of the spinal cord. With the Berlin neurobiologist Johannes Gad, Flatau performed experiments on dogs and criticized the Bastian-Bruns law concerning the loss of function following spinal cord injury (1893). On the basis of numerous clinical spinal cord surgeries, experiments, and subsequent observations, he discovered that the "greater the length of the fibres in the spinal cord the closer they are situated to the periphery" (Flatau's law). He provided evidence for the laminar arrangement of spinal pathways. He also described the fifth, seventh, and eighth cranial nerves, and carefully outlined their nuclei. The paper on this topic, Das Gesetz der excentrischen Lagerung der langen Bahnen im Rückenmark, was published in 1897. For this work he received a PhD in medical sciences in Moscow in 1899 (dissertation ) This work was presented in 1949, next to a portrait of the author, on display at the IV International Congress of Neurologists in Paris. The neuron theory Flatau began working at the Center for Anatomy of the Charité in Humboldt University of Berlin two years after the Wilhelm Waldeyer introduced the term neuron (Heinrich Waldeyer himself advocated and popularized the work of Ramón y Cajal). Thus, in 1895, Flatau became interested in neuron theory recently developed by Ramón y Cajal and Heinrich Waldeyer, and became one of its proponents. In several publications, he attempted to establish a unity between the physiology and anatomy of the neuron. Together with Alfred Goldscheider, he worked on the structure of nerve cells and their changes under mechanical, thermal, and toxic influences. They published results of their experiments in 1897 and 1898 in Fortschritte der Medizin and Polish Gazeta Lekarska, which were subsequently published as a special monograph. They state that the character of changes in neuron cells could provide information about the type of influences acting on them. This work, in which the normal and pathologic anatomy of the V, VII, and VIII (cochlear) cranial nerves was included, created much discussion and was adversely criticized by Franz Nissl, who opposed the neuron theory. He modified Golgi's method of tissue staining and on the basis of studies of physiological effects of transverse intersection of the spinal cord in dogs carried out together with Johannes Gad, he provided criticism of the Bastian–Bruns sign of disappearance Patellar reflex as a result of this treatment (1896). Together with his friend Louis Jacobsohn-Lask, he continued anatomy work. In 1895 and 1896, Flatau