ILLUSTRATIONS 



Plate; l 

 , 1. Foot maggot, ventral view, X 7. 



2. Posterior spiracles, greatly enlarged. 



3. An aberrant stigmal plate, greatly enlarged. 



4. Foot maggot, dorsal view, x 7. 



5. Anterior ventral portion of foot maggot, X 4 



6. A portion of the body surface, showing the re 



1. Cephalopharyngeal skeleton of screw worm. 



2. Cephalopharyngeal skeleton of foot maggot. 



3. Puparium of foot maggot, X 4. 



4. Anterior end of puparium of foot maggot, X 



5. Egg of foot maggot, showing "flap," X 50. 



6. .Egg of foot maggot, X 52. 



Plate 3 

 1. Anterior end of foot maggot, X 45. 



Posterior end of screw worm, X 45. 



Plate 7 

 Posterior view of foot of Hereford bull, showing foot-maggot injury. 

 Posterior view of foot of goat, showing screw-worm injuries sub- 

 sequent to foot-maggot attack. 



