THE TAPE -WORM. 
51 
from ten to thirty feet in length; 
eight hundred joints in a worm 
ten feet long. The head ends 
in a proboscis armed with a 
double crown of hooks; the 
first proglottis or sexually ma- 
ture segment begins at the 
450th. While in some persons 
the presence of a tape-worm is 
simply an annoyance, in ner- 
vous and irritable persons it 
causes restlessness, undue anx- 
iety, and various dyspeptic 
symptoms. Among the pre- 
ventive remedies against tape- 
worms is the disuse of raw or 
underdone pork, and measly'^ 
pork — i.e,, the flesh of swine 
containing the little bladdor- 
like vesicles. Cysticerci, or 
young " tape - worms, can be 
readily distinguished, but when 
thoroughly cooked are harm- 
less, as the temperature of 
boiling water is sufficient to 
kill them. As a matter of 
course, in the use of drugs to 
expel a tape-worm they should 
be pushed so as to carry off the 
entire animal, as new segments 
grow out from near the head 
as rapidly as the joints are de- 
tached. 
The history of the human 
tape-worm, Tcenia soliwii (Fig' 
53), is as follows: The 
there are upward of 
Fig. bS.—Tcenia solium. Natural size, 
with the head magnified. Strobila 
