NATURE OF THE DRACUNCULUS, OR GUINEAWORM. 111 
owing to the arrangement of the fibres into prominent fasciculi, is very evident for about 
the first two inches from the head. Further on the fasciculi are less prominent, and, the 
muscles acquiring a more uniform thickness, each pair becomes fused, apparently, into 
one great muscle, oceupying the dorsal and ventral regions respectively. "Where much 
compressed by the distended ovisae, the muscles seem to undergo partial absorption * 
(Pl. XXI. fig. 20). 
Many contradictory statements have been made both as to the presence and arrange- 
ment of transverse muscular fibres in the Nematoid worms; and though Mr. Carter 
states that they occur in the Guineaworm, I have failed, after most careful search, to 
discover any trace of them. The transverse markings of the integument, dimly shining 
through the peritoneal membrane, present a very deceptive appearance. 
Nervous System.—The only traces of a nervous system that I have been able to discover 
are two delicate ganglionated cords, extending the whole length of the worm, one occu- 
pying the centre of each lateral intermuscular space. They are situated, with a minute 
vessel to be afterwards described, in the midst of a pulpy substance, between the peri- 
toneum and inner layer of integument, on which they lie. Some slight change, too, is 
produced in the texture of the integuments at this place, by which its refractive power 
is increased ; for when quite bared on the inner side, and seen a little beyond the proper 
focal distance, a bright line is observed, of the same position and breadth as the nervous 
cord which had lain over it. : 
1 have traced these cords close up to both extremities of the worm, but have not 
been able to discover any connecting central ganglion anteriorly, or distinct termina- 
tion posteriorly. The two cords pursue a slightly wavy course, and seem to give off no 
branches in any part of their length. Each is about j,/55th of an inch in diameter, and 
marked with distinct, elongated swellings, or ganglia, at intervals of about ;'sth of an 
inch (Pl. XXI. figs. 22, 25, ره‎ c, 26). The average breadth of the ganglia, at the widest 
part, is ;i5th of an inch, each having an irregularly crenated margint. The intervals 
between the swellings are not perfectly equal, neither do the ganglia on opposite sides of 
the body correspond in longitudinal position. 
* The powers of locomotion possessed by this worm whilst still in the body seem considerable; they RE 
times be felt quite superficially beneath the skin, and in a few days have disappeared entirely from nee ae 
situation, having either penetrated deeply between the iniermuscular planes of cellular tissue or else moved considerably 
in the subcutaneous tissue, as in the following case related by Dr. Smyttan in the “Transactions of the ent pied 
Physical Society of Caleutta, vol. i. p.182. He says, in the case of a Lieut. F——, “The worm could be distinctly 
traced under the skin at the top of the left shoulder. By-and-by it found its way to = elbow, where it was as 
distinct, and in the course of a few weeks made its way by gradual progress to the wrist, from which place it was 
extracted." This power of locomotion accounts perhaps most feasibly for the very exceptional case quoted in the 
same paper, in which two Guineaworms were found alive in the cavity of the abdomen—one attached to the 
peritoneum, on the surface of the liver, and the other to that of the kidney, but otherwise floating freely amongst the 
coils of intestine, This is the only recorded case I have met with of these worms being found within any of the great 
cavities of the body. 
t A bright, highly refracting body, about zj5oth of an inch in diameter, is seen in the centre of nearly a the 
ganglia ; but careful examination shows that the dot is in no way connected with the ganglion, but belongs to a faintly 
outlined gland-cell, to be afterwards described, lying on its surface, à 
i Q 
