Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 17 On the Lumbar Vertebrae

Appendix: the 1555 ending of Chapter XVII (See note 19 above)

But the especial use of this process is not that it is created mostly to protect the nerve running in front of it from injury and to act as a bulwark for it. 21 It is built for a special muscle (you will find it by dissecting a monkey or a dog) which monkeys have in common with dogs and which humans, who do not bend the lower part of their back in a circle as much as those animals, lack so much as to have no sign of this process. // p. 96 // This muscle originates from a sinewy and quite wide beginning in the hipbone where the main muscles that flex the femur are twisted downward. Ascending obliquely from here and becoming fleshy first in the lumbar region, it is inserted into all the acute vertebral processes on its side and ends at the upper extremity of its insertion into the vertebra situated immediately beneath the vertebra which is supported at both ends. At its lower extreme it does not descend the same distance in dogs as in apes, since it is inserted in more lumbar vertebrae in monkeys than in dogs. This is because more lumbar vertebrae of monkeys have this process, which is always more prominent and extends farther from the vertebrae, the closer these vertebrae are to the vertebra which is supported at both ends, and the stronger the insertion the muscle we are talking about makes into them. As a result the thoracic vertebrae as well that are situated below the vertebra which is supported at both ends — in those animals generally the tenth — have this process just as do the upper lumbar vertebrae. Those closest to the sacrum, also not fully receiving an insertion of this muscle, lack the process. This had been observed by Galen 22 when he wrote that this process became known to him first, 23 and when elsewhere he boasts that muscles situated in the loins and serving there the motions of the spine had been wrongly understood by the ancients: everywhere propounding his apes to us where he pursues some subject or another with greater care and, as it were, zeal.

There are fewer 24 than five vertebrae in the loins of apes and dogs

But all the apes I have dissected so far, especially those which were caudate, and dogs as well, had more than five vertebrae in their loins; nor do I know whether there happen to be found other kinds of ape which have just five vertebrae in their loins like humans, having a shorter trunk than the apes we have. Yet Galen everywhere counts only five, 25 nevertheless accommodating the rest of his account to apes (as we have just shown) rather than man. It is possible that because the number had been set by all the ancients together, he agreed and handed on to posterity fewer vertebrae than were presented to him in apes. Perhaps in humans he found in the country or at least, as is likely, in skeletons not brought home he saw a number of specimens with five, while in the rest of the frame and in his fuller account of the bones he persuaded himself (as he often did elsewhere) that human vertebrae were similar and equal to simian without considering the matter more carefully.



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 17 On the Lumbar Vertebrae