JMS PearceHull, England A variety of dysraphic states, recorded since antiquity, (Fig 1)1 are caused by the failed closure of the neural tube during the fourth week of embryonic life. They include hydrocephalus, Chiari malformations, and various types of spina bifida with meningocele or meningomyelocele. Nicolaes Tulp (1593–1674)—subject of Rembrandt’s The Anatomy Lesson—in Observationes Medicae…