( 335 ) 



lying next to these first ones either eranially or caudally, were 

 destroyed, the originally observed dark zone was afterwards con- 

 stantly found uniformly broadened, either the cranial boundary being 

 removed cranialward or the caudal boundary being removed caudal- 

 ward, according to the case. By these means a series of indications 

 was furnished, tending to prove that the skin-areas supplied with 

 pigmento-motor fibres by each connecting branch or by the ganglia 

 of the sympathetic column, are themselves likewise uninterrupted, 

 zone-shaped tields. Still further data on this subject were obtained 

 in the following manner. 



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Fig. 3. 



Solea impar. Isolation of tour spinal nerves between four nerves cut through 

 cranially and four other ones cut through caudally of them. 



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Fig. 4. 

 Another solea, on which a similar operation had been made. 



If a few, viz. four connecting branches weve destroyed, and again 

 also four other ones cranially or caudally from these, leaving intact 

 e.g. four branches between the two, two dark zones appeared of about 

 equal breadth, enclosing between them a somewhat broader zone of 

 lighter colouring, corresponding to the uninjured branches. (Fig. 3 

 and 4). By means of similar experiments the supposition that the 

 ganglia of the sympathetic column innervate zone-shaped skin-areas 

 becomes nearly a certainty. Some results too were obtained as to 

 the extent of these areas. Comparative calculations, as shown before, 

 starting from measurements of the darker and lighter zones, made 

 with as much accuracy as was possible, have shown that the cranial- 



