NATURE OF THE DRACUNCULUS, OR GUINEAWORM. 125 
contagion, as contrasted with the great scarcity of the disease in other situations, where 
careful observation has failed to discover these microscopic Filaride. As an instance of 
this, he states that, ** out of a school of fifty boys bathing and dabbling throughout the 
day in a small pond in their enclosure, whose muddy sediment swarmed with the so- 
called * Tank-worm,' not less than twenty-one in one year had Dracunculus in more or 
less plurality; while such was not only not the case in any of the other schools of the 
island, but in the school of which I have had medical charge for more than ten years, 
with an average number of 346 children present, only two or three cases have occurred* 
during that time ; and microscopic Filaridze do not exist, so far as I have been able to 
ascertain, in the sedimentary deposit of the tank in their inclosure, from which the 
children of this school are solely supplied with bathing-water." Secondly, he dwells 
upon the close similarity he has observed in the anatomy of the parasitic Guineaworm, 
its young, and of these microscopic Filaridz, especially one species to which he has given 
the provisional name of Urolabes palustris. But, for these anatomical details and the 
plates, I must refer to the author's own paper. He has discovered and given descrip- 
tions of several distinct species whose young have all the same kind of long, linear tail 
as that described in the young Guineaworm, by the extremity of which they have a great 
tendency to attach themselves to external objects, and then by a kind of wriggling 
motion are enabled to imbed themselves in any soft substance. He thinks that in this 
way, soon after they have escaped from the ovum, when imperfectly developed and not 
broader than a human blood-corpuscle, they may insinuate themselves into the ducts of 
the sudatory glandst, whose average size is nearly three times as broad, viz. about 
i3gothof an inch}. From this situation, or perhaps directly, without the intermediation 
of a perspiratory duct, they may bore their way into the subcutaneous tissue by means 
of a very small, rigid, exsertile cesophagus which was capable of being protruded in all 
the species examined. : 
This supposition of a boring-power possessed by these small animals is fully in 
harmony with recognized facts long known with regard to species of the order Trematoda. 
The young and immature forms of many of these species are known to penetrate from 
* And these could mostly be accounted for by visits the children had made to other localities. 
T In a more recent paper (Trans. of Med. & Phys. Soc. of Bombay, 1861, App. p. 1) Mr. Carter says, “ No -— 
however, has yet occurred where a young Filaria of the free species has been found entering or in one of the sudorific 
ducts ; so this is still an assumption ; but having met with an instance in which young Filaridæ 5 found sib 
fungus by analogous apertures on the surface, even smaller than those of the sudorific ducts, it seems desirable that the 
facts should be recorded to show that at least in the vegetable kingdom this kind of entrance takes place." 
On examining a large fungus of the genus Xylaria growing on the decayed trunk of a A he — 
“Some delicate, glistering, thread-like bodies were seen to project from the summit of the عات مده‎ these "nad 
* little globe-shaped sacs imbedded in and scattered over the surface of the fungus, upon which they open by — 
mouths or ostioles respectively, which, when measured, were found not to exceed the zglşgth of an inch in mn, 5 
that they are smaller than the orifices of the sudorific ducts of the human body ; and from each of these ostioles was 
rojecting a single Filaria—the head in the conceptacle.” agp 
j He adds ا‎ tha rnm es too immature " discover their pet we Seip map found similar worms 
in the great le i ies of fi in the neighbour : ^ 
i The full nin mae uae ih aren long by s}ath broad, though some of the other species 
are much smaller. 
VOL. XXIV. z 
