48 THE EEPOET OF THE JSFo. 36 



of deep lethargy and absolute helplessness and died. Since Col. Bruce made his 

 discovery a continuous series of investigations have been carried on in Uganda, 

 with a view to discovering the habits of the fly and the nature of the disease. 

 The chief preventive measure which so far has been adopted is the removal of 

 the natives from the shore of the Lake and the islands, and the clearing of the 

 bush around the shore of the lake. It was found that these were the localities most 

 frequented by the fly. 



The other disease. Malaria, is far more widely spread than Sleeping Sickness, 

 and is responsible for a far greater mortality. There is no doubt that of all diseases 

 it is the most serious, and has had the greatest effect on the distribution of the white 

 man. The disease and its symptoms have been known for over two thousand 

 years, but it was not until 1895, through the researches of Eoss, that it was dis- 

 covered how the disease was carried. In 1880, a French army surgeon, Laveran, 

 when examining the blood of a soldier suffering from Malaria in Algiers, dis- 

 covered the microscopic organism inside the red blood corpuscles which proved to 

 be the causative organism of this disease. This small organism belongs to siome 

 of the lowest types of animal life known as Hcemamceha, but notwithstanding its 

 low organization it was found to have a marvellous life-history. It was not until 

 fifteen years after its discovery that the rest of its life-history and the means by 

 which it was carried from man to man was discovered by Eoss in India, and by 

 others subsequent to his discovery. The idea that the mosquito might take a part 

 in the transmission of the disease, however, was not unknown, and had been pre- 

 viously suggested by King in the United States and Manson in England. Briefly 

 stated, the life-history of the parasitic organism is as follows : When the malaria 

 mosquito, which has previously sucked the blood of a malarial person, punctures 

 the skin of a new person, it injects a number of microscopic needle-like organisms 

 or spores which penetrate the red blood corpuscles, and there lose their needle- 

 like shape and change into Amcehulce. These organisms feed on the interior of 

 the red corpuscles and destroy the same. In doing so they increase in size until 

 they almost fill the cell or corpuscle, and then break up into a large number of 

 spores which are cast into the blood to reinfect other red corpuscles. When they 

 are cast out, a certain amount of pigmented matter known as melanin is cast into 

 the blood and gives malarial patients their characteristic colour. This breaking 

 up of the malarial organism to form spores induces the fever, as all the spores of 

 one lot of AmoehulcB are cast into the blood fluid at the same time. In the different 

 types of fever this breaking up into spores or sporulation takes place at different 

 periods. In Tertian fever it occurs every forty-eight hours, and consequently the 

 feverish attack manifests itself every second day. In Quartan fever the feverish 

 attack takes place every third day. If some of the blood of a person suffering from 

 Malaria is taken up by a mosquito the malarial organism now pasises through a 

 complicated series of changes. Instead of breaking up into spores in the normal 

 way the Amcehulce assume a dimorphic character, one kind containing a single 

 nuclear body and corresponding to the female cell and the other containing several 

 nuclear bodies and corresponding to the male cells. On the surface of the male 

 cells long filaments are formed into which the nuclei pass. These filaments, corres- 

 ponding to spermatozoa, break off and unite with the female cells to form a single 

 cell known as the Zygote. This process takes place inside the stomach of the mos- 

 quito, but now the Zygote becomes motile and bores its way through the wall of 

 the mosquito's stomach on the outside of which it forms a cyst. This cyst gradually 

 increases in size, and the growth in size is due to the remarkable changes taking 



