310 ME. J. L. CLAEKE ON THE. INTIMATE STEUCTUEE OF THE BEAIN. 
CHAPTEE III. 
(73) Although in the course of these researches I have carefully endeavoured to 
investigate the facts independently of any particular physiological views with which 
they might seem to be connected, I shall nevertheless conclude this memoir with a few 
remarks on some of the physiological and pathological points which they either modify 
or explain. 
(74) Before the publication of my memoir “ On the Medulla Oblongata,” in 1858, it 
was believed by anatomists that the decussating fibres of the anterior pyramids are con- 
tinuous only with the lateral columns of the opposite side of the spinal cord. I have 
shown, however, that they are connected not only with the lateral , but with the anterior 
columns, and with both the anterior and posterior grey substance. These facts, which 
must modify to a certain extent the current opinion concerning the functions of the 
anterior pyramids, have been confirmed by the investigations of M. Vulpian, announced 
in his recent and valuable work on the 4 Physiology of the Nervous System*. “Nos 
recherches anatomiques, d’accord en grande partie avec celles de M. Lockhart Clarke, 
montrent que les pyramides anterieures sont formees par des fibres emanees : (1) des 
faisceaux anterieurs ; (2) des faisceaux lateraux ; (3) des faisceaux posterieurs ; (4) de la 
substance grise de la moelle epiniere. A ces fibres, il faut meme en aj outer d’autres 
qui font partie du groupe des fibres arciformes, et qui constituent parfois, soit d’un seul 
cote, soit, mais plus rarement, des deux cotes du bulbe, une portion assez notable de la 
pyramide anterieuref.” 
(75) Besides the antero-lateral white columns, the particular parts with which I have 
shown the decussating fibres of the anterior pyramids to be connected, are (1) the 
antero-lateral grey substance, (2) the anterior border of the caput cornu, or expanded 
extremity of the posterior horn, (3) the base of the cervix cornu on each side of the 
central canal, (4) the continuation of this part of the cervix cornu in the posterior 
column, forming its grey nucleus, and subsequently contributing to form a large portion 
of the outer nucleus of the auditory nerve, and (5) the side of the spinal-accessory and 
hypoglossal nuclei. From some of these facts M. Vulpian thinks it not improbable 
that the anterior pyramids are to a certain degree sensitive and excito-motor : “ Nous 
presumons,” he remarks, “ que les pyramides anterieures pourraient bien etre sensitives 
et excito-motrices, parceque l’anatomie nous demontre qu’elles sont en relation avec les 
faisceaux posterieurs et avec les diverses parties de la substance grise ”J. Their con- 
nexions, however, with the sensory portions of the medulla oblongata and cord do not 
afford sufficient ground for the conclusion that they are sensitive ; although it is pre- 
sumable that, by virtue of these connexions, they are excito-motor, probably through 
the grey substance within the pyramids themselves, the pons Varolii, or both. 
* Logons snr la Physiologie Grenerale et Comparee du Systeme Neryeux. Par A. Yulpiam, Paris, 1866. 
f Ibid. p. 468. t Ibid. p. 484. 
