200 



TROPICAL MEDICINE AND HYGIENE 



penis, and rectum. The larvae are popularly known as 

 " screw-worms." 



Wherever they occur they cause extensive destruction. 

 The larvae bury their heads in the tissue, which they 

 destroy, and cause an extensive cellulitis. The depth and 

 extent of their ravages are best seen in the orbit. The 

 lids, muscles, and connective tissue are rapidly destroyed, 



FIG. 76. Effect of Nasal Myiasis. 



whilst the eye, protected by the thick sclerotic, is not at 

 first affected. In the nose they soon reach the nasal 

 cartilages and bones, which are destroyed and the skin 

 perforated. Whilst small they travel widely, so that they 

 pass into the frontal and ethmoid sinuses, causing destruc- 

 tion and necrosis wherever they find their way, and death 

 from meningitis is common. The condition is always a 

 grave one, the mortality high, and in case of recovery 

 there is usually much mutilation (fig. 76). 



