In most species, the myxamoeba stage may also vary according to the environment. Although two flagella are present, One the long, anteriorly directed flagellum is visible. The second, very short flagellum is usually not visible. Typical Spore of Myxomycetes is a haploid, globose, uninucelate structure. In the case of P .
Spore germination occurs by the cracking of the spore wall and releasing a single myxamoeba in P .
Phase Contrast optic of two swarm cells, more highly magnified than above. Upper left swarm cell can be seen to be flagellated. During conditions unfavorable for myxamoebae growth, the cells may round up and form the resistant microcyst stage. After a period of time, when a critical number of swarm cells or myxamoebae are formed, sexual reproduction will occur and these vegetative stages will then function as gametes. Gametes that are all derived from a common myxamoeba, however, are usually self sterile .