380 CLINICAL BACTERIOLOGY. 



The tertian parasite causes typical tertian fever (1010101). 

 Two generations of the parasite may give rise to a false 

 quotidian, a so-called double tertian (1212121). Several 



generations not separated from one another by intervals of 

 twenty-four hours give rise to irregular fever. 



j. The Quotidian Parasite. The commencement of the 

 cycle of development, which in its entirety occupies twenty- 

 four hours, is like that of the other parasites. The juvenile 

 form, unpigmented, consisting of plasmic body and nucleus, 

 infects the red blood-corpuscle. The parasite is actively 

 motile, and is often recognized by this property, while by 

 reason of its extremely delicate contour and its color, which 

 is only slightly less pale than that of the red blood-corpus- 

 cle, it is scarcely distinguishable from this. On removal of 

 the blood the parasite soon loses its motility, at the latest 

 after the lapse of an hour. A whitish ring is then seen to 

 form, with a reddish center. In consequence of a pro- 

 jection at one point of the periphery the ring frequently 

 resembles a seal-ring. Mannaberg believes that these 

 forms are only closely attached to the red blood-corpuscles, 

 and are not contained within them. The red spot in the 

 center is thought to depend upon dilution of the plasma and 

 the appearance of the underlying red blood-corpuscle as 

 seen through this. The annular form may return to the 

 ameboid. The ameboid parasite does not grow much alto- 

 gether to only about one-third the size of the red blood- 

 cell. At the same time a fine pigment, which is often only 

 reddish and is but slightly motile, collects at the periphery. 

 After the lapse of twenty-four hours the pigment becomes 

 concentrated at the center or at the periphery in the form 

 of dark, resting clumps, and the parasite disintegrates within 

 the. red blood-corpuscle into the smallest spores (from five 

 to ten). This process of sporulation takes place, according 

 to Marchiafava and Celli, only in the internal viscera of the 

 body, and scarcely at all in the peripheral blood. For this 

 reason the spores are encountered in abundance in the 

 blood obtained from the spleen, whereas they are found not 

 at all, or only isolated, in blood, from the finger-tip. The 

 red blood-cells infected with the quotidian parasites con- 

 tract and become brass-colored (brassy bodies.) After the 

 quotidian parasite has been present in the blood for several 

 days the crescents already described invariably appear, with 



