486 THE BRAIN. 



u amnesic aphasia." The patient cannot say what he wishes, because 

 he cannot recollect the word he wants. For the same reason he is also 

 incapable of writing it. But if the word which he requires be spoken 

 to him, he can repeat it immediately, though in a few seconds it has 

 again escaped him. This disease is an aggravated form of that condi- 

 tion to which many otherwise healthy persons are occasionally liable ; 

 namely, that of forgetting for a time a particular word at the moment 

 they wish to use it. In some cases of aphasia the loss of power is so 

 complete that the patient can utter only two or three words, which he 

 employs indiscriminately whenever he speaks at all. 



In the second variety of the affection, the patient knows the word he 

 wants, but cannot succeed in articulating it. He can, therefore, express 

 himself by writing perfectly well, but cannot read aloud even what he 

 has written himself. This is called " ataxic aphasia," because it de- 

 pends not upon an imperfection of memory, but upon a want of power 

 to effect the necessary nervous combinations. 



There is no question that the power of language resides somewhere 

 in the cerebral hemispheres, and many observations have tended to 

 locate it more especially in the convolutions surrounding the lower end 

 of the fissure of Sylvius, and in those of the Island of Eeil. Broca 

 fixes it more especially in the third frontal convolution, surrounding the 

 anterior, ascending branch of the fissure of Sylvius, while others have 

 referred it to the frontal lobe in general. The evidence for this locali- 

 zation of the faculty of language consists in the number of instances in 

 which aphasia more or less complete has been found, on post-mortem 

 examination, to be accompanied by lesions of the brain substance con- 

 fined to the points indicated. It is often accompanied by hemiplegia 

 of the opposite side of the body, but may sometimes exist independently 

 of any paralytic affection. 



According to Broca, it is, as a rule, the third cerebral convolution of 

 the left hemisphere alone which is concerned as a nervous centre in the 

 production of articulate language. This conclusion is derived from the 

 fact, which is generally conceded by pathologists, that in the large 

 majority of cases in which aphasia is accompanied by hemiplegia, the 

 hemiplegia is on the right side of the body, the lesion accordingly occu- 

 pying the left side of the brain. But as aphasia is generally due to 

 occlusion of the middle cerebral artery by an embolism, and as embolism 

 is more likely to occur on the left side than on the right, owing to the 

 different angle at which the vascular branches are given off, this fact may 

 not indicate the exclusive, or even preponderating influence of the left 

 side of the brain in the function of articulate language. Notwithstand- 

 ing some remarkable cases which would tend to show a special location 

 of this function upon the left side, such as that of chronic left hemiplegia 

 without aphasia, followed in the same individual by a sudden attack of 

 right hemiplegia with aphasia, 1 yet instances of an opposite kind are 



Bateman on Aphasia. London, 1870, p. 152. 



