The Human Malarial Parasites 537 



area the pigment is distributed throughout the parasite. 

 The larger or macrogametocyte, the female parasite, measures 

 10 to 14 H in diameter. It has a greenish or grayish-green 

 or almost colorless protoplasm, containing an oval or bean- 

 shaped colorless area almost half as large as the organism 

 itself. Yellowish-brown pigment in short broad rods is spar- 

 ingly scattered throughout the substance elsewhere. 



The microgametocyte or male form is approximately the 

 size of a red blood-corpuscle 8 to 9 ft in diameter. It 

 stains more deeply than its mate and contains more and 

 coarser pigment granules. 



III. Plasmodium Falciparum (Blanchard, 1897). This 

 is the parasite of estivo-autumnal or malignant tertian 



Fig. 179. Parasite of estivo-autumnal fever: a, b, c, Ring-like and 

 cross-like hyaline forms; d, e, pigmented forms; /, g, segmentary forms; 

 h, i, j, crescents. 



malarial fever. It is a very small parasite, whose occur- 

 rence, even multiple occurrence, in the corpuscles does not 

 change their size or shape. It does, however, quickly change 

 the appearance of the corpuscles, which become polychro- 

 matophilic, and frequently show numerous small dots the 

 granulations of Schuffner in the corpuscular substance. 



The first appearance of the schizont is in the form of tiny 

 rings, which appear to lie upon rather than in the corpuscles, 

 and are first seen at the edges. The rings are outlined by 

 extremely fine lines and sometimes seem to be incompletely 

 closed, so that they are like horseshoes rather than circles. 

 They increase to several times the original size without losing 

 the ring shape, and are variously known as "middle-sized 

 rings " and " large rings." They are with difficulty differ- 

 entiated from the " tiny rings " of the tertian parasite. As 



