( 404 ) 



along the back. The \eiitml pieces are pressed on one another against 

 the sternum about the second rib. 



2ncl The ventral and dorsal pieces, pressed on one another, are 

 becoming gradually smaller and of less importance. It is only the 

 lateral pieces that are pushing on the extremity. 



In isolating the 1I>'' dermatoma (fig. I. 5) it has been shown that 

 the cranial jmrtion of the lateral part of it is stretched on the extremity. 

 At the same time its cranio-caudal axis is displaced. On the trunk 

 it was parallel to that of the ventral and dorsal pieces, here it 

 forms with them an acute resp. an obtuse angle. On the boundaries 

 between lateral and ventral part the dermatoma suffers a rather 

 deep indentation. 



In isolating the 10''' dermatoma (tig. II, 4) the stretching of the 

 cranial lateral portion is even more important, and the difference in 

 direction between the cranio-caudal axis of the lateral and that of 

 the ventral part has become so great, that here they are already 

 placed nearly perpendicularly to one another. 



The indentation here has become so deep, that apparently the 

 dermatoma has been split into two parts, the lateral piece being 

 torn from the ventral. Apparently only, for most probal)ly this result 

 of isolating the 10^^^ dermatoma is but a caricature. For in cases 

 where it is isolated together with the 9^^ (fig. V) or with the 6'^ 

 (fig. Yl 3) dermatoma, a narrow sensible zone unites the ventral 

 to the lateral area. 



Thus much however is sure: only tlie lateral part, not the ventral 

 part of the 10''' dermatoma passes on the extremity. 



Something similar happens for the dorsal pieces of the 10^'' and 

 of the 11^'' dermatoma. Here we find likewise an indentation, 

 though a less profound one, on the boundary of the lateral pieces 

 towards their cranial side. 



Yet there exists a great difference between the ventral and the 

 dorsal indentations. Because of the fan-shaped extension of the 

 displaced cranio-caudal axes of the lateral pieces, there must of 

 necessity remain towards the ventral side, between two axes, close 

 to the indentation, on the caudal portion of the extremity, a skin-area 

 that owes its sensibility to one dermatoma oidy. Close to the dorsal 

 indentation such is not the case. 



This is shown if the 11''' or 10^'' I'oot are cut through. There are 

 always produced two insensible areas, a small ventral area, such as 

 we found much larger on the trunk and an area on the caudal 

 portion of the extremity, where the lateral pieces of the 12^'' and 

 lOfi' dermatoma no longer overlap the 11^'', or those of the 11'*^ 



