The renaissance of stereotactic functional neurosurgery has resulted in increased interest in its origins. Twenty articles concerning this field trace the history back to a paper published in 1873 by Dittmar: "Uber die Lage des sogenannten Gefaesszentrums in der Medulla oblongata" [On the location of the so-called vasomotor center in the medulla oblongata]. Few facts are presented. But, taken together, the impression given by the secondary sources is that Dittmar, in 1873, presented a guiding device for localization of intracranial structures for the positioning of electrodes/blades in the medulla oblongata in rats. Of the publications that cite Dittmar's original article as their only quoted source, half did not specify the inserted object and the animal of the experiment. The remaining articles reported either that the introduced object was an electrode or that the experiments were performed on rats. Dittmar's original article, however, did not report use of his apparatus for insertion of electrodes, nor did he use rats. All experiments were performed by making incisions in the medulla oblongata in rabbits. Dittmar's apparatus was constructed to allow more precision when performing incisions in the medulla oblongata than could be obtained performing incisions freehand. The incision point was chosen and the blade introduced with direct visual guidance. This has been described as "spatial localization of intracranial structures," "a special targeting instrument," or simply, "a guiding device." In our opinion, it can most properly be classified as a supportive arm.