front matter 1

Sp

in

o

c

e

p

h

a

li

c

t

r

a

c

t

s

?

Sp

in

o

c

e

p

h

a

li

c

t

r

a

c

t

s

?

VVentral funiculusentral funiculus

VVentral grayentral gray

Intermediate grayIntermediate gray

Lateral

funiculus

Lateral

funiculus

Vestibulospinal tract?

Dorsal grayDorsal gray

Dorsal funiculus

Dorsal root bifurcation zone

Superficial fasciculus cuneatus

Deep fasciculus cuneatus

Superficial fasciculus gracilis

Deep fasciculus gracilis

Dorsal root collateralization zone

Lissauer's tract

Myelinating terminals of

dorsal root collaterals

Ventral

corticospinal

tract

Ventral

corticospinal

tract

Lateral

corticospinal tract

Lateral

corticospinal tract

Dorsal root

Central canal

surrounded by ependyma

Central canal

surrounded by ependyma

Int

ra

sp

in

al

tr

a

c

ts

?

Int

ra

sp

in

al

tr

a

c

ts

?

S

p

in

o c e r e b e l

l a r t r a c t s?

S

p

in

o c e r e b e l

l a r t r a c t s?

Incipient

subgelatinosal

plexus

Incipient

subgelatinosal

plexus

Reticulated

area

Reticulated

area

Dorsal median septum

Dorsal intermediate septum

Ventral median fissure

VVentral white commissureentral white commissure

VVentral gray commissureentral gray commissure

Lateral
reticulospinal
tract?

Lateral
reticulospinal
tract?

See the matched cell body stained section in Plates 68A and B

The medial and central fi bers in the intraspinal tracts have a greater stain-

ing density than the dorsolateral parts. That same gradient is seen at the

thoracic level of the GW26 (Plate 51) and GW 31 (Plate 56) specimens.

PLATE 67B