36 The > Be@ 1G. 
to diminith flowly: wherefore the inteftines 
are afterwards feen to be more and more 
diftended with excrements, which fometimes 
lie in them regularly divided, as it were, into 
globules. The reafon of this is, that the in- 
teftines do not, at one and the fame timé, con- 
tract themfelves about the feces, and therefore 
they caft or extrude them out of the body at 
different times. I have already treated of the 
mufcles of the abdomen in this infect, I fhall 
now proceed to the parts of the breaft. 
In this part, and in the back, are feen feveral 
mufcles, which move the legs and head; and 
herein are alfo vifible the appendages of the 
ftomach, and a great number of pulmonary 
pipes and particles of fat. In the fame view 
is alfo feen the gullet and fpinal marrow, to- 
gether with the nerves arifing from thence, of 
which I fhall now fpeak diftinly. 
In the middle of the back is feen a certain 
tendenous point, under the {mall fhield there 
fituated, where the skin does not appear to be 
fo tranfparent as in the reft of the body. ‘This 
fhield feems there to be hollow, being thraft 
down into a little pit. At this point almoft all 
the mufcular fibres are feen to concur, and their 
motion and contraction are here very vifible. 
As to the appendages of the ftomach, and other 
parts of the breaft and back, we have before 
treated of them at large. 
The {pinal marrow is properly fituated in the 
breaft, and therein reaches to the infertion of 
the laft pair of legs. When this is difcovered, 
it is eafy to judge what that fhort whitith 
groove is, which appears through the breaft, 
between the appendages of the ftomach ; for 
thefe appendages are placed on both fides of 
the {pinal marfow. 
The ftructure of the fpinal marrow itfelf, 
does not differ much from that found in the 
Worm, from which the Scarabeus Naficornis, 
or Horned Beetle, by the ancients confecrated 
to Mercury, is produced, as is manifeft from 
the hiftory and figures of the latter. It confifts 
of three remarkable fwellings, expanfions or 
dilatations, fig. v11. aaa, from which, on either 
fide, we obferve three nerves 464 to arife, 
which reach to the mufcles of the fix legs ; 
but underneath, or in the hinder part of it, I 
diftinguithed fix nerves ce iffuing, which doubt- 
lefs are diftributed through the reft of the vif- 
cera, to give them life, fenfe and motion. The 
loweft of thofe little knots, whereof the fpinal 
marrow is compofed, is formed in a different 
manner from the upper ones, which are alike. 
The membrane which covers the marrow is 
interwoven with a great many pulmonary pipes, 
and feems to be compofed of irregular and glo- 
bular little parts dd, in the fame manner as we 
have fhewn in refpect of the coat of the ftomach : 
and this texture, together with the great number 
of pulmonary pipes belonging to the part, afford 
a very agreeable fight in the living infect. 
I could difcover no fibres in the nerves, 
which arife from the pofterior part of the mar- 
row, though I viewed them fiefh with the 
of BNGALH SURI Ye: 
ot, 
microfcope; they feemed indeed to be made up 
of a homogeneous, bright and tran{parent mat- 
ter, and at their fides were hung a great many 
pulmonary pipes; with particles of fat. 
The origin of the marrow, where it is con- 
nected with the brain, is feen like a fine 
thread ¢. But in all other infects this beginning 
of the marrow is perforated, and through its 
aperture or cavity the gullet paffes. 
The brain of the Loufe is’ thaped like a 
pear 7, and is divided into a right and left part. 
The dura mater, furrounding it, is formed like 
the membrane that covers the marrow, and is 
provided with pulmonary pipes and particles of 
fat gg. I can very eafily at any time fhew the 
marrow, but the demonftration of the brain 
muft be obtained rather by chance, than with 
any premeditated defign or art; it is clearly 
feen when by any accident it happens to be 
{tript of the parts wherewith it is covered. 
The optic nerves b/ are fhort, and the eyes 77, 
which are connected to them, are fo {mall, that 
I could not diffect them to my fatisfaction; as 
well becanfe this operation is but aukwardly 
performed under mifcrofcopes, which magnify 
objects fo much, that all inftraments are too 
coarfe for this purpofe. ‘Thus much, however, 
I diftinétiy faw, that this black part in the eyes 
might be feparated or lifted up from them; 
which part in other infects I call the tunica 
uvea, not being fituated on the bottom, but on 
the fuperficies of the eye; after this appears 
the tunica cornea; this feemed divided as it 
were into hexagons, as it is in other infects, 
though the other was not: but that I would 
not affirm for certain, for we are not to fuppofe 
or imagine, but to purfue by our fenfes, and 
difcover the actions and productions of nature. 
This opinion, however, does not pleafe fome 
anatomi{ts, who therefore efteem all comments 
on the brain merely as ingenious fancies. The 
younger Bartholinus, who, fpeaking of the 
fiction that filkworms had no brain, expreffes 
himfelf thus: ‘‘ Behold, how many are pleafed 
*© with their own blindnefs! who, although 
*« they are blind, and fhall for ever remain fo, 
*< yet cry aloud they can fee, fince thefe their 
“© contemptible works, which ought to be re- 
‘* moved from their eyes, and buried in obli- 
“ vion, are lafting monuments of their cloudy 
“* arrogance ; for by this means they might 
‘¢ afterwards feek for the light of truth.” 
Whether Lice are diftinguifhed by the parts 
of generation, into males and females, as other 
infects are, I could not difcover. Heretofore, 
indeed, I had fometime remarked that Lice get 
upon each other; but this I could not obferve 
while employed in this diffection. I found an 
ovary in every one of forty, which I diffected ; 
this almoft inclined me to think that thefe little 
animals are Hermaphrodites; and perhaps they 
really have in each animal a penis and an ovary 
together, in the fame body, as I have found in 
{nails. Whether indeed it be fo, is ftill a fecret 
to me, for though I faw the ovary very 
diftin@tly, I could difcover no penis, notwith- 
ftanding 
