MYCETOMA 



479 



ETIOLOGY AND PATHOLOGY (Castellani). 



The causal fungi belong to the genera numerated above, the 

 saprophytic life of which is quite unknown, except that of Nocardia 

 bovis, which lives in cereals. Barefooted natives are usually affected, 

 the fungus entering in at some wound about the foot, the wound heal- 



Mycetoma of the foot. 



ing, but enclosing the fungus which grows slowly within, without 

 there being any real attempt at repair by the body except for some 

 lymphocytic infiltration and the formation of some granulation tissue. 

 Fibrous tissue is formed about the fungus; endarteritis and peri- 

 arteritis cut off the blood supply; the cellular exudate becomes oily, 

 often foul, discharges at the surface through sinuses, the exudate 

 carrying witli it some of the parasites. As Nature thus tries to throw 



