CHAPTEK Y. 

 INTEKNAL PAEASITES. 



PARASITES of the fluke family, as a rule, enter the body by way 

 of the alimentary tract, and pass thence to the liver by means of 

 the bile duct. They may produce symptoms of biliary obstruction 

 with jaundice and sometimes liver abscess. Occasionally ascites 

 and hsematemesis also occur, indicating portal obstruction. One 

 member of the family, Distoma Ringeri, is parasitic in the lungs 

 of man, being found in small cavities which communicate with 

 the bronchi ; it is the cause of endemic haemoptysis in Japan. 

 Unlike the common flukes, it may be more widely disseminated 

 in the body of its host, and has been found in the brain, the 

 connective tissues of the orbit and the peritoneum. It probably 

 finds access to tbe pulmonary veins, and so is carried to the right 

 heart, and ultimately into the arterial stream. It is obvious 

 that the liver flukes are not thus favourably situated for 

 dissemination. 



The parasite Bilharzia h&matolia also belongs to the fluke 

 family, but differs from others in the fact that the sexes are 

 separate. Its mode of entry into the body is not, as yet, accurately 

 determined; the mouth, urethra, anus, and skin have all been 

 suggested as portals. Sexually mature worms are usually found 

 in the submucous tissues of the bladder and rectum, and in the 

 large venous sinuses of the latter. In the female they may occur 

 in the walls of the vagina. Young worms may be discovered in 

 the portal system and sometimes in the general venous system, as 

 might be expected from the location of the adult worms at the point 

 of union of the two. The spiked ova may be found infiltrating the 

 tissues of the urethra, bladder, ureters, rectum, and even the 

 liver. Urethral fistulse, vesical calculi and growths, cystitis, 

 dilated ureters, secondary renal inflammations, and sometimes a 



