746 
We may consequently admit, that both the dermatomes and the 
strychnine-segmentzones, when they shrink, do so in the same manner, 
and both have their weakest point in the ventral-crossed overlap- 
region and in the caudo-ventral part. 
) 
3.  Strychnine-segmentzone of Th. VIL right. 
As after the expiration of the above-mentioned determinations, the 
cat was still in a very good condition, | undertook the poisoning cf 
another root, now on the right side of the spinal cord. I selected 
for this operation Th. VII, where | performed the application of the 
strychnine as carefully as possible, and did not cut the adjoining 
roots. I had previously convinced myself that to the right there 
was not a vestige of byperreflexion in the skin. At the same time 
the first isolated root Th. VIII to the left was cut. 
After the poisoning soon a distinctly hyperreflectory zone appeared 
that could easily be limited. 
The zone had a great extent now, and no distinct contrasts between 
the inner- and the outer-zone could be discovered. 
Description of the total zone of Th. VIL right. 
The cranial limit leaves the d. d. at about the level of the pro- 
cessus spinosus of the 7‘ thoracal vertebra, and runs almost per- 
pendicularly to the axis of the body, with slight convexity in a caudal 
direction on the lateral surface. On the ventral surface it deviates 
again somewhat more in a cranial direction. The v. d. is reached 
10 mm. eranially from the cranial limit of the left VIII thoracal 
zone. (Comp. figure 3). 
The caudal limit leaves the d.d. about 30 mm. caudally from the 
former and runs almost parallel with it with a slight inclination to 
diverging in a caudal direction. [t reaches the v.d. together with the 
caudal limit of the left VIII thoracal zone. (Compare the description 
given above and fig. 3). In the v. d. the width of the whole zone 
amounts to 43 mm. A ventral-crossed overlap could not be ascer- 
tained. This fact and likewise the comparatively slight width of the 
zone can justify the supposition that we have here to do with a be- 
ginning of shrinking, at all events the zone as strychnine-segmentzone 
has not the maximum extent which it can have. (Th. VII on the 
left side was much wider). Although we have here not even to do 
with an optimum, I found, when exactly fixing the limits in the 
fixed bone-points under the skin, that the extent on the lateral surface 
answered already to above 3 ribs and the spaces between 3 ribs. 
