376 CLINICAL BACTERIOLOGY. 



corpuscle has, without especial external alteration, been trans- 

 formed, grows and deprives the red blood-corpuscle of nutritive 

 material. It converts the hemoglobin of the host into melanin, 

 which it collects in the outer layer of its protoplasmic body. It 

 grows until it reaches the height of its development, when it 

 sometimes entirely fills the red blood-corpuscle, and it then gives 

 rise to new spores, in the setting free of which the residuum of 

 the blood-cell is ruptured. 



With regard to the relation of the crescentic bodies to this 

 process of development of the parasites, it is commonly assumed 

 that the crescents result from the small ameboid parasites, of 

 which Laveran considers them to be the encysted form, while 

 Councilman believes them to be their spores. Mannaberg con- 

 siders the crescents as copulation-bodies (syzygia), which result 

 from the union of two ameboid malarial parasites. The two 

 parasites do not completely coalesce (pseudo-conjugation), and 

 they may subsequently separate (segmentation). Kruse believes 

 the crescentic bodies to be no longer capable of infection, but he 

 considers them the harmless residue of the infectious process. 



Polymorphism or Multiplicity of the Malarial Para- 

 sites. The appearances presented by the blood in the dif- 

 ferent types of malarial fever are most variable, and for a 

 long time there has been a difference of opinion as to 

 whether there are various forms of malarial parasites, with 

 a special species of parasite for every type of fever, or 

 whether the various forms of the parasite are but different 

 phases of the same organism. Laveran and his adherents 

 consider the parasites as polymorphous. They believe 

 that the various types of fever are induced not by different 

 species of parasites, but as a result of variations in the 

 predisposition of the organism attacked. The Italian 

 school, on the other hand, considers the exciting agents of 

 the various types of fever as belonging to different species. 

 Golgi makes three varieties : the parasites of quartan, those 

 of tertian, and those of irregular, febrile type. According to 

 his view, the quotidian type is dependent upon either two 

 generations of parasites of the tertian or three generations 

 of the quartan type, of which each generation is separated 

 in its development from the other by a period of twenty- 

 four hours. Golgi has described the cycle of development 

 for these three varieties. Marchiafava and Celli recognize 

 Golgi's tertian and quartan parasites. As the exciting 

 agent of the irregular fever, however, they consider the 

 small ameboid forms from which the crescents are derived. 



