544 PHYSIOLOGY CHAP. 



removal of the fore-brain. The only part of Gall's theory which 

 Flourens accepted unreservedly is that which modern research has 

 proved untenable. On the other hand, the great merit of Flourens 

 as the pioneer in cerebral physiology is indisputable. But he went 

 too far in his work of destruction ; it is one thing to show that 

 Gall's localisations are unfounded, and another to deny absolutely 

 all localisation of the intellectual functions in the brain. 



The most recent researches show plainly that there is a nucleus 

 of truth in phrenology. All portions of the cerebral hemispheres 

 have not the same functions ; distinct areas of the cerebral cortex 

 are concerned in different sense perceptions, in different ideas and 

 memories, and in the various voluntary impulses. But the new 

 theory of cerebral localisation is quite different from that proposed 

 by Gall, and has been gradually developed upon a scientific and 

 experimental basis. 



G. K. Bouillaud (1825), a follower of Gall, published a memoir 

 called " Clinical researches to demonstrate that loss of speech 

 corresponds with lesions of the anterior lobules of the brain, and 

 to confirm Gall's opinion on the seat of the organ of articulate 

 language." In this memoir, which is of great historical importance, 

 he describes the symptoms of aphasia as observed by himself in a 

 series of cases, in some of which he was able to make a post- 

 mortem examination, and to show that in all the lesion involved 

 the orbital part of the frontal lobe. He drew the following general 

 conclusion from his clinical and anatomo-pathological observa- 

 tions : The human brain has an important function in the 

 mechanism of a great number of movements ; it regulates such as 

 are under the control of the intelligence and the will. There are 

 many special organs in the brain, each of which governs special 

 movements. The organs for the movements of speech are directed 

 by a distinct and independent brain centre, which lies in the 

 anterior lobes. Loss of speech is due either to loss of memory for 

 words, or to loss of the muscular movements from which speech 

 results. Loss of speech does not imply loss of the movements of 

 the tongue as an organ of mastication and deglutition of food, nor 

 loss of taste which suggests that the tongue has three distinct con- 

 nections in the brain. Many nerves have their origin in the brain ; 

 those which innervate the muscles that co-operate in the produc- 

 tion of speech originate in, or at least necessarily communicate 

 with, the anterior lobes. 



A little later (1836) M. Dax, who was probably unaware of 

 Bouillaud's important memoir, communicated a series of clinical 

 cases which demonstrated that disorders of spoken language are 

 constantly associated with a lesion of the left cerebral hemisphere. 

 A new memoir pointing out the same constant coincidence was 

 presented to the Academic de Paris (1863) by D&xfils, when it 

 was badly received by Lelut, but defended by Bouillaud. 



