( 305 ) 



laris lias been ciit ofT almost up to tlie i)lac'e of bifurcation of the 

 pi'iuiary radius. 



The lesiou itself peuetrates inward, a little into the medullary 

 nucleus, moreo\ei' the secondary and tertiary lobules, lying adjacent 

 to the sulcus priiuarius, are for the greater part, if not wholly, 

 destroyed. 



This becomes still more evident from the tig. V and VI, where 

 all that belongs to the convolution (>', has been destroyed. The 

 lesion itself penetrates still deeper, in tig. V it has nearly cleft the 

 radius medullaris, in fig. VI it has done so entireh^ 



We may therefore conclude : that in the median portion, more 

 especially in its rigid half, the p)Osterior lobule of the lobiis ayiterior 

 has been seriously injured, that even nearly the whole of it has been 

 removed. 



I stated already, that from the anterior portion of the lobus 

 posterior, i. e. the lobus simplex, nothing has been destroyed on the 

 surface, as the place where it bends inward sub a, remains visible 

 on all sections in fig. Ill, IV, V and VI. Deeper however, the case 

 becomes difterent. 



In ng. IV we observe that all secondary lobules, lying adjacent 

 to the sulcus primarius in the depth, have been completely destroyed. 

 In fig. V there has been removed still more, nearly the whole of 

 the secondary radius medullaris having been extirpated. In fig. VI 

 it is entirely destroyed, whilst moreover the primary radius medul- 

 laris of the small lobe c^ has been completely divided from the 

 medullary nucleus. 



We may thence conclude that, though the lobus simplex in its 

 median portion is not injured at its surface, on the contrary in the 

 depth, in the portion adjacent to the sidcus primarius, it has been 

 entirely destroyed, even those convolutions that remained intact on 

 the surface in the paramedian area {figure III sub a) having been 

 divided from the primary radius medullaris. 



Considering next the lateral portion, fig. VIII enables us to survey 

 the situation and the division of the folia under ordinary circum- 

 stances. The sulcus primarius (s. p.) still subsists, as the convolution 

 sub 4 fig. II, the last convolution of the lobus anterior, is removed 

 considerably sideways. All that lies before this sulcus, accor- 

 dingly to the left in fig VIII, belongs to the lobus anterior. Con- 

 sequently the small lobe sub 1 is the last folium of this lobe. All 

 that lies behind the sulcus primarius, thus belongs again to the 

 lobus simplex sub 2. 



Considering next fig. VII, it is shown thereby that on both sides 



21 



Proceedings Royal Acad. Amsterdam. Vol. VIII. 



