226 ANIMAL PARASITES 



cellular bodies and polymites if they develop flagella in the moist 

 chamber. There may be two infections in which schizogony occurs 

 every other day in alternate days 12121212. 



PLASMODIUM FALCIPARUM. 



The plasmodium of aestivo-autumnal fever, or pernicious malarial 

 fever, also called tropical. The outbreaks of this occur irregularly. 

 The disease produced by them is very much more malignant and is 

 harder to cure. The young spore appears in the corpuscle as a 

 small hyaline body, smaller than the other forms and much more 

 active. The size and shape of the red cells are little if any altered 

 but they become granular and polychromatophilic. The pigment 

 is very finely granular and the body frequently presents the signet 

 ring appearance. There may be more than one parasite to a red 

 cell. The cycle of development (schizogony) is twenty-four to 

 forty-eight hours. The plasmodium in its schizogony divides into 

 7-25 merozoites or spores, and are arranged in a spore-like form. 

 The extra-corpuscular bodies may resemble a crescent or sickle; this 

 form is very characteristic of aestivo-autumnal fever. There are 

 two forms of these crescents, one delicate, the male and one larger 

 and ovoid, the female. They are very resistant to quinine and 

 persist for a long period in the blood. Plasmodia undergoing 

 schizogony are often found in the brain capillaries after death, which 

 accounts for the cerebral symptoms in such cases. This form can 

 be differentiated from the others by the irregular and pernicious 

 type of fever produced; by its great resistance to quinine; the fewer 

 number of merozoites; the finely granular appearance of the pig- 

 ment; the relatively small size of the young intra-corpuscular body; 

 and, by the ring shape of some of the young forms. 



Often, in blood from malarial cases, pigmented leucocytes are 

 seen, and ghost, or shadow, red corpuscles from which the haemo- 

 globin has been dissolved are often met with. Spherical extra-cor- 

 puscular bodies become flagellated (polymites) in freshly drawn 



