(U 
DUKATTOX OF IXFECTIOX. 
The duration of infection as determined by the actual observation 
of eggs in the feces after the time they were tirst seen was 2 months 
in one case (No. 43), 6 months in 3 cases (Xos. 36, 45, 53), 7 months in 
2 cases (Nos. 48, 86), 1 year to 2 years. 3 cases (Nos. 4, 47, 49), 24 
years, 1 case (No. 38). 
As determined also by the length of time tlie symptoms existed, 
which were cured or improved by anthelmintic treatment: 3 months, 
1 case (No. 42): 7 months, 1 case (No. 41): 1 to 2 vears, 7 cases (Nos. 
37, 43, 44, 49, 81, 94, 95): 54 years, 1 case (No. 38). In 1 case (No. 
36) the symptoms disappeared spontaneously after lasting 6 months, 
reappeared after a lapse of 1| years, then disappeared again after 
anthelmintic treatment, but recurred with the reappearance of eggs 
in the feces. 
In cases which were not treated the symptoms lasted 3 years, ending 
in death in 1 case (No. 9); and for 2 years in another case (No. 55); in 
a third case (No. 48) symptoms, which may have been caused by the 
presence of //. ncma, were exhibited for nearly 6 years. 
GENERAL SYMPTOMATOLOGY OF INTESTINAL HELMINTHIASIS. 
Before taking up the analysis of s\’mptoms exhibited in cases of 
IIy}nen(jlej)i'< nona^ it is considered advisable to review shortlv the 
symptomatology of other intestinal worms, especialh' tape\vorms. 
Generali V speaking, the injurious ellects of intestinal worms may be 
looked upon as due to one or more of the following causes, namely, the 
mechanical obstruction occasioned bv their presence, the irritation to 
the wall of the intestine, the influence of this indtation upon the ner- 
vous system, the loss to the host of nutritive materials which go to 
supply the parasites, and finally, the elminination by the parasites, of 
toxic principles Avhich are absorbed by the host. 
In discussing the phenomena produced l)v worms, Davaine (1860a, 
pp. 48 et seep), the eminent French helminthologist, says in part 
essentially as follows: 
The presence of worms in the intestine does not always result in appreciable phe- 
nomena; it is compatible with the most ])erfect health; ))iit is frequently manifest 
by variable j»henomena of a local and often of a sympathetic nature. 
The local phenomena consist of derangements of the intestinal functions, abdomi- 
nal pains, anal pruritus, and occasionally anatomical lesions of some importance. 
Any organ may Vje affected reflex ly by intestinal worms; false perception of odors, 
dilation of the pupil, permanent or ti’ansitory amaurosis, abnormal sensitiveness of 
hearing, perversion of taste, itching and formication of the skin, bear witness to the 
sympathetic action of the })arasites upon the senses; from another side, somnolence, 
vertigo, frightful dreams, spasms, vague pains, cough, dyspnea, cardiac palpitations, 
irregularities of inilse, insatiaV)le hunger or anorexia, salivation, quality of the urine, 
