| Based on reviewing study and development history of the biology of myxomycetes a general situation was systematically expounded from local to abroad. The cultures of 8 species of myxomycetes, belonging to Physarales and Trichiales, was proceeded in the laboratory. The life cycle of spore-to-spore were completed in agar culture in Petri dish.With the aid of stereo microscope, optical microscope and scanning electron microscope, the periduim, spore and capillitium of all 8 species of myxomycetes, including field collections and agar-development fruiting, were observed and compared from apparent morphology, microstructure to ultra-structure. The result shows that no apparent difference was ascertained between field collections and agar-culture fruiting. Agar-culture spores resemble those of on nature substrate in size, shape and ornamentation.Moist chamber cultures, oat-agar cultures, hanging drop cultures and scanning electron microscope were used to observe and study the life cycles of the myxomycetes. The general regulation, the distinct between Physarales and Trichiales and the difference among species in the life cycles of the myxomycetes were mastered. The result shows that the life cycle of all the species comprises a unicellular amoeboid or swarm cell stage, a multinucleate plasmodium stage and a sporulation stage. The life cycle begins from spore germination. Spore germination is split method in Physarales. At the earliest developmental stage of the myxomycetes, the un-nucleate amoeboid or swarm cells of all the species are similar to each other in the aspects of morphology, structure and habit. All the swarm cells have an obvious flagellum. Myxamoebaand swarm cell can change between each other.The experiment observation and research indicate that at the earliestdevelopmental stage of the plasmodium, myxomycetes of Physarales and Trichiales exist not only difference but also common characteristics. The appearance and structure of 7 species of Physarales which have been grown in culture, including Didymium iridis, are resemble. The plasmodium has a small colorless flatten aspect and a more or less round outline. Soon the plasmodium elongates and develops a definite channel in which the protoplasm begins to stream back and forth more or less rhythmically. One end of elongated structure soon becomeswider. Polarity has now been established and the plasmodium moves in the direction of its wider portion. The anterior portion now begins to take the shape of a fan. The differentiation of the plasmodia protoplast into a streaming and a non- streaming portion is vary definite. Because of the three dimensional structure and the granular protoplasm, the plasmodium can be identified even if within 1mm.At the earliest developmental stage of the plasmodium of Arcyria cinerea, has a homogeneous structure, a small colorless flatten aspect and a more or less strip or irregular outline. One end of elongated structure soon becomes wider. The anterior portion now begins to take the shape of a fan which has indefinite edge and indenture, but the polarity has now been established. The inner protoplasm has little amount granular material, the plasmodium can not be identified even if large.The difference and common characteristics of the mature plasmodia of Physarales and Arcyria cinerea were mastered. All the mature plasmodia of Physarales were typical phaneroplasmodium which exhibit a thick, large fan-shaped advancing edge consisting of a continuous sheet of protoplasm. In the sheet structure, the granular protoplasm is distinct. Behind the advancing edge, the network is composed of bigger, well-defined vein with open spaces between them. The general form of the plasmodium is maintained as it grows and moves across the plate, but the pattern of the veins in any one area is constantly changing.Compared to the mature plasmodia of Physarales, Arcyria cinerea forms a thick ,large fan-shaped advancing edge consisting of a continuous sheet of protoplasm which resemble the phaneroplasmodium. Bu...
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