(313) 
For if the marginal area’s are supposed to be larger — even until 
their overlapping the whole of the nearest central area —, still in 
isolating the 4tt dermatoma (see fig. 14) the analgetic areas (always 
dependent on two dermatomata) remain twice as large as the sensible 
central area, which they encompass. In other words: the central 
areas necessarily must always overlap one another. 
The third thesis which follows immediately is: 
34, The ranks of dermatomata are not filled so thickly, that 
each central area overlaps one half of the next. The case is repre- 
sented by fig. 15. 
Fig. 15. The ranks of the dermatomata towards the mid-dorsal line, if the central 
areas overlap one another halfway. In isolating the 4th dermatoma the analgetic 
area becomes equivalent to 4 of the sensible area. 
== Central areas. —--— Marginal areas. 
Truly, this being the case, after taking away one dermatoma, 
the uninjured central areas of the neighbouring ones would under- 
take sensation, which would be in accordance with the first fact. 
But the isolation of one dermatoma is only possible between analgetic 
bands half as broad as the sensible area (or even narrower, if the 
marginal areas exert any influence). 
Consequently each central area must possess a part, not overlapped 
by one neighbouring central area, but by fwo marginal areas of 
neighbouring dermatomata. 
If both pre-supposed experimental facts may be taken for granted, 
it would follow thence: 
4th, The central areas overlap one another each for one third, 
the remaining third, situated in the midst is overlapped by two 
marginal areas, 
For if, as in fig. 16, that part of the central area, overlapped 
by a neighbouring central area, is called y, and the part, of the 
central area overlapped by marginal areas x, then the central area, 
isolated as sensible area is «© + 2y. 
