SOUTH AMERICAN TRYPANOSOMIASIS 155 



(2) Sporogony. — This takes place in the bug Lamus magistus. 

 Sexual and asexual forms develop, the final stage of development 



being found in the salivary glands when they are ready to infect a new 

 vertebrate host. The development in the gut requires about eight 

 days . 



(3) Agaviony. — This is an asexual form of reproduction and takes 

 place in the cells of the various organs of the callithrix, i.e., in the 

 hypertrophied endothelial cells of the lungs, in the cardiac muscle, 

 in striped muscle and in the neuroglia of the central nervous system. 

 In these situations it appears as a rounded body but without flagellum 

 or undulating membrane. 



The trypanosome is not known to undergo any longitudinal 

 division in the peripheral blood or the internal organs of the host. 



The trypanosome is easily cultivated on blood agar. 



The Lamus is infective to vertebrates, 8-10 days after an infective 

 feed and remains infective for a long time. 



PATHOLOGY. 



The trypanosome enters the body cells, especially of the muscle, 

 more frequently about the back and extremities. In these cells it assumes 

 a Leishmania-like form without flagellum but with a tropho-kineto 

 nucleus. Division is by binary fission, the two daughter cells dilat- 

 ing the mother cell, or more correctly, the cyst membrane which 

 ruptures, liberating the two enclosed forms. The parasites now 

 become flagellates and move about. Local inflammation now sets in 

 with the presence of trypanosomes in the blood. There may also be 

 a production and liberation of toxins because the liver undergoes fatty 

 degeneration. 



Different organs may be attacked in this way, the local symptoms 

 and pathological changes being in accordance with the organ or 

 organs selected. 



P. M. : MACROSCOPIC. 



There is serous effusion into the abdomen. 



The liver is enlarged with fatty degeneration. 



The spleen is enlarged, hyper^mic and soft. 



The mesenteric glands are enlarged, hypera^mic and soft. 



There is serious effusion into the pleural cavities. 



The same condition affects the pericardial sac, there may also be 

 hjemorrhagic pericarditis. 



The heart may be much enlarged, there may be intense myo- 

 carditis. 



The lymphatic glands are swollen and h_yper£emic. 



The thyroid gland is enlarged. 



The dura mater is congested. There may be signs of leptomenin- 



