gh the bacilli have effected a lodgment and have inaugurated
disease, the relation between them and the tissues remains one of mutual
antagonism; which of them is to gain and keep the upper hand in the
conflict depends on their relative powers of resistance.

If the tissues prevail, there ensues a process of repair. In the
immediate vicinity of the area of infection young connective tissue, and
later, fibrous tissue, is formed. This may replace the tuberculous
tissue and bring about repair--a fibrous cicatrix remaining to mark the
scene of the previous contest. Scars of this nature are frequently
discovered at the apex of the lung after death in persons who have at
one time suffered from pulmonary phthisis. Under other circumstances,
the tuberculous tissue that has undergone caseation, or even
calcification, is only encapsulated by the new fibrous tissue, like a
foreign body. Although this may be regarded as a victory for the
tissues, the cure, if such it may be called, is not necessarily a
permanent one, for at any subsequent period, if the part affected is
disturbed by injury or through some other influence, the encapsulated
tubercle may again become active and get the upper hand of the tissues,
and there results a relapse or recrudescence of the disease. This
_tendency to relapse_ after apparent cure is a notable feature of
tuberculous disease as it is met with in the spine, or in the
hip-joint, and it necessitates a prolonged course of treatment to give
the best chance of a lasting cure.

If, however, at the inauguration of the tuberculous disease the bacilli
prevail, the infection tends to spread into the tissues surrounding
those originally infected, and more and more tuberculous granulation
tissue is formed. Finally the tuberculous tissue breaks down and
liquefies, resulting in the formation of a cold abscess. In their
struggle with the tissues, tubercle bacilli receive considerable support
and assistance from any pyogenic organisms that may be present. A
tuberculous infection may exhibit its aggressive qualities in a more
serious manner by sending off detachments of bacilli, which are carried
by the lymphatics to the nearest glands, or by the blood-stream to more
distant, and it may be to all, parts of the body. When the infection is
thus generalised, the condition is called _general tuberculosis_.
Considering the extraordinary frequency of localised forms of surgical
tuberculosis, general dissemination of the