A Study of Cerebral Anthropology 39 



(1890) thinks that the presence of less than five convolutions in 

 the anterior zone indicates arrest of development. This is refuted 

 by Cherie-Ligniere (1911). Spitzka (1902&) expresses much 

 the same idea as Giacomini when he says, " The insula is on the 

 whole somewhat of an index of the degree of development of the 

 cerebral surface, particularly of those parts which are in juxta- 

 position to it." 



The question of the relative importance of the central and 

 longitudinal furrows is answered by HoU in favor of the sulcus 

 longitudinalis, because of the fact that the longitudinal fissure is 

 embryologically and phylogenetically the primary one. Retzius 

 by a statistical study found that the central sulcus was the prin- 

 cipal fissure of the insula because of its fuller development and 

 more constant appearance (97 per cent.). I think in the light of 

 Sergi's work we may disregard the contention of both Retzius and 

 Holl. The suggestion of Woldschmidt, Spitzka and others that 

 the insula by its development may be an index of the elite mind 

 has too little foundation to be considered more than a theory. 



LOBUS TEMPORALIS. LATERAL SURFACE 



The lateral surface of the temporal lobe is made up of three 

 gyri and two fissures, gyrus temporalis superior, gyrus temporalis 

 medius, gyrus temporalis inferior, sulcus temporalis superior, and 

 sulcus temporalis medius. The superior temporal gyrus has been 

 thought in certain classes (criminals) to be incompletely devel- 

 oped, but after a study of these observations I am convinced that 

 they are valueless, for they have no unit of comparison and no 

 extensive study of the normal brain has been made. 



Generally speaking, the fissures of this region are simple and 

 their variations have not been shown to have a morphological 

 significance. The connections established by the sulcus temporalis 

 superior have been studied by recent observers, principally Duck- 

 worth (1907), who finds that anastomosis with the sulcus parie- 

 talis is an infrequent one, with the praelunate in about the same 

 proportion (12 per cent.). Retzius (1896) mentions an occa- 

 sional communication established with the sulcus temporalis 

 medius through a small fissure integer which he terms the sulcus 



383 



