Diagram showing the division of the lower part of the bulbus aorta, aorta, and the formation of the semilunar valves. A, undivided truncus arteriosus with four endocardial cushions; B, advance of the two lateral cushions resulting in the division of the lumen; C, projection of three endocardial cushions in each part; D, the separation into aorta and pulmonary trunks completed. Jones Quain (November, 1796 - January 31, 1865) was an Irish anatomist, professor of Anatomy and Physiology in the University of London, and author of Elements of Anatomy. The first edition was published in 1828 and it quickly became a standard text-book in English-speaking countries. 10th edition, 1896. This image has been colorized.