DOI Page / Citation link:
https://doi.org/10.11588/diglit.68888#0265
178
Ml OR O GR AP H I A.
Thirdly ,that those which they call the eyes of Crabs,Lobsters,Shrimps,
and the like, and are really lb, are Hentijpherd, almost in the same man-
ner as thefe of Flies are. And that they really are so, I have very often
try’d, by cutting off thele little movable knobs, and putting the creature
again into the water, that it would swim to and fro, and move up and
down as well as before, but would often hit it self against the rocks or
stones, and though I put my hand just before its head, it would not at
all start or ssy back till I touch’d it, whereas whil’st those were remain-
ing, it would start back,and avoid my hand or a stick at a good distance
before it touch’d it. And if in crufiaceous Sea-animals, then it seems very
probable also,that these knobs are the eyes in cruft aceo™\nfe&'si which are
allb of the same kind, onely in a higher and more astive Element 5 this the
conformity or congruity of many other parts common to either of them,
will strongly argue,their crustaceow armour,their number of leggs,which
are six, belide the two great claws, which answer to the wings in Infests 5
and in all kind of Spiders, as allb in many other Infests that want wings,
we (hall find the compleat number of them, and not onely the number,
but the very lhape, figure, joints, and claws ofLobsters and Crabs, as is
evident in Scorpions and Spiders, as is visible in the fecond Figure of the
3 i.^e^and in the little Mite-worm,which I call a Land-crab,describ’d
in the lecond Figure of the 33. <SrZ)ez^,but in their manner of generation
being oviparous, &c, And it were very worthy obfervation, whether
there be not feme kinds of transformation and metamorphosis in the se-
veral states of crustaceous water-animals, as there is in several sorts of In-
sests 5 for if such could be met with,the progress of the variations would
be much more conspicuous in those larger Animals, then they can be in
any kind of Insests our colder Climate afford!;.
These being their eyes, it affords us a very pretty Speculation to con-
template their manner of vision, which, as it is very disfering from that of
biocular Animals, lb is it not lest admirable.
That each of thele Pearls or Hewijpheres is a perfest eye, I think we
need not doubt, if we conlider onely the outlide or figure of any one of
them, for they being each of them cover’d with a transparent protube-
rant Cornea^ and containing a liquor within them, resembling the watry
or glassie humours of the eye, must necessarily refrast all the parallel
Rays that fall on them out of the air, into a point not farr distant within
them, where (in all probability) the Retina of the eye is placed,and that
opacous, dark, and mucous inward coat that (I formerly shew’d) I found
to subtend the concave part of the cluster is very likely to be that su-
nicle or coat, it appearing through the Microfcope to be plac’d a little
more than a Diameter of thofe Pearls below or within the tunica cornea.
And if so, then is therein all probability, a little Pisture or Image of the
objests without, painted or made at the bottom of the Retina against
every one of those Pearls, so that there are as many impressions on the
Retina or opacous skin, as there are Pearls or Hemijpheres on the cluster.
But becaufe it is impossible for any protuberant surface whatsoever, whe-
ther jpharial or other, so to refrast the Rays that come from farr remote
lateral
Ml OR O GR AP H I A.
Thirdly ,that those which they call the eyes of Crabs,Lobsters,Shrimps,
and the like, and are really lb, are Hentijpherd, almost in the same man-
ner as thefe of Flies are. And that they really are so, I have very often
try’d, by cutting off thele little movable knobs, and putting the creature
again into the water, that it would swim to and fro, and move up and
down as well as before, but would often hit it self against the rocks or
stones, and though I put my hand just before its head, it would not at
all start or ssy back till I touch’d it, whereas whil’st those were remain-
ing, it would start back,and avoid my hand or a stick at a good distance
before it touch’d it. And if in crufiaceous Sea-animals, then it seems very
probable also,that these knobs are the eyes in cruft aceo™\nfe&'si which are
allb of the same kind, onely in a higher and more astive Element 5 this the
conformity or congruity of many other parts common to either of them,
will strongly argue,their crustaceow armour,their number of leggs,which
are six, belide the two great claws, which answer to the wings in Infests 5
and in all kind of Spiders, as allb in many other Infests that want wings,
we (hall find the compleat number of them, and not onely the number,
but the very lhape, figure, joints, and claws ofLobsters and Crabs, as is
evident in Scorpions and Spiders, as is visible in the fecond Figure of the
3 i.^e^and in the little Mite-worm,which I call a Land-crab,describ’d
in the lecond Figure of the 33. <SrZ)ez^,but in their manner of generation
being oviparous, &c, And it were very worthy obfervation, whether
there be not feme kinds of transformation and metamorphosis in the se-
veral states of crustaceous water-animals, as there is in several sorts of In-
sests 5 for if such could be met with,the progress of the variations would
be much more conspicuous in those larger Animals, then they can be in
any kind of Insests our colder Climate afford!;.
These being their eyes, it affords us a very pretty Speculation to con-
template their manner of vision, which, as it is very disfering from that of
biocular Animals, lb is it not lest admirable.
That each of thele Pearls or Hewijpheres is a perfest eye, I think we
need not doubt, if we conlider onely the outlide or figure of any one of
them, for they being each of them cover’d with a transparent protube-
rant Cornea^ and containing a liquor within them, resembling the watry
or glassie humours of the eye, must necessarily refrast all the parallel
Rays that fall on them out of the air, into a point not farr distant within
them, where (in all probability) the Retina of the eye is placed,and that
opacous, dark, and mucous inward coat that (I formerly shew’d) I found
to subtend the concave part of the cluster is very likely to be that su-
nicle or coat, it appearing through the Microfcope to be plac’d a little
more than a Diameter of thofe Pearls below or within the tunica cornea.
And if so, then is therein all probability, a little Pisture or Image of the
objests without, painted or made at the bottom of the Retina against
every one of those Pearls, so that there are as many impressions on the
Retina or opacous skin, as there are Pearls or Hemijpheres on the cluster.
But becaufe it is impossible for any protuberant surface whatsoever, whe-
ther jpharial or other, so to refrast the Rays that come from farr remote
lateral