The Thorax, 113 



from a little beyond the middle of the clavicle to the cri- 

 coid cartilage; (b) the clavicular, beneath the clavicle; 

 (c) the infraclavicular, below the clavicle and bounded 

 inferiorly by the lower border of the third rib; (d) the 

 mammary, from the lower border of the third rib, down 

 to the lower border of the sixth rib; (e) the inframam- 

 mary, from the lower border of the sixth rib, to the lower 

 limit of the thorax. 3. Axillary region, bounded in front 

 by the coracoid line, and behind by the axillary border of 

 the scapula, and below this by the scapular line. This re- 

 gion is divided into (a) the axillary from the apex of the 

 axilla to the level of a line drawn from the lower border 

 of the sixth rib in front and crossing this region about the 

 lower border of the eighth rib; (b) the infra-axillary, ex- 

 tending from the above line downwards to the lower limit 

 of the chest wall. 4. Posterior region, from the axillary 

 border of the scapula and from the scapular line externally, 

 to the midspinal line internally, including, therefore, 

 (a) the supra, and (b) the infraspinous areas, above and 

 below the spine of the scapula, respectively; (c) the in- 

 terscapular between the scapulae; (d) the infrascapular 

 between the scapular line externally and the midspinal line 

 internally, the upper limit of this infrascapular space 

 being the line from the angle of the scapula to the spine, 

 and the lower limit, the margin of the thorax below. 



The Structures covering the Thorax are: 

 In front, the integument and fascia with the following 

 muscles external to the ribs, viz., the subclavius, the pec- 

 toralis major and minor, the serratus magnus and the ex- 

 ternal oblique; posteriorly, are the latiss. dorsi, the tra- 

 pezius, the scapular muscles and the deeper muscles of the 

 lateral spinal regions. Between the ribs, the following 

 structures are found : The external intercostals covered by 

 the external intercostal fascia and separated from the in- 



