from descriptions by Bracy Clark,* and German entomological writers 
up to date. 
With regard to some of the internal characteristics of the infestation, 
I am able to give some amount of reply to the enquiries most 
frequently made, by extracts precisely bearing on these points from a 
paper by Mr. D. Hutcheon, C.Y.S., Government Veterinary Surgeon, 
Cape Colony, and also by some observations placed in my hands by 
Mr. Hy. Thompson, M.R.C.V.S., Aspatria, Cumberland, who has also 
favoured me by the important assistance of revising this paper before 
publication. 
This attack is widely distributed. It is found all over Europe, in 
widely separated parts of Africa, notably at Cairo and the Cape of 
Good Hope, and also in Asia and North America. 
Horse Bot Fly, 1, male ; 2, female; 3, maggot; 4, chrysalis, nat. size, after Bracy 
Clark. 
The flies are from half an inch to two-tliirds of an inch in length. 
The male with the end of the abdomen blunt, the female with it pro¬ 
longed, as shown in the accompanying figures, and also at p. 64, 
where a side view of the ovipositor as curved under the body and much 
magnified, is given. The colour may be generally described as 
yellowish brown with black or dark markings (as shown in the figures) 
on the bodyjbetween the wings and down the abdomen. The somewhat 
shaggy hair is very various in colour, being black or brown or yellowish 
or whitish, so as to make it difficult to describe the colouring clearly; 
in the specimen before me it is much varied with chestnut or foxy 
colour on the abdomen.f The long ovipositor of the female is of a 
shining black brown. 
* Essay “ On the Bots of Horses and other Animals,” by Bracy Clark, F.L.S. 
f For minute description of colours and details, see ‘ Monographie der CEstriden,’ 
von Friedrich Braner, pp. 69—71, and also, for the above and life-history, ‘ Praktische 
Insekten Kunde,’ by Dr. E, L. Taschenberg, pt. iv., pp. 73—76. 
