Vesalius devotes one hundred and eighty-eight pages to a description of
the ligaments and the muscles. This part of his treatise, while it
contains a few errors and does not reach the high plane of the first
book, is superior to any work of its kind that had preceded it. Vesalius
was the first writer to describe the internal pterygoid muscle. He
denied the existence of a general muscle of the skin, and stated that
the intercostal muscles merely separate the ribs without expanding or
contracting the thorax. He held the view that nerves and muscles do not
stand in any relation of proportionate strength to one another, large
nerves often being distributed to small muscles. He also held that the
tendons are similar in structure to the ligaments.
[Illustration: PLATE OF THE ARTERIAL TREE BY VESALIUS
(From the “Fabrica”, 1543. Reduced one-half)]
Vesalius’s plates of the superficial muscles are among the most
beautiful that have ever appeared. They have been copied in practically
all later treatises on anatomy, and have been used extensively by
art-anatomists. His plates of the deeper muscles, while naturally not so
pleasing to the eye, are wonderfully near accuracy. The different
muscles are drawn to show function as well as structure.