72 ANATOMY OF THE DOMESTIC FOWL 



Dermo-frontalis. 1 Location. This muscle is somewhat rudimen- 

 tary and may be entirely absent. It is located in the frontal region 

 and is about 2 or 3 centimeters long and not so wide. 



Origin and Insertion. Closely attached to the skin. 



Shape. Flat and rather rectangular. 



Relations. Superiorly with the skin and inferiorly with the frontal 

 bones. 



Action. By contraction the feathers on the top of the head lie 

 flat. Those above the eyes are elevated. 



Dermo-dorsalis. Location. In the median line of the neck and 

 back. 



Origin and Insertion. Adhering closely to the skin, it generally 

 becomes lost at the occiput; it is most highly developed in the 

 mid-cervical region, and it gradually disappears over the caudal 

 region. 



Shape. Delicate and ribbon-shaped. 



Relations. Superiorly it is attached to the skin. Fat sometimes 

 surrounds the muscle. 



Action. By contraction it raises the feathers along the superior 

 part of the neck and dorsal region. 



Dermo-tensor Patagii. Location. Between the root of the neck 

 and top of the shoulder. 



Origin and Insertion. Attached to the skin in the region of the 

 anterior part of the root of the neck, some fibers passing obliquely 

 upward and blend with fibers of the dermo-temporalis. It blends, 

 by a slender tendon, with that of the tensor patagii longus. 



Shape. A bundle of muscular fibers later becomes thin, delicate, 

 and triangular in shape. 



Relations. Externally to the skin. 



Action. Auxiliary to the tensor patagii longus. A tensor of 

 this region. 



The patagii are associated with the wing fold of skin which fills 

 the angle between the arm and forearm. This fold contains elastic 

 tissue and muscle. 



Dermo-humeralis. Location. Lateral thoracic region. 



Origin and Insertion. Fan-like delicate fibers from the skin in 

 the abdominal integument, contracting into a long narrow fasci- 

 culus of fibers, again spreading out in fan-shape to be inserted to the 

 tendon of the pectoralis major, just below its insertion. 



classification of Shufeldt is used. 



