Book excerpt: This fourth edition of "The Mule Companion" is a comprehensive book on mules with new photos of many real people and mules doing real mule activities. "The Mule Companion" has been called an excellent 'mule primer' for those people just getting into mules. However, the book also hosts an in-depth study of why mules do what they do, their idiosyncrasies, training, and problem solving. Also, the book is rich with 'how to' information on: caring for, breeding for, fitting tack on, buying, and mule activities, past and present.