BREVIORA Mmseiuim of Comparative Zoology Cambridge, Mass. Xovkmhkk lo, \\)ii'2 Number 170 THE BRAIN OF THE EMU (DROMAEUS NOVAEHOLLANDIAE, LATH )' 1. Gross Anatomy op^ the Braix and Pineal Body' B>-Stanley Cobb and Tii.LY Edinger The histology of the cerebral hemisphere of the einii has been extensively studied by Craigie (1935a, 1935b, 1940) and three diagrams of the hemisphere have been published. Drawings of the whole brain have also appeared in the literature (Strong, 1911; Kiienzi, 1918), and a photograph was published hy Anthony (1928). No description of the whole brain, however, is to be found. Since the emu is, next to the ostrich, our largest living bird, and since it belongs to a taxonomically controversial group, it seem>s of value to describe the brain and compare it with the brains of other birds. Moreover, the emu is considered, by Py-craft (1900) and many others, to be one of the most primitive of birds. The concept of "primitiveness" will be considered in the discussion at the end of this paper. MATERIAL Three specimens of Droiiiacus novachollandiae were collected by S. J. J. Davies in November 1960 in Western Australia for Professor Ernst Mayr, Director of the Harvard Museum of Com-parative Zoology. Two of them were kindly given to us by Pro-fessor Mayr for neurological study. The lieads had been cut off 1 'I'liis spellirifT of Dronidciis is not the (iiic iU'CPiitpd by soJiii' newer cliecklists. but beciUise Dromiccius (an alternative si)elling) is the jierpetuation of a grapho-logical error (Newton, 1896) and because Dromaius is a less proper Latinization, it seems better to vise the older form. 2 From the Museum of Comparative Zoology and the Department of Neurology and Psychiatry, Harvard University, and the Laboratory for Psychiatric Research, Massachusetts General Hospital. This investigation has been aided by grants from the Foundations Fund for Psychiatry and the National Institute of Neurological Disease and Blindness, grant #03429-02.