THE DEVELOPMENT OF THE BRAIN 155 



olfactory apparatus itself, the atrophy in the arboreal 

 stock is extremely well marked, and smell impressions 

 play but little part in the more important r61es in the 

 lives of the Primates. In Man the sense of smell, and 



FIG. 62. DIAGRAM OF A TYPICAL MAMMALIAN FORM OF BRAIN 

 IN WHICH THE NEOPALLIUM HAS EXPANDED AT THE EXPENSE 

 OF THE ARCHEPALLIUM (FINELY DOTTED AREA), AND 

 OCCUPIES THE GREATER PART OF THE LATERAL PORTION OF 

 THE CEREBRAL HEMISPHERE. 



FiG.f63. THE FINISHED MAMMALIAN BRAIN. 

 Diagram showing the general expansion of the cerebral hemi- 

 sphere (neopallium), upon which fissures are beginning to 

 appear. The archepallium is represented only by an in- 

 considerable (finely dotted) margin of cortex. 



what may be termed the smell-life, are very minor 

 factors in the whole physiological economy (see Figs. 62 

 and 63). 



Nevertheless, this early sense which first gained a 

 pallial representation, and became the first subject of 

 memories and experiences, still shows in Man a subtle 



