MALARIA 257 



consists of plasma and a nucleus, is devoid of pigment, and infects the 

 red blood-corpuscles. The parasite is strongly motile, which assists in 

 its identification, as on account of its fine contour and colour, which is 

 only a little paler than the blood-corpuscle, it is scarcely distinguishable 

 from the latter. The parasite loses its motility in blood preparations 

 quickly, one hour at the latest. A whitish ring is now formed, and 

 owing to an outgrowth at one part of the periphery, it frequently 

 resembles a signet ring. 



Mannaberg considers these forms do not live within the blood cell, 

 but adhere firmly to the outside. The red spot in the centre, according 

 to the same authority, is due to thinning of the plasma, and the shining 

 through of the underlying red blood-corpuscle. The ring-form can 

 again return to an amoeboid condition. The amoeboid parasite does 

 not grow very large, occupying at the most about one-third of the red 

 blood-corpuscle, forming a very fine pigment on the periphery, and 

 exhibits slight motility. In twenty hours the pigment concentrates in 

 the middle or edges of the cell in dark dormant lumps, and the parasite 

 divides inside the red blood-corpuscle into small spores (five to ten). 



According to Marchiafava and Celli, the sporulation takes places 

 only in the internal organs of the body, almost not at all in the peri- 

 pheral blood. The spores are plentiful in blood taken from the spleen, 

 while in blood from the finger they are either absent, or only present in 

 very scanty numbers. Red blood-corpuscles affected with the quotidian 

 parasites shrink, and acquire a yellow copper-colour, and when the para- 

 site is several days in the blood, the Laveran half-moon or disc-shaped 

 bodies, and additional forms (spindle or cigar-shaped, and' spherical) 

 appear. The quotidian parasite causes quotidiana, and when several 

 generations are in evidence, a continual or irregular fever. The fever caused 

 by the tertian and quartan parasites is distinguished from that of the 

 quotidian parasite by the malignant clinical symptoms of the latter 

 obstinate recurrence, great anaemia, and other pernicious symptoms (diar- 

 rhoea, cachexia, coma, etc.), the relapse appearing about fourteen to fifteen 

 hours after the first cycle. The half-moon forms are considered answer- 

 able for the recurrent form. They are found in the blood during the 

 fever-free stages, and by segmentation or genuine spore formation can give 

 rise to the formation of new amoeboid forms. Then the new paroxysms 

 do not exhibit a genuine recurrence, but, according to Golgi, the mani- 

 festation of a long-interval type. According to other authorities this is 

 disputed, and the half-moon variety is considered a degenerative form 

 incapable of forming new individuals. 



(4.) The Malignant Tertian Parasite is considered by Marchiafava and 

 Begnami as a distinct species closely resembling the quotidian parasite, 

 but distinguished from the latter by completing its cycle of development 



