738 FUNCTIONS or THE CEREBRUM [CH. L. 



motor area. No cortical centre is purely motor or purely sensory, 

 and this one, though usually called motor, has its sensory complement 

 probably from the eyeballs and eyelids (5th nerve). The newly 

 developed grey matter between it and the Eolandic region is an area 

 probably concerned in the association of eye movements with 

 equilibration and the maintenance of the erect position ; we know, 

 moreover, that the fibres from the frontal lobe to the cerebellum (the 

 centre for equilibration) are very numerous (see fig. 437, A, p. 699). 



The Auditory Area is in the posterior part of the upper 

 temporal convolution. This has been definitely proved by clinical 

 observation in man, and supported by experiments on animals, though 

 it is by no means easy to ascertain whether or not an animal is deaf. 

 It is doubtless surrounded, as are the visuo-sensory area and other 

 sense areas, by a psychic or association sphere, and is connected to 

 surrounding parts, and especially to the visual area, by annectent gyri. 

 A good deal of the auditory area is situated in the depth of the 

 Sylvian fissure where the gyri tranversales which cross it are found. 



Taste and Smell are closely connected ; their cerebral area is the 

 uncinate and hippocampal gyrus, and the tip of the temporal lobe. 

 These parts are relatively more important in animals who rely upon 

 smell and the oral sense for their guidance. This part of the cortex 

 is of simpler structure than the rest, and on account of its early 

 appearance in the animal scale is known as the archipallium (see 

 p. 698). 



The Silent Areas. On referring once more to the maps of 

 the brain, it will be seen that there are many blanks; one of 

 these is in the anterior part of the frontal region. Extirpation 

 or stimulation of this part of the brain in animals produces but 

 little result. The large size of this portion of the brain is very 

 distinctive of the human brain, and it has therefore been sup- 

 posed that here is the seat of the higher intellectual faculties. 

 Such a question is obviously very difficult to answer by experi- 

 ments on animals. Both experimental physiology and pathology 

 have localised the sensory areas (and sensations are the materials 

 for intellect) behind the Eolandic fissure, but this does not 

 necessarily mean that the frontal convolutions have nothing to 

 do with intellectual functions. The celebrated American crowbar 

 accident is generally quoted as a proof to the contrary; owing 

 to the premature explosion of a charge of dynamite in one of the 

 American mines a crowbar was sent through the frontal region of 

 the foreman's head, removing the anterior part of his brain. He is 

 usually stated to have subsequently returned to his work, without 

 any noteworthy symptoms. Eecent examination of the records of 

 the case has shown that this is not correct ; when he returned to 

 work he was practically useless, having lost just those higher 



