ows the first, the big,
dark-blue Fly who, after effecting her designs in the ill-watched
meat-safe, settles on our window-panes and keeps up a solemn buzzing,
anxious to be off in the sun and ripen a fresh emission of germs. How
does she lay her eggs, the origin of the loathsome maggot that battens
poisonously on our provisions whether of game or butcher's meat? What
are her stratagems and how can we foil them? This is what I propose to
investigate.

The Bluebottle frequents our homes during autumn and a part of winter,
until the cold becomes severe; but her appearance in the fields dates
back much earlier. On the first fine day in February, we shall see her
warming herself, chillily, against the sunny walls. In April, I notice
her in considerable numbers on the laurustinus. It is here that she
seems to pair, while sipping the sugary exudations of the small white
flowers. The whole of the summer season is spent out of doors, in brief
flights from one refreshment-bar to the next. When autumn comes, with
its game, she makes her way into our houses and remains until the hard
frosts.

This suits my stay-at-home habits and especially my legs, which are
bending under the weight of years. I need not run after the subjects of
my present study; they call on me. Besides, I have vigilant assistants.
The household knows of my plans. One and all bring me, in a little
screw of paper, the noisy visitor just captured against the panes.

Thus do I fill my vivarium, which consists of a large, bell-shaped cage
of wire-gauze, standing in an earthenware pan full of sand. A mug
containing honey is the dining-room of the establishment. Here the
captives come to recruit themselves in their hours of leisure. To
occupy their maternal cares, I employ small birds--Chaffinches,
Linnets, Sparrows--brought down, in the enclosure, by my son's gun.

I have just served up a Linnet shot two days ago. I next place in the
cage a Bluebottle, one only, to avoid confusion. Her fat belly
proclaims the advent of laying-time. An hour later, when the excitement
of being put in prison is allayed, my captive is in labour. With eager,
jerky steps, she explores the morsel of game, goes from the head to the
tail, returns from the tail to the head, repeats the action several
times and at last settles near an eye, a dimmed eye sunk into its
socket.

The ovipositor bends at a right angle and dives into the junction of
the beak, straight down to the root. Then the