K K, Two little hairy oblong Bodies, growing within the Mouth from either Side of
the Proboscis. These Parts are differently shaped, and much larger in the Head of the
Dr?-Fly, where they are marked G G. Dr. HOOKE imagines these may probably be
its Organs of Smelling.
The Middle-Part or Tborax of this Fly is crustaceous, and strongly made ; rounded on
the Top, and covered with large long black Bristles, standing like the Quills of a Porcu-
pine, in parallel Order, all pointing towards the Tail. From the hinder and under Part
grow out three large Legs on each Side, (as represented in the Figure) all covered with a
strong hairy Shell, and resembling the Legs of a Crab or Lobster. Each Leg is jointed,
and made up of eight Parts, 1, 2, 3, 4, 5, 6, 7, 8 ; on the eighth of which grow the
Sales or Spunges, and Claws, described before in the Twentieth Plate.
Of these six Legs she seldom employs any more than four to walk with, the two fore-
most serving instead of Hands, to take up any thing to eat, to clean her Mouth, Eyes,
Wings and Body, and for many other Purposes.
L L, The two Wings, fastned with strong Joints to the upper Part of the Tborax.
Many Particulars of their Contexture have been already given, Fig. 4. Plate XX, and
something further will be said concerning them in the next Figure of the prefent
Plate.
The hinder or Tail-Part is of a most lovely shining Blue, looking exactly like polished
Seel, brought to that curious Colour by annealing, and feems like a kind of Armour,
thickly beset with such-like Bristles as grow upon its Back.
In this and most Kinds of Flies, the Female is furnished with a moveable Tube at the End
of ber Tail, by extending of which she can convey her Eggs into convenient Holes and Re-
?cles either in Flesh or such other Matters as may afford the young ones proper
Nourishment. From the Eggs come forth minute Worms or Maggots, which after feed-
ing a while in a voracious manner, arriving at their full Growth, become transformed in-
? brown Aurelias, whence after some time longer they issue perfect Flies.
Upon opening a Fly, numberless Veins may be discovered dispersed over the Surface of
?ts Intestines ; for the Veins being blackish, and the Intestines white, they are plainly vi-
? by the Microscope, though two hundred thousand times slenderer than the Hairs of
? Man's Beard. According to Mr. LEEUWENHOEK
|
Art. Nat. Tom. II. p. 77. |
, the Diameter of four hundred
and fifty such minute Veins were about equal to the Diameter of a single Hair of his
?rd : And consequently two hundred thousand of them put together would be about
the Bigness of such a Hair.
This Creature is extremely nimble and quick-sighted, so that it will commonly escape,
though you approach it ever so cautiously and swiftly. On seeing any thing it fears, it
though down, to be the readier for its Rise ; and is very vigorous in its Motions, as well as
impudent ; for it will return several times to the same Place after being driven away.
Was it not from a preposterous Humour in Mankind, that constantly inclines us to de-
sp?fe and overlook whatever is continually before us, we should often divert ourselves with
observing the pretty Actions of this little familiar Animal, which are very well worth our
Notice. To see it, like a little Bird, taking its Flight about us, and when it thinks fit to
settle, using its Fore-feet to clean its Body, Head and Wings, and afterwards rubbing them
back wards and forwards one against the other, to clear away any Dirt they may have con-
tracted in making the other Parts clean : To see its Manner of feeding, the Motions of
all its little Members, and the delicate Structure and Contrivance of them : To see all
this, I say, and consider how many Veins, Arteries, Nerves, and Muscles, must be em-
p?yed to give Motion to, and furnish all these Parts with animal Spirits and circulating
?ds, and reflect on the Contexture and Delicacy of Vessels so inconceivably minute,
?st fill the Mind with Delight and Admiration.
As corrupting Animal Bodies afford the most kindly Nourishment to its Young, it is
?dued with a wonderful Capacity, either by its Smell, or some other Way, of finding out
?ch Bodies, and laying its Eggs among them.
All the Winter it lies torpid in some Hole or Corner, whence it creeps out at the Re-
turn of Spring : But no Cold, nor even being frozen, kills it ; for when thawed gently by
a Fire, or in the Sun-shine, it revives again : If put into Spirit of Wine, it seems quickly
?, but on taking it out, letting it lie three or four Hours, and then bringing it to a
gentl? Fire, or putting it in the Heat of the Sun, it will again appear alive.
* Microscope made?sy, p. 220.
