OX WARBLE. 
109 
be interested to hear that a heifer, 8 years old this summer, has been 
doing very badly; and though I have had two or three tenant farmers 
who keep cattle on a large scale here to see her, none of them suggested 
any reason for her not thriving, while the other cattle, Irish beasts, 
are rapidly getting fat. 
“ Since reading your pamphlet to-day, I went down again to see 
her, and notice that she has a mass of Warbles on both sides of her 
back. I knew she had some, but thought little of the matter ; at a 
rough guess there must be well on for a hundred Warbles. I shall 
treat her to McDougall’s smear to-morrow.”—(R. F. M. T.) 
On the 19tli of May I was favoured with the further detail:—“ Out 
of the heifer that I mentioned as doing so badly, we have extracted 
65 Warbles, and there are several more still to be extermi¬ 
nated.” . . . . “ Now that I am alive to the injury they cause, I shall 
take good care in future to kill them as soon as their presence is 
recognised.” 
The conditions of locality, as exposure, or possibility of shelter in 
hot sunshine beneath trees or sheds, dry pasture land, or plenty of 
access to water, make a difference in amount of attack, but these 
arrangements do not lie, excepting to a small extent, at the disposal 
of most farmers. A correspondent in Kincardineshire noticed the 
large amount of Warble presence, which he conjectured was partly 
caused by the open nature of the pastures merely divided by wire 
fences. 
In the following note with which I was favoured by Prof. John 
Wrightson, President of the College of Agriculture, Downton, Salisbury, 
he notes absence of Warble attack under circumstances of the cattle 
having access to, or being in the neighbourhood of, water, which point 
(that is, the objection of the fly to crossing water) is specially brought 
forward by entomological writers. 
Prof. Wrightson observed :—“ On May 24th I examined most of 
our dairy of about 27 cows for Warble maggots. Two cows only were 
affected, and both of them had been purchased into the herd last 
autumn, and from them I extracted five large larvae, leaving a con¬ 
siderable number to mature a little further as they would not then 
come out on pressure applied around the part affected. Although I 
am not prepared to say there was no Warble on any of our home-bred 
stock, or upon those which had been here above a year, yet I can say 
that all those I examined (about 24) were quite free from Warble. I 
also notice that our cattle do not show any signs of distress in summer, 
at the season when CSstrus bovis is on the wing. I attribute this 
immunity to the fact that our farm is bounded by the river Avon all 
along one border of our grazing ground, while open ditches, full of 
water, traverse the pastures in several directions. A large proportion 
