1 84 THE SALAMANDER 



The appearance of the nerve during its course round the systemic 

 arch is very variable. Sometimes the fibres are so diffuse as to render 

 their dissection a virtual impossibility, but in cases where they are 

 amalgamated into a single, or at least into a double strand, a dissec- 

 tion of as much of the system as has been described above is by no 

 means impossible, though not easy. An idea of the difficulty may 

 be gauged from the measurements given by Hoffmann, who esti- 

 mated that the diameter of the strand is at most 0-05 mm. and is 

 frequently barely 0-035 mm. 



BIBLIOGRAPHY OF SECTION V 

 17, 19, 21, 22, 37,45,46,52,64,65, 66, 78,94, loi, 102, 113, 114, 115, 

 134, 135, 143, 144, 145, 146, 166, 187, 192, 199, 200, 201, 202, 208, 226, 

 235, 236, 250, 251, 262, 291, 292, 303, 304, 305, 306, 307, 308, 323, 333, 

 351, 374, 378, 404, 440, 44I5 489, 510, 516, 524, 525, 537, 543, 544, 545, 

 551, 57^y 579, 615, 619, 628, 629, 630, 631, 632, 634, 656, 658, 686, 698, 

 705, 725, 726, 727, 728, 731, 732, 738, 739, 759, 765, 794, 806, 807, 808, 

 809,810, 828. 



