O B S E R V A T I O N S O N T H E
T . I I I .
WHEN we carefully trace the anterior and pofterior bundles which f o rm
the fpinal nerves , we ihall find that each has its prope r hole in the fpinal
[heath of the dura ma t e r ; and f r om the inner layer of the dura ma t e r its proper
iheath, or that , between the two bundles which f o rm the fpinal nerves ,
a por t ion of the dura mater intervenes On the outer fide of the fpinal
Iheath of the dura mater, the cellular fubf lance condenfed, ties the two bundles
toge the r , fo that, at firil f ight , they appear like one nei-ve. Henc e
author s have defcribed them as palling through one hole f , and as f o rming
one nerve terminat ing in a gangl ion But , when we break the cellular
fuhftance which conne i l s the two bundles , it will be found tha t the pof terior
bundle only ends in the g ang l i on; and tha t the pofterior bundle has
not its nervous fibres incorporated wi th thofe of the anterior bundle till it
has paffed through the gangl ion [j.
T . I V .
ANOTHER memor abl e eircumftance alfo, entirely over looked b y mof t author
s , and not proper ly delineated by a f ew wh o have obferved it is, that
the pofterior bundles of all or mof t of the cervical nerves , for there is a variety
in different per fons , detach fmall bundles of ne rvous fibres to. the pofterior
bundles of the nerves above or below them In fome per fons I
have found a f ew fibres detached, in like manner , f r om fome of the pofterior
bundles of the dorfal nerves.
S E C T .
• See Tab. X. Fig. M. and T.
f Halier, Pr. Lin. § 361. El. Phyf. L. x. p. 339.
1 Blafius, Tab. VII. An. Comp. ^Bidloo's Tab. X. Fig. 4. F Hiiber, V. Halier, Fafc. An.
Tab. 3. ^Halier, B . Phyf. L. x. p. a+o.
1 Tab. X. Fig. 1. N. O. P. q . anil Tab. XI. N. O. P.
5 As Hnbei and Hallei. See Halier Fafc. An. . . Tab. HI. and F. An. 7. Tab. IV. and V.
See Tab. X. Fig. i . V. W. X. Y. Z.
N . E R V O U S S Y S T E M .
T . V .
BEYOND the gangha , or after the anterior and pofterior bundles of nervous
fibres are intermixed, the external anterior and pofterior branches of
fpinal nerves are detached, and, at the f ame places, c onne a i ons are formed
wi th the great fympa thet i c nerves * . T h e nature of which I lhall afterwards
a t t empt to explain.
S E C T V I .
IN hke manner , the acceflbry nerve, which comes out behind the ligamentum
dent iculatum, takes its rife part ly f r om the fide of the fpinal mar -
row, and partly, b y filaments, is c onne de d to the pofterior bundle of f eme
of the fpinal nerves
C H A R
• See Tab. X. Q^ R. S.
t See Tab. X. Fig. Winllow, S. 6. § 143. And Halier, El. Phyf. L. x. S. 6. p. 343;
make mention of filaments added to the acceflbry, from the pofterior branches of the cervical nerves.