CHAP. XL] DR. HALL'S HYPOTHESIS. 325 



stopped. If we are to adopt Dr. HalPs theory, it will be necessary 

 to suppose, with Dr. Carpenter, the existence of certain emotional 

 fibres to explain the phenomena of this particular case. But it 

 is difficult to admit the existence of three orders of fibres in each 

 muscle, which, to be effective, must have the same relation to the 

 component elements of the muscle. It is impossible to imagine 

 how each order of fibre should comport itself with reference to the 

 other two, so that their actions may not interfere. Nor can any 

 one fail to perceive that the emotional fibres must be infinitely less 

 frequently employed than the others, and in some individuals, so 

 little called into action, as to expose the fibres greatly to the risk 

 of atrophy for want of use. 



Paralysis of the sphincter ani is most frequently produced by dis- 

 ease of the spinal cord ; but it is by no means a rare accompaniment 

 of diseased brain, and generally indicates a lesion of grave import. 

 Now, such a lesion is always accompanied with paralysis, chiefly 

 of the hemiplegic kind, but not necessarily complete ; on the con- 

 trary, in several such cases we have seen distinct reflex movements, 

 indicating, that although the brain's influence was withheld from the 

 limbs, that of the cord was not. If then the cord be sufficiently 

 free from morbid depression to allow of reflex movements taking 

 place in the inferior limbs, why is the sphincter so completely 

 paralysed that it offers not the slightest resistance to the introduc- 

 tion of the finger into the anus ? It is admitted that the sphincter 

 is under the influence of the will ; according to Dr. HalFs theory, 

 this must be through special fibres of volition distributed to it : but 

 it is also under the influence of the spinal cord, as the limbs are ; 

 yet, if the cerebral fibres be diseased, there seems no reason why 

 the influence of the cord upon it should be at the same time 

 destroyed. A cerebral lesion ought not to affect the sphincter 

 further than to destroy the control of the will upon it, unless its 

 depressing influence extend to the whole cord, and in such a case 

 there ought to be complete paralysis of the limbs likewise. 



These are not unimportant pathological objections to this theory : 

 to them we must add the fact, that this view wants the support of 

 anatomy. However disposed we may be to admit the existence of 

 fibre implanted solely in the gray matter of the cord, it must be 

 confessed that it is as yet far from being proved that either such 

 fibres, or those which are continued up into the brain, exist in the 

 cord of vertebrata, or in its analogue of the invertebrata. Dr. Car- 

 penter and Mr. Newport, it is true, affirm that they have demon- 

 strated the two sets of fibres in insects the sensori-voHtional, and the 



