ii4 Anatomy Applied to Medicine and Swgery. 



ternal intercostal muscles by an areolar tissue in which 

 the intercostal nerve, artery and vein run. Beneath the 

 internal intercostals are the internal intercostal fascia, the 

 subpleural tissue and the pleura. In front, between the 

 pleura and the internal intercostal fascia, is the internal 

 mammary artery. 



Examining some of the above structures in detail we find, 

 1. That the superficial fascia is supplied by the supraclav- 

 icular, the suprasternal, and the supra-acromial branches 

 of the cervical plexus; by the anterior and the lateral 

 cutaneous branches of the intercostals, and posteriorly, by 

 the cutaneous branches of the posterior divisions of the 

 intercostal nerves. 2. This superficial fascia splits or di- 

 vides into two layers to enclose the mammary gland, hence, 

 the gland is an epidermic structure. 



The Mammary Gland is composed of from 15 

 to 20 lobes, each separated and supported by a fibrous 

 partition, and each having a duct converging to the nipple, 

 which is situated in the male, about four inches from the 

 middle of the sternum, in the fourth interspace. 

 From the anterior layer of the superficial fascia 

 covering the gland, there pass forwards into the skin nu- 

 merous fibres, termed "ligamenta suspensoria," while the 

 posterior layer of this superficial fascia is separated from 

 the deep fascia by a delicate areolar tissue in which lymph 

 spaces of considerable size may be found, termed the 

 "submammary bursae." The arteries supplying the mam- 

 mary gland are : The superior and the acromio-thoracic 

 above and externally ; the long thoracic and the external 

 mammary below and externally ; the perforating from the 

 internal mammary internally, and, lastly, branches from 

 the trunks of the intercostals distributed to the deep sur- 

 face of the gland. The lymphatics of the mammary 

 gland pass in three directions, the majority going to the 



