SUMMARY OF CHIEF CHARACTERS OF SPINAL CORD. 427 
as 1:5; and in the cervical region as 1:51. When it is remembered how the 
gray matter expands in the lumbar and cervical regions, and how greatly it becomes 
reduced in the dorsal region, the significance of these figures will become more 
apparent. 
SUMMARY OF THE CHIEF CHARACTERS PRESENTED BY THE CORD IN ITS 
DIFFERENT REGIONS. 
Cervical Region. 
Dorsal Region. 
Lumbar Region. 
Sacral Region. 
In transverse section, 
outline of cord 
transversely oval ; 
| the cervical swel- 
ling the transverse 
diameter being 
nearly one-third 
longer than the 
antero-posterior di- 
ameter. 
in the middle of 
| Postero-median cleft 
very deep, extend- 
ing beyond the 
centre of cord: 
antero-median cleft 
shallow. 
Gray matter greatly 
increased in quan- 
tity In the cervical 
swelling: anterior 
horn thick and 
massive ; posterior 
horn slender in 
comparison. Lateral 
horn only evident 
the fourth cervical 
nerve. Formatio 
| reticularis strongly 
| marked. 
above the level of 
In transverse section, 
outline of cord more 
nearly circular; but | 
still the transverse | 
diameter is greater 
than the 
posterior diaineter. 
Postero-median cleft 
very deep, extend- 
ing beyond centre 
of cord: 
median cleft shal- 
low. 
antero- | 
antero- | 
In transverse section, 
outline of cord more 
nearly circular than 
in dorsal region. 
| Postero-median cleft 
| not nearly so deep 
as In regions above: 
antero-median cleft, 
on the other hand, 
much deeper. 
Gray matter greatly 
reduced in quan- 
tity. Both horns 
exceedingly slender. 
Lateral horn well 
marked. Formatio 
reticularis scarcely 
apparent. 
White matter in great 
quantity, and es- 
pecially massed in 
the lateral and pos- 
terior columns. 
White matter less im 
quantity than in | 
cervical region, but 
bulking largely in 
comparison. 
the quantity of gray 
matter. 
with |} 
Gray matter greatly 
In transverse section, 
outline of cord 
nearly circular, but 
still somewhat com- 
pressed from before 
backwards. 
Postero-median and 
antero-median 
clefts of equal 
depth. 
Both horns of gray 
increased in the matter very thick 
lumbar — swelling. and massive. Lat- 
Both horns very eral horn apparent. 
thick and massive. No formatio reti- 
| Lateral horn ab- cularis. 
| sorbed in anterior 
horn. Kormatio 
reticularis absent. 
| White matter small | White matter very 
in quantity in rela- 
tion to higher re- 
gions, and very 
small in amount in 
relation toincreased 
| quantity of gray 
matter. 
small in quantity 
in comparison with 
the gray matter. 
Posterior paramedian 
groove and septum 
well marked. 
Posterior paramedian 
groove absent; but 
the 
septum can be 
traced as low down 
as the eighth dorsal 
nerve. 
corresponding | 
No posterior para- 
| median groove or 
septum. 
No posterior para- 
median groove and 
no corresponding 
septum. 
Central canal con- 
siderably nearer the 
anterior surface 
than the posterior 
surface of the cord. 
Central canal con- 
siderably nearer the 
anterior surface 
than the posterior 
surface of the cord. 
| 
| Central canal in the 
| eentre of the cord. 
Central canal in the 
centre of the cord. 
