BY W. J. S. McKAY. 267 



the presternum. Here it encounters a large gland (Fig. 1, 67.) 

 placed superficial to the sterno-mastoid. The muscular band runs 

 over the gland and, receiving an accession of fibres (which come 

 from the direction of the opposite epicoracoid region), the whole 

 turns suddenly outwards and runs forward over the clavicle, here 

 to be joined by the prolongation of the external division next to 

 be described. 



The inner border of the external division (Fig. 1, Pn. S.E.) of 

 the superficial stratum is not sharply defined, but fades away 

 into an aponeurosis (containing scattered muscular bundles), which 

 connects it with the median division, and beneath which the deep 

 stratum of the panniculus lies (i.e., the M. dermo-flexor brachii). 



As the external division runs forward it encounters the arm 

 and forearm, and the fibres now take different directions ; the 

 innermost pursue their course forward to the clavicle, there to 

 join the fibres of the median division, and spread out over the 

 lateral aspect of the cervical region, and coalesce with the dorsal 

 portion of the panniculus ; the outermost fibres turn out over 

 the olecranon, and joining the general dorso-lateral sheet run 

 along the dorso-external border of the forearm, and are inserted 

 on the external aspect of the distal extremity of the ulna, close 

 to its carpal articulation, forming a dermo-flexor antehrachii. 



Deep stratum of the Panniculus (Fig. 1, Pn. D. 1). — This lies 

 between the middle and external divisions just described. 

 Running forward for a short distance in the same plane as these 

 divisions it sinks deeper, and passing superficial to the P. quartus 

 it becomes narrow ; and having pierced the thick fascia, as it 

 approaches its insertion, it undergoes cleavage in a plane parallel 

 to its surface. This occurs from within outwards, but the cleav- 

 age does not extend quite to the outer border, and consequently 

 the two layers remain connected at the external border. The 

 upper (Fig. 1 et 2, Pn. D. 1) of the two layers thus formed runs 

 forward over the tendon of the P. quartus, and disappears under 

 the postero-internal border of the clavicular deltoid, to be inserted 

 on the posterior edge of the proximal third of the pectoro-deltoid 



