Lead encephalopathy may present all the signs and symptoms of intracranial tumors in children. A group originally thought to be cases of intracranial neoplasm, but subsequently classified as examples of "serous arachnoiditis" because of the absence of any signs of tumor at operation, have recently been shown to be examples of intoxication with lead. Case 1.— Roy C., aged 2 years; vomiting three months; two convulsions; staggering gait; large head; "cracked pot" sound; choked disks; hypo-active reflexes; glycosuria; separated cranial sutures; suboccipital decompression, no tumor found; demonstration of lead poisoning, lead line in roentgenograms, lead in blood, urine and feces; no anemia, lead line on gums or stippling of erythrocytes; complete recovery. The patient who first drew our attention to the possibility that some of our cases of "pseudotumor" or "serous arachnoiditis" were really examples of lead encephalopathy was a small boy (Roy C.), aged 2 years, who was referred