172 PARASITOLOGY. 
TAPEWORMS OF MAN. 
Two tapeworms of man find a lower animal as 
an intermediate host, viz.: Taenia Solium and 
Taenia Saginata. 
TaENIA SoLIuM (Taenia—ribbon) 
(Sola—alone) 
Synonym.—Taenia Armata. 
History.—Adult tapeworms in man and their effect 
upon the health of the host dates back to the begin- 
ning of history; we find the first description of tape- 
worms in the seventeenth century. The life cycle 
was worked out about 1850. 
Distribution.—Frequent in the United States; also 
found in many other countries. 
Description.—The head is scarcely larger than a 
pin head and is provided with four sucker discs and 
twenty-four to thirty-two hooklets. The worm may 
reach the length of forty feet. ‘The latter segments 
are as long or longer than broad; the genital pores 
are prominent and irregularly alternate; as soon as 
the segments are filled with mature ova they detach 
themselves and pass out to the ground with the feces. 
From one to half a dozen detach themselves at one 
time. Each segment contains many hundred ova. 
Lite Cyclee— The ova become disseminated 
through the water or food and are through these 
channels taken in by the intermediate host, which is 
the hog. In the stomach the ovum hatches into a 
six-hooked embryo, which, by means of its hooklets 
finds its way through the stomach or intestinal wall 
and wanders through the tissues or is carried by the 
blood stream or lymph current; in nine days the em- 
