40 
The above is the portion of the attack most commonly noticed, 
but the enormous yearly losses from injury by the maggot to 
condition of cattle, and by depreciation of hides, make it desirable 
that all the details of the life-history of the pest should be fully 
known, and in the following pages I have tried to give the account 
clearly. 
It is about two hundred years ago since the first noticeably 
recorded observations were made on what we now know as the 
Warble Fly; and in 1797 a paper by Bracy Clark (published in 
the Trans, of the Linnsean Soc. of London, vol. iii.) was the 
foundation which long served as the centre of practical knowledge 
for farm use. 
Since then many valuable observations were given by eminent 
writers, British and Continental, but these were not always easily 
accessible, and in many cases were simply entomological. There¬ 
fore, as it was greatly needed that some plain information, in a 
form accessible for reference regarding the life-history of this Ox 
Warble Fly, with practical means for prevention of the attack, 
should be placed at the disposal of those interested in the subject, 
I undertook in 1884, whilst Consulting Entomologist of the Royal 
Agricultural Society, to endeavour to gain trustworthy information. 
My applications were widely responded to by leading cattle 
owners, farmers, also by heads of hide and tanning firms, and of 
cattle and butchers associations, and, with regard to special points 
of investigation, I was greatly helped by co-operation of some of 
our leading veterinary surgeons. Specimens were sent me, and 
detailed information forwarded, until the history of every point 
of the infestation, and its effects on the animal, and cheap and 
practicable means of prevention, and also returns of losses, calculated 
or estimated as circumstances allowed, were furnished, and the 
results of the investigation being published yearly, afforded from 
our own qualified contributors a reliable mass of information on 
the infestation of this one kind—namely, the Hypoderma bovis, as 
it is found and treated in this country. 
In the following pages I have arranged the main points of the 
observations sent me since 1884 under the headings of history of 
the fly attack; the injury consequent on the infestation to health 
of animals, and also condition of hides ; the means found always 
serviceable for prevention and remedy when properly applied; 
statement of amount of damage, from depreciation of hide at 
per pound, up to yearly estimates; and various points of general 
interest. 
