The finding of yellow spinal fluid on lumbar puncture can no longer be considered rare; a review of the literature indicates its presence in a great variety of conditions. From a report by Nammack1 a yellow coloration is found in about 1.6 per cent, of spinal fluids. This percentage is based on nine years' work by the meningitis division of the New York Health Department. Of 5,801 fluids examined, only 96 showed a yellow color. Over 350 cases are reported in the literature in such conditions as new growths of the brain and cord, compression of the cord by neoplasm or deformities of the vertebrae, hemorrhage into the spinal canal, and inflammatory diseases of the cord and meninges. This will serve to point out that the yellow coloration is not pathognomonic of any one pathologic state, but is dependent on certain factors common to many. This phase of the