524 MALARIAL FEVER 



amoeboid movement varies somewhat in different types of fever. 

 As they increase in size, pigment appears in their interior as 

 minute dark brown or black specks, and gradually becomes 

 more abundant (Figs. 155, 156). The pigment may be 

 scattered through their substance, or concentrated at one or 

 more points, and often shows vibratory or oscillating movements. 

 This pigment is elaborated from the haemoglobin of the 

 red corpuscles, the parasite growing at the expense of the latter. 

 The red corpuscles thus invaded may remain unaltered in 

 appearance (quartan fever), may become swollen and pale (tertian 

 fever), or somewhat shrivelled and of darker tint (malignant 

 fever). In stained specimens a nucleus may be seen in the 

 parasite as a pale spot containing chromatin which may be 

 arranged as a single concentrated mass or as several separated 

 granules, the chromatin being coloured a deep red by the 

 Romanowsky method. The protoplasm of the parasite, which 

 is coloured of varying depth of tint with methylene-blue, shows 

 great variation in configuration (Fig. 156). The young parasites 

 not unfrequently present a "ring-form," a portion of the red 

 corpuscle being thus enclosed by the parasite. These ring-forms 

 are met with in all the varieties of the parasite, but they are 

 especially common in the case of the malignant parasite, where 

 they are of smaller size and of more symmetrical form than in 

 the others (Fig. 160); the pigment is usually collected in a 

 small clump at one side. 



Within the red corpuscles the parasites gradually increase 

 in size till the full adult form is reached (Fig. 157). In this 

 stage the parasite loses its amoeboid movement more or less 

 completely, has a somewhat rounded form, and contains a 

 considerable amount of pigment. In the malignant form it only 

 occupies a fraction of the red corpuscle. The adult parasites 

 may then undergo sporulation, but not all of thejn do so ; some 

 become degenerated and ultimately break down. 



3. Sporocytes or Schizonts. In the process of schizogony 

 the chromatin becomes divided into a number of daughter 

 nuclei which are scattered through the protoplasm ; the latter 

 then undergoes corresponding segmentation and the small 

 merozoites or enhsemospores result. The pigment during the 

 process becomes aggregated in the centre and is surrounded by 

 a small quantity of residuary protoplasm. Schaudinn has found 

 in the case of the tertian parasite that schizogony begins by a sort 

 of primitive mitosis, which is then followed by simple multiple 

 fission. The spores or merozoites are of rounded or oval shape, 

 as above described, and are set free by the rupture of the 



