The Evolatlon of Mind. 191 



derson,* and many others, have fixed definitely some func- 

 tional areas. t When neurologists can tell positively from a 

 l)atient's symptoms the location of a cerebral abscess, and 

 remove the same with a minimum of injury, what greater 

 evidence can we ask of the truth of some of their discov- 

 eries ? A large part of the brain unfortunately still remains 

 "a dark continent." Certain regions preside over sensa- 

 tion,! and certain others over motion. § No center of dis- 

 tinct consciousness has been fixed upon. If such a place 

 exists, the area would seem to be exceedingly small, if we 

 may be allowed to draw inferences from introspective obser- 

 vation. At any one moment the knowledge immediately 

 under attention is exceedingly minute, as compared with 

 the large amount stored away by retention. We can 

 only know a very few things at a time. If the area of 

 mental synthesis is as small in proportion to the total brain- 

 mass as the amount of knowledge we can at once be con- 

 scious of is to the total knowledge stored up for use, then 

 it is very small indeed. That consciousness is not all over 

 the brain at once is seen in the fact that we are not always 

 aware of everything we ever knew or now can know by in- 

 trospection. If that was the case, forgetting would be im- 

 ])()ssible in a brain free from lesions. Unconscious cerebra- 

 tion could not be possible. Experience daily indicates to 

 us that the brain is like a book. Consciousness looks into it 

 at various points, reading its contents, or else currents come 

 from such points to be translated into knowledge at some 

 center of synthesis. || All we know of evolution emphasizes 

 the fact of division of labor and the production of highei- 

 and higher centers of control over that below. Anatomy 

 exhibits an organic arrangement that physiology has thus 

 interpreted as far as it has gone. That a center of atten- 

 tion should exist where all sensational elements could be 

 put together, would seem to be but a fair inference. Ferrier 

 places such a center for man in the frontal lobes. If Atten- 

 tion is the uniting link of motor and sensory activity, and 

 takes part in every mental act however high or low it may 

 be. It is a form of will ; and the frontal lobes may only 

 be related to it in tlie production of mental work as the 



* Cal(kTvv( Kill's Kclations of Mind and ]".rain, p. 105. 



t Luy'M I'.raiii and its I'unclioiis, iij). .'J'.Ml. 



t Ferrifr's Functions, jij). I,s()-l,s«. § Ibid., pp. 22(>-2r>{J. 



II Morrison, Ivelations ot Mind and Matter, in .\incr. Xi'.t., A'ol. IJ), p. 8."3. 



11 Ferrier'.s Functions, pp. 31(J-:51s. 



