92 
THOMPSON YATES LABORATORIES REPORT 
by the sensory root of the nerve. But, on examining the following muscular nerves for undegenerate 
fibres, the sensory distribution of the nerve was found to include the following muscles : gastrocnemius, 
both heads : semimembranosus, semitendinosus, biceps, tibialis amicus, tibialis posticus, and muscles of the back. 
l^erve trunk. Condition of nerve fibres. 
n. to sartorius . . . . . .no sound myelinate fibres. 
obturator in pelvis . . . . . a few minute myelinate fibres in the 
perineurium : none sound elsewhere, 
no sound myelinate fibres, 
no sound myelinate fibres, 
plenty of sound myelinate fibres, 
plenty of sound myelinate fibres, 
a number of sound myelinate fibres. 
87 sound fibres, 17 fj. — 2 ^. 
7 sound fibres, 12 /x — 2 ju. 
94 sound fibres, 19 ju — 2 /m. 
52 sound fibres, 19 /ul — 2 /x. 
37 sound fibres, 
many sound myelinate fibres, 
very few sound myelinate fibres, 
a fair number of sound myelinate fibres, 
no ganglion cells or sound myelinate 
fibres, except a few minute ones in or 
near the sheath, 
condition same as that of Vth. 
obturator in thigh, deep division 
,, „ superficial division 
n. to tibialis anticus .... 
n. to extensor digitorum ... 
n. to tibialis posticus ... 
n. to gastrocnemius, lateral head, 3 bundL^ 
„ „ median head, 4 bundles 
n. to semimembranosus, 3 bundles 
n. to semitendinosus, 2 bundles 
n. to biceps, 4 bundles .... 
the most lateral plantal digital 
the most lateral dorsal digital 
the most medial dorsal digital 
the Vth post-thoracic nerve trunk from the scar outward 
for a centimetre .... 
the Vlth post-thoracic .... 
the Vllth post-thoracic nerve, with ganglion and ventral 
and dorsal roots and ventral and dorsal primary divisions 
of the nerve. The motor root 
ganglion and adjoining piece of dorsal root 
ventral primary division 
dorsal primary division 
3 sound myelinate fibres, .'recurrent, 
no degeneration, except where the 
scar is approached ; there plenty, 
traumatic, 
great numbers of sound fibres, 
about a half of the nerve consists of 
sound myelinate fibres, 
condition as in Vth and Vlth. 
the Vlllth post-thoracic nerve . 
In the above evidence for the existence in tlie limb of complete sensory as well as complete 
motor rays, the most convincing item is perhaps that furnished by the primary dorsal divisions of 
the Vth, Vlth, and Vllth post-thoracic, and of the Vlllth cervical and 1st thoracic nerves of 
Macacus. I have previously* pointed out that these divisions differ from the similar divisions of 
all the other spinal nerves in not entering the skin ; they are devoid of cutaneous branches. 
Their anomalous behaviour is confirmed by the examination of the cutaneous distribution of the 
nerve, which shows that these particular nerves have skin-fields confined to the limb proper (to the 
lc2; almost exclusively below the knee). They have, therefore, no cutaneous territory at all along 
the middle line of the body. But by the experimental method it is seen that after section of the 
motor roots of these particular nerves more than a half of the nerve-fibres in their primary dorsal 
divisions still remain intact ; the intact fibres are sensory ; the primary dorsal division, although 
not cutaneous, is therefore nevertheless largely sensory. When in the same way the contribution 
* ' Roy. Soc. Pioc.,' 1892. ' Phil. Trans.,' B, vol. 184, loc. cit. 
