Henry Gray (18251861). Anatomy of the Human Body. 1918.
Transverse section of pyramidal substance of kidney of pig, the bloodvessels of which are injected. a. Large collecting tube, cut across, lined with cylindrical epithelium. b. Branch of collecting tube, cut across, lined with cubical epithelium. c, d. Henles loops cut across. e. Bloodvessels cut across. D. Connective tissue ground substance.