77 
probable when the patients are children. Intestinal parasites, in fact, j^lay a con- 
siderable part in the production of infantile maladies, a circumstance which is sys- 
tematically disregarded by a great many physicians. When helminthiasis is once 
suspected, one ought to determine as nearly as possible to what species the offending 
parasite belongs. Success in treatment depends upon this point; a remedy which is 
sure in its effects upon one species may be useless against other worms. Entire worms 
or fragments which have spontaneously quitted the intestine may be found in the 
dejecta. A careful examination of these furnishes valuable data with regard to the 
treatment to be pursued, but one ought not to limit one’s self to such a superficial 
means of determination. Since it frequently happens that several parasites live side 
by side in the intestine of the same individual, it is indispensable, especially in grave 
cases, to make a more careful examination of the feces, in order to determine 
exactly what different species may be harbored by the patient. This examination 
presents no difficulties, and only requires a little patience, since all the eggs are not 
equally easy to distinguish. The egg of each species of parasite, however, has a very 
characteristic shape and size, which renders the diagnosis very easy. (Translation.) 
To make the examination it is necessary simply to rub up with a 
drop of distilled water on a glass slide, a very small particle of the 
feces to be examined, cover with a cover glass, and examine with a 
moderately high power, a Zeiss 4 or 8 mm., Leitz 5 or 7, Bausch and 
Lomb one-half or one-fourth, or other equivalent objective. Some 
care is requisite in looking for the eggs of II. nana^ otherwise they 
are ver}^ liable to be passed unperceived, because of their great trans- 
parency. The presence of three pairs of hooks on the embryo con- 
tained within an egg indicates that it is a cestode egg, while the pres- 
ence also of two distinct membranes, an inner one closely investing 
the embryo, and an outer separated from the inner b}^ a considerable 
intervening distance, is characteristic of Ilymenolejns eggs. The shell 
of the egg of Tsenia sagmata or of T. solhim is thick, radially striated, 
and lies closely against the embryo. The outer membrane of the egg 
of Ilymenolepis diminuta ma}^ likewise be radially striated, a character, 
which when present will distinguish it from Ilymenolejns nana. The 
substance intermediate between the outer and inner membranes is 
more prominent in IL diminuta^ and there are no filaments attached 
to the poles of the inner membrane as in II. nana. The presence of 
polar papillae on the inner membrane is a characteristic feature of 
Hymenolejns eggs not always readily apparent. The filaments in the 
egg of II. nana are often difficult to distinguish, but in case thej^ are 
not seen at once, careful observation of a number of specimens, espe- 
ciall}" if an immersion lens be used, will usuall}^ reveal them. 
Charcot-Robin crystals, which were found by Leichtenstern (1892) 
almost constantly present in the feces of patients with helminthiasis, 
have not been found in cases of Ilymenolepis nana. 
It is doubtful whether the spherical bodies described by Senna and 
referred to above (p. 33) can be considered of diagnostic importance. 
As already remarked. Senna at first considered these bodies to be eggs 
in course of development, but since he found them not only iw feces 
