This vascular net-work has only organic sensibility and insensible
organic contractility, which are necessary for its functions; and it
is this which especially distinguishes it from the medullary system of
the middle part of the long bones, whose animal sensibility is, as we
shall see, very great. Irritate in a living animal the interior of a
short or flat bone, or the extremity of a long one, no sign of animal
sensibility is manifested. Sawing the cranium, the condyles of the
femur and the head of the humerus is not painful.
Injuries of this system when they are very great may produce necrosis
of the bone, and the formation of a new osseous substance at the
expense of the periosteum; but if a small portion only is affected,
this phenomenon does not take place. I have many times perforated
transversely with a gimblet the extremity of a long bone of an animal,
and afterwards passed a red hot iron through the opening; the animal
has always recovered without necrosis; the articulation has only
remained swelled, and much injured in its motions, and some scales have
come from it during the suppuration.