749 
roots. In the middle of each dermatome meet each other the outer 
extremities of the two adjacent zones, which overlap each other here for 
ie Here conseqnently a threefold root-innervation takes place. In 
6 
the rest of the dermatome only two fields overlap each other. 
Let us now execute the same calculation for the v.d. Here, as 
will be remembered, no areflectory zone was found. We can however 
make an analogous, though somewhat more complicated calculation, 
taking into account the ascertained overlapping of the zones of 
Ths Vitleand: “Ph:- XT: 
If we express now the width of the whole dermatome in the v.d. 
in the above indicated symbols, the width of arootfield AL = Ab — 
—- BC’ — 6” = 22 — y. 
In the figure zone I represents consequently Th. VII and zone 
IV Th. XI. As Th. VT and Xi overlap each other 102m.my 1 
may suppose pg = 10. If now we call « the overlapping of two 
adjacent zones, and y the overlapping of two alternating zones, then 
we find for pq: 
pg= Cq—Cp = C' a—bB as Cp=bB 
Ab) as CYa=y (namely the overlapping 
of TF on II 
p¢ = y—(AB 
py = y Ary) 
ny AYE 2y = 10 mm. 
From this follows: 
2e—y =55') —a+2y = 10 
—_ Ardy = 20 dr —2y = 110 
Df =d oa. = 430 
= 25 x 40 
The overlapping of the immediately adjacent root-tields (x) is consequently 
1) [ take here for the calculation the width of Th. VILE and not that of Th. XI, 
because I suppose that this zone had somewhat shrunk, 
