Cerebral palsy may be defined as a condition characterized by paralysis, paresis, incoordination, dyskinesia, or any aberration of motor function that is due to involvement of the motor control centers of the brain. It should be differentiated from spinal palsies, such as poliomyelitis or transection of the cord, and from peripheral nerve palsies, such as peripheral neuritis due to lead poisoning or diphtheria. Since the brain has many functions in addition to control of motor ability, it is not surprising that in the cerebral palsied there may be many associated defects. Defects in intelligence, personality, and sensation or epileptic diatheses may coexist. In addition, there may be many sequelae of cerebral palsy, such as physical deformities due to contractures and personality defects incident to the lack of opportunity for normal social development. The present paper, however, is limited to a consideration of the classification and specific etiological correlations of the