60 THE INSECT WORLD. 
men bent, sticks her eggs to the horse’s hairs by means of a 
glutinous liquid with which they are provided, and which soon 
dries. This is repeated at very short intervals. It often happens 
that from four to’ five hundred eggs are thus deposited upon 
the same horse. Guided by a marvellous instinct, the female 
Cstrus generally places her eggs on those parts of the horse’s 
body which can be most easily touched with the tongue, that is, 
at the inner part of the knees, on the shoulders, and rarely on the 
outer part of the mane. 7 
Horses are much afraid of the attacks of these insects. Their 
skin contracts where the @strus deposits its eggs, and the effects 
of the bite soon become serious. 
The eggs of the Gstrus, which are white and of conical form, 
adhere to the horse’s hair as shown in Fig. 43. They are 
furnished with a lid, which at the time of hatching opens, to 
allow the exit of the young larva, which takes place, according 







eS 
= 
Fig. 43.—Eggs of the Gad-fly ( Zstrus ( gasterophilus) equi) deposited on the hairs of a horse. 
to M. Joly, about twenty days after they are deposited. In fact, 
it is not in the egg state, but really in that of the larva, that 
the horse, as we shall explain, takes into his stomach these para- 
sitical guests to which nature has allotted so singular an abode. 
When licking itself, the horse carries them into its mouth, and 
afterwards swallows them with his food, by which means they enter 
the stomach. It is a remarkable fact that it is sometimes other 
insects, as the Yabani for instance, that by their repeated stinging 
cause the horse to lick himself, and to thus receive his most cruel 
enemy. In the perilous journey they have to perform from the 
skin of the horse to his stomach, many of the larvee of the @strus, 
as may be supposed, are destroyed, ground by the teeth of the 
animal or crushed by the alimentary substances. There is hardly 
one C#strus in fifty that arrives safely in the stomach of the horse, 
and yet if one were to open a horse attacked by str, the stomach 
would be nearly always found to be literally full of these larvee. 
' 
