A Study of Cerebral AntJiropology 41 



complex. Retzius has figured seventeen of the more common 

 patterns found in the study of one hundred brains. He divides 

 tlie fissures into two complexes designating the upper one as the 

 sulcus praccunci and the lower as the sulcus subparietalis. As 

 indicated, each of these complexes may be made up of several 

 segments which may arrange themselves in various positions and 

 form various connections. A part of this group, probably the sub- 

 parietalis, Duckworth calls sulcus compensatorius. Tenchini 

 (1892) considers that a simple arrangement of sulci in the prae- 

 cuneus indicates incomplete development, since in the early life of 

 the embryo the surface is smooth and then becomes grooved by a 

 simple sulcus, and since this condition is a characteristic of most 

 apes including the anthropoidae. Anastomosis of the sulci of this 

 region and the sulcus cinguli are noted by Retzius in 34 per cent., 

 bv Sernoff in 37 per cent., by Giacomini in 26 per cent., and by 

 \\'einberg in 52 per cent. 



Lobus Occipitalis (C uncus.) 



Beginning with Gratiolet, there has been so much written on the 

 fissures of this region that it is impracticable to attempt to trace 

 the subject or present anything like an accurate or comprehensive 

 account of the various views that have been held by investigators. 

 Reference to the work of Cunningham (1892) will furnish a 

 verv complete account of the work preceding his and will also 

 give an explanation of the variations he encountered explained 

 on an embryological basis. We may for discussion consider the 

 division which he used and build on it the later investigations. 

 Cunningham considered two principal sulci, fissura parieto-occip- 

 italis and fissura calcarina, each represented by segments separate 

 or confluent, or recognizable by deep annectants. 



Fissura Parieto-occipitalis: This fissure name must represent 

 instead of a fissure a complex. On the dorso-mesial aspect of the 

 hemisphere is a deep notch which is the incisura parieto-occip- 

 italis, which in many cases is surrounded by a ring-like gyrus 

 (Smith, 1904). Below this incisura on the mesial surface is a 

 deep fissure, which contains on its walls and floor, or represents a 

 number of sulci, that should be called the fossa parieto- 



385 



