CHAPTER XIV. 



THE URINARY TRACT. 



THE KIDNEY. 



This organ is a compound tubular gland, consisting 

 of about twenty lobules, surrounded by a dense layer 

 of white fibrous tissue called a capsule. In this cap- 

 sule is found some smooth muscle tissue. The kid- 

 ney is of a bean shape. And the hilum is directed to- 

 wards the median line of. the, abdominal cavity. At 

 the hilum the artery enters, and the vein and ureters 

 leave. The nerves are of both kinds : the medullated 

 and non-medullated. 



The outer investment is called a capsule, having in 

 it a few smooth muscle fibers. The cortex of the kid- 

 ney is located just under the capsule and constitutes 

 one-third of the kidney substance. It contains the 

 labyrinth, Malpighian bodies and uriniferous tubules. 

 The labyrinth is . the space found between the upper 

 end of the uriniferous tubules, and extends down- 

 wards to the point where they all unite to empty into 



(109) 



