THE CEREBELLUM, AND ITS FUNCTIONS. 673 



The number of purely automatic actions diminishes in proportion to the 

 development of the Cerebrum, and to the subjection of the Automatic appa- 

 ratus to its control ; but even in Man, those most closely connected with the 

 maintenance of the organic functions, or most necessary for the conservation 

 of the bodily structure, remain quite independent of any mental agency, 

 and most of them do not require consciousness for their excitation. But if 

 the activity of the Cerebrum be suspended or be otherwise directed, without 

 any affection of the automatic apparatus, movements which have long been 

 habitually performed in a particular sequence, may be kept up, when the 

 will has once set them in action, through the automatic mechanism alone; 

 the imprcssional or sensational change produced by each action, supplying 

 the stimulus which calls forth the next, It may further be concluded that 

 the Sensory Ganglia, which are the instruments whereby we are rendered 

 con*<-!<>t(s of external impressions, are also the seat of those simple feelings 

 of pleasure and pain which are immediately linked on to that consciousness : 

 for it can scarcely be doubted that such feelings must be associated with 

 particular sensations, in animals that have no gauglionic centres above 

 these ; since we must otherwise regard the whole series of Invertebrated 

 tribes as neither susceptible of enjoyment, nor capable of feeling pain or 

 discomfort. And it likewise seems probable that the Sensory Ganglia are 

 also the seat of those perceptional acts, which bring the consciousness into 

 direct relation with the external object that aroused the sensation ; since the 

 recognition of externality seems evident in the actions of the tribes just re- 

 ferred to. 1 A few remarks may here perhaps appropriately be introduced, 

 indicating the effects of lesion of the several ganglia at the base of the brain 

 from above downwards. In the event of lesion, as haemorrhage, occurring 

 in front of or above the corpora striata, no paralysis either motor or sensory 

 is observed unless the damage be very great. The intellectual faculties are 

 probably always more or less affected, though it may not be easy to deter- 

 mine in what mode or to what degree. As will subsequently be shown, if 

 the posterior frontal convolutions, especially of the left side, be affected, 

 aphasia is likely to occur. If the haemorrhage occur in the Corpus Striatum, 

 there is motor pai'alysis of the opposite side only. If in the Thalamus Op- 

 ticus, there would be motor paralysis of the opposite side, with more or less 

 paralysis of sensation. If in the Cms Cerebri there would be paralysis of 

 the opposite side, which might be either motor or sensory, or both. If the 

 muscles of the eye be paralyzed, it is on the same side, and would chiefly 

 affect those supplied by the third. If in the Pons, there would be paralysis 

 of motion or of sensation, or of both, of the opposite side of the body and 

 the same side of the face, in those muscles mainly supplied by the 5th and 

 7th, that is there would be crossed paralyses. If in the Medulla Oblongata, 

 the great centres of respiration, deglutition, etc., would be affected, and a 

 fatal issue soon occurs. 



4. Of the Cerebellum, and its Functions. 



546. The Cerebellum is an organ which, though confined to the Vertebrated 

 sub-Kingdom, is yet in peculiarly intimate relation with the Automatic ap- 

 paratus. In that highest state of development which it presents in Man, we 

 find it to consist of two lateral lobes or hemispheres, composed of nerve-fibres 



1 It may here be remarked that the term Sensation is now understood to imply the 

 simple consciousness of an impression, whilst Perception refers that impression to 

 something out of the ego. For the production of a Sensation a conscious state of the 

 mind is all that is required ; but for the exercise of the Perceptive power a certain 

 decree of attention is requisite. 



