THE FILIARIASES 271 



The oesophagus is one quarter the length of the whole body. 



The anus is just in front of the tail tip. The sex is doubtful. It 

 is perhaps an hermaphrodite. 



It is found in the duodenum and jejunum, deep in ihe mucosa. 



The parasite is widely distributed. 



The ova are 54^^ by 32 ^^i and occur in the fccces during attacks of 

 diarrhoea. The ova are normally deposited in the mucosa, here the 

 embryos hatch, reach the lumen of the gut and pass out in the faeces. 

 They grow into male and female adults on reaching the water. These 

 conjugate and the females then lay eggs. Free living embryos develop 

 from these which moult and become filariform embryos which will 

 penetrate the horny layer of the skin and reach the corium (Mozocchi). 

 They pass, via the lungs, trachea and oesophagus to the small 

 intestine (Fiilleborn). They may also pass directly by the blood 

 stream. In the small intestine they burrow into Lieberkiihn's follicles 

 and lay their eggs. 



These parasites cause an intestinal catarrh. 



They are the only worms that pass embryos in fresh fa?ces. 



GNATHOSTOMA SPINIGERUM (Family Gnathostomidas) . 



The male, about 10 mm. long, has two fleshy lips guarding the 

 mouth. 



The cuticle in front of the neck has eight transverse rows of hooks 

 pointing backwards. 



There are two unequal spicules. 



These parasites are very rarely found in man. Only two specimens 

 are known. 



They wander about the connective tissue and form subcutaneous 

 tumours. 



THE FILARIDiE. 



Diseases caused by Filarice are called Filaruiscs, manifestations of 

 which include F. lymphangitis, orchitis, lymphangiectasis, abscesses, 

 phlebectasis, varicose lymphatic glands, chylous extravasations and 

 elephantiasis, Loasis, Calabar Swellings, and Volvulosis. 



These will be dealt with seriatim. 



THE FILARIASES. 

 HISTORICAL NOTES. 



Elephantiasis was noticed by the ancient Indian writers. 

 Celsus first used the term to indicate leprosy, and all writers since 

 have repeated the error. 



Arabian physicians described it in the ninth and tenth centuries. 

 Hillary in 1750 clearly differentiated it from leprosy. 



