r62 THE SALAMANDER 



inferior 2 posterior ; and (iv) a branch to the ventral body muscles and 



the skin of the neck. 



With the exception of the first branch this does not seem to give 

 a very accurate picture of the branching of the nerve, which is much 

 more variable than Fiirbringer's figure and description suggest. 



(i) A^. thorackus superior 2 comprises two or three fine branches 

 which turn dorsalwards and supply, {a) the M. thoraci-scapularis 

 (t.s.), and {Jy) the M. cucullaris minor (c') near its insertion. 



(ii) Almost immediately after giving off this branch the nerve 

 turns a little anteriorly and sends two fairly stout cutaneous branches 

 which spread over the skin at the base of the neck region and over the 

 procoracoid and the anterior edge of the scapula. After separating 

 from the nerve they pass directly laterally and emerge at the angle be- 

 tween the procoracoid and the M. cucullaris. It is very difficult to 

 be sure whether or not they supply any motor-fibres to the MM. pro- 

 coraco-humeralis and cucullaris, but it is very probable that they do 

 not. These nerves supply a region corresponding with that supplied 

 by the supra-clavicular nerves of man, and as this name is hardly 

 appropriate in an animal not possessing a clavicle, they are therefore 

 called here cutaneous cervical^ or NN. cutanei cervkales (n.cut.cer.). 



(iii) After a very fine twig to the M. pectori-scapularis has been 

 given off the nerve very soon divides, more or less equally into its 

 three terminal branches, as follows : — 



(iv) R. communkans ad N. spinalis J, which has already been 

 described — see above. 



(v) A R. muscularis to the MM. rectus cervicis superior and pro- 

 fundus. The branch to the former muscle passes mesial to the 

 profundus muscle. 



(vi) A R. communicans ad N. spinalis 3 (r. com. 2-3) which arises 

 somewhat variously. It may consist of a single bundle, separating 

 from the main nerve near the point where it turns anteriorly, 

 close to the N. thoracicus superior 2, to join the third spinal nerve 

 near the point where the N. supracoracoideus emerges. It bifur- 

 cates at this point, one branch entering the N. supracoracoideus 

 direct, while the other crosses this nerve and enters the main trunk 

 of N. spinalis 3. Quite frequently, however, an auxiliary bundle 

 arises separately from the second spinal nerve, and passes obliquely 

 to join the N. supracoracoideus just before it passes through the For. 

 supracoracoideum in the pectoral girdle. 



The series of anastomoses, Spino-occipital — N. spinalis i ; N. 

 spinalis i — N. spinalis 2; and N. spinalis 2 — N. spinalis 3, is fre- 

 quently spoken of as the cervical plexus. 



