Among 700 neonates examined, 4 were noted to have this symptom. These 4 infants have shown severe disturbances in development during the 1st year of life. In addition to light sensitivity all 4 had shown a wide discrepancy between the muscle tone of their upper and lower limbs, with flaccidity of the arms and hypertonicity of the legs. By drawing attention to these symptoms we hope that others will collect additional information on the frequency with which severe developmental disturbances are found in infants having 1 or both of the above-mentioned symptoms in the 1st days of life.