HAP. ii.] THE BRAIN. 1057 



Let us consider first the movements of speech in man, the 

 evidence touching the connection of which with an area on the 

 third frontal convolution appears so very clear. Speech is 

 eminently a ' skilled ' movement ; it involves the most delicate 

 coordination of several muscular contractions, and we may certainly 

 say of it that it has to be ' learnt.' The whole chain of co- 

 ordinated events by which the utterance of a sentence, a word, or 

 any vocal sign is accomplished consists of many links, the breaking 

 of any of which will lead to failure of one kind or another in the 

 act. Something may go wrong in the glossal or other muscles, in 

 the nerve endings in those muscles, or in the fibres of the nerves, 

 hypoglossal and others, between the central nervous system and 

 the muscles, or something may go wrong in that part of the 

 central nervous system, the bulb to wit, in which a certain amount 

 of coordination is carried out just previous to the issue of the 

 motor impulses. Damage done to any of these parts of the 

 mechanism may lead to dumbness or to imperfect speech. In the 

 latter case the imperfections have a certain character ; if we are 

 at all able to gather the wish of the speaker, we recognize that he 

 is attempting to utter the right words in the right sequence, but 

 that his efforts are frustrated by imperfect coordination or imperfect 

 muscular action ; his speech is ' thick ', the syllables are blurred 

 and the like. Disease of the bulb at times leads to imperfect 

 speech of this kind in which the imperfection may be recognized 

 as due to the lack of proper coordination of motor impulses. The 

 affection of speech, known as ' aphasia,' which is caused by 

 lesions of the cortex is of a different character, and the forms 

 of imperfect speech caused by bulbar disease have justly been 

 distinguished from true aphasia by the 'use of other terms. Cases 

 of complete aphasia in which all power of speech is lost, do little 

 more than help us to ascertain the topographical position in the 

 cortex of the ' speech ' area, but cases of partial aphasia are 

 especially instructive. Without attempting to go into the details 

 of the subject and into the many considerations which 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 substitute 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 psychical 

 processes more complex than those involved in the mere voli- 

 tional effort to say the word. An instructive 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 



672 



