'38 MALARIA 



liquid of the blood is also the time at which the 

 administration of quinine is said to be most effective. 

 Further, it is only at this stage that the disease can be 

 artificially transferred from one man to another. All 

 efforts to transmit the gametocytes have ended in 

 failure. 



Hcemamceba vivax, which causes the tertian fever, 

 passes through the various stages of its life-history in 

 man in forty-eight hours ; hence the febrile paroxysm 

 occurs every second day. Malaria is usually of the 

 tertian type, and this is certainly the most common 

 form in temperate climates. Occasionally the infection 

 has been repeated, and we may find that there are two 

 groups of the parasite present in the blood, which 

 arrive at the sporulating stage on alternate days; in 

 this case the febrile symptoms manifest themselves 

 every day, and the type of malaria is designated 

 ' quotidian intermittent fever.' In this case, if a single 

 dose of quinine be administered at the right time, one 

 group of parasites is killed off and the quotidian fever 

 is reduced to a tertian. There may occasionally be 

 more than two groups present, or the parasites may 

 for some reason have failed to arrange themselves in 

 groups, in which case the fever becomes irregular or 

 continuous. 



In the quartan fever the parasite Hcemamaba 

 malarice takes seventy -two hours to complete its 

 cycle in man, and the paroxysms occur every three 

 (Jays — that is, there are two days without febrile 

 symptoms, followed by a day when there is a 

 paroxysm. This form is common in Sicily and in 

 certain parts of Italy— for instance, around Pavia. Just 

 as in the tertian fever, so in quartan there may be a 

 second infection, in which case paroxysms arise on 

 two successive days, followed by a day of intermission 

 of the fever. If a third group be present, we have a 

 quotidian fever. The asstivo-autumnal fever, due to 



