ONE TEXT FIGURE AND ONE PLAT~E (FOUR FIGURES)
I t has been the general opinion (Bauer, '09 ; Obersteiner, '12; Spatz, '27) that melanin pigmentation of the substaritia nigra and locus coeruleus is peculiar to the human brain. HOTVever, Scherer ( '39) published observations 011 the brains of soiiie higlicr and lower primates, which showed that melanin was present in the substantia nigra of all the primates which lie had examined. I n all instances the size of the melanin granules was smaller, their number less and their coloration lighter than in adult human brains. The pigmentation was more pronounced in anthropoids than in the lower apes. Chimpanzees and orangutans were the only antliropoids in his series. Apparently because of the extreme difficulty in obtaining such material, his series did not include the brain of the highest anthropoid, the gorilla. MATERIAL Tlic material f o r this study consists of the brain of a n adult Gorilla hcringei, which was collected by the McGill University C'ongo Expedition in 1938, under the direction of RIr. Duncan RI. Hodgson. The material was presented to the Department of Anatomy of the Harvard Medical School through the cwurtesy and interest of Mr. Hodgson and Mr. Harold ?J. Coolidge, J r . I wish to express riiy gratitude to Prof. George B. Wislocki, mlio put the gorilla's brain at my disposal for