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 14 On the Spine and its Various Bones

The cartilage growing near the tips of the spines

A cartilage grows on these posterior processes in most vertebrae possessing an epiphysis (F, G in figs. 2 and 3, ch. 17), a suitable defence for what lies beneath, as it cannot be broken or fractured like things that are fragile, friable, and hard, nor severed and bruised like soft and fleshy parts. 27 The size of the individual processes which we said protrude like a spine is somewhat irregular in all the vertebrae; this too is equally the result of Nature’s marvellous foresight. For in those places where any very important part takes for itself the same place as the dorsal medulla, it was by no means just to neglect the priority of this part, nor in places occupied by the medulla alone was it just that long spines be grown. Similarly, it was inexpedient for a long spine to grow out of little vertebrae, or a short one from a large vertebra. So with the best reasoning, since the heart is located in the thorax and the great artery [aorta] lies upon the spine, in these portions of the backbone Nature put forth the longest spines, and shorter ones in other places. The bodies of the lumbar vertebrae are great, and to the inside of them is supported the great artery [aorta abdominalis] and the vena cava (the figs. of Bks. 5 and 6 show what is placed before the anterior of the vertebrae); but the mass of the sacrum is greater and more remarkable, though no particular organ is situated in front of it. It was therefore reasonable that the rear processes [processus spinosi] after the vertebrae of the thorax be grown largest in the loins and shortest in the sacrum. The neck vertebrae, since they are the thinnest of all, were not able at the same time to obtain long processes that were fit for enduring injuries without harm since they are easily broken because of their thinness. 28



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 14 On the Spine and its Various Bones