680 THE BKAIN. 



have to be had in mind in dealing with it, for there are different kinds of 

 aphasia, we may venture to say that the striking feature of partial aphasia 

 is the failure to say certain words or syllables, and the tendency to substi- 

 tute some wrong word or syllable for the right one. The words or syllables 

 which are uttered are rightly pronounced without defect of articulation ; 

 and in many cases, though the right word cannot be produced as a direct 

 effort of the will, it may be uttered under the influence of an emotion, or, 

 indeed, sometimes as the result of some physical processes more complex 

 than those involved in the mere volitional effort to say the word. An in- 

 structive case is recorded of a man suffering from slight aphasia, who, after 

 several failures to say the word "no" by itself, at last said, "I can't say 

 no, sir." 



From the phenomena of partial aphasia we may draw the deduction 

 that the cortical speech area does not carry out the whole of the coordina- 

 tion of the impulses involved in articulation. That coordination is exceed- 

 ingly complex, and we ought, perhaps, to recognize in it more than one de- 

 gree or kind of coordination. The failure of articulation in disease of the 

 bulb shows that a certain amount of coordination takes place there ; for the 

 affections of speech due to bulbar disease are not the same as those resulting 

 from the mere loss of this or that muscle or nerve. We must, of course, 

 admit that some, possibly a great deal, of coordination of a certain kind 

 takes place in the cortex, for the bulb cannot by itself be made to speak ; 

 exactly how much, the knowledge at present at our disposal leaves a matter 

 of great uncertainty; but it is sufficient for our present purpose to recog- 

 nize that whatever may be the nature of the events taking place in the 

 cortical area during the act of speech, those events make use of the machin- 

 ery already provided in the bulb. The word spoken does not start, so to 

 speak, ready made in the cortex ; it is not that a group of impulses start 

 from the cortex with their coordination fully achieved, and pass along cer- 

 tain nerve-fibres to certain muscles, making their way without change 

 through the tangle of the bulb, as if this were merely a bundle of lines 

 offering paths for, but exercising no influence over the impulses. We must 

 rather suppose that something takes place in the cortex of the third frontal 

 convolution, as the result of which efferent impulses pass along the appro- 

 priate fibres of the pyramidal tract to the bulb, and there start a series of 

 events leading to the issue of the coordinated impulses by which the word is 

 spoken. 



574. We have no reason whatever to think that the cortical area for 

 speech differs in its fundamental characters from other divisions of the motor 

 region, and are justified in carrying on to other areas the deduction we have 

 just drawn in connection with the speech area. With that end in view we 

 may now turn back to the experimental results obtained on the dog, and it 

 will make our discussion simpler if we take as an illustration some large area 

 such us the fore-limb area. 



We have seen that stimulation of this area produces what we may, to 

 start with, speak of simply as movements of the fore limb ; and guided by 

 the analogy of speech in man we may confidently conclude that when the 

 dog voluntarily moves the fore limb, the act is carried out by means of 

 events taking place in the fore-limb cortical area. The simplicity of the 

 electrical phenomena resulting from cortical stimulation, which we described 

 in 658, might at first sight lead us to conclude that the whole matter was 

 fairly simple ; and, indeed, some writers appear to entertain the conception 

 that in a voluntary movement such as that of the fore limb, all that takes 

 place is that the " will " stimulates certain cells in the cortical area, causing 

 the discharge of motor impulses along the pyramidal fibres connected with 



