The reputation of Vesalius rests securely upon the _Fabrica_. This grand book, which is dedicated to Charles the Fifth, consists of six hundred and fifty-nine folio pages of text; thirty-four pages of index, disposed in three columns to the page; six pages of preface; and two pages of a letter which is addressed to “Joannes Oporinus, the renowned professor of Greek letters in Basel”. The work is printed in excellent style. The printed page measures 8 by 12½ inches, including the marginal notes. There are fifty-seven lines to a page, averaging twelve words to a line, or approximately seven hundred words to a page. This was written, amid many duties and distractions, in the short period of three years. It is truly a monument of diligence. The text of the _Fabrica_ is clear and concise; it describes what has to be described and does it well. The errors which Vesalius rectified, and the improvements which he made in anatomy, are so numerous that references can be made to only a few of them. His anatomical writings are of such bulk that they cannot be reviewed adequately within the limits of the present chapter. As regards the _Fabrica_, we may say, with Richardson, that “The dissections and the plates are the book”. [Illustration: FIFTH VESALIAN PLATE OF THE MUSCLES (From the “Fabrica”, 1543. Reduced one-half)] The _Fabrica_ contains the rudiments of anthropology as well as the first illustrations of comparative anatomy. Vesalius portrays a human skull resting upon the skull of a dog. He also shows a simian and a canine sacrum and coccyx, to prove his contention that Galen’s anatomy was derived from dissection of the lower animals. The _Fabrica_ is more than an anatomy. Throughout the work physiology goes hand in hand with the anatomical description. The use and function of each part of the body is given in short, clear sentences. The _Fabrica_ is built upon a practical plan. It treats of anatomy in a logical manner and is composed of seven books, which deal with the following subjects: (1)—Bones and Cartilages; (2)—Ligaments and Muscles; (3)—Veins and Arteries; (4)—Nerves; (5)—Organs of Nutrition and Generation; (6)—Heart and Lungs; and (7)—Brain and Organs of Sense. The First Book