mesodermal melanosis, dermatosis papulosa nigra and porphyria. The criteria for distinguishing various cells in the basal layer of the epidermis are not easily applied in Riehl's melanosis. Their individuality as cell types is open to doubt. Attention is drawn to the association of Riehl's melanosis with pains in the trunk and limbs, alterations in hair growth, attacks of muscular weakness and mental disturbance, where the better known causes for these symptoms can be excluded.
1. Twenty-eight cases of puerperal sciatic palsy are reviewed, collected over a 14-month period in a large nonEuropean hospital. 2. Theories of causation are discussed. 3. In this series some degree of disproportion, prolonged or difficult labour has usually been present. 4. The pelves were of the type descriptionbed by Cole, i.e. flattening of the sacral promontory and shallow sacral alae in the majority of cases where pelvimetry was done. 5. The shape of the pelvis and the degree of pelvic contraction is probably the most important cause of the relatively high incidence of puerperal sciatic palsy in the Bantu.