English: First illustration by Cajal (1888) of a Golgi impregnated preparation of the nervous system. (A) First page of the article and (B) illustration whose legend states: “Vertical section of a cerebellar convolution of a hen. Impregnation by the Golgi method. A represents the molecular zone, B designates the granular layer and C the white matter”. (C) photomicrograph from one of Cajal’s preparations of the cerebellum of an adult bird stained with the Golgi method. (D) higher magnification of (C) to illustrate a Purkinje cell and a basket formation (arrow). (E) dendrite of the Purkinje cell which is covered with dendritic spines. The histological images were obtained by Pablo García López, Virginia García-Marín, and Miguel Freire (Legado Cajal, Instituto Cajal). Scale bar: 200 μm in (C); 60 μm in (D); 8,4 μm in (E).