Chap. XXIV.] PRINCIPAL PARTS OF THE BRAIN. 



489 



sciousness of the individual to remain unaltered, even in 

 the ahsence of sensorial stimuli from one half of the hody. 



It is most important to recollect that the results above 

 described follow lesions of the posterior third of the 

 Cerebral Peduncle, just before its fibres come into rela- 

 tion with the Thalamus. The effects are very different 

 when lesions exist above or outside the great ' basal gan- 

 glia ' (see p. 493), even though these lesions may involve 

 extensive destruction of one Hemisphere. 



It is only in the sphere of the three higher senses, 



Fig. 171.— Transverse section through the Cerebrum of i\ Dog opposite the middle 

 of the Thalami, showing the portion of the ' internal capsule,' the section of which 

 produces Hemi-ansestliesia. (Charcot after Buret.) 0, 0, Thalami connected by 

 Middle or Soft Commissure ; P, P, posterior third of Cerebral Peduncle (' internal 

 capsule '). On the right side these fibres are represented as cut across at x ; S, intra- 

 ventricular, and L, extra-ventricular Corpus Striatum. 



however, that a blending of the subjective accompaniments 

 of impressions from the two sides of the body occurs, so 

 as to produce single Perceptions. An object which is 

 smelt is perceived as one ; a body which is seen is recog- 

 nized as single ; and similarly a sound, though stimulat- 

 ing both auditory organs, is heard as one sound. And 

 although we can localize gustatory impressions to one or 

 other side of the mouth, when our attention is directed to 

 the subject, we are not accustomed to do so, and there would 



