CEREBRAL CONVOLUTIONS — " SALLY." 63 



coudition of the human fissures, which is closely similar to 

 " Sally /^ the left hemisphere in each case being compared. 

 Again, the left side of the brain figured by BischofF (and repro- 

 duced in fig. 17) is like the right hemisphere of "Sally" (fig. 11) 

 so far as the " AfFenspalte " is concerned. The same oblique 

 direction is to be noted. On the right side of the same brain, 

 too (fig. 18), we have a very similar arrangement, but the 

 intraparietal fissure (;?*.), before entering the ^' Affenspalte " 

 (transverse occipital) sends inwards a short branch {z.) behind 

 the " arcus parieto-occipitalis." 



In a human brain in the Oxford Museum, to which I 

 have already referred, we have on the left side (fig. 16) a con- 

 dition of the transverse occipital which seems to support 

 Cunningham^s view. The intra-parietal appears to curve round 

 the "arcus," and nearly reaches the mesial fissure, where a 

 rather irregular furrow passes backwards from it ; this small 

 portion {x.) resembles a part of the " mediad fork" of the ramus 

 occipitalis of "Sally's" left side (on fig. 10). The "transversus 

 occipitalis " in this human brain would then be, according to 

 Cunningham, the upper (mediad) fork of the intra-parietal. 

 But the general direction of the " occipitalis transversus " is so 

 very similar to that on the right side of "Sally's" brain that it 

 is possible to explain this irregular furrow (x.) by supposing it 

 to be an independent adventitious furrow on the occipital lobe, 

 such as occurs in " Sally's " left hemisphere, which there has 

 gained a connection with one of the forks of the ramus 

 occipitalis. 



It is still, in fact, a debateable point as to whether there is 

 in the adult human brain a representative or homologue of the 

 " Affenspalte " of the ape. There are, indeed, three chief views 

 on the subject: (1) Ecker regards his "sulcus occipitalis 

 transversus " as such ; (3) Eberstaller (to quote from Cunning- 

 ham) draws a distinction between the upper and lower limbs of 

 the sulcus occipitalis transversus of Ecker. In it we can dis- 

 tinguish a medial and a lateral segment by the point of union 

 with the sagittal portion of the intraparietal furrow. The 

 former {x. in my figure) bounds the arcus parieto-occipitalis 



