186 C. W. M. POYNTER AND J. J. KEEGAN 
prominent parietal development is an indication of inferiority 
or superiority. On the other hand, it might be possible that the 
depressed frontal lobe and prominent parietal area should be 
interpreted as race characters being in some way correlated 
with head shape. 
The work of Smith (04) has done more than that of perhaps 
any other observer to place brain investigations on a sound 
scientific foundation, and, while his work is based on a small 
amount of absolute evidence of the primary relation of sulci 
and cortical functional areas, the excellent results of its appli- 
cation merit a tentative acceptance of the principle. His work 
was confined largely to the region of the area striata which 
definitely localized the cortex. The cause of the change in fis- 
sures between ape and man is attributed mainly to the growth 
of the parietal association center in the human brain. 
The difficulty of applying the principle to other regions of the 
brain is due to the obscurity of morphological or functional 
areas of the cortex, and this is particularly true of the association 
centers. Sundry influences are brought to bear on the sulci 
in their development which cause the disappearance of the 
original definite relationship to the cortical areas. Smith says: 
‘‘But when we consider how plastic a material the cerebral cor- 
tex is, and how complex are the factors that exert an influence 
on it during its expansion, the wonder is, not that the coincidence 
of a sulcus and the boundary line between two areas should not 
be mathematically exact in every case, but that it should ever 
occur: ”’ 
If we have correctly interpreted the results of observations 
on the fissure and convolution variations, we may conclude that 
the various lists of Simian or inferior characters which have been 
published from time to time are at present of doubtful value and 
that conclusions based on them are unreliable. Dr. Mall (09) 
has summed up the matter for the Negro as follows: ‘“‘ With the 
present crude methods, the statement that the Negro brain 
approaches the fetal or Simian brain nearer than does the White 
is entirely unwarranted.”’ 
