MUSCLES OF THE THORAX. 



187 



muscular fasciculi which pass from the inner surface of one rib near 

 its middle to the next or next but one below; these are the subcostal 

 or more correctly the infracostal muscles. 



Fig. 78 * 



* The muscles of the anterior aspect of the trunk ; on the left siile the superficial 

 layer is seen, and on the right the deeper layer. 1. The pectoralis major muscle. 2. 

 The deltoid ; the interval between these muscles lodges the cephalic vein. 3. The 

 anterior border of the latissimus dorsi. 4. The serrations of the serratus magnus. 

 5. The subclavius muscle of the right side. 6. The pectoralis minor. 7. The coraco- 

 brachialis muscle. 8. The upper part of the biceps muscle, showing its two heads. 

 9. The coracoid process of the scapula. 10. The serratus magnus of the right side. 

 11. The external intercostal muscle of the fifth intercostal space. 12. The external 

 oblique muscle. 13. Its aponeurosis; the median line to the right of this number is 

 the linea alba ; the flexuous line to its left is the linea semilunaris ; and the transverse 

 lines above and below the number, the linetB transversae, of which there were only 

 three in this subject. 14. Poupart's ligament. 15. The external abdominal ring; the 

 margin above the ring is the superior or internal pillar ; the margin below the ring, 

 the inferior or external pillar ; the curved intercolumnar fibres are seen proceeding up- 

 wards from Poupart's ligament to strengthen the ring. The numbers 14 and 15 are 

 situated upon the fascia lata of the thigh ; the opening immediately to the right of 15 

 is the saphenous opening. 16. The rectus muscle of the right side brought into view 

 by the removal of the anterior segment of its sheath : * the posterior segment of its 

 sheath with the divided edge of the anterior segment. 17. The pyramidalis muscle. 

 18. The internal oblique muscle. 19. The conjoined tendon of the internal oblique 

 and transversalis descending behind Poupart's ligament to the pectineal line. 20. The 

 arch formed between the lower curved border of the internal oblique muscle and Pou- 

 part's ligament; it is beneath this arch that the spermatic cord and hernia pass. 



