'54 



THE HUMAN SPECIES 



As the cerebrum increases in volume its surface begins to 

 assume folds, and the convolutions and fissures develop, these 

 being the standard of the position of the different orders in the 

 organic scale. 



The anatomist Hu- 

 schke, 1 speaking of the 

 importance of the convo- 

 lutions, says : " The more 

 complex the convolutions, 

 the more impressions and 

 branches they exhibit, the 

 deeper thefissures between 

 them, and the more sym- 

 metrical their structure, 

 the higher is the organ- 

 ism ". 



Theconvolutions reach 

 their highest development 

 in man, the insula cerebri, 

 for instance, only in man 

 attaining its four to five 

 fanlike branches. Now 

 it is of special interest 

 to ascertain in how far 

 the human brain (in spite 

 of a certain general cor- 

 respondence) differs from 

 the brain of those apes 

 most closely resembling 

 him. (See Plate iii.) An 

 exhaustive study, " Ueber 

 die typische Anordnung 

 der Furchen und Win- 

 dungen auf den Gehirn- 



hemispharen des Men- 

 schen und der Affen " ( " On 



FIG. 80. Nervous system of man. a, cere 

 brum ; b, cerebellum ; c, spinal cord ; on 

 either side of the same the sympathetic 

 ganglia. 



the typical distribution of the 



fissures and convolutions in the cerebral hemispheres of man 

 and the apes "), has been published by Pausch, and a second 



1 Huschke, Schddel, Him und Seele. Jena, 1854. 



