This article is part of the series "A Moment in History" where we honor those who have contributed to the growth of medical knowledge in the areas of anatomy, medicine, surgery, and medical research.

Wilhelm His Jr.
Wilhelm His Jr. (1863-1934). Also known as Wilhelm His the Younger, was born in Switzerland in the city of Basel. His father was a well-known and famous anatomist by the same name who worked at the University of Basel. Wilhelm His Jr. studied in several universities, including Leipzig, Strasbourg, Bern, and Geneva. He received his medical degree from the University of Leipzig in 1889.
Although not an anatomist, his 1893 single and most brilliant contribution to the eventual understanding of the conduction system of the heart was the discovery and description of a muscular bundle that connected the atrial septum with the ventricular septum. Until that moment it was known that no muscles crossed from the atria to the ventricles, leading anatomists and physiologists to wonder how does the heart contract.
In his article His states "after long search I have succeeded in finding a muscle bundle which unites the auricular and ventricular septal walls, and which, up to now, has escaped observation because of incomplete exposure, for it is visible in its entire extent only when the septa are cut exactly in their longitudinal direction".
What is interesting is that His not only found the bundle that today honors his name, but he included in that description the atrioventricular node, the actual structure that crosses the atrioventricular connective tissue barrier known as the "skeleton of the heart". The AV node was later to be clearly identified and researched by Sunao Tawara (1873 - 1952).
Dr. His continued his research on gout and joint diseases. He became a German citizen and joined the German army as a consulting physician. He retired in 1932 and died in 1934.
Although Wilhelm His Jr. did not discover or described the esophagogastric angle, in 1906 JD Cunningham started calling this angle the "Angle of His" in honor of Wilhelm His Jr. This eponym has stayed with us until today.
Sources:
1. "Wilhelm His Jr." JAMA. 1964;187(6):453-454
2. "His, Jr., W.: The Activity of the Embryonic Human Heart and Its Significance for the Understanding of the Heart Movement in the Adult" Arb Med Klin Leipzig, pp 14-49, 1893; Bast, TH,Gardner, WD trans: J Hist Med 4:289-318, 1949
3. "Wilhelm His, Jr. and the Bundle of His" Bast, TH, Gardner, WD J Hist Med All Sci; 1949; 4, (2) 170 -187
4. Firkin BG (1996) Dictionary of medical eponyms.London: Parthenon Publishing Group, 181
Original image in the public domain, courtesy of the National Library of Medicine.