This was pretty much "the" go-to book for anything about pigeons through most of the 20th Century. The author also owned and operated one of the largest squab plants in the U.S.A. The book is encyclopedic in content covering everything from a great number of the world's pigeon breeds, rearing practices, squabbing, racing, showing, and pigeon genetics. While Levi gets rightful credit as author of the book, Dr. Willard F. Hollander wrote the genetics section.