$ 102. THE HELMINTHES. 105 
CHAPTER II. 
MUSCULAR SYSTEM AND ORGANS OF LOCOMOTION, 
§ 102. 
The muscular system is well developed with the Helminthes; its primitive 
fibres are flattened, and never transversely striated. In the Cystici, and 
Cestodes, the muscles dre least distinct, although in Cysticercus there can 
be no question as to the muscular fibres which traverse in every direction 
the walls of the caudal vesicle. Equally distinct is a subcutaneous layer 
of longitudinal fibres in the rings of Bothriocephalus and Taenia.® More- 
over from the great contractility of the rings, and especially those of the 
cephalic portion of the Cystici and Cestodes, there must be muscular fibres 
eoncealed in the parenchyma, but which from their tenuity escape our 
:bservation. In the Trematodes, having also an extreme ‘contractility, a 
sarge portion of the parenchyma of the body is composed of a muscular. 
reticulated tissue, the transverse and longitudinal muscles of which embrace 
the various organs in a retiform manner. In the Acanthocephali, the 
Gordiacei, and Nematodes, the general movements of the body are due to 
a subcutaneous muscular layer, which surrounds the visceral cavity in a sac- 
like manner. Its longitudinal and transverse muscles are quite distinct 
from each other; and their fibres, although parallel, communicate with each 
other by angular anastomes, and in this way form a net-work. 
In most of the Nematodes, the longitudinal muscles form four, large 
bands, two upon the ventral, and two upon the dorsal surface. 
In the Cestodes, this error is unnecessary, for in 
the posterior portions of their body the eggs can 
easily be distinguished from the corpuscles ; more- 
ver, these last are the most numerous about the 
neck and anterior rings,— localities where the 
genital organs are scarcely and sometimes not at 
all developed. It may be added, also, that these 
bodies dissolve in a weak acid with the escape of 
gas, while the eggs of Taenia under the same cir- 
remain d. In the Cystici, 
which are sexless, and where therefore eggs are 
vainly sought for, these corpuscles, as to their 
structure, chemical position, and position, so 
closely resemble those of the Cestodes, that it ap- 
pears strange that they have always been taken 
for eggs. Eschricht (Nov. Act. Acad. Leopold 
Carol. Vol. XIX. Suppl. alter. 1841, p. 59, 103), 
mot having perceived that they contain carbonate 
of lime, has described them as el tary gran-~ 
These 
the nucleus; and sometimes there are two nuclei 
thus enclosed, and then the corpuscles have ex- 
actly the aspect of the precious stones of Imatra. 
Those of Taenia erina, Bothriocephal 
solidus, and Cysticercus fasciolaris, are usually 
of an oval form, sometimes irregular, and of a 
variable size. T'schudi (Die Blasenwurmer, 1837, 
p. 24, Taf. II. fig. 21) has figured those of the last 
species as eggs. 
1 I have easily seen these muscular fibres in the 
caudal vesicle of Cysticercus cedlulosae, and 
tenuicollis. But they are wholly absent in the 
parent-vesicle of Echinococcus hominis, and vete~ 
rinorum. This vesicle, therefore, has’ probably 
no spontaneous movements, whilst the embryos it 
contains at certain times have distinct locomotive 
organs. 
2 The longitudinal fibres of the subcutaneous 
lar layer, have been observed in Bothrio- 
ules, and thinks that they have a nutritive function 
analogous to that of the blood and lymph corpus- 
cles, 
Gulliver (Med.-Chir. Trans. VI. London, 1841, 
p. 1; see Wiegmann’s Arch. 1841, IL. p. 314) has 
given an exact description of those of Cysticercus, 
but he also has taken them for eggs. In T'aenia 
Jjilum, linea, serrata, and infundibuliformis, 
they are spherical or oval; and in the first two 
species, Goeze (Versuch einer Naturgesch. d. 
Eingeweidewtirmer, p. 399, Taf. XXXII. A. fig. 6, 
7, 12) has taken them for eggs, and the concentric 
rings of the calcareous layers for the coils of the 
embryo. With those of Cysticercus cellulosae, 
and pisiformis, the discoid form prevails ; I have 
often seen here four to six calcareous layers about 
cephalus latus, by Eschricht (loc. cit. p. 65) 
and in T'aenia angulata, lanceolata, nasuta, and 
villosa, by myself. 
8 The reticulated lar p hyma of the 
Trematodés (Amphistomum giganteum) has been 
represented by Diesing very beautifully (Ann. d. 
Wiener Museums I. Abth. 2, Taf. XXII. fig. 4-8). 
4 In Ascaris lumbricoides, as in most Nema- 
todes, the muscular fibres are so closely approxi- 
mated that the meshes of their net-work are not 
seen except by tearing asunder the muscles; see 
Bojanus, Isis 1821, Taf. ILI. fig. 48. The reticu- 
lated form of the longitudinal muscles is very dis- 
tinct in Cheiracanthus gracilis ; see Diesing, 
Annal. d. Wiener Museums, II. Hft. 2, p. 225, Taf. 
XVII. fig. 1, 2. 
