110 
THE HELMINTHES. 
§ 104. 
‘The central nervous system of the Acanthocephali is very distinct. It is 
always concealed at the bottom of the sheath of the proboscis, which this 
last, being never in a state of complete retraction. does not fill. 
Tt consists 
of a dense mass of ganglionic, cellular globules blended together, and here 
and there may be seen through the cell-membranes their nuclei and corpus- 
cles. 
This comparatively large mass sends off nerves in every direction, but 
the tenuity of these prevents their being traced, especially after they have 
entered the muscular walls of the proboscideal sheath. 
With the Gordiacei,™ and Nematodes, a nervous system has been found 
with certainty only in Strongylus gigas. 
Here a cord arises from a swell- 
ing in the head, traverses the whole length of the body upon the median 
ventral line, and terminates at the posterior end of the body in another 
swelling. 
nervous system of the Sipunculidae. 
4 Ihave thus found the nervous system of the 
, Acanthocephali in Echinorhyncus gigas, angus- 
tatus, haeruca, and proteus. It can be easily ob- 
served by carefully pressing or tearing the probos- 
cideal sheath. In thus tearing, you sometimes 
completely expose the ganglionic mass with the 
roots of the nerves. In no species that I have dis- 
sected have I been able to find the ganglionic ring 
mentioned by Henle (Froriep’s neue Not. No. 
285, p. 330, and Miiller’s Arch. 1840, p. 318) as 
found about the genital orifice of Echinorhyncus 
nodulosus. 
Dujardin also (Hist. Nat. d. Helm. p. 495, 491, 
Pl. VI. fig. D. 4), has not observed it, but he dis- 
tinctly perceived the central mass at the base of 
the proboscis, and has figured and named it as un 
corps glanduleux ou ganglionaire. 
- 5 As yet no nervous system has been found in 
the Gordiacei. Berthold (Uber den Bau des Gor- 
dius aquaticus, 1842, p. 12) has been inclined to 
regard as nerves two delicate filaments which 
traverse the cavity of the body of Gordius ; but, 
as these give off no lateral branches, this opinion - 
cannot be admitted.* 
6 Many Helminthologists have err ly taken 
for nerves the delicate projecting lines which, situ- 
gus, which he regards as a brain; these observa- 
tions have since been confirmed by Van Beneden 
(Ann. d. Sc. Nat. XI. 1849, p. 319), who, however, 
regards this mass as belonging to the sympathetic 
system. But, however viewed, an cesophageal col- 
lar has been distinctly made out, thus confirming 
the views of Cuvier. 
In regard to the splanchnic system of nerves 
with these animals, Van Beneden (loc. cit.) de- 
scribes it as consisting of two ganglia lying on the 
cesophagus back of the wsophageal collar, and 
from which pass off two filaments, which run along 
the cesophagus, and enter the collar laterally. He 
thinks the two ganglia are united by a transverse 
It sends off in its course lateral filaments, thus resembling the 
ated directly subcut and often blended with 
the skin, traverse the whole length of the body of 
many Nematodes, and have been called the ventral 
and dorsal lines. Their lateral branches, as already 
observed, are only transverse muscular bands. 
Quite different from these is the longitudinal cord, 
which Otto (Magaz. d. Gesellch. naturf. Freunde 
au Berlin, 7th Jahrg. 1816, p. 225, Taf. V.) has 
described and figured as belonging to the nervous 
system ; a view which I am disposed to adopt, in 
spite of Nitzsch (Ersch and Gruber’s Encyclop. 
VI. 1821, p. 45) and other Helminthologists. 
In a large female Strongylus gigas, now under 
my eyes, there is a simple longitudinal cord beneath 
the muscular envelope, and therefore in direct con- 
nection with the skin, and which extends along 
the ventral surface. In its course it sends off 
less lateral branches, which in their inti- 
mate structure are quite different from the trans- 
verse muscular bands. But neither here nor upon 
the nerves of other worms have I ever seen the 
enlargements spoken of by Otto. Grant’s figure 
of a double nervous filament traversing the body 
of Ascaris is probably imaginary 3 see Outlines of 
Comp. Anat. p. 186, fig. 82, A. 
commissure. Further behind is another and larger 
ganglion on each side, and from which pass off 
filaments to the digestive cavity. See also my note 
under § 99. — Ep. ’ 
* [ § 104, note 5.] This view of Berthold is sup- 
ported also by Blanchard (Ann. d. Sc. Nat. 1849, 
XII. p. 6), who affirms that he has observed on 
both sides of the body a double longitudinal cord, 
which is usually very. distinct. This, examined 
microscopically, appeared to be composed like the 
nerves of the other Helminthes. Blanchard, how- 
ever, did not succeed in tracing these cords to any 
cephalic centres. Nothing of special value, there= 
fore, is known on this subject. — Ep. 
