

The Basal Ganglia 105 



and throughout all classes of vertebrates, in- 

 cluding human beings; in fact, it constitutes 

 a kind of matter which has passed through long 

 ages of evolutionary changes, and has thus 

 assumed a form which when brought into play 

 becomes manifest in instinctive action. In the 

 higher classes of animals by appropriate treat- 

 ment, the structural arrangement and functions 

 of this part of the brain may be modified ; one 

 of the main objects of education is to effect this 

 purpose, and thus to improve the innate disposi- 

 tion or character of an individual. 



Almost every part of the walls of a lamprey's 

 fore-brain contains nerve fibres proceeding 

 from the olfactory lobes, and terminating in 

 primordial cortical cells, "by means of which 

 smell impressions pass indirectly through the 

 intermediation of another part of the hemi- 

 spheres " l ; thus showing a disposition towards 

 the differentiation on the part of certain of the 

 nervous elements of the hemispheres of the 

 brain in this, the lowest genera of true verte- 

 brates. In the ascending classes of animals 



1 Prof. Elliot Smith's Arris and Gale Lectures, reported in the 

 Lancet for January isth, 1910, p. 150. 



