Cellularity of tissues from saline and Staph. aureus quarter lobules. A Depicts tissues from a saline infused quarter exhibiting diffuse intralobular stroma and non-secretory epithelium. Neutrophilic infiltration (arrows) of luminal and intralobular stoma compartments is depicted in B for tissues from a Staph. aureus infused quarter lobule. C Exemplifies the preferential infiltration of lymphocytes into intralobular stroma areas (dashed outline) that could be observed in saline quarters but were more frequent in Staph. aureus quarters. Plasma cells (arrows) could be observed in both saline and Staph. aureus quarter lobules D. Scale bars in A and C = 50 µm, B and D = 10 µm.