EXCRETORY SYSTEM—REPRODUCTIVE ORGANS 717 
Within the larynx there are stretched membranous bands—the vocal 
chords. Beside the larynx is the paired thyroid gland. 
Excretory .system.—This includes the blood-filtering 
kidneys, their ducts the ureters, and a reservoir or bladder, 
into which these open. The kidneys and their ducts are 
formed from the metanephros and metanephric ducts of 
the embryo. The bladder arises as a diverticulum from 
the hind end of the gut, being in fact. a remnant of the 
intra-embryonic part of the allantois. It loses its con- 
nection with the gut, and the ureters which originally 
opened into the rectum follow the bladder and open 
into it. 
The kidneys are dark red ovoid bodies lying on the 
dorsal wall of the abdomen; the one on the left is farther 
down than that on the right, because of the position of 
the stomach on the left side. When a kidney is dissected, 
a marked difference is seen between the superficial cortical’ 
part and the deeper medullary substance. On papille or 
pyramids in the very centre the coiled excretory tubules 
open, and empty the water and waste products into the 
“pelvis” or mouth of the ureter. 
The ureters run backward along the dorsal wall of the 
abdomen, and open into the bladder, a thin-walled sac 
lying in front of the pelvic girdle. 
In front of each kidney lies a yellow suprarenal body. 
Reproductive organs.—(a) Male.—The testes arise on 
the dorsal abdominal wall near the kidney, but as the 
rabbit becomes sexually mature, they are loosened from 
their original attachment, and pass out on the ventral 
surface, as if by a normal rupture, into the scrotal sac. 
A spermatic cord, consisting of an artery, a vein, and a 
little connective tissue, runs from the abdomen to the 
testis. 
The testis is attached to the base of the scrotal sac, and 
is bordered by a mass of convoluted tubes—the epididymis 
—consisting of the caput epididymis anteriorly, the larger 
cauda epididymis posteriorly, and a narrow band between 
them. ‘The cauda epididymis is connected to the scrotal 
sac by a short cord or gubernaculum. ; 
Througt the tubes a tae epididymis (the modified meso- 
nephros) the spermatozoa developed in the testis are 
