LATISSIMUS DORSI. 197 



pezium, or diamond-shaped quadrangle, on the posterior part of the 

 shoulders: hence the muscle was formerly named cucullaris (cucullus, 

 a monk's cowl). The cervical and upper part of the dorsal portion of 

 the muscle is tendinous at its origin, and forms, with the muscle of the 

 opposite side, a kind of tendinous ellipse. 



Relations. By its superficial surface with the integument and 

 superficial fascia, to which it is closely adherent by its cervical por- 

 tion, loosely by its dorsal portion. By its deep surface, from above 

 downwards, with the complexus, splenius, levator anguli scapulae, 

 supra-spinatus, a small portion of the serratus posticus superior, rhom- 

 boideus minor, rhomboideus major, intervertebral aponeurosis which 

 separates it from the erector spinae, and with the latissimus dorsi. The 

 anterior border of the cervical portion of this muscle forms the poste- 

 rior boundary of the posterior triangle of the neck. The clavicular 

 insertion of the muscle sometimes advances to the middle of the cla- 

 vicle, or as far as the outer border of the sterno-mastoid, and occa- 

 sionally it has been seen to overlap the latter. This is a point of 

 much importance to be borne in mind in the operation for ligature of 

 the subclavian artery. The spinal accessory nerve passes beneath the 

 anterior border, near to the clavicle, previously to its distribution to 

 the muscle. 



The ligamentum nucluE is a thin cellulo-fibrous layer extended from 

 the tubercle and spine of the occipital bone, to the spinous process of 

 the seventh cervical vertebra, where it is continuous with the supra- 

 spinous ligament It is connected with the spinous processes of the 

 rest of the cervical vertebrae, with the exception of the atlas, by 

 means of a small fibrous slip which is sent off by each. It is the 

 analogue of an important elastic ligament in animals. 



The LATISSIMUS DORSI muscle covers the whole of the lower part 

 of the back and loins. It arises from the spinous processes of the six 

 inferior dorsal vertebrae, from all the lumbar and sacral spinous pro- 

 cesses, from the posterior third of the crest of the ilium, and from the 

 three lower ribs ; the latter origin takes place by muscular slips, which 

 indigitate with the external oblique muscle of the abdomen. The 

 fibres from this extensive origin converge as they ascend, and cross the 

 inferior angle of the scapula ; they then curve around the lower bor- 

 der of the teres major muscle, and terminate in a short quadrilateral 

 tendon,* which lies in front of the tendon of the teres, and is inserted 

 into the bicipital groove. A synovial bursa is interposed between the 

 muscle and the lower angle of the scapula, and another between its 

 tendon and that of the teres major. The muscle frequently receives a 

 small fasciculus from the scapula as it crosses its inferior angle. 



Relations. By its superficial surface with the integument and 

 superficial fascia ; the latter is very dense and fibrous in the lumbar 

 region ; and with the trapezius. By its deep surface, from below up- 



* A small muscular fasciculus from the pectoralis major is sometimes found 

 connected with this tendon. 



