PA THOGENIC BA CTERIA.

When ingested the resisting power of the bacillus per-
mits it to pass uninjured through the acid secretions of
the stomach and to enter the intestine, where the chief
local disturbances are set up.

The bacilli enter the solitary glands and Peyer's patches,
and multiply slowly during the one to three weeks of the
incubation of the disease. The immediate result of their
residence in these lymphatic structures is increase in the
number of cells, and ultimately the necrosis and slough-

FlG. 108.—Intestinal perforation in typhoid fever. Observe the threads of
tissue obstructing the opening. (Museum of the Pennsylvania Hospital.)
(Keen, Surgical Complications and Sequels of Typhoid Fever."]

ing which cause the typical post-mortem lesion (Fig. 108).
From the intestinal lymphatics the bacilli pass, in all
probability, to the mesenteric glands, which become en-
larged and softened, and finally extend to the spleen and
liver, and sometimes to the kidneys. The growth of the
bacilli in the kidneys causes the albuminuria of the dis-
ease. Sometimes under these conditions the bacilli may