38 



external angle of the ilium and are distributed to the gluteus medius and 

 tensor fasciae latae. See p. 33. 



A. glutea anterior. The distribution of the A. glutea anterior to the mid- 

 dle and deep gluteals may now be demonstrated. The artery will have 

 been cut when the gluteus medius was turned back. Clean up the artery 

 in so far as it can be traced. See p. 34. 



A. glutea posterior or ischiadicus (continued, see p. 33). The distribu- 

 tion of the A. glutea posterior to the biceps femoris, the semitendinosus 

 and, in this specimen, to the internal part of the gluteus superficialis, may 

 now be demonstrated. 



Nn. glutei. There are 5 or 6 of these nerves which are usually described 

 as the anterior and posterior gluteal nerves. 



Nn. glutei anterior. There are three or four nerves in this group. They 

 pass through the great sciatic foramen and are distributed to the gluteal 

 and other muscles as follows: one large nerve lying at the anterior side 

 of the N. ischiadicus passes postero-laterally across the dorsal surface of 

 the shaft of the ilium and between the middle and deep gluteal muscles 

 and is distributed to the tensor fasciae latae and the gluteus superficialis as has 

 been already demonstrated (PI. IV, 22). Sometimes this nerve sends a 

 small branch to the gluteus medius. A short distance from its origin it 

 frequently gives one or more short branches to the gluteus profundus; 

 a branch from this nerve is also sent to the M. capsularis. The other large 

 anterior gluteal nerves have a very short course before entering the gluteus 

 medius ; they arise from the lateral side of the plexus but are so completely 

 hidden from view by the great N. ischiadicus that they are liable to be 

 overlooked. They accompany the A. glutea anterior through the great 

 sciatic foramen and immediately enter the gluteus medius. 



Nn. glutei posterior (PI. V, 55, 56). There are two large nerves in 

 this group, a dorsal or superior, and a ventral or inferior nerve, both of 

 which apparently arise from the dorso-caudal side of the N. ischiadicus. 

 The one first given off, the posterior dorsal gluteal (PL V, 56), really has 

 its origin from the 6th liimbar and the ist and 2d sacral nerves; only a few 

 fibres however come from the 6th. The nerve extends posteriorly between 

 the sacro-sciatic ligament and the gluteus medius and upon emerging from 

 beneath the latter muscle it extends between this muscle and the biceps 

 femoris to which it is distributed as has already been demonstrated (PL IV, 

 23). One small branch from this nerve is sometimes supplied to the gluteus 



