HOUSE BOX FLY. 
67 
observations by Mr. Hy. Thompson, M.B.C.V.S., of Aspatria :—“ I 
have never seen or known of the small insect after being hatched on 
the legs, shoulder, or sides of the Horse, creep along the body to get 
into the mouth. The shoulder and inside of the knee and foreleg 
generally are the places where we find the eggs are most frequently 
deposited, being naturally the most suitable situations, and, from the 
heat of the Horse’s body, I think the ova are hatched there, causing 
a tickling sensation in the part which the Horse licks with his tongue, 
and the small creatures are carried into the stomach with food and the 
secretion of the mouth.”—(H. T.) 
There the maggots fix themselves to the mucous membrane by 
means of two dark brown hooks (see fig. p. 64), one of which is placed 
on each side of the slit which serves for a mouth, and there they 
nourish themselves by suction. As they grow older they alter in 
shape to that figured at p. 65 (and much magnified as at heading, p. 
64), and are considered to pass from 8 to 10 months in maggot state, 
attached by their mouth hooks to the lining membrane of a portion of 
the stomach.* 
Sometimes there may be only a few of these maggots present, 
sometimes (as I have seen them myself) they are present in such 
numbers as to lie close up against each other over a large patch of 
surface, so that it hardly seemed possible to find room for another 
amongst them. 
Maggots or Horse Bots attached to membrane of stomach, after Bracy Clark. 
The above figure shows a number of partly grown Bot maggots 
attached to the membrane of the stomach. By this time they have 
gained their characteristic form, which is somewhat barrel-shaped, 
banded round at intervals by lines of prickles or horny points. They 
are widest about the middle, rather smaller at the tail extremity, in 
* For detailed remarks on this characteristic of the attack which is very 
important, see observations further on. 
F 2 
