Large intestine. Extensive multiple ulceration 

 is almost constantly present. Fungating granulation 

 tissue occurs in association with the ulcers. Purulent 

 peritonitis, broncho-pneumonia, septic infarcts, are 

 commonly met with. The other organs show no 

 particular change to the naked eye. 



MICROSCOPICAL CHANGES 



1. Make thin smears of spleen pulp, liver, bone 

 marrow, lung, kidney, testis, lymphatic gland, supra- 

 renal. Stain with Romanowsky. Parasites occur in 

 immense numbers in the spleen, liver, and bone marrow. 

 To a less extent in the lungs and testis. They are 

 present also in the suprarenals and lymphatic glands. 



2. Make thin smears from granulation tissue of 

 ulcers of the skin and intestine. Parasites are present 

 in both situations ; in the skin they are scanty, in the 

 intestine they may be very numerous. 



3. Place small pieces of these tissues on cover 

 glasses. Fix in sublimate-alcohol (p. 404). Embed in 

 paraffin. Cut sections. Stain with haematein. The 

 study of sections is essential for a clear understanding 

 of the relation of the parasite to the tissues. Observe 

 the following conditions : 



Liver. In the lumen of the capillaries of the lobule, often 

 applied closely to the capillary wall, occur numerous large cells crowded 

 with parasites. These cells are sometimes retracted and globular, but 

 more usually they are characteristically extended, and suggest the 

 idea that they are actually moving inside the capillaries. These cells 

 are of doubtful nature but resemble the macrophages seen in the 

 organs in malaria. In some cases these cells contain melanin. The 

 parasites in these cells have the characteristic structure. They 

 appear to lie in vacuoles, but these are undoubtedly the body of the 

 parasites (Fig. 24). 



Spleen. The parasites occur in similar cells. They are very 

 conspicuous in sections. Large mononuclear cells containing parasites 

 are more abundant than in the liver. Neither do the red cells contain 

 parasites, nor do free forms occur. 



