Also throughout the interior of the sporangium is the branched, thread-like capillitium . Cross section strand of plasmodium showing knotted, discrete units, with protoplasm pushing upwards. Each unit will give rise to a sporangium. Longitudinal section of a single, developing, P . polycephalum sporangium. As the nodule elongates, the basal portion, which will develop into the stalk, becomes more and more constricted while the upper portion, which is the sporangium proper, continues to expand and forms the finger-like projections characteristic of this species.
Arrows indicate points of constriction and expansion.
Upon completion of movement of protoplasm into the sporangium proper, the characteristic shape of P . The stalk by this time will have become more constricted and devoid of protoplasm. Within the sporangium, following meiosis, the formation of haploid spores and capillium will occur. The typical sporangia for P. polycephalum and D. iridis has previously illustrated. However, there are variations in sporangial types and structures.