Reports to the Board of A griculture. 129 
about through the connective tissues of the host and between the 
skin and flesh. They finally take up their position along the back, 
just under the hide, and then moult again, when they become spiny. 
At this stage they commence to produce considerable irritation, a 
swelling arises over them — the warble ” — which soon becomes 
perforated by a hole at the summit. The tail end is directed towards 
this aperture, the two spiracles or breathing pores situated on it 
being placed close to the opening. There is now formed much pus, 
upon which, together with blood, the larva or bot feeds and rapidly 
develops, and then moults for the last time. When mature the 
yellowish- white bot turns greyish- brown with grey stripes, and is 
about an inch in length, the body being very spiny. By means of 
these spines the maggot makes its way out of the warble-cells and 
falls to the ground. 
The larva then enters the puparium stage (Fig. 22, d), which may 
take place either in the ground or under some stone or foreign body 
lying on the ground. 
This puparium is formed by the bot’s old skin, which hardens 
and gradually becomes almost black in colour. In from three to six 
weeks the fly escapes from this case through a more or less circular 
opening or cap in the puparium. 
The perfect insect is half an inch long, very hairy, black, clothed 
with almost white, reddish-brown and black hairs ; there are white 
hairs on the head and thorax, and forming a band at the base of the 
abdomen. There are also blackish-brown hairs on the upper part 
of the head, the thorax, the legs, and the middle region of the 
abdomen. 
I his fly appears in Great Britain from the middle of May until 
the beginning of September. 
Life-history of H . bovis. 
The life-history of this species is not, I feel sure, properly known. 
Irobably it is the same as lineata. It is said to lay its eggs on or 
in the skin, but there is no evidence to show this. According 
to Miss Ormerod s notes it appears that the hots develop directly 
undei the hide, appearing first as small blood -red maggots between 
the hide . and flesh. These grow into the mature hots and cause 
warbles similar to the former species. 
I lie bots of bovis are easily told from those of lineata by the 
two last segments of the body being free from spines, whilst in 
lineata the last segment only is nude. The mature bot of lineata. 
K 
