CHAPTER XIX 



PROTOZOA CAUSING DISEASE 



I. Plasmodium MalaricB. — Laveran {Comptes Rendus,\%?>2, 

 No. 17) and Richard {ibidem. No. 8) were the first who dis- 

 covered in the blood of malaria cases in the febrile stages 

 peculiar bodies, spherical or crescentic, consisting of a pale, 

 homogeneous substance and enclosing clumps of pigment 

 granules ; these bodies are possessed of cilia by which they 

 are enabled to perform rapid movement. Laveran con- 

 sidered these bodies as the true cause of malaria and 

 identified them as protozoa. This discovery was a few 

 years later (1885) confirmed and considerably amplified by 

 Marchiafava and Celli. The credit of the important dis- 

 covery of the malaria parasite belongs therefore unquestion- 

 ably to Laveran, and the observations of Marchiafava and 

 Celli 1 have amplified by a good deal our knowledge of them, 

 they called the parasite Hamoplasmodium Malarice. or 

 Plasmodium Malaria. 



Marchiafava and Celli showed that during the beginning 

 of the febrile stage the parasite invades the red blood- 

 corpuscles as small, globular, pale, homogeneous corpuscles 



^ Untersuchungen iiber die Malaria-Infection, Fortschritte d. Med., 

 '885, F- 339 and 787. 



