650 MALARTA. 



later stages of fever, or durinpr the interval, or during any time but just before, 

 during, or soon after rigor. If we wish to see the early and nnjiigniented forms, we 

 mui^t look for them during the later stage of rigor or the earlier part of the stage of 

 pyrexia. And so with the other stages of the parasite; each has its appropriate 

 relationship to the fever cycle. 



There are numerou.s cases of malarial fever in whicli there is no dis- 

 tinct intermission and in which the course of the fever is either con- 

 tinued or remittent in charactor. Fevers of this type usually occur in 

 the late siunmor or in the autumn (a'stivo-autunuial) and are believed 

 to be due to infection hy two distinct varieties of the parasite; one, the 

 tertian a\stivo-autumnal. causes a fever characterized I\v a marked rise 

 in the temperature every second day; the other, a fever in which there 

 is a daily elevation of temperatui-e. There are ccM-tuin ])eculiarities 

 relatino- to the inti-a-corpusculai' development of these parasites which 

 enable us to ditlerentiate them from the tertian and (piartan parasites of 

 intermittent fever, but a more striking- difference to be observed in their 

 lifecydeof development in the ])lo()d of man is the ])i'(»senc(M)f peculiar 

 crcscentic-shaped bodies, which play an important part in their further 

 development in the body of an intermediate host — the mosquito. Asso- 

 ciated with these "crescents" fusifoi-m and o\'oid l)odies are often seen 

 which are no doubt similar in their origin and function. The crescents 

 are a little longer than the diameter of a red blood corpuscle and are 

 al)out three times as long as broad. They contain in the central portion 

 grains of pigment (melanin) derived from the ha'moglobin of the 

 infected corpuscle, which has been changed into a crescentic body as a 

 result of the development of the malarial parasite in its interior. 

 When a fresh preparation of malarial Idood containing these crescents 

 is observed under the microscope, while a majoritj'^ of them retain the 

 crescentic form, others may be seen, after an interval of ten minutes 

 or more, to change in form, lirst becoming oval and then round; then, 

 in the interior of these round bodies an active movement of the pig- 

 ment granules occurs; this is followed by the thrusting forth fiom the 

 peripher}' of several filaments — usually four — which have liagella-like 

 movements. These, as a rule, become detached and continue to move 

 rapidly among the blood corpuscles. With reference to the function 

 of these motile filaments, Marchiafava says: 



In these later days there is increasing belief in the theory, wliich we uphold, that 

 the crescents and the flagellata are sexual foribs of the malarial jmrasite, and that a 

 reproductive act (in which the flagellum represents the male element and an adult 

 crescent the female cell) gives rise to the new' being which begins its existence in the 

 tissues of the mosquito. 



The crescentic bodies may be found in the blood of man long after 

 all febrile symptoms have disappeared, and it is generally recognized 

 that they are not directly concerned in the production of the phenomena 

 which constitute a malarial attack and that the administration of 

 quinine has no influence in causing them to disappear from the blood. 



