4 
Amongst the worst kinds of these attacks we find 
three distinct sorts, namely, those of the Gad Flies, 
which suck the blood ; those of the Bot Flies, which live 
in their maggot-state in some part of the attacked 
animal; and those of the Flesh Flies, which (also in 
their maggot-state) will fairly devour the living flesh 
down to the bone. 
I purpose to-day to speak to you more especially of 
the family of the “Bot Flies,” and, amongst these, of the 
“ Ox Bot Fly ” or “ Warble Fly,” as I think, for the sake 
of distinction, it might more conveniently he called, and, 
by taking the main points in its life-history, I hope to 
show how much lies in our power towards checking its 
ravages. On this matter I have some slight personal 
knowledge, and also the advantage of communication 
with correspondents well acquainted with the subject; 
but, as this attack has hitherto not been so much 
observed popularly as that of the common Horse Bot 
Fly, I will give a short account of this also to show how 
the habits of these two Flies (save in immediate con¬ 
nection with the animals they attack) may in many 
points fall under the same kind of measures of pre¬ 
vention. In these histories I quote largely, regarding 
the Horse Bot Fly, from the treatise of Bracy Clark, 
which is still our chief English authority on the sub¬ 
ject, and, regarding the Warble Fly, from the same 
treatise, and from the more recent and exceedingly 
elaborate treatises of Friedrich Brauer. 
But before beginning the consideration I will just 
remark that such boundless confusion and really serious 
difficulty in understanding this subject has arisen from 
the indiscriminate use of the names of Gad Fly, Bot 
Fly, Breeze Fly, and other appellations, that it will be 
well first of all to attend to this matter that we may be 
sure what we are speaking about. 
The “ Gad Flies,” properly so called, have nothing at 
all to do with raising warbles on the backs of cattle, or 
causing deposit of maggots inside farm stock, whether in 
their nostrils, or stomachs, or elsewhere. They only do 
