ANATOMY OF THE HORSE. 423 
Attachment .—On either side, to the ischial portion of the os 
innominatum; in the middle, to the prostate gland. 
Relations . —Inferiorly, with the ischium and pubes; superior¬ 
ly, with the prostates, membranous part of the urethra, and w r ith 
the bladder. 
Structure . —It consists of a broad expansion of pale fleshy 
fibres (loosely connected by cellular tissue), clothing the mem¬ 
branous portion of the urethra and the prostates. 
Action . —It will contract this part of the urethra; and, probably, 
have some effect in discharging fluids from the prostates. 
r 
accelerator URiNiE.— ( P erineo-urethralis.) 
Situation .—Upon the bulb of the urethra, and around the 
under parts of the penis. 
Form .—Elongated; penniform. 
Attachment .—Incorporated with, and (may be considered as) 
forming part of the penis itself. Posteriorly, it springs from the 
middle and posterior part of the bulb of the urethra, where it is 
joined by other (scattered) fasciculi, arising on each side of the 
bulb from the perineum. It takes its course along the under part 
of the penis, and may be followed for some short distance upon 
the glans ; the entire muscle, throughout its extent, forming a 
complete fleshy investment to the urethra. 
Action .—To compress the urethral canal, thereby aiding in 
the forcible discharge of the urine ; but more particularly, it w r ould 
seem, in the ejection of the seminal fluid. 
FEMALE GENITAL REGION. 
ERECTOR CLITORIDIS 
Ischio-clitoricleus* 
Sacro-clitorideus. 
This pair of muscles spring from the perineum, at which place 
their fibres are mingled with those of the sphincter ani. They 
run to be attached to the upper and back parts of the clitoris. 
Action .—To erect the clitoris; and thereby protrude it into 
the vagina, in the act of coition. 
• 
sphincter vaginae. —( Perineo-clitoridcus.) 
Consists of a broad band of strong, red, fleshy fasciculi, en¬ 
circling and clothing the orifice of the vagina; and spreading 
around the adjoining parts of the canal. 
In action the sphincter will contract (and has the power to 
close) the mouth of the canal. 
