THE RABBIT 3*3 



extends beneath the skin over the entire side of the body ; the latter 

 covers the sides and back of the neck and the sides of the head. 



Study the superficial muscles of the left side of the body. Re- 

 move the fat which may overlay any of these muscles. Note the 

 broad, white membrane which covers the back in the abdominal 

 region : this is the lumbodorsal fascia. Note also the narrow, white 

 midventral line : this is the linea alba. 



On the side of the trunk between the forelegs and hind legs two 

 large muscles occupy almost the entire space, the external oblique 

 and latissimus dorsi. The former is a thin plate which covers the 

 lateral and ventral portions of the abdomen. It has its origin in 

 the lumbodorsal fascia and the posterior ten ribs and extends 

 ventroposteriorly to the midventral portion of the abdomen, where 

 it is inserted in the linea alba and the inguinal ligament. The 

 latter is a broad muscle which covers the lateral portion of the 

 thorax, extending from the back toward the upper arm. It has its 

 origin in the lumbodorsal fascia and the four posterior ribs and 

 passes over the dorsal portion of the anterior end of the external 

 oblique to the forearm, where it is inserted in the humerus. Its 

 action is to draw the arm back. 



Immediately anterior to the latissimus dorsi and above the 

 shoulder are the trapezius muscles. The posterior trapezius covers 

 the dorsal portion of the thorax ; it has its origin in the lumbo- 

 dorsal fascia and the neural spines of the thoracic vertebrae and is 

 inserted in the spine of the scapula. The anterior trapezius covers 

 the back of the neck ; it has its origin in the posterior surface of 

 the skull and the mid-dorsal line of the neck and is inserted in the 

 metacromion process of the scapula. The action of the trapezius 

 muscles is to draw the shoulder and limb upward and forward. 



A slender muscle, the levator scapulae major, will be seen along 

 the ventral border of the anterior trapezius on the side of the neck ; 

 its origin is in the ventral surface of the skull, and its insertion, 

 with that of the anterior trapezius, is in the metacromion process 

 of the scapula. Its action is to draw the shoulder forward. Just 

 dorsal to this muscle, and between it and the forward portion of the 

 anterior trapezius, will be seen parts of two muscles,— the broad 

 splenius, the more ventral of the two, and the levator scapulae 



