MACALISTER, ON ASCARIS DACTYLURIS. 83 
of these bodies we may hazard several conjectures ; they might 
be the representative of such a compound or branched 
alimentary canal as is found in other Entozoa and in Annelida, 
or they might be special secreting organs. With regard to 
the first of these theories, it is known that intestinal cceca do 
occur in other species of Entozoa. Mehlis, in ‘ Isis,’ for 
1831, p. 91, describes several of these in various species of 
Ascaris; and Leidy (loc. cit., p. 49, and Pt. vii, of art. 2) 
figures a large coecum in Zhelustomum appendiculatum. In 
these, however, the diverticula arise high in the digestive 
tract near the point of junction of the stomach and cesophagus, 
and often directly below the cesophageal constriction, which 
is far from being the case in the subject before us. Their 
granular nature, narrow necks, and constant low position, as 
well as their number, and the length and distinctness of their 
ducts, have led me to think that they might perhaps be 
organs of excretion; mayhap the earliest traces of renal 
organs in the animal kingdom. It may be remembered, wiih 
regard to this, that the presence of distinct secreting glan- 
dular organs in Nematoid Entozoa is no new fact, for Professor 
Owen has described salivary cceca as existing in Grathostoma 
aculeata. Other glands also have likewise been described, 
which I will notice more particularly hereafter. From the 
side of the intestine, below these ceca, fine lateral threads 
pass off, and are lost on the body-wall above the anus; these 
seem to suspend the gut and the cceca, and might be named 
retinacula. 
The nervous system, if any existed (which we may suppose 
to be the case from analogy), completely eluded my search. 
There are, as I have before stated, dorso-ventral lines, and in 
some individuals the ventral was much the larger and more 
distinct ; it may be nervous in its nature, but presented no 
distinct character by which I could recognise it as such. 
On the ventral aspect of both sexes, corresponding to a 
concave and well-marked sinuosity or depression of the super- 
ficial abdominal line, a very small bilobate aperture was visible 
on the body-wall opposite, or a little above the level of the 
upper dilated end of the intestine; in one or two, however, it 
was much below this point; from this a small tube passed 
for a very short distance inwards, and then gave off four 
small prolongations, two of which pass forward, and are lost 
in the anterior part of the lateral lines, while the other pair 
pass back into the posterior portion of the same lines, where 
they expand into very small dilatations, beyond which they are 
not traceable. 
It was with very considerable interest that I detected this 
