MUSCLES OF THE LIMBS. 211 



Insertion. — By tendons to the inferior surface of all the 

 coccygeal vertebrae successively. 



Relation. — Superiorly with the sacrum, coccyx, and curvator ; 

 ioferiorly with the rectum ; externally with the curvator and 

 sacro-sciatic ligament ; internally with its fellow. 



Action. — To bend the tail downwards ; singly, to draw it 

 downwards and to one side. 



CURVATOR COCCYGIS. 



{Sacro-coccygeus Lateralis.) 



(PL. IIL 32.) 



Situated on the side of the tail, and similar in structure to the 

 preceding, it is merely a continuation of the semispinalis lumborum. 



Oricfin. — From the spines of the last lumbar, and lateral aspect 

 of the sacral and coccygeal vertebrae. 



Insertion. — The side of the coccyx, between the erector and 

 depressor. 



Relation. — Superiorly with the erector and sacral ligament; 

 inferiorly with the depressor ; externally with the compressor. 



Action. — To curve the tail, drawing it sideways over the 

 quarter. 



COMPRESSOR COCCYGIS. 

 (Ischio-coccygeus. ) 



Situated at the side of the pelvis, it is a large, thin, and tri- 

 angular muscle. 



Origin. — By aponeurosis, from the superior ischiatic spine and 

 the inner surface of the sacro-sciatic ligament, running upwards 

 and backwards. 



Insertion. — By fleshy fibres, to the side of the terminal sacral 

 and first two coccygeal vertebras. 



Relation. — Externally with the sacro-sciatic ligament ; inter- 

 nally with the curvator and rectum. 



Action. — To depress the entire tail. 



Muscles of the Limbs. 



The muscles of this class are those which are specially related 

 to the limbs, for the most part acting upon them alone ; they arc 

 intrinsic aud extrinsic, according to their origin. These muscles 



