DISSECTION OF THE BODY 37 



upper part of the lumbar region, and it fades away below 

 at the level of the spine of the third sacral vertebra. The 

 finger should next be passed along the crest of the ilium as 

 it pursues its sigmoid course forwards and laterally. The 

 highest point of the iliac crest corresponds in level with the 

 spine of the fourth lumbar vertebra, and the posterior superior 

 spine of the ilium can be easily detected, seeing that its 

 position is indicated by a small but distinct depression or 

 dimple on a level with the second sacral spine. 



The scapula or shoulder blade is for the most part thickly 

 covered by muscles ; but, in spite of this, its general outline 

 can be made out. It covers a considerable area of the 

 upper portion of the posterior aspect of the thorax. With 

 the hand by the side its medial angle lies over the second 

 rib, the root of its spine is placed opposite the spine of the 

 third thoracic vertebra, whilst its inferior angle reaches 

 down as far as the seventh, or even the eighth, rib. The 

 scapula is very mobile, and moves to a greater or less 

 degree with every movement of the limb. The spine and 

 acromion of the scapula are subcutaneous throughout. 

 Below the scapula the lower five ribs can be felt, and the 

 tip of the last rib can be made out at a point about two 

 inches above the iliac crest. 



DISSECTION OF THE BACK. 



In this dissection the following are the parts which 

 require to be examined : 



1. The cutaneous vessels and nerves of the back. } 



2. The m. trapezius. > ist day. 



3. The m. latissimus dorsi. 



4. The mm. rhomboidei and their nerves. 



5. The m. levator scapulae. 



6. The n. accessorius and the nerves from the cervical plexus 



which supply the trapezius. 



7. The a. transversa colli and its two terminal branches (viz. the 2nd da y* 



ramus descendens and the ramus ascendens). 



8. The posterior belly of the m. omo-hyoideus. 



9. The a. transversa scapulae and n. suprascapularis. 



This dissection must be completed in two days, in order that 

 the dissector of the head and neck may be enabled to con- 

 tinue the deeper dissection of the back. Theyfctf day's work 



