DURATION OF INFECTION. 
The diu’ation of infection as determined by the actual observation 
of eggs in the fece- after the time they were lirst seen wa> '1 months 
in one case (Xo. To). 6 months in 3 cases (Xos. 36. To. 53). 7 months in 
'1 cases (Tsos. TS. S6). 1 year to '1 year<. 3 ca>es (Nos. T. T7. T9). 2T 
years. 1 case (No. 3-S). 
As determined also by the length of time the symptoms existeil. 
which were cured or improved by anthelmintic treatment: 3 month-. 
1 case (No. T:?i: 7 month-. 1 case (No. Tli: 1 to 2 years. 7 ca.ses (No-. 
37. T3. TT. T9, ol. 9T. 95i: oT 'years. 1 ca-e (No. 3S). In 1 case (No. 
36) the symptoms disappeared spontaneou.-ly after lusting 6 months, 
reappeared after a lapse of 14 year-, then disapjieared again after 
anthelmintic treatment, but recurred with the reappeai*ance of egg- 
in the feces. 
In cases which were not treated the >ymptom- lasted 3 years, ending 
in death in 1 case (No. 9): and for '1 year- in another case (No. 55); in 
a third case (No. T"^) symptoms, which may have been caused by the 
pre-ence of 77. nano, were exhibited for nearly 6 veal's. 
GENERAL SYMITOMATOLOGY OF INTE-TINAL HELMINTHIA-IS. 
Before taking up the analysi- of symptom- exhibited in ca-es of 
Hijinenolej'i^ nano, it is considered advi^^ble to review -hortly the 
symptomatology of other intestinal worm-, especially tajieworms. 
Generally speaking, the injuriou- etfects of inte.-tinal worms may be 
looked upon a- due to one or more of the following causes, namely, the 
mechanical obstruction occasioned by their presence, the irritation to 
the wall of the intestine, the intiuence of this irritation upon the ner- 
vous system, the loss to the host of nutritive materials which go to 
supply the parasites, and tinally. the elminination l\v the |iarasite-. of 
toxic principles which are absorlied by the host. 
In discussing the phenomena prcaluced by worm-. Davaine (ls6«ia. 
pp. TS et seq. I. the eminent French helminthologist' suvs in part 
e-sentially as follow-: 
The presence of worms in the intestine <k>es not alway> result in appreeiable phe- 
nomena: it is c*ompatible with the most i*eriet.-t health; l»ut is fre«iuentlv manifest 
by variable phenomena of a lo*-al an<l often of a symp»athetic nature. 
The Lx-al p>henomena consist of derangements c»f the intestinal fimctions, al»donii- 
nal pains, anal i»mritns. and occasionally anatomical lesions of some imp*ortance. 
An y organ may l>e affec*te«l reflexly by intestinal worms: false j*erveption of o«:lors, 
dilation of the pupal, pxrmauent or transitory amaurt :*sis, abnormal sensitiveness of 
hearing, p*erversioii of taste, itching ami formication of the skin. l>ear witness to the 
sympathetic action <:a the parasites up:»n the senses; from another side, ss^mnolence, 
vertigo, frightful dreams, sp»asms, vague pains, cough, dyspaiea, vanliac palp*itations, 
irregularities of pulse, insatiable hunger or anorexia, salivation. •|iiality of the urine, 
