74 



SECRETION. 



What is the function of the kidney ? 



The secretion of the urine. The kidney is a compound tubular 

 gland. The medullary portion of the organ is almost entirely 



FIG. 17. 



Vertical Section of Kidney. 



made up of tubules, which take origin in the cortex and empty 

 upon the apices of the pyramids of Malpighi of the medullary 

 portion. 



What are the Malpighian bodies? 



In the cortical portion of the kidneys are found minute tufts of 



