80 DIPTERA. 



holds her body nearly upright in the air, and her 

 tail, which is lengthened for the purpose, curved 

 inwards and upwards : in this way she ap- 

 proaches the part where she designs to deposit 

 her egg; and suspending herself for a few se- 

 conds before it, suddenly darts upon it, and 

 leaves her egg adhering, by means of a glutinous 

 secretion, to the hair. This operation is repeated 

 by various flies of the same kind, till four or 

 five hundred eggs are sometimes placed on one 

 horse. After the eggs have remained on the 

 hairs four or five days they become ripe ; and 

 if at this time, the horse in licking itself touches 

 the egg, its operculum is thrown open, and 

 a small active worm is produced, which ad- 

 hering to the surface of the tongue is conveyed 

 with the food into the stomach. These larvae, 

 says Mr. Clark, attach themselves to every part 

 of the stomach, but are generally most nume- 

 rous about the pylorus ; and are sometimes, 

 though much less frequently, found in the in- 

 testines. They have two small hooks at the 

 lesser end, with which they fix themselves, com- 

 monly in clusters, to the inner membrane of 



