51 
Examined. 
Infections. 
Per 100 
persons. 
Ascaris lumbricoides— Continued. 
Army before 1898 
179 
0 
0.00 
Navy 
103 
0 
0.00 
Army after 1898 
90 
1 
1.11 
Philippine service 
115 
1 
0.87 
Strongyloides stercoralis: 
Soldiers’ Homes 
395 
1 
0.25 
District of Columbia 
397 
2 
0.50 
Army before 1898 
179 
0 
0.00 
Navy 
103 
1 
0.97 
Army after 1898 
90 
0 
0.00 
Philippine service 
115 
1 
0.87 
Hymenolepis nana and Txnia saginata gave no infections in any of 
the above groups. 
The soldiers admitted to the hospital from the Soldiers’ Homes in 
various parts of the country gave the lowest rate of total infection. 
These patients were, for the most part, men of advanced years. It 
would seem, therefore, that age and long institutional life were the 
factors most concerned in causing the low percentage of infection 
found in this group. This probability is strengthened with regard to 
the factor of institutional life by the figures for whipworms and pin- 
worms. As has been already mentioned (p. 37) , the conditions present 
in institutional life, while unfavorable to the propagation of infection 
with an intestinal worm of a more or less complex life cycle, such as 
that of Trichuris, would be especially favorable to the spread of a 
directly transmissible parasite like Oxyuris. Accordingly, whipworms 
gave a lower rate of infection among the men admitted to the hos- 
pital from an earlier period of institutional life in the Soldiers’ Homes 
than in any other of the groups under consideration, while pinworms 
presented a higher frequency of infection among these patients than 
in any other group but one. 
The civilian patients admitted to the hospital from the District of 
Columbia presented a higher percentage of total infection than the 
patients admitted from the Soldiers’ Homes, but a lower rate than any 
group of patients admitted from military service. These facts would 
seem to indicate that the conditions of life in the general population 
even of a large city are more favorable to helminthiasis in general than 
the conditions of such institutional life, and, furthermore, that army 
life, even in the Regular Army posts, is more conducive to intestinal 
worms than that of cities. When we consider the infections with 
whipworms and with pinworms separately, however, the above indi- 
cations are seen to hold only in the case of the former parasite, since 
pinworms gave a higher rate of infection among both the old soldiers 
from the Soldiers’ Homes and the soldiers from the Regular Army posts 
