have each of them corresponding Parts in the Brain : so that when any of those Fibrillæ
are struck by any Part of an Object, the corresponding Parts of the Brain are thereby af-
fected, and the Soul thereby informed. The Archbishop of Cambray says, we never see
an Object double, because the two Nerves that are subservient to Sight in our Eyes, are
but two Branches that unite in one Pipe, as the two Glasses of a Pair of Spectacles unite
in the upper Part that joins them both together. And lastly, our great Sir ISAAC
NEWTON, with his usual Modesty, hints to us his Opinion by the Way of Query. Are
not the Species of Objects (says he) seen with both Eyes, united where the optic Nerves
meet, before they come into the Brain, the Fibres on the right Side of both Nerves unit-
ing there &c? For the optic Nerves of such Animals as look the same Way with both Eyes
(such as of Men, Dogs, Sheep, Oxen, &c.) meet before they come into the Brain : but
the optic Nerves of such Animals as do not look the same way with both Eyes, as of
Fishes, and of the Camelion, do not meet, if I am rightly informed .
After this Digression, which 'tis hoped may be excusable on so curious a Subject, we
shall return to finish the Explanation of this Plate, wherein
F F shew the Horns.
G G the Smellers or Feelers.
H H and I the Proboscis.
K K K K the Hairs and Bristles.
All which will be described in explaining the following Plate.
An EXPLANATION of the TWENTY-SECOND PLATE
A Blue-Fly, or Flesh-Fly
WE see here the Blue-Bottle or common Flesh-Fly, enlarged by the Microscope, in
such a Manner, as to shew distinctly all its particular and minute Members and
A A, Its protuberant and pearled Eyes, which make a considerable Part of the Head,
though much smaller than those of the Drone-Fly, described in the last Plate. These
Pearls or Hemispheres were ranged in the same triangular Order as in that Fly, but with-
out any such Difference in Size.
B B, A scaly prominent Front between the Eyes, adorned and armed with large ta-
pering sharp black Bristles, which growing on either Side in Rows, and bending towards
each other near the Top, form a Kind of Arch of Bristles, that almost covers the
Front B B.
C, a Projecting Part at the anterior End of this Arch, and about the Middle of the
Face, on which grow D D, two little oblong Bodies, not unlike the Apices or Pendants
in Lillies, each having one small Joint where it unites to C, and another that joins it to
the Front Part B.— These in the Head of the Drone-Fly are called Horns, from the
great Resemblance they bear to the Horns of some Kinds of Beasts.
E E, Brushy Bristles or Feathers, somewhat like the Tufts of a Cock-Gnat, growing
from the upper Part and Outsides of the Horns, D D.
F F, Four strong Bristles, placed two and two, and bending towards each other, just
above the Opening of the Mouth.
G H I, The Fly's Proboscis or Trunk, coming out from the Middle of the Mouth.
It seems to be a hollow Body, and by means of several Joints is moved to and fro, thrust
out or pulled in at pleasure. There's a Knee or Bending expressed at H, which from
thence to the Extremity is slit, as it were, into two Lips, H I, H I, which on their outer
Sides are covered with pretty large Hairs ; though the Hairs on the upper Part of the
Proboscis are very small. These Lips open or shut easily, and serve to hold or take in
little Pieces of solid Food ; but when the Fly sucks any thing from the Surface of a Bo-
dy, she spreads them open, and applies their hollow Part perfectly close thereto ; in which
Condition they become a kind of Pump, to draw up the Juices of Fruits or other Li-