MYOLOGY 93 



Origin. — From the inner portion of the anterior margin of the 

 ihum, and from the various surfaces afforded by its walls and the 

 walls of the iHo-neural canal; by a series of short and distinct ten- 

 dons alternately from the anterior and posterior extremities of the 

 summits of the neural spines of all the dorsal vertebrae. From the 

 diapophyses of the dorsal vertebrae, from the crests of the neural 

 spiaes of the last three dorsal vertebrae, from the bodies of the dorsal 

 vertebrae, and from the fascia between them and the sacro-lumbalis; 

 and also by a tendinous sheet continuous with the origin of the lon- 

 gus coUi posticus. 



Insertion. — By four fasciculi into the free posterior margins of 

 the obUque processes of the eleventh, the twelfth, the thirteenth, 

 and the fourteenth cervical vertebrae. 



Shape. — ^A large flat sheet. 



Relations. — Laterally, with the superior spinous processes of the 

 vertebrae, and with the superior surface of the ribs. 



Action. — Singly, flexes the back laterally; with its fellow, aids in 

 elevating the body upward. 



THE COCCYGEAL MUSCLES 



Levator coccygis Levator caudae 



Transversus peronei Depressor caudae 



Depressor coccygis Lateralis caudae 



LateraUs coccygis Infracoccygis 



Levator Coccygis (Fig. 23, No. 2). Location. — The superior part 

 of the caudal apparatus. 



Origin. — From a limited area of the ihum just beyond and to the 

 side of the anterior free caudal vertebrae. 



Insertion. — Into the tuberosity of the anterior margin of the 

 pygostyle." 



Shape. — Short, 'fleshy. 



Relations. — Superior portion of the coccygeal vertebrae. 



Action. — Elevates the tail. 



Levator Caudae (Fig. 23, No. 4). Location. — ^Supero-lateral side 

 of the tail. 



Origin.T-FTom. the posterior surface of the post-acetabular area of 

 the pelvis, and from the superior surface of all the coccygeal ver- 

 tebrae except the pygostyle. 



