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Mémoires 
The Intestinal Worms of three hundred insane 
patients detected by spécial methods 
By Dr. S. T. ETARLING. 
Nearly ail the routine examinations of foeces for ova, larvae or 
worms, and nearly ail the published accounts of the prevalence of 
intestinal worms in man and animais are defective on account of 
the imperfect means used in detecting ova or parasites. The me- 
thod of examining undiluted or of diîuted foeces in cover slip pré¬ 
parations, is uncertain and when many préparations are to be 
examined, too laborious to yield results of high relative accuracy. 
When results giving the absolute incidence of infection are de- 
sired, spécial methods must be used. 
During a recent investigation of Strongyioides infections, a fa¬ 
vorable opportunity presented for noting the incidence of intes¬ 
tinal worms in 300 insane patients at Ancon Hospital, Canal 
Zone. The results reported here were obtained by a combination 
of three methods. 
a) Plate-culture method, 
b) Differential-density method. 
c) Direct smear method. 
Each method is designed to give spécial information more 
exactly and when many stools are to be examined more quickly 
with less labor and eye fatigue than the direct smear method does 
when used alone. 
The specimens of the stools were collected in heavy glass test 
tubes, 5” x 5/8”, each tube was labeled with adhesive plaster so 
that its number would not be lost in centrifuging. First a portion 
of the stool was placed in the center of a Pétri dish, several 
drops of stérile tap water added, the dish covered and incubated 
at room température, 76-84° F., for 18 to 24 hours. Upon exami¬ 
nation with the dissecting microscope the présence of S. stercora- 
