8 
Fig. 7 Drawn from a cross-section through the primary milk-duct of the left 
first inguinal gland of a female albino rat at birth. Zenker’s fixation; Weigert’s 
iron-hematoxylin stain. Drawn with the aid of a camera lucida. c.t., develop- 
ing connective tissue forming sheath around the duct; ep.w., epithelial wall com- 
posed of epithelial cells without definite arrangement into layers; /., developing 
lumen. X 800. 
Fig. 8 Drawn through a cross-section of a terminal duct (about 20u from its 
termination) of a female albino rat of eleven days. Zenker’s fixation; Weigert’s 
iron-hematoxylin stain. Drawn with the aid of a camera lucida. c.t., connec- 
tive tissue; 7./., inner or glandular layer of epithelial cells; 0./., outer or myo- 
epithelial layer of cells. X 800. 
417 
