Roelans (or Roelants), who wrote the text of the third incunabulum, was a Flemish physician, born in Mechlen in 1450. At the age of 16 he entered the University of Löwen, and while there, or on subsequent visits, he must have made good use of his time in studying the books and manuscripts of the early writers. Later, he returned to Mechlin, where he practiced until he died, in 1525. In 1494, he married Caecilie von Duffel, who bore two children. He must have been a physician of ability as well as one of learning, for he was "Hospital und Stadtarzt."
His book is a rare one, but fortunately it is now available through the efforts of Karl Sudhoff, who, in his "Erstlinge der Pädiatrische Literatur," has reproduced the text in facsimile and accompanied it by an illuminating essay. The original may be seen in the library of the University