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

Observ. XLI. Of the eggs of silk-worms, and other insects,   pp. 181-182


Page 181


               M I C ROG RAP HI A*
were divided into feveral fmaller and greater black teeth, was nothing
but one fmall bended hard bone,which was plac'd in the upper jaw of the
mouth ofa Houfe-Snail, with which I obferv'd this very Snail to feed on
the leaves of a Rofe-tree, and to bite out pretty large and half round
bits, not unlike the Figure of a ( C ) nor very much differing from it in
bignefs, the upper part A B C D of this bone, I found to be much whiter,
and to grow out of the upper chap of the Snail G G G,and not to be any
thing neer fo much creas'd as the lower and blacker part of it H I I H K
K H
which was exaftly fhap'd like teeth, the bone growing thinner, or taper-
ing to an edge towards K K K. It feem'd to have nine teeth, or prominent
parts I K, I K, I F, &-c. which were join'd together by the thinner inter-
pos'd parts of the bone. The Animal to which thefe teeth belong, is a
very avomalouf creature, and feems of a kind quite diftin& from any
other terrestrial Animal or Infea,the Anatomy whereof exceedingly dif-
fering from what has been hftherto given of it I ihould have inferted,but
that it will be more proper in another place. I have never met with any
kind of Animal whofe teeth are all join'd in one, Save onely that I lately
obferv'd, that all the teeth of a Rhinocerot, which grow on either fide
of its mouth, are join'd into one large bone, the weight of one of which
I found to be neer eleven pound Haverdeipoir. So that it feems one of
the biggeft fort of terreftrial Animals, as well as one of the fmalleft,
has his teeth thus fhap'd.
   Obferv. XLI. OftheEggsofSilk-worms,andother 1fe#fs.
fT   He Eggs'of Silk-worms(one of which I have defcrib'd in the fecond
TFiguire of 2 5. scheme) afford a pretty Obje& for a Microfcope that
magnifies very much, especially if it be bright weather, and the light of
a
window be caft or colle&ed on it by a deep convex-glafr, or Water-ball.
For then the whole furface ofthe Shell may be perceiv'd all cover'd over
with exceeding fmall pits or cavities with interposed edges, almoft in the
manner ofthe furface of a Poppy-feed,but that there holes are not an hun-
dredth part fcarce of their bignefs i the Shell,when the young ones were
hatch'd (which I found an eafie thing to do, if the Eggs were kept in a
warm place) appear'd no thicker in proportion to its bulk,then that of
an Hen't or Goos's Egg is to its bulk,and all the Shell appear'd very white
(which feem'd to proceed from its tranfparency) whence all thofe pit-
tings did almoft vanifh, fo that they could not, without much difficulty,
be difcern'd, the infide of the Shell feem'd to be lin'd alfo with a kind
of
thin filmnot unlike (keeping the proportion to its Shell)that with which
the fhell of an Hen-egg is lin'd 5 and the fhell it felf feem'd like common
Egg-fhells, very brittle, and crack'd. In divers other of thefe Eggs I
could plainly enough, through the {hell, perceive the fmall InfeCt lie
coyled round the edges of the fhell. The fhape of the Egg it felf, the
Figure pretty well reprefents (though by default of the Graver it does
                                                                no;


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