722qQ 
bat to the vigour and health of the body also ; 
that to ensure the fall developement of the 
mens sana we must secure the possession of the 
corpus sanum. 
ertain diseases are evidently associated 
with disturbed or excited states of emotion. 
In such cases, the nerves most affected are 
those connected with the mesocephale and 
medulla oblongata, denoting an excited state of 
these portions of the encephalon. Of these 
diseases the most remarkable are Aysteria and 
chorea; both of which may be induced either 
by a cause acting primarily upon the mind} or 
by functional disturbance of the body, as de- 
ranged assimilation, in persons of a certain 
character of constitution. In hysteria, the 
globus, the tendency to cry or laugh, the dis- 
turbed breathing, the variously deranged state 
of the respiratory acts, all denote affection of 
most, if not all, the nerves coming from these 
segments. In chorea the frequent movements 
of the face and eyes, the peculiar and very 
characteristic mode of protruding the tongue, 
the impaired power of articulation, are depen- 
dent on an aliered state of that part in which 
the portio dura of the seventh pair, the third, 
fourth, and sixth, and the ninth nerves are 
implanted. In both diseases the principal 
central disturbance is in the mesocephale; and 
this may be caused either by the direct in- 
fluence of the mind upon it, or by the propa- 
gation of a state of irritation to it from some 
part of the periphery.: Chorea, even of the 
most violent and general kind, is very commonly 
produced by sudden fright; and it is well 
known how frequently mental anxiety or ex- 
citement developes the paroxysm of hysteria. 
There is no part of the cerebro-spinal centre 
which appears to exercise such extensive sway 
over the movements and sensations of the body 
as this portion, the mesocephale, which may be 
regarded as the centre of emotional actions. 
Its influence extends upwards to the cerebral 
convolutions—bhack s to the cerebellum— 
downwards to all the nerves of sensation and 
motion. Through its connection with the 
terior horns of the spinal grey matter, it can 
excite the sensitive as well as the motor nerves 
of the trank. Hence it is not to be wondered 
at that a highly disturbed state of this centre is 
capable of deranging all the sensitive as well as 
motor phenomena of the body and even the 
intellect. Hence we may explain the extra- 
ordinary movements in hydrophobia and ge- 
neral chorea, in both of which diseases this 
art of the nervous centre is doubtless affected. 
t has often been remarked how much more 
powerful are the voluntary actions when 
prompted by some strong emotion, than when 
excited only b hr effort * a will. Rage, 
or despair, is able to magnify the power of the 
fined to an incalculable aren” This may 
be due to the increased stimulus derived from 
the influence of the centre of emotion being 
conjoined with that of the centre of volition. 
The intimate connection of the olivary co- 
lumns with the grey matter of the cord, and 
through that with all the roots of the spinal 
nerves, illustrates the power of emotional 
PHYSIOLOGY OF THE NERVOUS SYSTEM. 
changes upon the organic . How 
often does the state of the feelings influence 
the quantity and quality of the secretions, no 
doubt through the power of the nerves over — 
the capillary circulation! Blushing is pro- — 
duced through an affection of the mind, <a ; 
? 
primarily on the centre of emotion. 
through it on the nerves, which are distributed 
to the capillary vessels of the skin of the face. | 
The sexual passion must be ranked 
the mental emotions. Like them, it may be 
excited and ministered to by a certain line of 
thought, or by particular physical states of the — 
sexual organs. It therefore, more 
-_ 4 refer this emotion to the common cei 
of all, than to a special oi —aecording: J 
Gall’s theory; and Te euty bb VOR that: 
great developement of this part of the brain is” 
just as likely to produce great width of cs 
in the occipital region as a large cerebellum. 
Of the functions of the cerebellum.—Allana- 
tomists are in admitting, in the whole. 
vertebrate series, (the amphioxus, pee X- 
cepted,*) the existence of a portion of n- 
cephalon which is analogous to the cerebellum. 
This extensive existence of such an organ indi- 
cates its great physiological importance, as’ 
special clament ‘of #6 @ on. The 
rebellum exhibits much di both as 1 
gards size and complexity of strueture in 
different classes; and although, upon t 
whole, it increases in its devel ‘in th 
same ratio as the hemispheric lobes, it exbibi 
no constant relation of size to those parts. 
commissural connection with that segment 
the encephalou is not extensive,—have exci 
the interest and curiosity of speculative phi 
logists; and, accordingly, we no | 
respecting which a greater variety D 
have been suggested, most of them being 
tirely devoid of foundation. The experim 
of Flourens have, however, thrown more 
on this subject than any previous obse 
and his hypothesis appears nearer the truth 
any which has been proposed. ol 
The facility with which the cerebell 
be removed or injured, especially in | 
without involving the other of 
brain, renders it a much more favoura 
ject for direct experiment than them, A 
ful operator may remove the greater part ¢ 
whole of the cerebellum without inflict 
injury on the hemispheres or other f 
Flourens removed the cerebellum ff 
geons by successive slices. During the 
of the superficial layers there appeared” 
slight feebleness and want of harmony it 
movements, without any ion 0 
On reaching the middle layers an 
versal agitation was manifested, 
sign of couvulsion: the animal performed 
and ill-regulated movements; it could I 
* The observations of Quatrefages rer 
doubtful that even the amphioxus can be re 
as forming an exception. Ann. des Se. 
aa 
