D I P T E R A # 
6 3 
The ceftrus which choofes the inteftines of horfes 
for the cradle of its young, Barbut calls a foreft 
infeft : he adds, there is fome reafon to think this 
ceftrus is viviparous, and tnat the pain the quad¬ 
ruped feels is occafioned by the action of the lai\ a 
that grapples for its hold ; for the grub is all over 
hooks and fpines, which ierve as io many anchois to 
prevent it being caft out with tne excrement. 
When full grown, it lets itfelf down to the 
ground, turns to a chryfaiis, &c. 
In 1713. many horfes in Verona and Mantua 
peri fired by the quantities of thofe larvae deponted 
within their entrails. 
Oejlrum Ovis . 
m ^ , » 
The ceftrus of fheep is of a lazy fluggifh dif- 
pofition. The female makes her way into tne flieep s 
noftrils, depofits its eggs within the frontal finus, 
and retires. The eggs turn to grubs, which feed 
on the mucous matter which they there meet \v T ith : 
whenever thofe grubs, armed with hooks, ftir, or 
change their fituation, the fheep is in pain. That 
creature, fo gentle, 10 peaceable, falls then into a 
kind of phrenzy, exprefling the keennefs of its 
anguifh by its leaping and bounding, and beating 
its head againft the trees and ground. After a while, 
the full-fed larvae drop from thofe creatures notes, 
together with the mucus which they ejeft, conceal 
themfelves in the ground, and there undergo their 
change. G 2 One 
