FORMS OF MALARIAL FEVER 373 



but, in a few hours, mauy others reappear in the blood and inaugurate 

 another stage. 



5. The Infection of the Corpuscles. — The spores now attach them- 

 selves to healthy blood corpuscles, slowly pass into their interior, 

 and set up a precisely similar series of changes; the actively 

 amoeboid stage, the increase of size and pigmentation, the con- 

 centration of the pigment, the mature form, and the segmenta- 

 tion resulting in the rosette body, and eventual escape of 

 sporocytes. In this way the multiplication of the parasite is 

 carried on in the human host. This is known as the Cycle of 

 Golgi. Each paroxysm of malaria is related to the evolution cycle 

 of a generation of these parasites — probably many millions in 

 number — the commencement of each paroxysm coinciding with the 

 maturation of a generation of parasites. The severity of a paroxysm 

 in a given type of fever is also in direct relation to the number of 

 parasites in the blood. It does not necessarily follow that the 

 gravity of the case is in proportion to the intensity of the paroxysms. 



Malaria is characterised by marked intermittency, which is usually 

 divided clinically into three leading forms : — 



(a) Quartan, depending upon a parasite which takes seventy-two 

 hours to pass through its cycle of development, and produces fever 

 every third day. The corpuscles invaded do not become so much 

 decolorised, hypertrophied, or altered in shape as in other forms. 

 The parasite shows distinctly less amceboid movement, and is not 

 so deUcate in structure or definition as in the Tertian varieties, 



8^®o 



Fig. 29. — Quartan Malaria Parasite. 



though it carries a large amount of dark brown, pigmented material, 

 which is coarse in grain. The developed sporocyte has what is 

 described as a " daisy-head " appearance. The six to fourteen spores 

 are rounded in form, and possess a well-defined nucleus. Quartan 

 fever is relatively much more common in temperate and subtropical 

 latitudes than in the tropics. 



(h) Benign or Mild Tertian. — In this fever the parasite takes 

 forty-eight hours to complete its cycle. The amoebula is actively 

 motile inside the corpuscle, giving rise to great and rapidly-changing 



