176 THE SALAMANDER 



At the point where it joins the sixteenth nerve a branch arises 

 from the posterior edge of N. spinalis 17 which suppHes the muscles 

 attaching the tail to the pelvic girdle. This branch is A^. pudendus 

 (n.pd.). A little distal to this nerve one or two cutaneous branches 

 are given off to the skin covering the ventro-posterior region of the 

 thigh — they are the A^. cutaneusfemoris posterior (n.c.fm.p.). 



N. pudendus (n.pd.). Appleton (1928). 



Leaves the seventeenth spinal nerve, as above described, just 

 proximal to its junction with the sixteenth, and passes posteriorly 

 mesio-dorsally to the M. caudali-femoralis. Almost immediately 

 after its origin it gives one or two fine cutaneous branches to the 

 postero-dorsal side of the leg. They pass dorsal to the M. caud. fem. 

 and form part of the N. cut. fem. post. At about the same level 

 a branch from the eighteenth spinal nerve enters the N. pudendus. 

 The latter ner\^e then divides into four terminal branches, of which 

 one enters the M. caudali-femoralis (cd.fm.), another supplies the 

 M. caudali-pubo-ischio-tibialis (c.p.i.t.), and from this a cutaneous 

 branch passes between the two muscles above-named to the skin 

 at the side of the cloaca. Another branch passes to the cloacal gland 

 in the male — or to the equivalent tissue in the female — between the 

 MM. caud. pub. isch. tib. and ischio-caudalis, giving a small twig 

 to supply the latter muscle in passing (is.cd.). This nerve would 

 appear to be the N. perinealis (n.pe.) of Appleton. It is larger and 

 better seen in the male. 



A^. sciaticus (n.s.). 



Sciatic nerve ...... Humphry (1871). 



N. ischiadicus ...... Hoffmann (1873-8). 



N. tibialis communis ...... Osawa (1902). 



N. tibialis ........ Appleton (1928). 



The sciatic nerve passes down the thigh in company with the 

 sciatic artery, and, a little proximal to the knee, gives off the follow- 

 ing branches. First, one or more cutaneous branches which leave 

 the thigh between the MM. pub. isch. tib. and isch. flex, and supply 

 the skin covering the ventral (flexor) surface of the leg distal to 

 the knee; they represent the ISf. cutaneus surae medialis (n.c.s.m.). 

 One of these nerves — when there is more than one present — passes 

 either close to, or through the 'pars plantaris' of the M. ischio- 

 flexorius and supplies it with a small twig (is. P.). The other branch, 

 which leaves the sciatic nerve near these cutaneous branches, is a 

 muscular one. It divides to supply the M. femoro-fibularis (fm.f.), 



