Posted on Sep 5, 2011
Marrow fills up cylindrical cavities
in the bodies of the long bones;
blood vessels pass into minute orifices
through canals that traverse substance.
The intimately combined animal and earthly part
make it a hard structure of the adult body:
earthly matter confers its hardness and rigidity
while the animal matter determines its tenacity,
a degree of toughness and elasticity
pinkish-white externally and deep red within.
SOURCE: Henry Gray, Anatomy of the Human Body (http://www.bartleby.com/107/)