38 
MORBID ANATOMY. 
The following summary of the post-mortem appearances of the 
disease are based on the findings in seven eases from the Bitter Root 
Valley. 
Rigor mortis. — Usualh^ intense and appears early. 
Skin. — Jaundiced, sometimes deeply. One or more wounds appar- 
ently caused by tick bites usualh^ present. The skin has a marbled 
appearance, well shown by the cut on page 23. On the non-dependent 
parts of the body spots, petechial in character, from bright red to 
dark purple in color and from 1 to 3 cm. in diameter; most abundant 
on wrists, ankles, arms, and back. The capillaries are congested; 
minute extravasation in the rete extending into the stratum mucosum. 
JTervous .system . — The cerebral and spinal meninges are normal 
except for slight h\^postatic congestion. Xo increase in fluid. The 
brain and spinal substance normal. 
Respiratory organs . — Pleurae normal and do not contain excess of 
fluid. Lungs show h 3 ^postatic congestion; occasionalh^ pneumonia. 
Circulatory system . — Pericardium normal. A few small petechial 
hemorrhages under the epicardium over left ventricle were constantly 
found. The heart muscle is flabbv, softened, and pale. Right heart 
full of blood; left, contracted and empt}'. The nuclei are faintlv 
stained; libers granular and fragmented. 
Digestive 6>/y/u/? 6'.— Stomach normal. Small and large intestines 
normal in appearance throughout; Pe^^er's patches rather pale in color. 
INlesenteric and retroperitoneal glands not enlarged. Spleen usaally 
dark purple in color, soft, diffluent, aiid from three to four times its 
normal weight; vessels engorged with blood; manv mononuclear leu- 
cocvtes containing from one to four red corpuscles; no free pigment. 
Liver enlarged, fattv, and in portions areas outlined bv bile pigment; 
sections usualL show an advanced degree of fattv inflltration; bile 
capillaries full. Pancreas about twice its normal weight. 
Kidneys. — Enlarged; capsule usualA not adherent. Small subcap- 
sular hemorrhages on ventral surface. On section, congested and 
swollen cortex; pvrainids well outlined and deej:) red color. Small 
hemorrhages in pelvis. Microscopicallv there are minute extravasa- 
tions of blood in cortex and under the capsule; veins tilled with blood. 
Nuclei of the convoluted tubules stain poorh- cells granular and in 
some places detached; newl}^ formed casts in tubules. Bladder normal 
and usuallv with small amount of dark urine. 
PROGNOSIS. 
Of 121 cases which have occurred in or near the Bitter Root Valiev, 
81: died, giving a case inortaliL^ of about TO per cent. The mortalitv 
varies within narrow limits from vear to vear, some }’ears as man^^ as 
