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formerly determined root-field was no more hyperreflectory. This 
strip extended along the posterior boundary when I had cut the 
posterior radicularia, and along the anterior boundary when I had 
cut the anterior radicularia. 
In this way I had determined Lumbalis 1 with the cat of Fig. 7. 
Thereupon I cut the three posterior radicularia of this root. The 
hyperreflectory field had then shrunk from behind and extended now 
only over that part that is indicated in the figure by transversal 
dashes. 
1 have repeated this experiment with many dermatomes with the 
same result. If now, after the determination of a dermatome accord- 
ing to the stryehnine-method, I cut all fila radicularia but one, 
I could still obtain a sensible field covering about */, of the width 
of the original one. Just like the dermatomes the fields of the fila 
radicularia consequently cover each other mutually rather for a great part. 
If this is indeed correct and it seems to me to be very likely, it 
might open new points of view with regard to the arrangement 
established by Winkier and van RIJNBERK of the theoretical derma- 
tome in a nucleus field and a border zone. The nucleus field would 
then be that part of the dermatome where the radicularia mutually 
cover each other. 
The borderzone would then be the exterior edge where no covering 
of adjoining radicularia-fields takes place. 
It is likewise the borderzone, that was found most vulnerable by 
these investigators, which might be expected, if we admit that the 
borderzone is only formed by the most exterior radicularia, whilst 
