GENERAL RECAPITULATION, PHYSIOLOGICAL APPLICATIONS. 847 



still manifested ; but if the former be involved, these reflex actions are suspended 

 no less completely than are the sensori-volitional. There are many peculiar 

 phenomena of Paralysis depending on Spinal lesion, however, which have not 

 yet been explained on any physiological basis. Among these is the fact, to 

 which Dr. Gull has prominently directed attention, 1 that in Paraplegia dependent 

 upon lesion of the Cord, there is usually greater loss of motion than of sensation j 

 whilst in Paraplegia dependent upon Encephalic disorder, or upon toxic agencies 

 rather affecting the peripheral than the central portions of the nervous system 

 (as seems to be generally the case, for example, in poisoning by lead), affections 

 of the sensibility sometimes beginning with hyperaesthesia and then proceeding 

 to more or less complete anaesthesia, usually constitute the prominent symptoms. 



xix. Our present knowledge of the Physiology and Pathology of the Cere- 

 bellum seems to justify the inference, that its special function consists in the 

 co-ordination of voluntary movements; and the effects of lesions whose influence 

 is limited to this organ display themselves most constantly in the impairment 

 of this power. But there are pathological phenomena which seem to indicate 

 that a centre of sexual sensation has its place in or near the central lobe of the 

 Cerebellum, and that, according to the degree of excitement or of depression of 

 its functional activity, will be the strength or weakness of the sexual desire 

 prompted by the sensation. 



xx. Of the morbid affections of the Sympathetic System, it is impossible to 

 state anything with precision, in our present state of almost complete ignorance 

 of its physiological actions. It may be stated, however, as an indubitable fact, 

 that, in virtue of the afferent Cerebro-spinal fibres which it contains, it may 

 receive impressions from morbid states of the organs which it supplies, and may 

 transmit these to the Spinal cord ; through which, general convulsive move- 

 ments, or irregular actions of the Sensorial or even of the Cerebral centres, may 

 be excited. Of this we have an example in the erratic phenomena of Hysteria 

 already referred to. 



[In the foregoing view of the Functions of the Nervous System, the Author has endea- 

 vored to exhibit this most difficult and in many parts obscure subject, under the aspect in 

 which it now presents itself to his own mind: believing that he could thus best explain it 

 to his readers. As his views have been arrived at by his own careful study of the sub- 

 ject, he has not thought it necessary to be continually referring to other Physiologists, 

 with whose doctrines his own may have more or less of coincidence. He would here state, 

 once for all, that of the older writers on this branch of Physiology, he regards Unzer 

 and Prochaska (whose treatises have been lately republished by the Sydenham Society) as 

 having displayed the deepest insight into the truth ; their doctrines requiring little more 

 than the correction and extension which subsequent anatomical discoveries have afforded, 

 to form part of the present fabric of the science. And he considers it as no unimportant 

 confirmation of his own views that, although arrived at in complete ignorance of what Unzer 

 had long previously put forth, they have proved to be in harmony, on all essential points, 

 with those of so philosophic and penetrating a thinker. Of modern Neurologists, the fore- 

 most rank is justly to be assigned to Sir C. Bell, for his discovery of the anatomical distinct- 

 ness of the sensory and motor nerves, and for the inferences to which this discovery led. 

 And the author is quite of opinion that the rediscovery of the Reflex Function of the Spinal 

 Cord by Dr. M. Hall (which he believes to have been entirely original on that gentleman's 

 part) has constituted an era of no less importance ; although his limitation of the doctrine of 

 reflex action to the Spinal ganglia has subsequently tended, in the Author's opinion, rather 

 to retard than to promote the progress of Neurology. In extending this view to the Sen- 

 sory Ganglia, and in showing that they minister to a class of " reflex" actions peculiarly 

 their own, the Author believes that he may claim to have made the first definite attempt to 

 free it from this limitation ; and for its further extension to the Cerebrum, Science is in- 

 debted to Dr. Laycock, to whose Essay on the Reflex Action of the Brain, the Author has 

 already expressed his obligations. To these he would add the names of Dr. Holland and 

 Dr. Todd, as those of writers from whom he has derived many valuable suggestions, which 

 have not, he trusts, been without fruit in his own mind. It is a circumstance not devoid of 



' " Gulstonian Lectures on the Nervous System," in "Medical Times," 1849, No. 495. 



