ex Journal of Comparative Neurology. 



8. In brain I : a. — There is an enormous increase of the grey mat- 

 ter at the expense of the white. This peculiarity is especially notice- 

 able in the parietal lobes and in the anterior portion of the central 

 convolution. This is accompanied by an enormous development of 

 the ventricles, b. — The fissura calcarini fuses with the sulcus am- 

 monis. c. — The grey matter of the olives is so subdivided as to re- 

 semble numerous accessory olives. 



9. In brain II : a. — The fissura parieto-occipitalis is continued into 

 the sulcus occipiio-transversus . b. — There is a pronounced diminution 

 of the cuneus. 



10. In brain III the structure of the parieto-occipital fissure is 

 abnormal. 



C. H. T. 



Notes on the Frontal Lobes and the Isle of Reil of Anthropoid Apes. 1 



The following is a partial list of the subjects used in these inves- 

 tigations : 



Chimpanzee No. I. A young female with twenty milk teeth. 

 Length of cerebrum, 9.3 cm.; height, 4.6 cm.; breadth, 8.2 cm. 



Chimpanzee No. II. Brain of an adult female. Length of cer- 

 ebrum, 9.5 cm.; breadth, 8.2 cm. 



Chimpansee No. III. Brain of male. Length of left cerebral 

 hemisphere, 8.7 cm.; length of right cerebral hemisphere, 8.2 cm. 

 breadth, 8.7 cm. 



Chimpanzee No. IV. Length of cerebrum, 10 cm.; breadth, 

 9.0 cm. 



Brain of male gorilla. Length of hemisphere, 10 cm.; breadth, 

 9.0 cm. 



Brain of female orang. Length of right hemisphere, 8.6 cm.; 

 length of left hemisphere, 9.0 cm.; breadth, 8.6 cm. 



It will be noticed that these brains, especially those of the gorilla 

 and chimpanzee IV, approach in size the brains of microcephalic 

 idiots. It will be noticed also that one hemishere is often much longer 

 than the other. This is the case in the brains of microcephalic idiots. 



1. Sulcus proicentralis . In its most highly developed from this 

 sulcus is divided into a superior, an inferior and a median portion. In 

 chimpanzee II right, gorilla left and orang VI left, 2 all three of these 



^elix Marchand. Die morphologie des Stirnappens und der Insel der 

 Anthropomorpheu. Jena, 1893, 108 pp., 3 plates. Monograph. 



2 The roman numerals refer to the number of the specimen. The words 

 "left," "right," "both," refer to the side of the hemisphere. 



