The Natural History of Pliny, Volume 3 · the Elder Pliny
CHAP. 86.—THE MARROW: ANIMALS WHICH HAVE NO MARROW.
The marrow seems also to be formed of a similar material; in the young it is of a reddish colour, but it is white in the aged. It is only found in those bones which are hollow, and not in the tibiæ of horses or dogs; for which reason it is, that when the tibia is broken, the bone will not reunite, a process which is effected[309] by the flow of the marrow. The marrow is of a greasy nature in those animals which have fat, and suetty in those with horns. It is full of nerves, and is found only in the vertebral column[310] in those animals which have no bones, fishes, for instance. The bear has no marrow; and the lion has a little only in some few bones of the thighs and the brachia, which are of such extraordinary hardness that sparks may be emitted therefrom, as though from a flint-stone. CHAP. 87.—BONES AND FISH-BONES: ANIMALS WHICH HAVE NEITHER. CARTILAGES.
The bones are hard, also, in those animals[311] which do not grow fat; those of the ass are used by musicians for making flutes. Dolphins have bones, and not ordinary fish-bones; for they are viviparous. Serpents, on the other hand, have bones like those of fish. Among aquatic animals, the mollusks have no bones, but the body is surrounded with circles of flesh, as in the sæpia and the cuttle-fish, for instance; insects, also, are said to be equally destitute of bones. Among aquatic animals, those which are cartilaginous have marrow in the vertebral column; the sea-calf has cartilages, and no bones. The ears also, and the nostrils in all animals, when remarkably prominent, are made flexible by a remarkable provision of Nature, in order that they may not be broken. When cartilage is once broken, it will not unite; nor will bone, when cut, grow again, except in beasts of burden, between the hoof and the pastern. Man increases in height till his twenty-first year, after which he fills out; but it is more particularly when he first arrives at the age of puberty that he seems to have untied a sort of knot in his existence, and this especially when he has been overtaken by illness.
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