The Museum Vrolik collection of the Department of Anatomy and Embryology of the Academic Medical Center, University of Amsterdam, founded by Gerardus Vrolik (1775-1859) and his son Willem Vrolik (1801-1863), consists of more than 5,000 specimens of human and animal anatomy, embryology, pathology, and congenital anomalies. Recently, the collection of congenital anomalies, comprising 360 specimens, was recatalogued and redescribed according to contemporary morphogenetic views. The original descriptions, if preserved, were compared with the clinical, radiographical, and magnetic resonance imaging findings. In 120 specimens the following midline anomalies, primary field defects, and sequences were diagnosed: holoprosencephaly sequence; aprosencephaly/atelencephaly; cleft lip; Pierre Robin sequence; omphalocele; diaphragmatic hernia; ectopic heart; bladder exstrophy; cloacal exstrophy; caudal dysgenesis; prune belly sequence; sirenomelia; fetal akinesia sequence; and disruption sequences. Polytopic field defects and associations were diagnosed in 25 specimens. We discuss the opinions of Gerardus and Willem Vrolik, who tried to find reasonable explanations for the dysmorphogenetic entities they investigated, rather than accepting the traditional superstitions.