Cysts of the Central Nervous System.
—At a meeting of the Italian Society of Neurosurgery in December, 1953, Professor Chiasserini of Rome presented a paper on epidermoid and dermoid cysts of the central nervous system. In regard to the pathogenesis of these cysts, the inclusion of cutaneous germinal epithelium in the structures from which various segments of the central nervous system are derived is possible in the course of the development of the embryo. The evolution toward an epidermoid or a dermoid cyst depends on the thickness of the enclosed germinal epithelium or on the early formation of the invagination. In exceptional cases, trauma could be the cause of these cysts, but, generally, trauma is more important in their later growth. Epidermoid and dermoid cysts of the central nervous system are not common, although they undoubtedly occur more frequently than is believed. In comparison to other tumors of the central