484 URINARY ORGANS OF THE DOG 



wide. Cortex, limiting zone, and medulla are clearly defined. On frontal sections 

 it is seen that the medullary substance forms a horizontal renal crest like that of 

 the horse, but with the important difference that curved ridges proceed dorsally 

 and ventrally from the crest somewhat like buttresses. Sections above or below 

 the renal crest often cut these ridges in such a manner as to give the appearance 

 of conical papillae, and thus tend strongly to produce a false impression. The 

 pelvis is adapted to this arrangement of the medullary substance. It incloses a 

 central cavity into which the renal crest projects, and is prolonged outward 

 between the ridges, forming cavities for the latter, thus simulating the appearance 

 of calyces which do not exist. 



The ureters present no special features. 



The bladder is abdominal in position, the neck lying at the anterior border of 

 the pubic bones. It is relatively large, and when full, the vertex may reach to the 

 umbilicus. It has a practically complete peritoneal coat. 



THE ADRENALS 



The right adrenal lies between the anterior part of the inner border of the kid- 

 ney and the posterior vena cava. It is somewhat prismatic, and is pointed at 

 either end. 



The left adrenal lies along the posterior aorta, from the renal vein forward, 

 but is not in contact with the kidney. It is elongated and flattened dorso-ventrally. 

 (There is a furrow on the ventral surface for the vein which crosses it ; the part in 

 front of this furrow is discoitl, and may be taken for the entire organ in a fat 

 subject.) 



The cortex is pale yellow in color, the medulla dark brown. 



