30 PARASITOLOGY. 



with tar. It is advocated to make troughs with holes 

 bored in sides large enough for a sheep to lick salt 

 from. Tar, smeared around these holes, is lodged 

 on the nose in the sheep's efforts to get the salt. 



(Hypo — under) 

 Hypoderma Lineata (derma — skin) 

 (linea — line). 



Sy7i07iyins. — Oestrus lineata. Ox gad-fly; warble- 

 fly; grub-fly; striped hypoderma ; heel-fly. 



History. — A species found in America ; most com- 

 mon in southern states. 



Descriptio7i. — About the size of a honey-bee. Its 

 body is black, covered with fine hair. The thorax is 

 ornamented with longitudinal gray bands. The fe- 

 male is provided with a cone-shaped ovipositor, with 

 which she deposits her eggs, cementing them to the 

 hair. 



Life Cycle. — The fly deposits its eggs upon the 

 hair in the vicinity of the 

 heel. From this point the 

 larvae are taken into the 

 mouth and become lodged 

 in the mucous membrane 

 of the oesophagus. The 

 eggs are laid in summer ^i^- b-Hypoderma Lineata 



Larva. 



and the larvae are found in a, Dorsal view 



their most fully developed ^' '^^"^'"^^ ^'^^• 



stage in the oesophagus about November. At 



this time they are about five-eighths of an inch 



long. They now leave this locality and wander 



through the connective tissue to a position mider- 



neath the skin in the region of the back. Here 



