FILARIA VOLVULUS 129 



As regards (i) the destruction of cyclops, it would be 

 difficult in places used for bathing. Possibly, as Alcock 

 points out, the addition of a small quantity of liquor 

 potassae might be successful, or injection of steam so as 

 to raise the temperature of the water sufficiently to kill 

 the cyclops, as proposed by Leiper, may be practicable in 

 some places. The simple practical manner of dealing 

 with the question is that water used for bathing should 

 be distinct from that used for drinking purposes. Where 

 water is limited, or sufficient control over the use of 

 water cannot be maintained, the wells must be so con- 

 structed that water used for bathing does not flow back 

 into the well, and that people, in obtaining water for 

 drinking purposes, are not able to enter the water, but 

 draw it up by bucket or pump. A good pipe supply 

 from water that cannot be contaminated by bathing 

 should be supplied in all the larger stations. 



ONCHOCERCA (FILARIA) VOLVULUS. 



.Filaria volvulus is a not uncommon parasite in parts 

 of West Africa, particularly in Nigeria and the Cameroons, 

 and in inland districts. Cases have also been reported 

 from the Congo. 



Clinically the characteristic of the infection is the 

 formation of subcutaneous fibroid tumours varying in 

 size from a split pea to a hen's egg (Parsons). These 

 tumours are frequently multiple, and are more common 

 on the chest than elsewhere, but may occur in any part 

 of the body. They are not painful or tender, they do 

 not suppurate, and they cause no general symptoms. The 

 tumours are freely movable over the subjacent tissues, 

 but are more closely connected with the skin. They 

 can, as a rule, easily be enucleated, but Gray reports two 

 cases in which the tumours were firmly attached to the 

 periosteum once to that of the pubis when the tumour 

 simulated a hernia, and once to the sacrum. The 

 tumours consist of a dense fibrous capsule, and in the 

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