294 
MR. J. L. CLARKE ON THE INTIMATE STRUCTURE OF THE BRAIN. 
nucleus (c' o ) runs through the commencement of the superior peduncle, or processus e 
cerebello ad testem (E' E"), from which it extends into the vermiform process (I' I"). The 
light spaces between the bundles of the plexus at E" are the longitudinal fasciculi of the 
superior peduncle. The same kind of appearances are observable in the human medulla. 
In fig. 46, Plate XII. a plexus of fibres containing nerve-cells is seen to extend back- 
ward from the outer nucleus (c J o ), partly toward the corpus dentatum cerebelli (J'), but 
chiefly, in company with other fibres from the inner nucleus («), over the fourth ventricle 
to the inferior vermiform process. 
(44) A brief account of the formation of the auditory nuclei and of the course and 
connexions of the auditory nerves was given in my “Notes” published in the ‘Proceedings 
of the Royal Society ’ for June 20, 1861, and has since been confirmed by Dr. John Dean, 
whose descriptions are much superior to those of either Stilling or Schroder van der 
Kolk. Stilling, however, was the first anatomist that described the course and attach- 
ment of the auditory nerve within the medulla, and his descriptions, so far as they go, are 
very correct, and faithfully illustrated by very beautiful engravings. But he failed to 
trace the posterior auditory root to any nucleus within the medulla ; that which I have 
shown to be its proper nucleus, he mistook for the nucleus of the glossopharyngeal 
nerve*; and although he was the first to trace the anterior auditory root to what I have 
called the outer auditory nucleus {d o), he scarcely seems to consider this as its proper 
originf. Stilling had evidently not discovered the morphological changes through 
which, as I have shown, the auditory nuclei are developed. Moreover the bundles of 
longitudinal fibres which run along the front of the grey tubercle, and which I have 
shown to belong to the descending root of the trigeminus, were mistaken by Stilling 
for the primitive fasciculi of the posterior columns of the spinal cord, — “ pristina pars 
funiculorum alborum posteriorum.” Schroder van der Kolk’s account of the origin 
and connexions of the auditory nerves, although fuller than that of Stilling and in 
many respects superior, is nevertheless imperfect, and in some points erroneous. Like 
Stilling, he had evidently not detected the important morphological transformations 
through which, as I have already shown, the auditory nuclei are developed, and he was 
certainly not acquainted with the real nature and connexions of what I have termed 
the inner nucleus. Whether, like Stilling, he mistook this nucleus for that of the 
glossopharyngeal nerve, is not easy to say, as he has nowhere given us any account of 
the origin of that nerve. Certain it is that he had not discovered the connexion of the 
inner nucleus with the true posterior root, which he evidently confounded with the striae 
medullares$. He corrected, however, the error which Stilling had made in describing 
the longitudinal fibres in front of the grey tubercle as the primitive posterior columns 
of the spinal cord, and showed that they consist of the descending root of the fifth cere- 
bral nerve §. 
* Ueber die Medulla Oblongata, p. 40, tab. vii. f Pons Yarolii, pp. 158, 159. 
J Spinal Cord and Medulla Oblongata, pp. 126, 127. 
§ This important anatomical fact was discovered independently by Schroder van der Kolk and myself at 
