Polish pioneers in research on vertebrate circulatory systems at the Jagiellonian University of Krakow (Poland).

At the end of the XIX century and during the first half of the XX century, Henryk Hoyer and Zygmunt Grodzinski, two eminent Polish researchers, were carring out research on the lymphatic circulatory and blood circulatory systems. Later, these investigations were continued by their students and followers until 1966. Embryos from all groups of vertebrates were used for investigation and on that basis, models of the lymphatic and blood circulatory systems were proposed.