Salivary gland 



Midgut 



Ovary 



Uteru s Oviduct , Mnln,nh,nn 

 Centrclqanglion — I — I \ \ l^ialpign'On 



Phcrynx 



57 



o oSo/ -"^ ,^ oc ^Spirochete 



^ ,<yn t^o^'c-^Host blood cells 



58 



Figures 57 and 58, 5, Unengorged and Engorging 



Spirochetes of African tick- borne relapsing fever, Borrelia duttonii , 

 are illustrated, as short wavy lines, in the positions they occupy m 

 the tick's body. Note their escape routes from the tick's body and 

 into the host's body while the tick is feeding. 



ORNITHCDCROS MOUBATA D lAGRAl^IMAT IC SAGITTAL VIEW 



/"After Burgdorfer (1951), with permission of 

 the editor of ACTA TR0PIGAJ7 



PLATE XX 



_ 158 _ 



