92 ' REPORT—1846. 
MEDICAL SCIENCE. 
On the Physiology of the Encephalon. By W.B.Carventer, M.D.,F.R.S. 
Tue object of this communication was to bring under consideration the inferences 
to which we are led by the study of Comparative Anatomy, in regard to the functions 
of different parts of the human encephalon. He first pointed out that our com- 
parisons need not be restricted to vertebrated animals, since the ganglionic centres 
of invertebrata may be shown to be analogous with certain portions of the cerebro- 
spinal system of the vertebrata. He stated it to be a universal fact, that all organs 
of special sense have distinct ganglionic centres, which must be regarded as the 
instruments of their respective sensations and as the sources of motions directly 
connected with those sensations; and that the whole cephalic mass of invertebrated 
animals was composed of a collection of such ganglia, without any vestige (except 
in the highest) of cerebrum or cerebellum. These organs make their first appear- 
ance in fishes; and bear at first but a small proportion to the chain of sensory 
ganglia, which forms the anterior termination of the spinal cord. In fishes we find 
distinct olfactive, optic and auditory nervous ganglia, together with thalami optici 
and corpora striata, the degree of development of which has no reference to that of 
the cerebrum ; in fact, the bodies usually called the cerebral lobes of fishes are (ex- 
cept in the sharks, &c., which have vestiges of cerebral hemispheres) almost entirely 
composed of the homologues of the corpora striata. Hence Dr. Carpenter con- 
sidered that these bodies, instead of being appendages to the cerebrum, really belong 
to the group of sensorial ganglia, and are to be regarded as together making up the 
ganglionic centres of common or tactile sensation, and of the movements prompted 
or directed byit. This chain of ganglia, although comparatively small in man, with 
reference to the bulk of the cerebral hemispheres, still exists in him, and must be 
regarded as the instrument of the same operations as those to which it ministers in 
the lower animals. Arguing from actions in the latter, and analogous phenomena 
in man in health and in disease, the author attributes to the sensory ganglia the 
formation of sensations, and the origination of respondent movements, which may 
be distinguished as consensual. To this category the purely instinctive actions of the 
lower animals, which seem executed without any idea of purpose, and in simple 
respondence to the promptings of sensation, appear referrible ; together with a variety 
of actions in man, such as that of yawning, from the sight or sound of the act in 
another. Dr. Carpenter hence endeavoured to show that we must regard the 
cerebrum as the instrument of the formation of ideas, of the memory of ideas and 
sensations, and of the intellectual proeesses founded upon them, which terminate in 
an act of the will; and he pointed out that zdeas may produce the same effect on 
muscular movement as sensations themselves, as when the suggestion of the idea of 
yawning induces the action. He also showed how the anatomical connexions of 
the cerebrum with the sensory ganglia would cause its communicating fibres to exert 
an influence on the latter, corresponding with that which is effected by the sensations 
directly received from the organs of sense. With respect to the emotions, he endea- 
voured to show that they may be regarded as compound states resulting from the 
simple feelings of pleasure and pain associated with certain ideas, or elasses of 
ideas: the feelings of pleasure or pain he would locate, with the sensations which 
commonly excite them, in the sensorial ganglia; whilst the formation of the ideas, 
which are essential parts of the emotions and propensities, is clearly a cerebral ope- 
ration : and he showed, in conclusion, how this view of the functions of the principal 
parts of the encephalon harmonizes with the known duplex action of the emotions,— 
first in producing involuntary movements, and secondly in stimulating and influencing 
the reasoning processes. 
On the Relations of Sensation to the higher Mental Processes. 
By R. Fowirr, M.D., FRS. 
The author observed that man, when viewed as a whole, should be considered as 
consisting of a body, constituting the instrument of the mind, as the telescope is of 
the eye, adjustible but not adjusted: that its indications are perceived through the 
