88 PHYSIOLOGY FOR THE LABORATORY. 



Notice : 



a. The pelvis is the widened end of the ureter. 



b. The cups, or calices, are the smaller cavities that unite 

 to form the pelvis. 



c. The cortical portion is the outer part of the wall of 

 the kidney. What is its color and structure ? 



d. The medullary portion is within the cortex. It is 

 divided into separate pyramidal portions, called the pyra- 

 mids of Malpighi. How does it compare in color and 

 structure with the cortex? 



e. Sketch. 



III. THE MICROSCOPICAL STRUCTURE OF THE KIDNEY. 



Material. A prepared radial section of injected kidney. 

 Apparatus. A compound microscope. 



Examine under a low power and determine : 



a. The uriniferous tubules, or small tubes, compose the 

 larger part of the medullary and cortical portions. Each 

 tube is very complicated and is composed of straight and 

 convoluted parts. It arises in a Malpighian body (see b) 

 and after passing through the cortical and medullary 

 portions, finally opens at the apex of a pyramid. 



b. The Malpighian bodies are small spherical bodies in the 

 cortical portion of the kidney. Each one is composed of 

 a network of capillary blood-vessels, surrounded by a thin 

 membrane which narrows to form the beginning of a tubule. 

 The fluid is secreted in the capsule and in a part of the 

 tubules. 



