1134 
8 and 11 on one side. From the measures of the widths of these 
dermatomes and the areflectory field between these he calculated 
the measure of these root-fields and of those lying between them. 
In this way he arrived at the conclusion, that on the dorsal median- 
line this covering amounts to °/,,, on the ventral median-line to 
*/,,. Kurssens concluded likewise 
from this calculation that on the 
dorsal medianline strips of covering 
of 3 fields alternate with strips of 
2 root-fields, and that on the ventral 
median line this covering is stronger, 
so that there alternately strips of 
4and 3 root-fields cover one another. 
With these calculations we must 
not lose sight of the fact that they 
are the result of the mensuration 
of two tields. To indicate the cover- 
ing of adjoining dermatomes expe- 
rimentally I applied the strychnine- 
method of Dusser DE BARENNE. 
Consequently I proceeded in the 
following manner for my experiments 
on cats. The spinal cord was first 
laid bare, the dural was split fora 
certain length. After the spinal 
moisture had been removed with a 
piece of cotton wool, the spot where 
a hind-root entered was moistened 
with a piece of cotton wool drenched 
in a coloured solution of sulphate 
strychnine (1°/,) and squeezed out. 
If now the cat has awaked from 
its narcosis the hyperretlectory 
region of the skin can easily be 
ascertained by touching it softly 
with a pencil, and marked out with 
water-colour. Then the hind-root 
issuing from the poisoned region of 
the spinal cord, is cut through, 
afterwards the spinal cord near the 
adjoining hindroot is in the same 
way locally poisoned. We find then 
