525 
Sacralis I. Anterior boundary This field has at the dorsal and at the ventral 
side again contact with the medianline. The anterior boundaryline issues from the 
dorsal medianline, proceeds over the trochanter, coinciding with the posterior 
boundary of the field of lumbalis IV. On the middle of the upperleg these 2 boun- 
darylines diverge. The anterior boundaryline proceeds then nearly parallel to 
the posterior rim of the leg to the malleolus lateralis, continues about 1}/, cm. 
past this malleolus, and turns then with an acute angle to the calcaneus. The 
inner-side of the leg is then reached over the calcaneus; then about the middle 
of the lower- and the upperleg is followed towards the posterior boundary of the 
field of lumbalis IV; this is then farther followed to the ventral medianline. 
Posterior boundary. This issues from the dorsal medianline near the root of 
the tail, proceeds over the tuber ossis Ischii with a curve under along the scrotum 
to the ventral medianline. which is reached at about the centre between the posterior 
rim of the symphysis and the opening of the anus. This root is now cut, and the 
spinal cord round the place of entrance of the succeeding root is moistened with 
a solution of strychnine. The hyperflectory field is determined. 
Sacralis Il. Anterior boundary. This issues from the dorsal medianline at 
about the centre of the former field, proceeds along the anterior side of the tuber 
ossis Ischii and reaches the ventral medianline behind the symphysis. 
Posterior boundary. This issues from the dorsal medianline in the beginning 
of the root of the tail, proceeds frontally round the opening of the anus and 
reaches the ventral medianline between the scrotum and the opening of the anus. 
The scrotum falls consequently inside this field, and the anus outside it. 
After these fields had been determined and marked on the skin 
of the cat with watercolour of different hues, these fields were trans- 
mitted to a plastermould, likewise in different colours. The skin is 
finally prepared in the way I described before, and tanned. 
At the section it is ascertained that the cat had 7 cervical, 13 
thoracal, and 7 lumbar vertebrae. As was presumed, the hindroots 
of lumbalis 4, 5, 6, 7 and sacralis 1 and 2 have been experimented on. 
Sketches were made of the arrangement of these fields on the skin 
of the hindleg, which I reproduce here in fig. 1 and 2 *). 
Fig. 1 represents the outerside of the hindleg, fig. 2 the innerside. 
A first glance teaches us already, that likewise on the hindleg the 
mutual overlap of the rootfields is considerable. 
The overlap at the toes is likewise rather important. The skin 
of the toes is innervated from 3 hindroots (5, 6 and 7). 
In the same way as I described above, | determined the derma- 
tomes of the left hindleg with 19 cats. 
From these determinations it appeared to me, that, also in this 
series of experiments, in which we had to do with cats showing 
no deviations, either of the vertebral column or at the plexus, the 
situation of the separate dermatomes is very inconstant. 
x The figures of this communication were drawn by Prof. WILLEM, to whom 
| pay my sincere thanks. 
