University of Wisconsin Digital Collections
Link to University of Wisconsin Digital Collections
Link to University of Wisconsin Digital Collections
History of Science and Technology

Page View

Hooke, Robert, 1635-1703 / Micrographia: or some physiological descriptions of minute bodies made by magnifying glasses : with observations and inquiries thereupon
(MDCLXVII [1667])

Observ. XXXIX. Of the eyes and head of a grey drone-fly, and of several other creatures,   pp. 175-180

Page 176

window, one thing of which was a large Tree, whofe trunk and top I
could plainly ditcover, as I could alfo the parts of nmy window, and my
hand and fingers, if I held it between the Window and the ObjeJ; a
fmall draught of nineteen of which, as they appear'd in the bigger Mag-
nffying-glafs to reflea the Image of the two windows of my Chamber,
are delineated in the third Figure of the 23. scheme.
  Foerthlj, that thefe rows were fo difpos'd, that there was no quarter
vifible from his head that there was not fome of thefe Hemifpheres direfted
againf* j fo that a Fly may bc truly faid to have an eye every way, and to
be really circurnfpeu7. And it was further obfervable, that that way where
the trunk of his body did hinder his proljpet backward, thefe protube-
rances were elevated, as it were, above the plain of his fhoulders and
back, fo that he was able to fee backwards alfo over his back.
  Fifthly, in living Flies, I have obferv'd, that when any fmall mote or
duft,which flies up and down the air, chances to light upon any part of
thefe knobs, as it is fure to flick firmly to it and not fall, though through
the Microfcope it appears like a large Prone or flick (which one would ad-
mire,lefpecially fince it is no ways probable that there is any wet or gluti-
nous matter upon thefe Hemifpheres,but I hope I fball render the reafon in
another place) fo the Fly presently makes uie of his two fore-feet in ftead
of eye-lids, with which, as with two Brooms or Bruthes, they being
all beftuck with Bridles, he often fweeps or bruihes off what ever hinders
the profpet of any of his Hemifpheres, and then, to free his Ieggs from
that dirthe rubs them one againft another.the pointed Brifles or Tenters
of which looking both one way, the rubbing of them to and fro one
againft another, does cleanfe them in the fame manner as I have obferv'd
thofe that Card Wool, to cleanfe their Cards, by placing their Cards, f
as the teeth of both look the fame way,and then rubbing them one againft
another. In the very fame manner do they brufh and cleanfe their bodies
and wings, as I (ball by and by fhew ; other creatures have other contri-
vances for the cleanfing and cleering their eyes.
  sixthly, that the number of the Pearls or Hemifpheres in the cluflers
of this Fly, was neer 14000. which I judged by numbering certain rows
of them feveral ways, and caffing up the whole content, accounting
each clufter to contain about feven thoufand Pearls, three thou fand
of which were of a cize, and consequently the rows not fo thick, and
the foure thoufand I accounted to be the number of the fmaller Pearls
next the feet and probofcis. Other Animals I obferv'd to have yet a
greater number, as the Dragon-FIy or Adderbolt: And others to have a
much lefs company, as an Ant, &c. and feveral other fmall Flies and
seventhlythat the order ofthefe eies or Hemifpheres was altogether curi-
ous and admirablethey being plac'd inallkind of Flies,and aerialarnimals,
in anmoft curious and regular ordination of triangular rows, in which or-
der they are rang'd the neereft together that poflibly they can, and con-
fequently leave the leaft pits or trenches between them. But in shripxs,
c'rarsf~pesr, L9iers, and filch kinds of Crtflaceovis water Animals, I have

Go up to Top of Page