ME. J. L. CLAEKE ON THE OEET SUBSTANCE OE THE SPINAL COED. 46. 
ment; the tractus intermedio-lateralis, F, rests on the lateral projection of 
the anterior cornu, behind a group of large vesicles, and is connected by a net- 
work with the cervix cornu posterioris. 
Figs. 8 & 9, Plate XXI. Sections of the lateral half of the grey substance, successively 
nearer the middle of the cervical enlargement -N, large bundles of longitu- 
dinal fibres near the lateral edge of the grey substance. 
Fig. 10, Plate XXI. Lateral half of the grey substance, through the middle of the cer- 
vical enlargement : the tractus intermedio-lateralis is no longer visible, but 
the lateral projection of the anterior cornu, on which it rested, is still con- 
nected by a network with the side of the cervix cornu, which is pierced by 
several bundles of longitudinal fibres, N, 
Fig. 11, Plate XXI. A similar section of the grey substance at the fourth cervical 
nerves:— N, longitudinal bundles of the lateral column, enclosed in the 
meshes of a network proceeding from the grey substance, and containing 
small cells, thiough this network the roots of the spinal-accessory nerve pro- 
ceed from behind forwards to the tractus intermedio-lateralis^ F, and to the 
cells of the anterior cornu ; P , posterior roots of the spinal nerves ; M, poste- 
rior vesicular column traversed by bundles of the posterior roots, and by the 
transverse commissure. 
lig. 12, Plate XXV. Similar section at the upper part of the third cervical nerves, 
magnified 60 diameters: N, N, N, network proceeding from the side of the 
posteiior cornu and tractus intermedio-lateralis, containing small cells and 
enclosing bundles of fibres of the lateral column, between which the roots of 
the spinal-accessory nerve proceed foi-wards to the tractus intermedio-lateralis, 
F, and to the anterior cornu ; the extremity, and particularly the outer por- 
tion, of the anterior cornu is pierced by numerous longitudinal bundles (repre- 
sented by the dark round or oval masses), between which the fibres of the 
anterior roots (O') cross each other in an intricate plexus ; amongst this plexus 
are several large nerve-cells, which partially embrace the bundles and send 
some of their processes longitudinally. 
Fig. 13, Plate XXL Transverse section of one lateral half of the grey substance at the 
upper part of the lumbar enlargement ; the posterior vesicular column, M, is 
larger than in any other region. 
lig. 14, Plate XXI. A similar section, nearer the middle of the lumbar enlargement. 
lig. 15, Plate XXL Another section, through the middle of the same enlargement: 
the posterior vesicular column, M, is composed almost entirely of small cells ; 
the lateral part of the cervix cornu is pierced by several bundles of longitu- 
dinal fibres. 
lig. 16, Plate XXIII. A similar section, through the lower part of the lumbar enlarge- 
ment. ® 
lig. 17, Plate XXIII. Section through the upper part of the conus medullaris. 
3p 2 
