ME. J. L. CLAEKE ON THE INTIMATE STEUCTUBE OE THE BEAIN. 315 
sible to say how far it might have been dependent on the numerous and extensive 
alterations which were found in other parts of the brain, particularly about the nuclei 
of the vagal and hypoglossal nuclei. The same objection may be made to Schroder 
van der Kolk’s cases, when they are adduced as proofs that the olivary bodies are the 
central organs of articulate speech. 
(81) Neither are the anatomical points which Schroder van der Kolk brings forward 
in support of this opinion exactly as he states them to be. According to his theory, the 
olivary bodies effect the bilateral movement of the tongue by their action on the hypo- 
glossal nuclei, because the actions of these nuclei are unilateral ; “ for the greater part 
of each nucleus,” he says “ seems to be isolated in its action, and not to be connected 
with that of the other side.” Now it is not true that the hypoglossal nuclei are scarcely 
connected with each other other ; for, as may be seen, especially in longitudinal and 
horizontal sections along the fourth ventricle, at different depths of the nuclei, there is 
a very evident decussation of fine fibres ; and at the upper end of the nucleus, the com- 
missural fibres between the anterior groups of cells are particularly striking, as may be 
seen at J, fig. 57, Plate XIV. Vulpian speaks almost in derision of Schroder van der 
Kolk’s theory of the action of the olivary bundles ; but, nevertheless, there are not 
wanting anatomical facts in favour of the opinion that these bodies are subservient to 
articulate speech. In this process, the tongue, the lips, the jaws and the expiratory 
muscles are simultaneously combined in action. Now I have already shown that the 
connexion of the olivary bodies with the hypoglossal nuclei is very striking. I have 
also shown that a column of cells connected with longitudinal fibres and continuous with 
the fasciculus teres, whence the facial nerve takes its origin, descends low down into the 
medulla and lies at the back of the hypoglossal nucleus (see K', fig. 25, Plate X., and 
figs. 38, 39 & 40, Plate XI.). Moreover, a band of fibres descending from the loop of 
the facial nerve (T", fig. 57, Plate XIV.) passes downwards beneath the hypoglossal 
nucleus (J). The close commissural connexion between the hypoglossal nucleus (J 7 , fig. 
31, Plate X.) and the vagal nucleus (H, H') has been already pointed out. And lastly, 
we have seen that the lower end of the column of cells constituting the nucleus of the 
motor root of the trigeminus is imbedded in the columns Avhich ascend from the olivary 
body. But whether the olivary bodies really act through the channels just mentioned, 
and thus coordinate the movements of articulation, is not proved by the anatomical facts 
alone. On the other hand, amcngst birds, in which scarcely any traces of olivary bodies 
are to be found, the Parrot-tribe have the power of distinctly articulating particular 
words; while in the Porpoise, which emits only a kind of moaning sound, the olivary bodies 
are enormously developed*'. Experiment throws no light whatever on this subject, so 
* I obtained, through the kindness of Mr. W. II. Flower, of the College of Surgeons, part of the medulla of 
a Porpoise,” and found that the large olivary bodies overlaying the pyramids were everywhere crowded with 
nerve-cells. The cerebrum of the Porpoise is large and globular, and the convolutions are very numerous and 
deep. The only remarkable points in the actions of the animal, are its great agility and vivacity of movement, 
and its extraordinary speed and muscular power. 
