212 NORMAL HISTOLOGY. 



With the decline of the reproductive power the 

 mammary gland undergoes a marked and permanent 

 involution : the terminal alveoli disappear, the 

 smaller ducts are obliterated, and finally little is left 

 of the organ excepting the deformed and collapsed 

 larger ducts and a mass of connective tissue. 



TECHNIQUE. 



Sections of Hardened Gland. Portions of the gland 

 from the human subject or from some of the lower 

 mammalia if possible, both in a condition of rest and 

 of functional activity should be hardened in Miiller's 

 fluid, and the sections stained double and mounted in 

 glycerin or balsam. 



