76 
g’eneral population. Thus it has happened that a comparatively large 
number of cases have presented themselves in which severe symptoms 
were associated with the occurrence of Hymenolepis nana^ while prob- 
ably a very large number of cases have never been noticed because 
there have been no symptoms. A case of Tdenia saginata or T. soJiurru 
on the other hand, is very likely to come under observation; the aver- 
age individual, when he has once observed the passage of worms from 
his intestine, usuallv does not delav, whether there are anv other 
unpleasant symptoms or not. to seek relief from the presence of his 
unwelcome guests; the case consequently stands a very good chance 
of being placed somewhere on record. Another point might be noticed 
in this connection. Hyrnenolepu nana is more especially a parasite of 
children: the larger tapeworms are more common among adults. It 
is rather to be expected that children would, in general, experience 
more severe effects from parasitic infection than adults; for example, 
nearly half of Cobbokhs cases (as noted above), which exhibited severe 
nervous symptoms, were children, while the great majority of all his 
cases were adults; an indiscriminate comparison of statistics, therefore, 
without taking into account the question of age of affected individuals, 
is not likely to give a true idea of the relative nocuity of the different 
parasites. 
The symptomatology of helminthiasis with Ilymenolejyis nana may 
be summed up as follows: 
The effects of helminthiasis with II. nana are no more severe than 
may occur from infection with other tapeworms, nor, if it is consid- 
ered that many cases of the former are probably overlooked, are 
serious symptoms more common. Although the effects are usually sa 
slight, even when the parasite is present in considerable numbers, 
that the S 3 unptoms are only veiy mild or absent entirely, it occasion- 
ally happens, as with the larger tapeworms, that severe symptoms 
(persistent diarrhea, epileptiform attacks, etc.) are exhibited. The 
most frequent symptoms determined by the presence of II. nana are 
abdominal pain, which ma}^ or may not be associated with diarrhea; 
convulsions of various sorts, frequently epileptiform; headache and 
strabismus. Xasal or anal pruritus, common in cases of infection with 
other tapeworms, is rarely seen with II. nana. In many cases in 
which a neuropathic condition is already present, infection with 
Ilymenolejns nana is likeh^ to result in an aggravation of the morbose 
phenomena^ and, in general, a predisposition to nervous disease seems 
to be the important factor in the appearance of nervous symptoms. 
DIAGNOSIS. 
In speaking of the diagnosis of helminthiasis, Blanchard (1891a, 
p. 100) remarks as follows: 
The persistence of digestive troubles and the diversity and irregularity of other 
symptoms are very suggestive of helminthiasis. The diagnosis is rendered more 
