In sub-adult animals the cortex generally appeared tightly packed with large follicles that exhibited no, mild or moderate depletion (Figs. 3A, 4) . In adult shrews, the cortex often contained only a small number of follicles (9/20 animals; 45%), frequently with large areas of cortex devoid of follicles (5/20; 25%; Fig. 3B ). Follicles occasionally seemed to extend outwards into marginal sinuses and in two animals exhibited central collagen deposition. Follicles in adults (n = 21) were both smaller than those in sub-adults (n = 18; Wald = 11.06, p,0.05, Fig. 4 ) and exhibited greater levels of depletion (Wald = 13.28, p,0.05, Fig. 4) . No difference was found between males (n = 17) and females (n = 22) with respect to follicle size (Wald = 0.30, NS) or depletion (Wald = 0.42, NS).