THE STRUCTURE OF THE SPINAL CHORD. 
617 
attachment, but sometimes run for a short distance transversely along its circumfe- 
rence (see Plate XXL fig. 6). They then traverse the antero-lateral columns somewhat 
obliquely, and in straight and distinct bundles, which do not, like those of the pos- 
terior nerves, cross and interlace each other, but proceed directly to the anterior 
grey cornu*. Their (connection with the latter is still doubted by many physiolo- 
gists of eminence, but in the preparations which illustrate this paper, it may be seen 
as clearly and satisfactorily under the microscope, as their connection with the white 
columns is perceived by the naked eye-f-. On reaching the grey cornua, they break 
up into smaller bundles and separate fibrils, which diverge in various directions. 
Some of the fibres proceed to the right and left, crossed by others from neighbouring 
bundles (see Plates XXIII. and XXV, figs. 14 and 15). Of those proceeding within the 
external border of the cornu, a few pass out to the antero-lateral columns ; u'hile 
others, after winding round groups of caudate vesicles, curve inwards and join the 
fibres of the transverse commissure. Of those proceeding along the inner border of 
the cornu, a few pass into the white column at the side of the median fissure ; while 
others, on reaching its base, curve round, and, in company with fibres from the poste- 
rior cornu, cross obliquely through the junction of the anterior columns in front of 
the spinal canal, where they decussate with corresponding fibres from the opposite 
side. The remaining bundles of the roots plunge into the central portion of the 
cornu, and winding among its vesicles, are lost in the intricate network (see fig. 14). 
A few of their fibres, after proceeding to some depth in the grey substance, bend round 
and take a more or less longitudinal direction, 
* I have not yet ascertained whether any of the fibres of the spinal nerves ascend with the white columns 
without entering the grey substance, as maintained by Mr. Grainger, Mr, Solly, and Dr. J. Budge. 
•j* Dr. Sharpet, one of the most recent authorities on the subject, observes, “ The anterior roots have been 
said to reach the anterior grey cornu, by passing through the superficial stratum of white substance over it, 
but actual demonstration of the fact is yet wanted.” — Quain’s Anat. 5th edit. p. 727. Bellingeri states merely 
that some of the anterior roots perhaps reach as far as the grey substance. His account of their origin is as 
follows : “ Cernuntur filimenta radicum anteriorum nervorum spinalium partim exoriri a fasciculis anterioribus 
medullse spinalis, et quidem filimenta aliqua nervea directb secedunt a superficie medullae spinalis ; alia verb 
filimenta nervea per canaliculum a pia matre suppeditatum profunde descendant in substantiam albidam me- 
dullae, et fortasse nonnulla usque ad cineream substantiam perveniunt.” — Op. cit. p. 50. It is well known 
that Mr. Grainger was the first who professed to have traced the connection of the anterior roots of the nerves 
with the grey substance of the chord ; and that Dr. Stilling has since described and represented it ; but the 
statements of these eminent men failed to convince most of the physiologists of this country. I may take this 
opportunity, however, of observing, that we are much indebted to Dr. Stilling for having thrown consider- 
able light on some of the most obscure points in the anatomy of the spinal chord and medulla oblongata ; and 
for having originated and suggested new methods of further inquiry. His researches prove him to be not 
only a skilful, ingenious and laborious investigator, but, in general, a correct and acute observer. The 
plates attached to his second work, although a little embellished, are, with a few trifling exceptions, exceedingly 
correct. 
