1. Strychnine-segmentzone Th. VI left. 
After the cat had been made a spinal-cord-animal by a transverse 
section at Thor. II a piece of thoracal spinal cord is laid bare in the 
usual way, and the place of introduction left of Th. VIII moistened 
with strychnine. Moreover the dorsal roots of Th. VI, VII, IX and 
X are cut intradurally. Soon it is possible to ascertain a strongly 
hyperreflectory zone of the skin, wich gradually widens and a few 
minutes after the poisoning reaches its maximal extent. It is then 
still very easy to distinguish an inner-zone and two outer-zones. 
a. Description of the inner-zone. 
The e ntral-zone is almost string-shaped. The cranial and caudal 
limits first run parallel to each other, perpendicular to the axis of 
the body. On the centre of the lateral surface the cranial limit makes 
however a curve convex to cranial. A similar phenomenon is scarcely 
indicated in the caudal limit. *) 
The bordering lines continue to run parallel and perpendicular 
as far as the ventral surface. Here they converge slightly, so that 
the central zone that was at the d. d. 30 mm. wide, measures in 
the v. d. only 23 mm. The central zone however goes beyond the 
v. d. and finishes, sharply limited, about 4 mm. overlapping the 
crossed side. Here the hyperreflexion is somewhat slighter than in 
the rest of the zone. (A dorsal crossed overlap could not be fixed 
on account of the median skin-section). 
The zone hitherto described is surrounded by a ventrally strongly 
widening outer-zone which being itself less reflectory than the inner- 
zone, contrasted however strongly with theladjoining areflectory resp. 
normally reflectory zone. The outer-limits of the outer-zone are of 
course at the same time the boundary of the totai strychnine-segment- 
zone, which I am going to describe now. 
\ 
b. Description of the total strychnine-segmentzone (vuter-limits of 
the outer-zone). 
Searcely to be recognized at the d. d., running closely along the 
1) A similar fact is often indicated by W. and R. Compare e.g. their fig. 27 
of their Illrd communication. Here the 13th and 16th spinal roots were isolated. 
The caudal zone of the ventral part seems to be considerably shrunk, whilst 
cranially the lateral outward curve of the central area breaks through the anaesthetic 
zone. To explain these phenomena they admitled a widenirg of the ceutral area 
in the lateral part, whilst at the same time it is supposed that here a relative 
minimum of sensibility is found. As now a similar removal of the border existed 
cranially and not caudially Jikewise with my cat, this fact may perhaps also be 
regarded as a peculiarity of the 16th root-field. 
