20 Pranklin P. Mall. 



one attempts to separate brains into complex and foetal types he 

 does not realize the difficulties in doing it and I think the deviation 

 in a second attempt might be fully ± 10 per cent of the first determi- 

 nation. If the personal equation were added the deviation might be 

 much greater. 



The above tables are given to show how unreliable the statements 

 regarding the complexity of the gyri and sulci may be, and that 

 with the present crude methods the statement that the negro brain 

 approaches the foetal or the simian brain more than does the white 

 is entirely unwarranted. 



In this connection the recent statement of Elliott Smith regarding 

 racial peculiarities in the brain should also be considered. It relates 

 to the so-called Affenspalte. Smith^"^ says: "It often happens 

 (especially in the brains of lowly human races, such as negroes 

 and aboriginal Australians, and in the anthropoid apes) that the 

 sulcus occipitalis anterior, together with the sulcus occipitalis inferior 

 form a large arc (parallel to the sulcus lunatus) forming the anterior 

 limit of a great tongue of cortex, the tip of which often reaches the 

 upper end of the sulcus temporalis superior in those cases in which 

 there is no temporo-parietalis. The presence of this great arcuate 

 sulcus explains much of the misleading literature relating to the 

 search for an 'Affenspalte' in the human brain." 



The "Affenspalte" first described by Kiidinger has caused anato- 

 mists much trouble and its presence in all human brains was often 

 questioned. A few years ago Elliott Smith-^ demonstrated that 

 a marked occipital operculum which is identical with that of the 

 gorilla's brain is often present in the brain of the Egyptian fellah. 

 However, the operculum is not always well marked, but it is bounding 

 sulcus, which Smith calls the sulcus lunatus, can be seen in every 

 human brain. Smith's studies are directed rather towards the 

 homology of the Affenspalte which he has fully demonstrated with 

 the aid of the structure of the cortex, i. e., the extent of the stripe 

 of Gennari.22 At first he showed that the Affenspalte (sulcus lunatus) 



="'B. Smith. Jour. Anat. and Physiol., Vol. 41, 1907. 

 "Smith. Anat. Anz., 24, 1904, p. 74. 

 =^Smith. Anat. Anz., XXIV, p. 437. 



