front matter 1

Floor plateFloor plate

Central

canal

Ventral horn

motoneuron

columns

Ventral horn

motoneuron

columns

Ventral horn

interneurons

Ventral horn

interneurons

Intermediate

interneurons

Intermediate

interneurons

Dorsal root

bifurcation zone

Dorsal root

bifurcation zone

Fasciculus cuneatus

Fasciculus gracilis

Dorsal root

collateralization zone

Lissauer's

tract?

Lissauer's

tract?

Dorsal funiculus

Dorsal

horn

Substantia

gelatinosa

Substantia

gelatinosa

EpendymaEpendyma

Central

autonomic

area

Central

autonomic

area

Lateral

cervical

nucleus

Lateral

cervical

nucleus

Lamina ILamina I

Laminae

IV-V

Laminae

IV-V

Central

cervical

nucleus?

Central

cervical

nucleus?

axial motoneuronsaxial motoneurons(skull and neck?)(skull and neck?)

Ventral

white

commissure

Ventral

white

commissure

Ventral

median fissure

Dorsal median septum

Dorsal intermediate septum?

Retreating roof plate

diaphragm?diaphragm?

V e n t r a l

f u ni

c u

l

u

s

V e n t r a l

f u ni

c u

l

u

s

L a t e r a l f u n i c u l u s

L a t e r a l f u n i c u l u s

PLATE 22B