Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Dr. Charles Edward "Ed" Stevens was an American scientist, professor, and veterinarian. An internationally recognized expert in the field of comparative physiology and digestive systems, Dr. Stevens was responsible for over 70 publications including text books used in Veterinary Schools worldwide, including Comparative Physiology of the Vertebrate Digestive System. Dr. Stevens graduated from the University of Minnesota with a Bachelor and Master of Science, Doctor of Veterinary Medicine and Doctor of Philosophy degree.