SENSORY DISTRIBUTION. 343 



supplied by the ilio-inguinal and geni to-crural nerves (1 /). The greater part of the 

 penis, the lower and hinder parts of the scrotum, and the perineum are supplied by 

 the pudic nerve (2, 3, 4 s), the scrotum also receiving branches from the inferior 

 pudendalof the small sciatic (2, 3 s). The branches to the penis are derived mainly 

 from the second sacral nerve, to a less extent from the third ; those to the scrotum 

 and fore part of the perineum chiefly from the third nerve, but in part also 

 from the second ; and those to the hinder part of the perineum from the fourth and 

 third sacral nerves (Paterson). 



3. In the upper limb. The shoulder, supplied superiorly by the descending 

 branches of the cervical plexus (3, 4 c), receives its cutaneous nerves inferiorly from 

 the circumflex nerve (5, 6 c). 



The arm internally is supplied by the intercosto-humeral nerve (2 d) and 

 the nerve of Wrisberg (1 d). The inner and anterior part is supplied by the 





Fig. 223. NERVE-SUPPLY OP THE SKIN OP THE SOLE. (Gr.D.T.) 



The areas enclosed by red lines are those supplied by the external cutaneous nerve, the middle and 

 internal cutaneotis, and the internal saphenous branches of the anterior crural nerve, the perforating 

 cutaneous nerve, and the lateral cutaneous, rnusculo-cutaneous, and anterior tibial branches of the 

 peroneal nerve, i.e., the dorsal offsets of the limb-plexus. Those enclosed in blue lines are supplied by 

 branches derived from the ventral offsets of the limb-plexus, viz., the calcaneo-plantar branch of the 

 posterior tibial and the plantar nerves. The area of the small sciatic is enclosed internally by a blue 

 and externally by a red line, corresponding to the double nature of the nerve (see p. 325). The area of 

 the inner side of the leg supplied by the obturator and internal cutaneous in common, and that supplied 

 by the external saphenous, are enclosed in interrupted black lines, the nerves concerned being derived 

 partly from dorsal and partly from ventral divisions. 



internal cutaneous nerve (8 c, 1 d} and the posterior and outer parts by the circum- 

 flex (5, 6 c), and by the internal and external branches of the musculo-spiral nerve 

 (6, 7, 8 c}. 



The forearm, anteriorly and on the outer side, is supplied by the musculo- 

 cutaneous (5, G c) ; on its outer and posterior aspect by the lower external cutaneous 

 branch of the musculo-spiral (6, 7, 8 c), and inferiorly by the radial branch (6, 7 c) 

 of the same nerve. On the inner side, both in front and behind, is the internal 

 cutaneous nerve (8 c, 1 d), and inferiorly are branches of the ulnar (8 c, 1 d). 



On the lack of the hand are the radial and ulnar nerves, the radial (6, 7 c) 

 supplying about three fingers and a half or less, and the ulnar (8 c) one and a half 

 or more. 



On the front of the hand, the median nerve (6, 7, 8 c, 1 d) supplies three fingers 

 and a half, and the ulnar ( 1 d, or 8 c, Id) one and a half. In the palm is a branch of 

 the median, and also a branch of the ulnar, given off above the wrist. On 

 the thenar eminence are branches of the musculo-cutaneous, median, and radial 

 nerves. 



4. In the lower limb. The buttock is supplied from above by the cutaneous 

 branches of the posterior divisions of the lumbar nerves, with the ilio-hypogastric (17) 



