

TONGUE WORMS 343 



If the hooks are to be considered not as degenerated legs but antennse and palpi, 

 then there is no vestige of legs in the adult. The sexes are separate. 



Linguatula rhinaria. This has been observed in man both in larval and adult 

 stages. 



The male is white and about Y inch long while the female is about 4 inches 

 long, tadpole shape, yellowish in color, and has about 90 segments, lives in the 

 nasal cavity and frontal sinus of dogs, rarely in horses and sheep, and very rarely 

 in man. 



The female lays embryo-containing eggs which, gaining freedom through the 

 nasal mucus, are swallowed by various animals. A larva develops which bores its 

 way through the gut and encysts in the liver or mesenteric glands. After several 

 moultings, they work their way again to the intestines and so get out of the body 

 of their host; or they may wander to lungs and trachea and either escape or take up 

 their position in the nostrils to become adults and produce eggs. Consequently, 

 one animal may act as intermediate and definitive host or these cycles may take 

 place in distinct animal hosts. 



The larval form (^ inch) is far more common in man than the adult. Symptoms 

 are referred to liver in both larval and adult stage, and epistaxis and nasal symptoms 

 for adult stage only. 



Porocephalus constrictus. The adult form P. moniliformis lives in the lungs of 

 snakes and the eggs are probably ingested by drinking water. These eggs develop 

 into a curled-up, ringed larva, about ^ inch long with 23 rings, which is 

 encysted especially in the liver or lungs. These escape and are swallowed by the 

 snakes, their definitive hosts. 



While in the liver or lungs of man the patient may have signs of bronchitis, hep- 

 atitis or peritonitis. Cases usually only discovered at postmortem. Parasites, 

 however, might possibly be found in sputum or faeces. 



