498 



Malaria 



Plasmodia in their bloods. What may perhaps be regarded as the 

 final step in the perfection of the knowledge of the parasite was 

 reached in 1911, when C. C. Bass* devised a method of cultivating 

 the parasite in its asexual stage, in vitro. 



Thus from its time-honored place as the tjrpical miasmatic disease, 

 full of mystery and obscurity, malarial fever suddenly had a flood of 

 light thrown upon it by which every peculiarity was fully illuminated. 



In summarizing the knowledge thus set forth we find the following 

 facts: 



1880- — ^Discovery of the Plasmodium malarise by Laveran. 



1890 — Discovery of its human developmental cycle by Golgi. 



189s — Discovery of the mosquito cycle by Ross. 



1895 — ^Discovery of the transmission of the human parasite by 

 Anopheles by Grassi. 



1898 — Discovery of the sexual fertilization of the parasite by 

 MacCallum. 



191 1 — Discovery of the method of cultivation in vitro by Bass. 



The interest aroused by Laveran's original discovery gave a great 

 impetus to the study of hematology with special reference to para- 

 sites, and it soon became evident that the Plasmodium was but one 

 of a group of similar parasites. Of these we have now become ac- 

 quainted with the following: 



Parasite 



Plasmodium 



malariae. 



Plasmodium 

 vivax. 



Plasmodium 

 falciparum. 



Disease 

 Quartan fever. 



Tertian fever. 



Plasmodium 



kochi. 

 Plasmodium 



inui. 

 Plasmodium 



pitheci. 

 Plasmodium 



brazilianum. 

 Plasmodium 



cynomolgi. 



Plasmodium 

 grassii (Proteo- 

 soma grassi). 



Plasmodium 

 danliewskyi 

 (Halteridium 

 danliewskyi). 



Host 

 Man. 



Man. 



Aestivo-autumnal Man. 

 fever. 



Cercopithicus. 



Insect Host 



Anopheles, My- 

 zorrhynchus, 



Myzomyia, Cel- 



Ua. 

 Anopheles, My- 



zorrhy|n|chus, 



Myzomyia, 



Cellia. 

 Anopheles, My- 

 z rrhynchus, 



Myzomyia, 

 Cellia. 

 Unknown. 



Macacus (Inuus Unknown. 



cynomolgus). 

 Orang-outang 



(Pithecus satyrus). 

 Brachyrus calores. 



Inuus cynomolgus 



and Inuus nem- 



istrinus. 

 Sparrows, canary 



birds, and other 



small birds. 

 Owls, hawks, crows, 



and other large 



birds. 



Unknown. 

 Unknown 

 Unknown. 



Culex pipens. 

 Unknown. 



* "Journal of the American Medical Association " 1911, XLVn, 1534. 



