( 397 ) 



To the right is found an interrupted sensible area, encompassed between 

 two insensible zones. 



a. The cranial insensible zone is bounded cranially by a line, leaving the 

 mid-dorsal line at the 6^'^ vertebra (see fig. II, 1), continuing in the direction 

 of the acromion, and then, avoiding this and the caput humeri, taking a 

 bend towards the mid-ventral line. It approaches this latter until a distance 

 of IV2 cm. (see fig. II, 2), continues parallel to it for 4 cm. in a caudal 

 direction, leaves it again at the third rib, borders cranially the sensible 

 ventral triangle of the 10 •' dermatoma, thus becoming itself the caudal 

 boundary line of the cranial insensible zone. As such it recedes to a distance 

 of 8 cm. from the mid-ventral line, circumscribing next caudally the sensible 

 triangle, it returns as the cranial boundary line of the caudal (interrupted) 

 insensible zone to the mid-ventral line, approaching this to a distance of 1 

 cm., taking again a caudal bend and accompanying it for 3 cm. Next 

 starting perpendicularly from the mid-ventral line, it continues along the 

 plica axillaris posterior towards the upper-arm, in a cranial direction and 

 turns with a sharp curve to the epicondylus medialis. Passing between 

 olecranon and epicondylus, it circumscribes the first (see fig. II, 2 and 4), 

 turns on the dorsal side of the arm towards the epicondylus lateralis, and 



Fiff. II. lO^h root. 



Dog IV. The 10 '^ root isolated to the right by cutting through 



the 6"', 7th, 8i'\ 9tii, li^'i, l^tii and 13^1' roots, 



cut through to the left, 



