HELMINTHES. 45 
outside of the kyst, the animals being restricted to its inside. It occurs in 
the liver, spleen, and other parts, and is not exclusively confined to man. 
b. Cestordea. 
Cysticercus is found in man as well as in animals, between the tissues of 
the muscles, sometimes penetrating to the eye-ball, the heart, and the brain. 
The form is that of the Cystica (with which it is usually and perhaps cor- 
rectly placed), whilst in some other respects it approaches the Cestoidea. 
What is called “ measles” in hogs arises from an abundance of enkysted 
worms (Cysticercus cellulose, pl. T7, fig. 30), which have been found occu- 
pying as much space as the brain in these animals, and causing convulsions 
and death. 
The intestinal worms of the genus Ligula (Z. congulum, pl. 77, fig. 34) 
are flat, ribbon-shaped, without articulations, marked with a longitudinal 
stria, and also transversely striate. They live in birds, and especially in 
fishes. The species figured is from one to five feet long, and is found in the 
Cyprinus brama of Europe. This worm is said to be eaten in some parts 
of Italy. Bothrimonus sturionis intests the American Acipenser oxyrhyn- 
chus. It is not articulated, it has a longitudinal impressed line above and 
below, with numerous raised points along it, thgse beneath having a pore. 
The head is sub-globular, with a double sucker. 
The genus Bothriocephalus (named from bothros, a groove, and kephale, 
the head) is a long, flat, jointed worm, with a longitudinal groove upon each 
side of the sub-quadrate head, distinguishing it from Zenza, or the true 
tape-worm. It is also distinguished by having the segments much wider 
than long, and the openings from the ovaries are beneath, and not lateral. 
The genus infests birds, fishes, and reptiles; and one species, B. latus 
(pl. 77, fig. 32), infests man in Russia, Switzerland, and some other parts 
of Europe. 
The common tape-worm, Tenia solium (pl. 77, fig. 38), is composed of 
flat, sub-quadrate articulations, which are very small and fragile for some 
distance from the head, so much so that this part is rarely obtained perfect, 
and the small head was for a long period unknown. The head is globular 
and provided with four terminal suckers, arranged in a square around the 
mouth. The alimentary canal is double, being composed of an intestine 
running along each side of the body, with a transverse canal connecting 
the opposite sides at the beginning of each segment, giving the interstices 
the appearance of a ladder. The centre of each segment is occupied by 
distinct generative organs of both sexes, which have their outlet in a lateral 
pore, alternately upon the right and left side of the segments. As each 
segment is capable of producing a large number of eggs, it is difficult to 
conceive why the animals should be comparatively so few in number. 
This species attains a length of twenty feet or more, and a single one is 
usually confined to a single individual, although as many as twenty have 
been found together. Tania cateniformis (fig. 31) is about an inch long, 
and infests the cat. 
II. ParencuyMara. 
These are soft contractile bodies, without any appearance of division 
249 
