FUNCTIONS OF THE NERVOUS SYSTEM 313 



The area for vision is in the occipital lobe. If this area 

 be diseased, blindness of half of each retina on the same 

 side results. 



The auditory area is believed to lie in the upper 

 portion of the temporal lobe ; the areas for taste and 

 smell 011 the under and inner side of the same lobe. 

 Tactile sensations have been located in certain portions of 

 the under surface of the occipital lobe ; but most recent 

 experiments indicate that some, at least, of the sensory 

 fibers end in what has been called the motor area about 

 the fissure of Rolando. If that is established, it will 

 appear that the fibers connected with conscious sensation 

 are in close association with those which convey voluntary 

 motor impulses, and the Rolandic area will be more 

 properly termed the sensori-motor area. 



456. It will be noticed that in the map of the cortex a 

 large portion of the front of the brain remains, like great 

 tracts of land in Central Africa upon old geographical 

 maps, without names and internal divisions. They are 

 unexplored or, at least, unknown regions. No specific 

 functions can be positively assigned to those frontal con- 

 volutions of the cerebrum. An animal deprived of them 

 appears to suffer little inconvenience in consequence, and 

 in one well-known case where a man lost the frontal por- 

 tion of his brain in an explosion of dynamite, full recovery 

 followed without any permanent noteworthy consequences. 

 It is a favorite theory with some that the frontal convolu- 

 tions are the seat of the intellectual faculties, but the 

 theory has not been confirmed. 



