2fi7 



A layer of large external pyramidal cells is wanting. 



The stellate layer is most difficult to define, being represented by a few small triangular 

 cells only. 



The layer of internal pyramidal cells is a good one and constitutes a very important feature, 

 because in all likelihood it is to these cells that the large fibres just mentioned come. The cells 

 are of pyramidal form, with an elongated apical and three or four basal processes. They stain 

 sharply, stand erect and are present in considerable numbers ; amongst them a larger cell, which 

 might almost be called a "giant," is occasionally seen. 



The layer of fusiform cells presents no special features. 



The diagram shows better than words can describe the distribution of this area, also that of the 

 field above it, which I shall now consider. 



ECTOSYLVIAN AREA B. 



Ceil Lii 



Though there are no large elements, variations in size, shape and arrangement render possible the 

 division into the usual seven layers. 



It may be specially noticed that two layers of large pyramidal cells can be identified, but it 

 must be understood that the cells composing these layers are only large by comparison with other 

 autochthonous elements ; they are also much elongated, and there are no obvious differences between 

 the two layers individually. 



1'ilin- 



The fibre arrangement is uninteresting. Compared with the crucial and postcrucial areas, the 

 cortex is very poorly supplied with fibres and consequently looks pallid. A line of Baillarger is 

 not obvious ; the radiations are delicate ; there are no fibres of gross size and only a few of 

 medium calibre. 



EXTRARHINIC AREA. 



By this name I wish to distinguish an area of considerable extent indicated by small circles 

 in the diagrams, and covering the convolutions bounding the rhinic fissure externally. 

 Its structure does not throw any light on its function. 



F'dirf Arrangeni' nl. 



Tn sections stained from nerve fibres it appears pallid, and under a high power, although 

 there is an abundance of delicate fibres, not one of large or even medium size can be discovered. 

 Still the general arrangement follows the common type and has not the bizarre features of the 

 lobus pyriformia to which it lies so close. 



Cell Lamination. 



The arrangement is peculiar. All the cells are small or medium-sized, closely packed and 

 deeply stained. An uninteresting plexiform layer is followed by a good layer of small pyramidal 

 cells, and to this succeeds a deep and unbroken layer of pyramidal elements of medium size, 

 remarkable in being all more or less equal in diameter. Below this are some fusiform cells, and 

 in the white substance, scattered, clumpy and rather large stellate cells occur. 



LIMBIC AREA. 



Broca's "grande lobe limbique" included the hippocampal region as well as the gyrus fornicatus; 

 here the term limbic is used in the narrow sense ; it applies to the latter only, or, more correctly 

 speaking, to the gyri surrounding the corpus callosurn. 



342 



