436 



ESSENTIALS OF ^iOOLOCY 



fusoria) also contain a number of parasitic forms. Examples of 

 parasitic Sarcodina are the three common human amoebae, Enda- 

 moeha histolytica, which invades and destroys the intestinal lining, 



7b cerebrospinal ffuld causing sleeping 

 sickness and death - 



Transmission by 

 bite of tsetse fJLy. 



4^ Man, Antelope, etc. 



Trypanosomes 



in human blood causing 

 Trypanosomc jz>/zr- 



Transmission by btbe 

 of tsetse f>y. 



Tsetse Fly 



Forms in salivary glands 

 ready for re. infection. 

 \20'''-30*'^ day) 



Crltbidial /brms ia 



salivacy jglands 

 (2. or o doya later) 



Forms in mtdgut,(VSM 

 after infective lyieal). 



newly arrived form in 

 ;3afivar;y aland. 

 iJ<a*^to20^''dqya.) 



Long ^lender forms In prove ntriculu.3. 

 ("about I0*>'tol5*''days) 



Fig. 181. — Life history of Trypanosoma gatnhiense. (Reprinted by permission 

 from Introduction to Human i^arasitologii by Chandler, John Wiley and Sons, 

 Inc.) 



thus causing amoebic dysentery ; Endmnoeha coli, a harmless com- 

 mensal in the intestine ; and Endamoeba gingivalis, a very common 

 parasite in the human mouth, usually harmless but sometimes ap- 

 parently injurious to the gums. Examples of parasitic Mastigophora 



