23 
the part of females. If we accept the excessive infection with whip- 
worms among males found at the Government hospital as due to 
infections introduced by the soldiers, the statistics obtained at the 
orphanage and at the Connecticut hospital would appear to establish 
a greater relative frequency of infection with this parasite among 
females than among males. 0 
The significance of sex as a factor in the prevalence of intestinal 
worms, especially in rural districts, is further discussed on page 29 
et seq. 
AGE. 
The results obtained from the first 500 cases examined (adult white 
males) seemed to show that the frequency of infection decreased as the 
age of the patients increased. 6 This indication is strikingly strength- 
ened in the total results obtained from our whole number of cases, 
including children and adults, whites and negroes, and males and 
females, but, as will be seen, it does not appear to hold for every class 
of patients. 
In order to study the frequency of intestinal worms among persons 
of different ages, our patients were divided into four age groups, the 
divisions being such that each group would include those ages which 
might be supposed to agree most closely with respect to the conditions 
which would seem to be the most important factors in determining the 
degree of prevalence of helminthiasis (environment, habits, occupa- 
tion, etc.). These groups, as arranged, are (1) persons under 15 years 
of age, (2) persons from 15 to 30 years old, (3) persons from 31'to 50 
years old, and (4) persons 51 years of age or older. 
The relative rate of total infection in the various groups for the 
whole number of persons examined c was as follows : 
Examined. 
Infections. 
Per 100 
persons. 
Total infections: 
Under 15 years 
123 
26 
21.14 
15 to 30 years 
572 
90 
15.73 
31 to 50 years 
1,341 
153 
11.41 
Over 50 years 
1,289 
91 
7.06 
It is seen that there is a decided fall in the rate of infection in each 
group as we pass from the youngest to the oldest. 
a For the relative frequency of helminthiasis in males and females as reported by other 
authors see page 7(5 > 
b See Garrison, Ranson & Stevenson, 1903, page 8. 
c Exclusive of 132 patients, whose ages could not be ascertained. 
