RESUMEN
The cardiac gland region in the stomachs of eleven babirusa (Babyrousa babyrussa) from zoological collections was studied by scanning and transmission electron microscopy. An array of tightly-packed, thin-walled tubes, closely resembling a 'honeycomb' covered this region. The tubes were between twelve and sixteen cells (200 and 260 microm) in height and usually two cells (8-20 microm) in thickness. Mucus granules present in the cytoplasm of cells in the lower half of the tube were largely absent from the ad-luminal half of the tube. Instead, open goblet-like structures lined the tube, apparently giving additional strength. Bacteria were present in the lumen of each thin-walled tube and in the underlying gland pit. The evidence suggests that this large area of the babirusa stomach may be structured to form a stable, self-refreshing environment to house and multiply autochthonous commensal bacteria.