Dr. E. Marshall Johnson is Professor Emeritus of Anatomy and Developmental Biology at Thomas Jefferson University, Philadelphia, P Dr. E. Marshall Johnson is Professor Emeritus of Anatomy and Developmental Biology at Thomas Jefferson University, Philadelphia, Pennsylvania, USA. There, for 22 years he was Professor of Anatomy, the Chairman of the Department of Anatomy, and the Director of the Daniel Baugh Institute. He was also the President of the Teratology Society. He has authored more ...