CORTICAL CELL LA:\I1NAT10N OF PAPIO HAMADRYAS. 617 



outlines of the blocks were carefully plotted in drawings of 

 the l)rain. From eacli block sections 10 fi thick were taken 

 and stained Avith polyclirouie metliylene-blue. As no satis- 

 factory sections of the insula were obtained, the cortex in 

 this part of the brain has not been described. 



In the investigation of these sections the admirable woi-ks 

 of Bi-odmaun^ on Cercopithecus and Campbell- on the chim- 

 panzee and orang-outang were of great assistance to me, and as 

 far as possible my observations have been brought into line 

 with theirs. 



My observations differ from Brodmann's in that I have not 

 described so many types of cortex. This is due to a difference 

 in judgment and not to antagonism with regard to matters of 

 fact. Since in the area covered by each main type local 

 differ'euces are present, and since tlie main types in manv 

 cases shade into one another, it would be possible to describe 

 man}" more varieties of structure than are mentioned by 

 Brodmann. One must arbiti'arily fix a limit to the number 

 of tyftes distinguished, and I have fixed mine at a smaller 

 number than he. 



For illustrating the structures described in the text, outline 

 drawings of the cells were made under the Abbe Zeichen- 

 npparat, and these were afterwards blacked in with ink so 

 that the cells are represented in silhouette. 



It was thought advisable to prefix a short description of 

 the fissures to the principal part of the paper. 



Fissures in the Bijain of Papio hamadeyas. 



The Sylvian fissure {FS.) and sulcus centralis (c.) call for 

 no special comment. Anterior to the latter the following- 

 fissures are present : 



' K. Brodmann. "■ Beitrage znr histoloo-ischen Lokalisation der 

 Grossheikrinde Dritte Mitheihmg ; Die Riudenfelder der Niederen 

 Aifen." ' Journ. fiir i^sycli. u. NeuroL," Bd. iv, Heft 5/6, 1905. 



- A. W. Campbell. ' Histological Studies in the Localisation of 

 Cerebral Function,' Cambridge. 1905. 



