FIG. 2. Virgin bat mammary tissues. A and B) Hematoxylin and eosin-stained sections at low (A) and high (B) magnifications. C and D) Sections stained with Masson trichrome. In the virgin state, bat glands are filled with sparse ducts (arrowhead), and the collagen (arrow) distribution is very similar to the lactating sample. Bar = 60 µm (A and C) and 20 µm (B and D)