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relation the respective situations of the sulcus primarius, the adjacent 

 gyri and the lesion. 



To this purpose I have designated in fig. Ill sub « and sub /? the 

 two convolutions l.ying next to the sulcus primarius on the surface. 



Looking ad «, which represents the first convolution of the lobus 

 posterior on the surface, we find that it consists of a secondary 

 radius medullaris ending in a bifurcation on the surface. Such not 

 being the case with the adjacent secondary medullary rays of Cj, 

 this convolution may be likewise easily recognized in the next figures. 



The same thing may be said for /?, which represents the most 

 posterior convolution of the lobus anterior on the surface. For we 

 observe that the medullar^^ ray of the lobule N°. 4 divides itself 

 into two portions : the posterior one /? being the prolongation of the 

 thick primary radius medullaris and therefore easily recognised. 



In photograph III, representing, as may be remembered, a section 

 taken from the place where to the left the lesion begins, we see 

 clearly that not the entire convolution ^ has been destroyed, but 

 mainly that portion of it that is lying next to the sulcus primarius. 

 The convolution of the lobus posterior, lying behind it, has not 

 been injured at all, its surface, on the spot where this convolution 

 bends inward towards the sulcus primarius being distinctly visible. 



This spot («) being of importance in order to determine whether 

 the lobus posterior, in case the lobus simplex, has been injured, 

 I have designated it likewise on the other photographs (IV, V and VI). 

 Anticipating for a moment on the subsequent description of these 

 photographs, I may state that they show clearly that this spot on 

 the surface, where the convolution bends inward, presents nowhere 

 any trace of lesion. 



The direct conclusion to be derived from this fact is that the lobus 

 simplex has not been injured at its surface. 



As to the convolution ^ however matters stand differently. 



In fig. Ill already we may see that from 4, representing the pos- 

 terior folium of the lobus anterior, the posterior secondary convo- 

 lution /? in the upper part has been almost entirely destroyed. Only 

 a small ])iece of its most anterior portion remains. 



In the direction of the medullary nucleus the lesion extends only 

 over the upper third part of the sulcus primarius. 



The secondary radius medullaris is still distinctly visible at the 

 spot where it is united to the anterior convolution. 



Surveying the successive aspects of the lesion in the figures IV, 

 V and VI, we find that in IV a veiy small remnant of the convo- 

 lution sub ,j still subsists, whilst the secondary radius niedul- 



