ME. J. L. CLAEKE ON THE INTIMATE STEUCTUEE OF THE BEAIN. 287 
others, but more particularly by Otto Fischer. According to Prochaska and others, 
these striae are sometimes entirely absent from the human medulla, and when they are 
present are wholly unconnected with the auditory nerves*. On the other hand, Burdach, 
Bergmann, Heusinger, and Arnold consider that they are directly connected, either 
wholly or partially, with the auditory nerves. Treviranus thought that the delicacy and 
variety of the sense of hearing in Man are due to these fibres because they are absent 
in animals f. Arnold found that, as a rule, a large proportion of these striee were always 
in connexion with the auditory nerves. According to Serres, the sense of hearing in 
the child is never very acute until the strise make their appearance J. Longet, Meckel, 
and Prochaska state that they are sometimes altogether absent. In one deaf and dumb 
subject examined by Schroder van der Kolk, they were scarcely to be found, while 
in another they were very fully developed. 
(32) In the large number of medullse that I have examined, I have always found 
these striae present in a greater or less degree ; but in every instance they differed to a 
certain extent both in size and direction. Sometimes they arose out of the fasciculus 
teres ; sometimes out of the posterior nucleus of the auditory nerve, on the floor of the 
ventricle; but more frequently they sprang from the median sulcus, and from the 
fasciculus teres along its edge. Some of them crossed the ventricle transversely, either 
in straight lines or in curves with their convexities upward, and winding round the 
restiform body or the inner edge of the flocculus , terminated somewhat abruptly, 
either in the flocculus itself or in the auditory nerve. Commonly one thick bundle, 
below the auditory nerve, turned round the restiform body to its anterior surface, and 
running between it and the olive, was continued into the pons (see Z", fig. 41, Plate XI.). 
This bundle, is pierced by the roots of the glossopharyngeal nerve, and by the upper 
roots of the vagus in their course inward to their nuclei §. Some of the striae, instead 
of passing transversely outward towards the auditory nerve, occasionally ran obliquely 
upward to the inner surface of the middle peduncle ; and I have sometimes found them 
taking an almost longitudinal course along the floor of the ventricle, beneath the supe- 
rior peduncle, toward the corpora quadrigemina. 
(33) On examining a transverse section of the medulla made in the course of a large 
stria which ran transversely in a straight line from the auditory nerve to the median 
* Prochaska. De structura nervorum. 
t TJntersuchungen fiber den Bau und die Funktionen des Gehirns. 
X Serres, Anatomie Comparee du Cerveau, tom. i. p. 424. 
§ This is probably one of the bundles described by Bergmann, Arnold, and Otto Fischer. Arnold thinks 
it is connected with the facial nerve : he says, “ Gewohnlich nimmt aber auch eine Partie der Streifen oder eine 
ziemlich starke Tcenia meclullaris (tab. viii. fig. 3, n) welche Bergmann den Klangstab nennt, ihre Eichtung 
aus- und aufwarts gegen den Pedunculus cerebelli und verbindet sich mit ihm ; nicht selten ziehen mehrere 
Streifen um die strangfbrmigen Korper nach aussen und unten, gehen in die Bruckenfasern, auch in die 
Wurzeln des Nervus facialis fiber, oder verlieren sich am obern Ende der Medulla Oblongata, in jener Grube 
zwischen der Brficke, den oliven und stranformigen Korpern.” Otto Fischer says only, “ Spatium triangulare, 
quod inter restiforme olivareque corpus et pontem Varolii interest, iniebant.” 
MDCCCLXVIII. 2 S 
