85 
MICROSCOPIC EXAMINATION' OP FECES. 
No special techniipie is necessary. Simply take a small amount of 
feces, preferably from near the surface, about the size of the* head of a 
large pin; spread this out in a drop of water on an ordinary micro- 
scopic slide and cover the preparation with a covm* slip. Kxamine 
under any moderately high power, as a Zeiss S mm.. Zeiss (\ or a 
Hausch Lomb one-third inch. Look carefully, with not too strono‘ 
illumination, for an elongate oval egg with thin shell, and with proto- 
plasm either unsegmented or in the early stages of segmentation. The 
older the feces and the warmer the weather the more advanc(*d will be 
the segmentation. In case of infection with Unctnaria amertnuto the 
fully developed embryo may lie found within the eggshell. Be cau- 
tious not to mistake for the egg of the Unctnartn the eggs of Ascar '(i< 
lumbricoidex. which have a thick gelatinous, often mammi Hated, 
covering and an unsegmented protoiilasm (tigs. 48-44), or the eggs 
(tigs. 57-05, of 0,rijuris verruicularis^ with a thin 
asymmetrical shell (one side being almost straight) 
and containing an embryo, or the eggs of whip- 
worms (77*/c7/?//‘/.y more commonly known 
to ph}’sicians as Trlchocephalus di^par), possessing a 
smooth, thick shell, apparenth' perforated at each 
pole, and an unsegmented protoplasm (tig. To). 
As a rule, in fecal examination I jirefer to use the 
thick, large, by 3 inch slide, such as is used in 
examining for trichina", rather than the ordinary 1 
by 3 thin English, slide." The larger slide is not 
onh" more steadily and niore easily manipulated 
in case one is working' without a mechanical stage, but it is much 
cleanei* to handle. 
In mo.st cases of infection with intestinal worms the siinplt' method 
just described will sulHce for a })ositive diagnosis. Bidore giving 
a negative ojiinion, howevei’. 1 invariably make ten pn'parations 
or follow a procedure which we may call “.'.sedimenting the feces.' 
Experience has shown me that in ca.'^es of m‘gativ(' diagnosis by the 
simple method ]>ositive diagnosis occasionally result‘d it the fi'ces are 
washed and “ sedimented." 
Mefhod(>f 'it'(isJt!)Hf and sed mumf ni(j — lake one oi' two ounces 
of feces, fresh or dry, mix with watrn-, and jilaci* in a large bottle, 
retort, jar, or any other receptach*: add enough watm* to make Irom a 
pint to two (juarts, according to the amount <>t ie<-(*s; shake oi’ stir 
thoroughly and allow to .settle; i)our otl th«‘ lloating matter and the 
water down to near the sediment; repeat the washing and .'fettling 
several times, or as long as any matter will lloat. 1 he last time this is 
done u.'^e a bottle or graduate with a smallei- diaim*tor, and whim tin* 
material is thoroughly settled examine thi‘ lint; .sediment. It will be 
Fio. ft's.— Egpr of the 
•hvarf tiipewonn (//»/- 
meuolrpin vann) of 
imin. Greatly magni- 
lied. (After II. II. Kan- 
soni, unpublishe<l, > 
