1862.] DR. T. S. COBBOLD ON HUMAN ENTOZOA. 301 



pond, whose muddy sediment swarmed with the microscopic Tank- 

 worm (Urolabes palustris, Carter), twenty-one were attacked with 

 Dracunculus during the year ; whilst the boys of other schools bath- 

 ing elsewhere in the island were not infected, with the exception of 

 one or two individual instances here and there. This remarkable 

 occurrence, taken in connexion with Schneider's discoveries (respect- 

 ing the causes inducing sexual maturity in Alloionema appendiculatum 

 infesting the Black Slug, and in Pelodytes hermaphroditus in- 

 festing Snails), and also in combination with a multitude of other 

 facts, some recorded by recent investigators, and others handed down 

 to us by earlier writers, convincingly suggest the following conclu- 

 sions : — (1.) The Dracunculus is a bisexual nematode, the female 

 being parasitic during a portion of its lifetime. (2.) The male is 

 probably very much smaller, non-parasitic so far as animals are con- 

 cerned, and in all likelihood a constant inhabitant of fresh water and 

 the mud of marshes or low-lying districts in the East. (3.) Guinea- 

 worms do not gain access to the human body indirectly, by the 

 mouth or stomach of the host, but directly, by penetrating the skin. 

 (The young when introduced into the stomach of animals rapidly 

 perish, as proved by Dr. Forbes.) (4.) The young acquire sexual 

 maturity after their escape from the parent, the sexes associating in 

 muddy waters during the monsoon, soon after which period the males 

 probably perish, the females being left to watch their opportunity 

 for further development by migration into the human body. (5.) 

 Within the host it gives rise to a formidable entozootic disease (dra-' 

 contiasis of Galen), which, after prolonged monsoons, is not unfre- 

 quently severely endemic. (In the above remarks I have referred 

 more particularly to the writings of Busk in ' Trans. Micr. Soc.,' old 

 series, vol. ii. p. 65 ; of Moquin-Tandon in his ' Zoologie Medicale ;' 

 of Robin in ' Gazette Medicale de Paris,' 3rd series, vol. x. p. 365 ; 

 and of Carter in 'Annals of Nat. Hist.' 3rd series, vol. iv. &c.) 



15. FiLARiA LENTis, Dicsing. 



F. lentis, Diesing, Moquin-Tandon, Weinland. 



F. oculi-humani, Nordmann, Gescheidt, Ammon, Siebold, Leidy. 



F. oculi, Owen, Moquin-Tandon. 



As Kiichenmeister suggests, this worm may possibly turn out to 

 be identical with the Filaria lacrymalis (Gurlt), a viviparous species 

 infesting the eye of the horse. It was first discovered by Nordmann 

 (1831) in a case of lenticular cataract under the care of Von Grafe, 

 and subsequently found by Jiingken under similar circumstances. 

 Under the title of F. oculi, Moquin-Tandon (in his ' Zoologie Me- 

 dicale') speaks of certain minute Filarice, "not uncommon in the 

 negroes of the Angola coast ;" and he gives other localities of its 

 occurrence. As, however, he does not state what part of the body 

 is infested by them, I am inclined to think the authorities he quotes 

 have mistaken the little Oxyurus vermicularis for the species in 

 question. In both the well-known cases above referred to, the 

 Filarice appear to have been immature, notwithstanding that the 

 first was described as possessing ovaries, oviducts, &c. 



