MUSCLES OF THE LIMBS. 211 



Insertion. By tendons to the inferior surface of all the 

 coccygeal vertebra successively. 



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

 inferiorly 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. III. 32.) 



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

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

 Origin. 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 vertebra. 



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 are 

 intrinsic and extrinsic, according to their origin. These muscles 



