Light micrograph of the septum between two alveoli of a rat coagulating gland lined by a simple columnar epithelium stained with haematoxylin and eosin (top) and the Da Fano silver method for Golgi apparatus (bottom). At top, epithelial cells show a supranuclear light band corresponding to the Golgi apparatus location (negative Golgi image). At bottom, these cells show a dark silver stained band above the nucleus corresponding to the location of the Golgi apparatus.