(311) 
line it is shown that isolation of one dermatoma leads to equivalent 
bands. | 
This schema is pretty well in accordance with the facts, as may 
be seen from the following instance. 
In experimenting on a dog the 16 and 17 root to the left, 
the 14%, 15%, 18% and 19% root to the right, are cut through, 
Dee. 17 1901. The 16% and 17 root to the right remain intact. 
Along the mid-dorsal line there are found therefore two analgetic 
areas on the right, one on the left. From the animal’s back these are 
directly counterdrawn on transparent paper (see fig. 16 A). 
According to the requisites of the schema the sensible area on the 
right ought to stand towards the analgetic areas in reason as 5:3 
or 1: 0.6. The relation found in reality is: Analgetic areas on the 
right 25 and 2.7, on the left 2.6 c.M.; sensible area 4.6 c.M., 
consequently as 1: 0.58. 
Towards the mid-ventral line other conditions prevail. 
As has been made evident in a previous communication, the 
central areas towards that region are placed so far between, that 
mutual overlapping is impossible.. Here too the ranging of the 
dermatomata may be found, if the supposition be taken for granted, 
that the marginal area, however much it may have been enlarged 
at the cost of the central area, can never become so large that it 
overlaps the neighbouring central area '). 
Starting e.g. from the relations found on dog I (fig. 17 B) towards the 
mid-ventral line, the sensible area in that region has a breadth of 
3.2 c.M., the opposite (somewhat prefixed?) insensible area of 6.5 cM., 
the upper insensible area of 6.2 cM. and the lower one of 4.7 cM. only. 
Suppesing that a relation may be stated between the insensible 
and sensible area at the mid-ventral line as 6.5: 3.2, or that the 
sensible area being =1, the insensible area is = 2, then fig. 18 
represents the calculation. 
Calling in this case the central area k, and the marginal area, 
inasmuch as it overlaps another marginal area y, inasmuch as it 
overlaps a central area a, it will be made clear by a simple 
reasoning that the two isolated dermatomata must cover an area 
equivalent to 24+-y (for the marginal area does not extend beyond 
the neighbouring central area). It is clear too that the analgetic 
1) Afterwards, when treating about the middle of the dermatomata, it will perhaps 
become clear why these suppositions concerning mid-dorsal and mid-ventral line 
ought to be taken for granted. 
