Where there has been local mischief due to inflammation the dead leucocytes must be removed, and this is done either by their being converted into pus in one mass, and making their way through the tissues to the nearest surface, whether of skin or mucous membrane, from which it can be discharged, or they may undergo a process of fatty degeneration and absorption, leaving behind in some cases cheesy matter, in others hard connective tissue.
By the aid of the new fibroblasts this fibrous tissue zone gradually encroaches on the pus area and replaces the phagocytic layer of cells as they proceed with the absorption of the pus mass (fig.
The Marsupials include the Macro pus or kangaroo; the opossums, Phalangista vulpina and P. Cookii; the opossum-mouse, Dromicia nana; Perameles or bandicoot; Hypsiprymnus or kangaroo rat; Phascolomys or wombat; while of Monotremata there are the Echidna or porcupine ant-eater and the duck-billed platypus.
When complete removal of the pus mass has been accomplished by the process of absorption, the damaged area is replaced by the new fibrous tissue, which later becomes condensed and forms the cicatricial or scar tissue (fig.
Heterophylly is rather common among aquatic plants, and is well seen in several aquatic species of Ranunculus, many species of Potamogelon, Sagittaria sagittifolia, Scir pus lacusiris, Castalia (Nymphaea) alba, Hippuris vulgaris, Callitriche spp., Sium latifolium.