67 



ravines and valleys have been cleared of jungle, and these places are 

 not malarious if the jungle over them has not been cut down. This 

 theory is based on (1) the actual incidence of the disease among people 

 living near jungle- covered ravines, and (2) evidence afforded by the 

 mosquitos. Malaria is unknown among the Tamil coolies living along 

 the Kuantan Road in Pahang. The line is surrounded on all sides by 

 forest and is close to two streams, both covered in by jungle. On the 

 other hand, fever was prevalent among coolies on an estate near 

 Gambang, on the same road. In Kuala Lipis the European com- 

 munity live in quarters at the head of ravines which are closely over- 

 grown with jungle ; the district is considered so free from malaria 

 that mosquito curtains are seldom used. 



Carriers of malaria are absent from the forest-clad ravine swamps. 

 Anopheles umbrosus, causing malaria on the flat land, does not breed 

 in the hilly jungle, nor does A. mactilatus breed in a similar situation. 

 A. aitkeni is the only common species and has never been found inside 

 houses, nor is it known to bite man. In human habitations near the 

 jungle no Anophelines are found except those which breed in collections 

 of w^ater from round which the jungle has been cleared. In cuttings 

 made in the jungle, A. sinensis, A. albirostris, A. maculatus, A. karwari, 

 A.fuliginosus, A. rossi and A. kochi are commonly found. 



The author believes that this hypothesis provides a working basis 

 for the prevention of malaria in the hill-land. The remedy lies in not 

 clearing the ravines within a line several feet outside the bounding hill 

 contour when opening-up hill-land, or, if the ravines have been already 

 cleared, in allowing the forest to grow up again. Assuming this 

 hypothesis to be correct, it w^ould appear that while on the alluvial 

 coast-belt malaria is present in districts close to undrained jungle, in 

 the hills the opposite is the case. This means that A. umbrosus, 

 causing malaria on fiat coast land, will not breed in the hills and that 

 A. nutculatus, which causes fever in the hills, will not breed on the coast 

 alluvium. An intervening area is present in which the ranges of 

 the two species overlap to a certain extent. 



RoDHAiN (J.). Note sur les Trypanoses et les Piroplasmoses des grands 

 animaux de rOuelI6. [Note on the Trypanosomiasis and Piro- 

 plasmosis of the larger mammals of Welle.]- — Bull. Soc. Path. Exot., 

 Paris, ix, no. 2, 9tix February 1916, pp. 95-109, 1 fig., 1 table. 



The trypanosomes and malarial parasites affecting man in tropical 

 Africa have their homologues in the trypanosomes and piroplasmoses 

 of wild and domestic animals. The question of the part played by 

 animals as reservoirs of trypanosomes pathogenic to man is therefore 

 of the highest importance. Of 89 head of cattle examined, 13 were 

 infected with T. congolense {=dimorpho7i) and T. cazalboui ; of 9 sheep, 

 one only was attacked by T. congolense ; 9 horses and 21 goats gave 

 negative results. T. congolense is transmitted by Glossina, while 

 T. cazalboui can be disseminated by species of Siomcxys, of which 

 S. calcitrayis is distributed throughout the Welle district. Among the 

 big game examined, no cases of infection were found, except in one 

 example of the duiker, CepJialophus dor salts, in the blood of which 

 T. ingens was detected. Specimens of Glossina were rare in the localities 

 in which the game were examined. 



