Ill 



Write a short Account of the Guinea- worm. 



The Guinea- or Medina- worm (Dracunculus, syn. Filaria 

 medinensis) is a subcutaneous parasite of Man in tropical 

 Asia and Africa and certain parts of South America (intro- 

 duced by negroes). It is also found in oxen, horses and dogs. 



The male is rarely seen ; the females attain a length 

 of from one to six feet. The mouth has two lips, the ali- 

 mentary canal is atrophied in greater part, and the body 

 is almost wholly occupied by the uterus which always 

 contains great numbers of young long-tailed larvae. 



" The worm can be felt beneath the skin like a bundle 

 of string." When it is ripe for parturition (at about a- 

 year old), it usually moves towards the ankle or foot. A 

 vesicle about the size of a penny is formed on the skin ; 

 this ruptures, exposing an ulcer from which the worm 

 partly protrudes, and the young larvae are then set free. 

 In water they enter an intermediate host, a species of 

 Cyclops, within which they mature. It is probable that 

 infection occurs when water containing infected Cyclops 

 is swallowed. 



Inflammatory abscess is the condition produced in 

 dracontiasis or guinea-worm disease. 



What are Eel-worms ? Mention some Examples. 



The Eel-worms or Anguillulidae are mostly small and 

 free-living Nematodes found in water, damp earth, etc. 

 Many live in decaying matter and are saprophytic ; some 

 are important parasites. The saprophytic and parasitic* 

 forms have a cutting-spine in the mouth. 



Anguillula aceti (the Vinegar or Paste- eel), is found 

 in vinegar, etc. 



Tylenchus devastatrix (Stem Eel- worm) produces " tulip- 

 root " in oats, etc., and is one of the causes of " clover 

 sickness." 



Tylenchus tritici, syn. scandens (Wheat Eel-worm), 

 causes " ear-cockles " in corn. 



Strongyloides stercoralis is an intestinal parasite of Man. 



