THE SPINAL COED IN MAN, MAMMALIA, AND BIEDS. 
935 
PLATE XLVI. 
Fig. 8. A transverse section through the spinal column and cord of a human foetus of 
nine weeks, from the cervical enlargement ; magnified 60 diameters ; — 
2 , lamina of vertebra ; z\ muscular fibres. 
Fig. 13. One, and part of the other, lateral half of a transverse section through the 
lumbar enlargement of the spinal cord of a foetal sheep 4 inches long: — 
I b, caput cornu posterioris. 
Fig. 14. A similar portion of a transverse section through the middle of the lumbar 
enlargement of a foetal ox 5 inches long : — I h, caput cornu posterioris, con- 
sisting of a dark mass of closely aggregated nuclei. From the outer edge of 
this mass, as well as from that of the rest of the grey substance, nuclei are 
scattered in smaller numbers through the white columns. 
PLATE XLVII. 
Fig. 11. Grey substance from the middle of the anterior cornu, traversed by anterior 
nerve-roots; from a foetal sheep 2^ inches long; magnified 670 diameters. 
Fig, 12. Portion of the anterior grey and white substances of a foetal sheep 2^ inches 
long; magnified 420 diameters : — ^ y\ internal part of the anterior white 
column, bordering the grey substance; x x, group of large nerve-cells in 
process of development ; v, granular and nucleated network nearer the middle 
of the anterior cornu. 
Fig. 15. Portions of a longitudinal section of the grey substance of the same foetus, in 
a direction before-backward ; magnified 420 diameters, i. Part of the caput 
cornu posterioris, intersected by the deep decussating fibres of the posterior 
roots, and posterior white column, ii. Middle portion of the grey substance 
(between h and f, fig. 14), in which the nuclei are much larger, and the 
network between them becomes gradually coarser and looser as it proceeds 
forward, iii. A group of the large nerve-cells of the anterior cornu (w w, 
fig. 14), surrounded by thick walls, with intervening nuclei. 
Fig. 16. Portion of a longitudinal section of the middle of the grey substance (corre- 
sponding to II, fig. 15), from a foetal sheep 8 inches long; magnified 420 dia- 
meters, Numerous fusiform, triangular, and crescentic cells have become 
developed in it. 
Fig. 17. Stellate nerve-cell from the nucleus cervicis cornu (posterior vesicular column) 
of a human foetus of six months ; magnified 420 diameters. Some of the 
processes are seen ramifying and becoming continuous with the surrounding 
network. It is not often seen so distinctly as in this case. 
Fig. 17"^. Cells from the posterior grey substance of a human foetus of four months; 
X670. 
6 M 
MDCCCLXII. 
