Arvo Henrik Ylppö was born in 1887 in Akaa in a rural part of central Finland, at that time part of Russia. His parents were farmers and he was the 5th of their 12 children. Born prematurely, he remained of small stature throughout his life (fig 11).). As a lad, his most impressive qualities included “curiosity, thirst for knowledge, a friendly, teasing humour, endurance and human sympathy”.1 From an early age he determined to become a paediatrician, perhaps because of his mother's anxiety over the illnesses of her many children. In 1906 he entered the University of Helsinki and studied medicine there and also later in Göttingen. At the same time he took every opportunity of travelling widely in Europe and the Near‐East to study the cultures of other peoples as well as their medical problems. In March 1914 he graduated Doctor of Medicine and Surgery in the University of Helsinki. The same year he obtained a PhD based on the bilirubin metabolism of infants. Using dogs, he was the first to demonstrate the enterohepatic circulation of bilirubin. He also made a number of valuable observations on icterus neonatorum. Congenital obliteration of the bile ducts he considered to be due to a failure of recanalisation.