HISTORY OF INSECTS. 23 



CHAPTER V. 



Class Diptera. | Genus CEstrus. 



Order GEstrites. I Species Equi, 



64. THE opinions respecting this singular 

 insect, as to the benefit or injury which horses 

 derive from it, are very various ; but observation 

 leads us to suppose that, like many other insect 

 parasites in various parts of the bodies of animals, 

 its existence is scarcely perceptible to the animal 

 which supports it. 



65. The female bot flies round the horse, 

 carrying her body nearly upright in the air, and 

 projecting a long tube (ovipositor) from the ex- 

 tremity of her body, this tube being bent inwards 

 and upwards : in this way she approaches the 

 part where she designs to deposit the egg ; and 

 suspending herself for a few seconds, darts for- 

 ward, and leaves the egg adhering to the hair. 



* Bracy Clark's History of the Bots of Horses. 



