Associated with the spores in the sporangium occurs the _capillitium_. This consists of most delicate thread-or hair-like elements, offering great variety both in form and structure. The threads composing the capillitium are not to be regarded, even when free, as cells, nor even of cellular origin; probably, as would appear from the researches of Strasburger and Harper, all forms of capillitial threads arise in connection with vacuoles in the protoplasmic mass. "Whether the thread is hollow or solid, simple or branched, free or connected with the peridium or a columella,--these are entirely secondary conditions, depending on the extent and form of the vacuoles."[6] They may occur singly or be combined into a net, they may be terete or flat, attached to the peridial wall or free, simple or adorned with bands or spires and knobs in every variety, uniform or profusely knotted and thickened at intervals, and burdened with calcic particles. In many cases, the capillitium contributes materially to the dispersal of the spores; in others, it doubtless contributes mechanically to the support of the peridial wall, and renders so far persistent the delicate sporangium. For more exact description the reader is again referred to the specific delineations which follow. The transition from phase to phase requires, as intimated, no great length of time. _Tilmadoche polycephala_ completed the transition from vegetative to fruiting phase in less than twelve hours. The germination of the spores ensues closely upon their dispersal or maturity and is unique in many respects.[7] The wall of the spore is ruptured and the protoplasmic content escapes as a zoospore indistinguishable so far from an amoeba, or from the zoospore of our chytridiaceous fungi. This amoeboid zoospore is without cell-wall, changes its outline, and moves slowly by creeping or flowing from point to point. At this stage many of the spores assume each a flagellate cilium, and so acquire power of more rapid locomotion. The zoospores, whether ciliate or not, thus enjoy independent existence and are capable of continuing such existence for some time, assimilating, growing, and even reproducing themselves by simple fission, over and over again. This takes place, of course, only in the presence of suitable nutrient media.