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20 
tlie higher female rate of infection with whipworms, while pinworms 
gave a decidedly higher percentage among the male patients. 
To draw a definite conclusion regarding the relative frequency of 
intestinal worms in males and in females from these seemingly con- 
tradictory results obtained from the different institutions is not unat- 
tended with difficulty, but there are certain considerations which will 
aid us considerably in arriving at a just interpretation of the figures 
above given. 
TTith regard to the higher rate of infection found among males than 
among females at the Government hospital, it must be borne in mind 
that in that institution there were over 200 males with a history of 
recent military life, of whom 115 had seen service in the Philippine 
Islands and among whom there appeared a relatively high percentage 
of infection with whipworms and hookworms, while the females at the 
Government hospital, with the exception of a few criminal cases, had 
a history of civil life in the District of Columbia and may be considered, 
therefore, to present more nearly the average amount of helminthiasis 
in the normal population. 
In explanation of the slightly higher rate of infection found among 
male civilians than among female civilians at the Government hos- 
pital. the suggestion may be offered that it might have been due indi- 
rectly to the influence of the soldiers admitted to the institution from 
the Army. It is not unnatural to suppose that the presence of the 
infections introduced by the soldiers among the male patients might 
be an additional source of infection to the civilians, civilians and sol- 
diers being more or less intimately associated in their hospital life. 
The female patients would remain free from this influence. If this 
explanation is correct, it must follow that the higher male rate was 
due to a higher percentage of infection with those parasites which 
were exceptionally frequent among the soldiers, namely, whipworms 
and hookworms. In considering the relative frequency of each para- 
site in the two sexes at St. Elizabeth we have already seen that a 
higher rate of infection was present among the males in the case of 
whipworms and of hookworms, but also in the case of pinworms. of 
Cochin China worms, and of the dwarf tapeworm, parasites which did 
not show a particularly high percentage of infection among the sol- 
diers: eelworms were more frequent among the female patients: the 
one infection with Taenia- saginata. occurring among the males. could 
not be considered of significance with regard to the relative frequency 
of this parasite in the two sexes. 
If now we consider separately the patients admitted to the Govern- 
ment hospital from civil life in the District of Columbia with regard 
to the relative frequency of each species of intestinal worm in males 
and in females, we shall find the results agreeing with those given 
