nS PHYLUM PROTOZOA- -THE SIMPLEST ANIMALS. 



inflammation of the intestinal mucous membrane. Several 

 flagellates of the genus Trypanosoma are serious parasites 

 of the blood affecting man, horses, cattle, camels, and 

 other domestic animals in both the old and new worlds. 

 Trypanosoma gambiense (Fig. 52) is the parasite causing 

 the fatal "sleeping sickness," a human disease dis- 

 seminated by the tse-tse fly, Glossina palpalis^ in Africa 

 (Fig. 51). The so-called Leishmann - Donovan body, the 

 parasite of dum-dum fever or splenomegaly, a disease 



FJG. 52. 



i . Trypanosonia ga mblcnsei. 



2 and 3. Individuals undergoing longitudinal fission. 



4. Leucocyte engulfing a trypanosomt. 



occurring in India and Africa, has recently been shown 

 to be a stage in the life history of a flagellate protozoon. 

 More recently the discovery of the protozoon nature of the 

 genus Spirochcete - -hitherto placed amongst bacteria a 

 member of which occurs in syphilitic lesions, has further 

 emphasised the significance of the group and given rise to 

 the expectation of further important discoveries in relation 

 to disease. Another highly important genus is Piroplasma, 

 a sporozoon. These are blood parasites, causing Texas 



