CHAPTER IV. 



THE FUNCTIONS OF THE SENSORIUM COMMUNE. 



SECTION I. WHAT IS THE SENSORIUM COMMUNE, WHAT ITS 



FUNCTIONS, AND WHAT ITS SEAT? 



The external impressions which are made on the sensorial 

 nerves are very quickly transmitted along the whole length of 

 the nerves, as far as their origin j and having arrived there, they 

 are reflected by a certain law, and pass on to certain and 

 corresponding motor nerves, through which, being again very 

 quickly transmitted to muscles, they excite certain and definite 

 motions. This part, in which, as in a centre, the sensorial 

 nerves, as well as the motor nerves, meet and communicate, 

 and in which the impressions made on the sensorial nerves are 

 reflected on the motor nerves, is designated by a term, now 

 adopted by most physiologists, the sensorium commune. 



Distinguished men have not agreed as to the seat of the 

 sensorium commune. Bontekoe, Lancisi, De La Peyronie 

 have placed the sensorium commune in the corpus callosum ; 

 Willis derived the perception of sensation and the source of 

 movements from the corpora striata ; Des Cartes attributed the 

 function of the sensorium commune to the pineal gland ; 

 Vieussens to the centrum ovale j Boerhaave decided that aggre- 

 gate of points to be the sensorium commune, in which all the 

 sensory nerves terminate, and from which all the motor nerves 

 arise, and accordingly placed it in the medulla fornicata, sur- 

 rounding the cavity of the ventricles.^ In a later work, ' De 

 Morbis Nervorum,^ Boerhaave places the sensorium commune 

 in the boundary line of the medullary and cortical substance, 

 which opinion Tissot thought to be extremely probable, regarding 

 it as confirmed by the observations of Wepfer.^ Mayer seems 

 to place the sensorium commune in the medulla oblongata;^ 

 that distinguished man, J. D. Metzger, appears to be also of 



' Praelect. Acad, in proprias Inst, cum Notis Halleri, torn, iv, § 574. 



'■' Abhandl. iiber Neiven und Nervenkrankh. Iten Bandes, 2ter Tlieil, § 236. 



3 Abhandlung vom Gehirn, Ruckenmark, &c., Seite 34 — 38. 



