John F. Fallon, PhD: fifty years of excellence in limb research and counting.

Passion and thoughtfulness. . . These are an unusual combination of descriptors perhaps, but fitting for the man to whom we dedicate this special issue on limb development, Dr. John F. Fallon. John has approached his work for more than 50 years with a combination of passion and thoughtfulness that has left indelible marks on the field and on the many scientists who have entered or passed through John’s scientific universe. John Fallon was appointed Assistant Professor of Anatomy at the University of Wisconsin-Madison on January 1, 1969, after earning the PhD degree in Biology at Marquette University and serving 2 years on active duty in the US Army Medical Service Corps. He was promoted to Professor of Anatomy in 1981 and had served as a member of the faculty for 41 years upon his retirement on December 21, 2009. During these years, John published 93 peer reviewed original research articles, 20 review articles/book chapters and 4 edited proceedings. Whereas these publications cover a range of topics from the gametes of Nereis limbata to the carapacial ridge of turtles, the majority of John’s contributions are in the field of limb development, a passion he developed in the 1960s as a graduate student in John Saunders’ laboratory at Marquette University. John left his home in Massachusetts when he was thirteen years old and attended high school at Roosevelt Military Academy in Aledo, Illinois. During high school, he became very interested in philosophy and entered Marquette University to pursue undergraduate studies in this subject, also working as a window and awning salesman during college to pay for his education. By his senior year of college, John was completing Bachelor’s degrees in both Philosophy and Zoology, and had applied, and was accepted, to pursue graduate studies in the Philosophy department at Marquette. It was also during his senior year, that John enrolled in a Cell Biology course, which was taught by Dr. John Saunders. He was riveted by Dr. Saunders’ teaching style and approached Dr. Saunders after a class one day and asked whether he might work in his laboratory during his senior year. This turned out to be a career-altering event (Fig. 1). John spent the first several months washing glassware, but he was allowed to watch, and sometimes assist, Mary Gasseling as she was performing some of the very first experiments on the function of the cell death and what would become the zone of polarizing activity in the chick limb. John was hooked! Toward the end of his senior year, he decided that he no longer was interested in pursuing philosophy, but instead wanted to turn his attention to biology. Dr. Saunders personally intervened on John’s behalf to permit a change in departments for his graduate admission in Biology. During his years under Dr. Saunders’ tutelage, John was allowed to spend a few summers at Woods Hole, times that John considers transformative. He published his first paper on collaborative work done there with Dr. C.R. ‘Bunny’ Austin (the Charles Darwin Professor of Animal Embryology, University of Cambridge, UK) using electron microscopy, and recalls his anxiety at the first formal presentation on this work, where he talked about how jelly was released fromNereis limbata eggs during fertilization when the sperm makes contact with the egg. This work tested theories put forth by Drs. Alex Novikoff and Donald Costello who were both present at D ev el op m en ta l D yn am ic s