8. Now as a soft and yielding substance, if it had no assistance from the hard parts, would certainly have, like molluscs, neither motion nor articulation, nature accordingly mingles in the body the hardness of the bones, and uniting these by close connection one to another, and knitting their joints together by means of the sinews, thus plants around them the flesh which receives sensations, furnished with a somewhat harder and more highly-strung surface than it would otherwise have had.