1 68 THE SALAMANDER 



and at the same time describes a half-spiral turn so as to lie on the 

 flexor side of the humerus, between the M. coracobrachialis longus 

 and the M. humero-antibrachialis inferior. The two rami run 

 parallel with one another separated by the A. brachialis. They are 

 usually approximately equal in size, but the R. super, may be larger 

 than the R. prof. Normally also this latter ramus passes to the elbow 

 without branching, but one or two fine muscular twigs may be given 

 from it. 



At the point where these two nerves separate, or immediately 

 afterwards, one or two branches are given off from the R. super- 

 ficialis to the MM. coraco-brachialis longus and brevis; they are 

 the NN. coraco-brachiales (n. cor.br.). 



Then follow one or two cutaneous branches which pass out to the 

 skin between the M. coraco-brachialis longus and the M. humero- 

 antibrachialis. One branch longer than the rest travels along the 

 arm to the elbow, and then takes a half-spiral turn to the lateral 

 aspect of the fore-arm, crossing the origin of the M. flexor primor- 

 dialis communis in doing so. These branches represent the N. cuta- 

 neus hrachii inferior lateralis of Fiirbringer, but are here called A^. cut. 

 hrachii inf. medialis^ to agree with the blood-vessels. The R. super- 

 ficialis also supplies the M. humero-antibrachialis inferior with one 

 or two fine branches. 



At the elbow-joint it bifurcates. One branch remains superficial 

 and passes along the skin on the radial side of the fore-arm and first 

 digit. At the base of the finger it sends a branch mesialwards which 

 supplies the short flexor muscles related thereto, and finally joins the 

 N. interosseus. This branch of the R. superficialis would appear to 

 represent Fiirbringer's A^. cutaneus hrachii inferior medialis^ here 

 called N. cut. hrachii inf. lateralis. 



The other branch turns mesially, and passing under the M. flexor 

 antibr. et carpi radialis, gives a small branch to this muscle, and 

 finally joins the R. profundus. As already indicated this latter nerve 

 passes right down the arm to this point without giving off any 

 important branch. The nerves arising from this plexus will be 

 termed N. ulnaris and N. interosseus.^ 



N. ulnaris (n.ul.). 



R. superficialis ulnaris McMurrich (1903). 



This branch passes distally and obliquely across the fore-arm, 

 deep to the MM. flexor primordialis communis and flex, antibr. ulna- 



' Ribbing applies these names to the proximal portions (R. superficialis and R. pro- 

 fundus) also, but they seem hardly applicable to this region of the limb. 



