The Axilla. 37 



runs from the axillary artery towards the thorax. The 

 base of the axilla is completed by the deep fascia, which 

 is a strong dense layer called the 



"Axillary fascia proper" and is formed by the 

 union of three planes of fascia ; two prolonged from the 

 pectoralis major and one from the pectoralis minor, and 

 these three uniting, stretch across the base of the axilla 

 to the border of the latiss. dorsi muscle. The two layers 

 from the .pectoralis major are the superficial and the deep 

 pectoral fascia, i. e.> the one in front and the one behind 

 the pectoralis major. These, attached to the clavicle 

 above, are separated at their origin, by the pectoralis 

 major but are united below at the lower border of the 

 muscle. The layer of iascia from the lower border of the 

 pectoralis minor is the continuation downwards ot the 

 clavipectoral fascia. 



The clavipectoral fascia is attached above to the 

 clavicle by two projections separated by the subclavius 

 muscle. Following this fascia downward, it passes, cur- 

 tain like, to the upper border of the pectoralis minor, 

 hiding -Jrom view the axillary vessels and nerves. At 

 the upper border of the pectoralis minor it splits, and one 

 plane passes down in front of and the other behind this 

 muscle. At the lower border of the pectoralis minor 

 these unite and the layer formed by their union blends 

 with that from the lower border of the pectoralis major 

 above mentioned, to form the axillary fascia proper. The 

 portion of the clavi-pectoral fascia between the clavicle 

 and the pectoralis- minor, being attached internally to the 

 cartilage of first rib and externally to the coracoid process, 

 is termed the costo-coracoid membrane, and a part of 

 this, thickened so as to constitute a white band, is termed 

 the costo-co^acoid ligament. 



Thus the general axillary space may be subdivided in- 



