THE CONQUEST OF DISEASE 



Trypano- 

 soma. 



Insects as 

 carriers. 



discovery of such an agent monkeys and rats 

 are now being used; and the prospects are 

 bright that such a substance will be found. 



Study of the Trypanosoma shows that it is 

 responsible for many other diseases, and that it 

 is a family of many species. The Trypanosom- 

 idce are protozoa, like the plasmodium of ma- 

 laria. They are elongated bodies, provided 

 with terminal flagellre, by which they propel 

 themselves through the tissues. They had been 

 found in the blood of fishes, reptiles, birds and 

 mammals. One of the species infests the grey 

 rat; another causes the Indian cattle fever 

 called "surra"; and another is the cause of the 

 tsetse-fly disease. An enormous amount of 

 research is being carried on with insects and 

 these parasites, and the mystery of tropical 

 diseases is being much illuminated. 



Among other diseases found to be conveyed 

 by flies are trachoma and 'pink-eye." Grassi 

 affirms as a result of his studies that flies can 

 ingest the eggs of many of the common intesti- 

 nal worms (tape-worm, round worm, pin 

 worm) and defecate the ova in a viable condi- 

 tion upon human food. 



The researches of Ross in Egypt, and Craig 

 and Ashburn in the Philippines, indicate that 



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