416 PHYSIOLOGY CHAP. 



consciousness or not ? The same question arose with reference to 

 the spinal cord (pp. 335 et seq.), and the student must refer to the 

 arguments there discussed. 



Flourens, in the first edition of his work on the Nervous System 

 (1823), stated that the cerebral hemispheres are the exclusive seat 

 of all sensation and volition, and consequently of all intellectual 

 activity. But it was pointed out by Cuvier, in his report to 

 the Acade'mie des Sciences (1842) on Flourens' work, that this 

 conclusion was not a logical deduction from experimental observa- 

 tions, from which on the other hand it was logical to conclude that 

 the cerebral hemispheres are the only centres through which 

 sensations can reach consciousness. Flourens accordingly, in the 

 2nd edition of his work (1842) modified his conclusions by. stating 

 that "I'animal qui a perdu ses lobes cerebraux n'a pas perdu sa 

 sensibilite ; il la conserve tout entiere. II n'a perdu que la 

 perception de ses sensations ; il n'a perdu que 1'intelligence." 



Johannes Miiller also argued from the experiments of Flourens, 

 Magendie, and Desmoulins, that the medulla oblongata was " der 

 Sitz des Empfindungsvermogens." He believed that the bulbo- 

 spinal animal has lost its memory and power of reflection and 

 attention, but that it continues to feel, and to react to sensations 

 by complex movements which are not mere reflex phenomena. 



Longet pointed out in his classical treatise that the bulb and 

 pons contain sensitive and insensitive parts as well as motor and 

 non-motor parts, and affirmed that the pons, besides being the 

 conductor for afferent sensory impressions and voluntary motor 

 impulses, must be a centre of special activity, owing to the large 

 amount of grey matter contained in it. According to Longet it is 

 especially in the pons that the centre of general sensibility and 

 the locomotor centre are seated. In claiming for the pons a sort 

 of sensorium commune Longet relied particularly on the fact that 

 rabbits, mice, and dogs, in which the whole of the brain except the 

 bulbo-pontine region has been destroyed, respond by repeated 

 cries expressive of pain, accompanied by convulsive movements,, 

 when a limb, tail, or ear is strongly excited. Owing to their varied 

 and persistent character Longet does not believe that these cries 

 can be simple, unconscious, reflex acts, but regards them as the 

 expression of pain really felt by the animal. 



Vulpian came to the same conclusion after repeating and con- 

 firming Longet's experiments. He added an observation that 

 seems to us important. If the whole of the brain, including 

 the pons, is destroyed in a young rabbit, it responds to each 

 stimulus by a brief, single, invariably uniform cry, which has no 

 significance or expression, but resembles the sounds made by 

 certain toys when squeezed at one particular spot. If, on the 

 other hand, the pons is also left intact, the animal responds to 

 stimulation by one or more prolonged cries which undoubtedly 



