hat do not, like the
acute forms, go on to suppuration or to death of bone, but result in
thickening of the bone affected, both on the surface and in the
interior, resulting in obliteration of the medullary canal.

A third group of chronic inflammations are those that begin as an acute
pyogenic inflammation, which, instead of resolving completely, persists
in a chronic form. It does so apparently because there is some factor
aiding the organisms and handicapping the tissues, such as the presence
of a foreign body, a piece of glass or metal, or a piece of dead bone;
in these circumstances the inflammation persists in a chronic form,
attended with the formation of fibrous tissue, and, in the case of bone,
with the formation of new bone in excess. It will be evident that in
this group, chronic inflammation and repair are practically
interchangeable terms.

There are other groups of chronic inflammation, the origin of which
continues to be the subject of controversy. Reference is here made to
the chronic inflammations of the synovial membrane of joints, of tendon
sheaths and of bursae--_chronic synovitis_, _teno-synovitis_ and
_bursitis_; of the fibrous tissues of joints--chronic forms of
_arthritis_; of the blood vessels--chronic forms of _endarteritis_ and
of _phlebitis_ and of the peripheral nerves--_neuritis_. Also in the
breast and in the prostate, with the waning of sexual life there may
occur a formation of fibrous tissue--chronic _interstitial mastitis_,
_chronic prostatitis_, having analogies with the chronic interstitial
inflammations of internal organs like the kidney--_chronic interstitial
nephritis_; and in the breast and prostate, as in the kidney, the
formation of fibrous tissue leads to changes in the secreting epithelium
resulting in the formation of cysts.

Lastly, there are still other types of chronic inflammation attended
with the formation of fibrous tissue on such a liberal scale as to
suggest analogies with new growths. The best known of these are the
systematic forms of fibromatosis met with in the central nervous system
and in the peripheral nerves--_neuro-fibromatosis_; in the submucous
coat of the stomach--_gastric fibromatosis_; and in the
colon--_intestinal fibromatosis_.

These conditions will be described with the tissues and organs in which
they occur.

In the _treatment of chronic inflammations_, pending further knowledge
as to their causation, and beyond such obvious indications as t