E0LLESI0N ON THE BRAIN OF THE OBANG UTANG. 217 



iii. The absence of the second pli de passage is well seen on both 

 sides of the brain ; and the wave-like anterior edge of the 

 occipital lobes constituting the " operculum" is especially- 

 well marked on the right side. 

 Fig. 4. Brain of orang dissected, so as to show the lateral ventricle of 

 the right side, its three cornua and the hippocampus minor, 19. 

 It shows, besides, the different relations which the bourrelet of the 

 corpus callosum holds in the ape and in man : — 

 i. To the commencement of the third cornu, 18. 

 ii. To the internal perpendicular fissure, 16. 

 iii. To the hemispheres which it connects. 



1. Inferior frontal convolution. — "Etage frontal inferieur" ofGratiolet. 



2. Middle frontal. — "Etage frontal moyen." 



3. Superior frontal. — "Etage frontal superieur." 



4. Eirst ascending parietal. — " Premier pli ascendant." 



5. Second ascending parietal. — "Deuxieme pli ascendant." 



5'. Lobule of second ascending parietel. — " Lobule du deuxieme pli 



ascendant." 

 6 and 6'. Convolution running below, and parallel with the lower lip of 



the Sylvian fissure. — " Pli courbe." 

 7. Lower lip of Sylvian fissure. — " Pli marginal inferieur." 



10. Superior occipital convolution. — " Etage superieur du lobe occi- 

 pital." 



11. Middle occipital convolution. — " Etage moyen." 



12. Inferior occipital convolution. — " Etage inferieur." 



13. Corpus striatum. 



14. Posterior edge of corpus callosum. 



15. Eornix. 



16. Internal occipital fissure. 



17. " Scissure des hippocampes." 



1 8. Third cornu of lateral ventricle. 



19. Hippocampus minor; 



a. Anterior lobes. 



b. Middle temporo -sphenoidal lobe. 



c. Cerebellum. 



d. Occipital lobes. 



e. Medulla oblongata. 



f. Fissure of Sylvius. 



g. Pons. 



a. Convolution connecting the superior occipital convolution (10), to the 

 lobule of the 2nd ascending parietal &'. 



VOL. T. N. H. E. 2 F 



