77 
then captured and placed in a large cage well supplied with light and 
air, and fresh faeces of the horse, sheep, and rabbit. A small 
percentage of the insects laid their eggs under these conditions; but 
the eggs were invariably removed to receptacles which were more 
convenient for the study of the metamorphosis. It was found that 
two important conditions were necessary for the development of the 
larvae, viz., an almost complete absence of light and an abundance •>/ 
moisture. Such conditions as these could only obtain in a state of 
nature in large faeces in shady or damp situations, or in heaps of 
manure. 
Towards the end of September the earlier stages of this insect 
were found under natural conditions, and the facts relating to them 
are given under the heading of additional field notes. 
HABITAT.— Farm-yards and stables are evidently the favourite 
haunts of this fly; it occurs also in the fields, parks, and open woods, 
especially where cattle are grazing, but is much less numerous in such 
places. It is evidently also by no means uncommon in some of our 
large towns, and numbers were seen at rest on the shop-fronts in the 
main streets of both Liverpool and Chester. It is fond of resting on 
surfaces fully exposed to the sun, such as doors, gates, and rails, and 
to a less extent also on stone and brick walls. Painted surfaces are 
also attractive to it, and the greatest number seen congregated 
together were disporting themselves on the sunny side of a red 
painted iron tank at the old Chateau de Goumont, Waterloo, Belgium. 
They are very active; but their flight is quite inaudible at a short 
distance, the noise produced being very feeble. When disturbed they 
frequently return to the same spot, but more especially so in favourite 
resting-places. At night they retire to some sheltered spot, and 
numbers may be found at rest on the beams and rafters in open sheds 
in farm-yards, where they remain, almost inert, till the morning sun 
tempts them out again. They will also occasionally enter stables in 
the day time, and they were seen to enter such places through a 
narrow opening or a crack in the door. 
They frequently clean their wings when in captivity, and this is 
accomplished with great precision, the hind legs being used for this 
purpose. The under surface of the wings are first combed, then the 
upper, the legs are then rubbed together, and the process is again 
repeated in exactly the same order. 
