DO THE TKICHOSTRONGYLIDAE 



4 mm.; width 0.06 mm.; anus terminal; vulva in anterior 

 region; lives in adult stage in small intestine of man, pig, 

 wild boar and rat; experimentally it may be introduced 

 into almost any mammal; larvae becomes encysted in 

 muscles of same host as adult; man gains infection by eating 

 raw or partly cooked pork containing these encysted larvae; 

 produces disease known as trichinosis which is very severe 

 when infection is heavy; found everywhere that man eats 

 pork. 



F. Family Metastrongylidae 



Bursa in male with true but rather stunted rays; buccal 

 capsule absent or slightly developed; vagina elongate; 

 uteri convergent; parasitic in the respiratory or circulatory 

 systems. 



The only species of this family which has been reported 

 from man is Metastrongylus apri, which is a common parasite 

 of the bronchial tubes of pigs. This form has been reported 

 only a few times and is evidently an incidental parasite of 

 man. 



G. Family Trichostrongylidae 



Bursa of male large with well developed rays; buccal 

 capsule absent or slightly developed; vagina short; uteri 

 divergent; ovejectors differentiated; parasitic in alimentary 

 canal. 



Trichostrongylus.orientalis. Body tapers gradually anter- 

 iorly; head with three small lips and blunt or pointed papil- 

 lae; cuticula transversely striated; esophagus long; male, 

 length 3.8 mm. to 4.8 mm.; spicules spoon like, with a 

 boat shaped accessory piece, 0.11 mm. to 0.13 mm. in length; 

 bursa closed around with large side flaps and without evident 

 median folds; female, length 4.9 mm. to 6.7 mm.; vulva 

 in posterior half of body; tail short with two small papillae 



