KINDS OF xMALARIA 99 



hours before its schizogony occurs, and on the 

 fourth day the patient has a relapse of " quartan " 

 fever. The worst form of malaria, known as per- 

 nicious malaria, is due to the activities of P. falcipa- 

 rum, also known as P.pracox and Laverania malaria. 

 This malignant parasite is remarkable in that it 

 divides only in the internal organs such as the 

 spleen, and in that it produces fever at intervals 

 which vary considerably. It consequently causes 

 what is known as malignant tertian or sometimes 

 as irregular or quotidian fever. Very many com- 

 plications occur in malaria, for a patient may be 

 bitten by mosquitoes containing sporozoites of 

 different parasites, and thus the sequence of attacks 

 may be completely altered. For instance, if two 

 mosquitoes, one carrying P. vivax and one P. 

 malaria, bite a man on the same day, in all 

 probability he will have a relapse on the third and 

 on the fourth day, due to the schizogony of P. vivax 

 and P. malaria respectively, and thus many irregu- 

 larities are brought about. 



Diagnosis of some forms of malarial parasites is 

 very difficult. The milder or benign forms of the 

 parasite are generally found in the form of small 

 rounded organisms, while crescentic gametocytes 

 are present in the pernicious malaria. These 

 " crescents " are bean or sausage shaped, and there- 

 fore unlike the schizonts, and so the parasite is some- 

 times put in a separate genus, as Laverania. Tertian 

 and quartan gametocytes are not unlike the schizonts, 

 but they are larger, and also possess more of the 

 dark pigment, melanin. The pigment (Fig. 23, p.) 



