THE 
VETERINARIAN. 
vol. in. AUGUST, 1830. 
ANATOMY OF THE HORSE. 
[Continued from page 365.] 
ANAL REGION, 
Comprehends a pair of muscles, and a single one. 
RETRACTOR AN I.— ( Ischio-aJUllis. ) 
Situation .—On the side of the rectum, near its termination. 
Figure .—Long, slender, cylindroid. 
Attachment .—Inferiorly and anteriorly, to the sacro-sciatic 
ligament, and to the os innominatum, below and behind the ace¬ 
tabulum ; superiorly and posteriorly, to the lateral parts of the 
rectum, close to its termination. 
Relations .—Externally with the sacro-sciatic ligament; inter¬ 
nally, with the sphincter ani. 
Direction .—Curving obliquely around the gut. 
Structure —Its posterior attachment is aponeurotic: at the 
mesian line, inferiorly, where it meets its fellow, it terminates in 
a small flat tendon. 
Action .—To retract the anus; to withdraw it within the pelvis. 
SPHINCTER ANI. 
Situation .—Encircling the termination of the rectum. 
Figure .—Oval; open in the middle. 
Attachment .—Superiorly, to the coccyx ; whence it descends 
in two divisions, which diverge to include the gut between them, 
around which they proceed, and again meet and unite inferiorly. 
Relations .—Posteriorly with the skin; internally, with the in¬ 
testine ; anteriorly, with the retractor. 
Direction .—Circular. 
Structure .—Pale and fleshy : connected, superiorly, with a 
broad tendinous expansion, which attaches it to the coccyx. 
Action .—To close the anus, after the expulsion of the faeces, 
and to retain it closed. 
3 L 
VOL. I IT. 
