ABDOMINAL VISCERA OF THE HORSE. 7^ 
On cutting horizontally across a supra-renal capsule, it is 
found to consist of an outer cortical and an internal medullary 
substance. The cortical substance is a brownish yellow, due to 
fat contained in vesicles, which, according to Professor Heinrich 
Frey, are smaller towards the surface than more internally. The 
medullary substance has a greyish aspect, and vessels are ap¬ 
parent in it, as also a yellow tinge, due, according to the above- 
named author, to similar vesicles as in the cortical substance, 
only much scantier in fat. 
The arteries of the supra-renal capsules are offsets of the 
renals and anterior mesenteric, as well as of the aorta, but verv 
_ ^ 
variable in number and origin. They are, however, always 
abundant, and enter the organ principally at its concave 
border. 
The veins are larger than the arteries, and pour their con¬ 
tents on the left into the renal vein, and into the vena cava on 
the right. 
The nerves of the supra-renal capsules are very abundant, 
and derived from the renal plexus. Professor Frey states, that 
in the horse, ganglion corpuscles constitute one of the structural 
elements of the nervous tissue in this situation. 
Ureters. 
The ureters, one to each kidney, are conduits between the 
kidneys and the bladder, for the passage of urine. Their caliber 
is various, being about one-third of an inch broad, but getting 
narrower posteriorly. 
As the ureters issue from the kidneys they converge towards 
the spine, then proceed suddenly backwards, till they reach the 
brim of the pelvis, having thus greatly diverged ; here they 
converge again, passing downwards and backwards to reach the 
sides of the body of the bladder, which they pierce. 
In their course the ureters are attached to the kidney and 
psoas parvus by loose cellular tissue, and by the peritoneum, 
which suspends them, by being stretched across their inferior 
surface. After the ureters have crossed the spermatic and iliac 
vessels they are received within a fold of peritoneum, con¬ 
stituting the false ligaments of the bladder. 
The}' pierce the muscular coat of the bladder at a distance of 
about three inches from each other, if the viscus be distended. 
They pass between the muscular and mucous coats for about an 
inch, being somewhat diminished in caliber, when they suddenly 
open into the cavity by an elliptical orifice, so that if the bladder 
be distended, the sides of the orifice are stretched, and thus 
closed. 
