x THE FOBE-BBAIN 545 



Bouillaud observed that a certain number of acts, e.g. writing, 

 drawing, painting, fencing, were carried out with the right hand. 

 They are associated and co-ordinated movements which imply 

 activity of a particular cerebral organ, a given centre for sensation, 

 motion, and special memory, which is undoubtedly seated in the 

 left hemisphere. Why, he asked, should we not be left-brained for 

 the movements of articulation also ? 



This acute conjecture was confirmed by Paul Broca, who 

 showed more definitely than Gall, Spurzheim, Bouillaud, and Dax 

 that the true site of the special organ of verbal articulation lies in 

 the left hemisphere of the human brain. 



In 1861 Broca presented a first memoir to the Anthropological 

 Society of Paris, in which he stated, on the basis of certain of his 

 clinical cases, that lesions of the lower segment of the third frontal 

 convolution of the left hemisphere (the so-called pars opercularis or 

 Broca's convolution) involved loss of the faculty of speech aphemia 

 or aphasia. This he showed to be the seat of the cerebral organ of 

 verbal articulation, or more precisely of the memory of a certain 

 kind of co-ordinated movements necessary for the articulation of 

 speech. In fact, in cases of lesions of this convolution the memory 

 of words is not lost, nor are the nerves and muscles that come into 

 play in phonation and spoken language paralysed ; it is only the 

 memory of verbal articulation that is affected. 



Broca was fully aware of the capital importance of his discovery 

 as the foundation-stone of a new theory of cerebral localisation in 

 opposition to the doctrine of Flourens. " We now know," he says, 

 " that all the parts of the brain properly so-called have not the 

 same functions, that all the convolutions represent, not a single 

 organ, but many organs or groups of organs, and that there are 

 large distinct regions of the brain which correspond to the large 

 regions of the mind." According to Broca, the new theory must be 

 built up upon normal anatomy and pathology, because a physio- 

 logical system that is not based on definite anatomical facts cannot 

 withstand criticism. 



Another French anatomist and anthropologist, P. Gratiolet 

 (1861), had a yet clearer conception of the modern theory of 

 cerebral localisation, though his view was obscured by doubts and 

 contradictions, as appears from the following extract : 



" It is legitimate to assume that there are as many distinct 

 regions in the cerebral hemispheres as there are different organs 

 of sensation at the periphery of the body. Thus we have the 

 brain of the eye, the ear, and so on ; and in each of these brains it 

 would be easy to locate a memory and an imagination. But where 

 are we to locate general intelligence ? If there were several organs, 

 several brains, of what use would they be to one another ? How, 

 for instance, could the brain of the ear assist the brain of the eye ? 

 The anatomical conditions of these associations and of this synergy 



VOL. Ill 2 N 



