CUAP. XXIX.] SPEECH AND THOUGHT. 621 



1. Diminished Excitability of the Auditory Word- 

 Centres. 



According to the degree in which the proper vitality 

 of the Auditory Word- Centres is affected, we may find 

 evidence that they cease to respond, first to ' volitional * 

 incitations, secondly to those coming to them hy way of 

 ' association,' and lastly to ' sensory ' impressions coming 

 from without. 



A good example of an ordinary case of Amnesia is 

 thus referred to by Trousseau in his " Lectures," in which 

 the ' volitional ' and ' associational ' recall of names was 

 impossible, though their ' sensory ' recall was preserved. 



" The patient does not speak, because he does not remember the 

 words which express ideas. You recollect the experiment which I 

 often repeated at Marcou's bed-side.* I placed his nightcap on his 

 bed, and asked him what it was. But after looking at it atten- 

 tively he could not say what it was called, and exclaimed, ' And 

 yet I know well what it is, but I cannot recollect.' "When told 

 that it was a nightcap, he replied, ' Oh ! yes, it is a nightcap.' 

 The same scene was repeated when various other objects were 

 shown to him. Some things, however, he named well, such as his 

 pipe. He was, as you know, a navvy ; and, therefore, worked 

 chiefly with the shovel and the pickaxe, so that these are objects 

 the names of which a navvy should not forget. But Marcou could 

 never tell us what tools he worked with, and after he had been 

 vainly trying to remember, when I told him it was with the shovel 

 and the pickaxe, * Oh ! yes, it is,' he would reply, and two minutes 

 afterwards he was as incapable of naming them as before." 



In the slighter forms of Amnesia the efforts at Kecol- 

 lection of a person who is " at a loss for a word "tend 

 also to call the Visual Word- Centres into an incipient or 



* The earlier condition of this man will hereafter be referred to 

 (p. 627), as at that time he manifested a distinct tendency to 

 ' echo ' words. 



