APPENDIX C. 



MALARIAL FEVER. 



IT has now been conclusively proved that the cause of 

 malarial fever is a protozoon of which there are several species. 

 They belong to the haemosporidia (a sub-class of the sporozoa) 

 which are blood parasites, infecting the red corpuscles of mam- 

 mals, reptiles, and birds. The parasite was formerly known as 

 the licp.inatozoon or plasmodium malarice, although the use of the 

 latter form is incorrect ; the term hcemamoeba is, however, now 

 generally employed. The parasite was first observed by Laveran 

 in 1880, and his discovery received confirmation from the 

 i in k'iendent researches of Marchiafava and Celli, and later from the 

 researches of many others in various parts of the world. Golgi 

 supplied valuable additional information, especially in relation 

 t<> the .sporulation of the organism and the varieties in different 

 types of malarial fever. In this country valuable work on the 

 subject was done by Mauson, and to him specially belongs the 

 credit of regarding the exfiagellation of the organism as a 

 preparation for an extra-corporeal phase of existence. By 

 induction he arrived at the belief that the cycle of existence 

 outside the human body probably took place in the mosquito. 

 It was specially in order to discover, if possible, the parasite in 

 this insect, that Ross commenced his long series of observations, 

 which were ultimately crowned with success. After patient and 

 persistent search, he found rounded pigmented bodies in the wall 

 of the stomach of a dapple-winged mosquito (a species of 

 Anopheles) which had been fed on the blood of a malarial 

 patient. The pigment in these bodies was exactly similar to 

 that in the malarial parasite, and he excluded the possibility of 

 their representing anything else than a stage in the life cycle of 

 the organism. He confirmed this discovery and obtained cor- 

 responding results in the case of the proteosoma infection of 

 birds, where the parasite is closely related to that of malaria. 

 In birds affected with this organism, he was able to trace all 



