154 BOTS. 
posit the egg; and, suspending herself for a few seconds before it, sud- 
denly darts upon it, and leaves the egg adhering to the hair: she hardly 
appears to settle, but merely touches the hair with the egg held out on 
the projected point of the abdomen. The egg is made to adhere by 
means of a glutinous liquor secreted with it. She then leaves the horse 
at a small distance, and prepares a second egg, and, poising herself 
before the part, deposits it in the same way. The liquor dries, and the 
egg becomes firmly glued to the hair: this is repeated by these flies till 
four or five hundred eggs are sometimes placed on one horse. 
THE ESTRUS EQUI. 
Copied from the Work on Bots, by Bracy Clark, Esq. 
1. The female fly about to deposit an egg. 5. The newly-hatched bot. 
2. The male fly. 6. The bot full grown. 
3. The egg, its natural size. 7. The head of a bot magnified. 
4. The egg, magnified. 8. The chrysalis. 
“The skin of the horse is usually thrown into a tremulous motion on 
the touch of this insect, which merely arises from the very great irrita- 
bility of the skin and cutaneous muscles at this season of the year, 
occasioned by the heat and continual teasing of the flies, till at length 
these muscles appear to act involuntarily on the slightest touch of any 
body whatever. 
‘The inside of the knee is the part on which these flies are most fond 
of depositing their eggs, and next to this on the side and back part of 
the shoulder, and less frequently on the extreme ends of the hairs of the 
mane. But it is a fact worthy of attention, that the fly does not place 
them promiscuously about the body, but constantly on those parts which 
