288 TlMEHRI. 



drinking water. But these worms unlike the common 

 round-worm, require an intermediary host before they 

 can attain to adult life in the human body, that is to say, 

 that were the young Filaria, as they are ejefted from their 

 parent, taken into the human stomach straight away 

 they would be unable to attain to any further degree of 

 development and so cause no future discomfort to their 

 hosts. But alas ! their intermediary hosts exist in large 

 numbers in any impure water. If, however, the young 

 Filaria are placed in pure water, they will die in a very 

 few days, simply for want of food. The importance of 

 insisting on a pure water supply, more especially in the 

 tropics, cannot be over-rated. 



The next entozoon which I propose to deal with is the 

 Filaria sanguinis hominis. This also is very commonly 

 met with in British Guiana, Dr. HiLLlS being the first 

 one to call attention to its existence here by recording a 

 case of haemato-chyluria in which he had discovered the 

 parent worm. In any case of chyluria occurring here, 

 where due search is made, the Filaria will be found to exist, 

 and indeed it may be found in a few cases where there 

 are apparently no signs of disease present. Its associa- 

 tion with elephantiasis yet remains to be worked out. 

 This parasite was first discovered by Dr. TiMOTHY R. 

 Lewis, of the Army Medical Service, in 1869, who found 

 it in the urine of patients suffering from chyluria. It is 

 of great interest and pra£lical importance for the inhabi- 

 tants of tropical and sub-tropical countries. " Ever since 

 Dr. Lewis discovered this parasite, evidence has been 

 accumulating to show that this haematozoon is more 

 or less intimately conne6ted with several severe and 

 intractable, and, unfortunately, by no means rare diseases 



