172 



F. HAGUENAU AND K. H. HOLLMANN 





Fig. 2(b). Electron microscope aspect of a lactating mammary gland at the 

 peak of its activity. At right glandular lumen filled with secretion product (nunierous 

 small protein granules and large lipid droplets). Note the typical parallel arrange- 

 ment of the "organized" ergastoplasm in the cytoplasm of the glandular cells. In 

 contrast, the myoepithelial cell (cm), not concerned with secretion, contains no 

 ergastoplasm. x 7100. 



