MALARIA 213 



to the bursting requires forty-eight hours for the tertian 

 malaria and seventy-two hours for quartan malaria, 

 while in estivo-autumnal malaria there is a slowly 

 progressive attack on successive cells by a curious 

 extracellular and intracellular crescent-shaped body. 



The anatomy of these plasmodia is of great intricacy, 

 and undergoes so many changes that it is hardly 

 desirable to go into detail here. Suffice it to say 

 that it is a body when adult somewhat larger than a 

 red blood cell, full of actively moving granules. The 

 young forms are homogeneous, and are found with 

 the greatest difficulty except when specially stained. 

 They probably get all their granules from the destruc- 

 tion of the red blood cells. Some adult forms have 

 flagella about their wall. The power of producing 

 disease lies partly in their destruction of the important 

 cells of the blood and partly in a poison they produce. 

 The internal organs, especially the spleen, are injured 

 first by the damage to the blood, and secondarily by 

 the extra work thrown on them in trying to destroy 

 the parasites. A slight immunity remains after an 

 attack. There is a relative racial immunity among the 

 negroes. The cases that do not wholly recover or 

 that have remote recurrences are said to be harboring 

 quiescent parasites in the spleen. A chronic inflam- 

 mation of this organ often results. 



Diagnosis. The disease is diagnosticated by making 

 fresh or dried and stained preparations of the blood and 

 examining them under the microscope. Should malaria 

 organisms be present, faint, irregular shadows or larger 

 bodies filled with dancing granules are seen in the 

 unstained blood, while in stained smears fairly well 



