36 
a greater precipitation, and while the greatest number (15) developed 
with a precipitation of 1.28, the average stands as follows: 2.33 cases 
between 0.37 and 0.68; 1.5 cases between 1.02 and 1.98; 3 cases at 
2.78; 7 cases at 3.81; 7 cases between 1.19 and 1.53. 
While these data are too incomplete to permit of definite conclusions, 
still, such as the}" are, the}" are in harmony with the view that cases 
are more likely to occur coincident with a rising of the streams than 
with their fall. 
Comparison. — Texas fever, in the United States, occurs in summer and fall; hemo- 
globinuria in the Danube region occurs usually in the late spring, summer, and late 
fall. Carceag is reported for the Danube region, especially in May and June. Canine 
piroplasmosis prevails at the Cape chiefly in summer and autumn, and is reported 
in Europe for April, September, and October. ■- 
^Ve should not be led astray by this comparison of months. The 
life history and seasonal occurrence of ticks in different places might 
vary according to the species of tick involved and according to the 
climate. 
AGE AND SEX OF PATIENTS. 
Idaho . — Fairchild (1896) says that all classes and all ages are affected, the rich, 
the poor, the weak, the robust, the young, the old, males and females, alike. Bowers 
(1896) agrees that the disease attacks persons in all conditions of life, but males in 
larger proportion. According to Dubois (1896, p. 64) “spotted fever” attacks per- 
sons of all ages, but adults of both sexes are more subject to infection than are 
children. According to Maxey (1899, p. 434) it is much more frequent in men on 
account of tlieir exposed occupations, and this will explain also wliy children are 
rarely, if ever, affected; the youngest case he knows of was in a patient 6 years old, 
the oldest in a patient nearly 70 years of age. 
^[ontana . — Gwinn (1902) reports that in his observations he has noted that age, 
sex, and amount of vitality play little or no role in infection. 
The first actual statistics concerning age and sex were collected by AVilson and 
Chowning (1903a, p. 43), based upon 114 cases; they conclude (1903a, p. 68; 1904a, 
p. 43) that the disease attacks alike patients of any age or either sex, though those 
whose occupations or pleasures take them to the foothills of mountains in the spring- 
time are most affected; they report one case (1903a, pp. 38,59) in a child 2 years 
old and another (p. 32) in a babe 2 days old; they give a very interesting table of 
114 cases, and conclude that the cases are too few to warrant elaborate conclusions, 
but that it is probable that the large number of cases occurring in males (36) of 20 
to 40 years, and in females (25) of somewhat younger age (10 to 40), is due to the 
increased exposure to infection through occupation or pleasure taking them outdoors 
in the foothills and mountains in the spring of the year. 
Anderson (1903c, p. 9) shows that of 121 cases 76 were males and 45 females, the 
difference in number in the two sexes being probably due to a greater liability to 
exposure on the part of men on account of occupation. He gives the ages of 15 to 
50 as being most liable to infection, and reports 18 months as the youngest and 74 
years as the oldest cases recorded. 
The Wilson and Chowning table (1903a, p. 43) of 114 cases was 
increased by them (1904a, p. 36) to 126 cases. It is here increased to 
139 cases, to contain the Bitter Root Valley patients observed in 
Aiigust-September, 1903, and in the 1904 outbreak. 
