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of the sulcus primarius tlie secondary lobules have been all destroyed, 

 and moreover from the lobus antei'ior even nearly the whole of the 

 radius medullaris. 



Accordingly we find for the lateral portion the same result as 

 for the median right half, i. e. that besides the greater part of the 

 lobus sijnplex, also a part of the lobus anterior has been destroyed. 



Originally we iii tended not only to find out hv means of the 

 sections, which portion of the cerebellum had been taken away by 

 Van RiJiNBERK, but likewise to demonstrate the microscopical changes 

 subsequent to the lesion. To this purpose we used the Weigert-Pal 

 method of staining. 



Unfortunately however, on microscopical examination, it was shown 

 that nearly" the whole mass of medulla had taken a granular aspect. 

 It was therefoi'e impossible to study the nerve-fibres, and any secon- 

 dary degeneration they might have suffered with the method of 

 Weigert-Pal, and for MARCHi-preparation the cerebellum proved unfit. 



Nevertheless one fact remains worthy of attention: in the part of 

 fig. VI, designated sub «, accordingly in that portion, separated by the 

 operation from the central medullaris originating in it, the radius 

 medullaris not only is stained black as distinctly as the other secondary 

 medullary rays, but moreover the Purkinje corpuscles and their 

 ramifications in this portion (stained by means of osmium acid), 

 do not present any changes worth mentioning, if compared to those 

 of the other, un-injured lobules. 



SUMMARY. 



A. According to Bolk's theory, the Lobus simplex is the seat of 

 an unsymmetrical centrum of coordination for the muscle-groups of 

 the neck. 



B. Operating on a dog, van Rijnbeek extirpated a part of the 

 cerebellum, about the Lobus simplex. In consequence of this opera- 

 tion, its secondary symptoms having passed away, the animal retained 

 a continual movement of the head as if it meant to say "no". 



C. Investigations at the laboratory in Amsterdam taught us that 

 the operation had destroyed : 



a. in the left median part, next to the median line, a small 

 superficial portion of the last gyrus of the Lobus anterior; 



b. between the median line and the paramedian line to the 

 right ; 



1st. nearly the whole of the last gyrus of the Lobus anterior; 

 2"^i. nothing from the Lobus simplex at its surface ; 



