10 
(b) Echinococcosis: Infection with the hydatid stage of Echino- 
coccus of dogs; it may occur in any organ, but chiefly in 
liver and lungs: diagnosis by symptoms or by aspiration 
and microscopic examination of the fluid to And the hooks 
or the heads: treatment surgical (p. 75). 
(c) Infection with Spargo/iwm rnansoni ; rare: diagnosis by find- 
ing the worm: treatment surgical, or bv extraction of worm 
per urethram (p. S3). 
(d) Infection with Sparganum prolifer urn : rare: Japan; diagnosis 
by finding the worm: treatment surgical (p. S6). 
THE PARASITES OF T^ENIASIS. 
The cestodes difier from the trematodes by the usual presence of a 
distinct head with 2 or I suckers, bv the segmented condition of the 
adult, each segment or proglottid representing, roughly speaking, a 
single trematode, so that the entire chain (strobila) may be viewed as 
a colony, and by the absence of an intestine. All of the species found 
in man are hermaphrodites. 
ANATOMICAL STRUCTURE OF CESTODES. 
The following technical description shows the systematic position 
and anatomical structure of the tapeworms under discussion: 
Superfamily Diboth r iosephaloidea . 
F ami ly Diboth riocephalidu. 
Genera Diboth riocephalus, Diplogonoporus, and Sparganum. 
Superfamily Tun io idea . 
Family Taeniidse. 
Subfamily Dipylidiinse. 
Genera Dipylidium and Hymenolepis. 
S ubf ami 1 y Da > a i n eim r . 
Genus Davainea. 
Subfamily Taeniinae. 
Genera Taenia with subgenera Taenia and Taeniarhynehus i and Echino- 
coccus. 
The head or scohx is provided with 2 Diboth rioceph alidu) or 4 Taeniidse suckers 
acetabula ) which may Davainea) be provided with hoohs; on its apex it has 
Tarn iid ae) a rostellurn, which in most species is armed with hooks; the head contains 
the brain and in some worms a circular excretory ring. Lateral nerves extend from 
the brain through the entire strobila to the distal end. Lateral canals extend from 
the circular ring distally through the segments; in the Taeniidae are distinguished 
dorsal and ventral canals , the latter being connected at the distal end of each segment 
by a transverse canal. The head is followed by a neck, which segments transversely 
to form the proglottides. Each proglottid or segment contains a full set i in some cases 
two sets of both male and female organs. The genital pores are lateral ( Tuniidu) or 
ventral ( Diboth r iocephalidae) . The male glands consist of testicles, which vary in 
number; from these extend vasa efferent ia which collect to form the vas deferens; the 
latter enters the cirrus-pouch, from which the cirrus penis ) is extruded. The female 
opening is close to the cirrus; the vagina runs toward the genital glands, swelling to 
a receptaculurn serninis; the glands are: shell gland , ovary, and viteUogene gland; the 
