Nuclear membrane behavior during mitosis in normal and heteroploid Myxomycetes

Summary Photomicrographic evidence is presented of the difference in behavior of nuclear membranes during mitosis in amoebae, zygotes and plasmodia of Myxomycetes. One of the species was cultured on bacteria and possessed a normal cycle of plasmogamy and karyogamy between the amoebal and plasmodial phases. The second species was axenically grown in liquid media and had become highly heteroploid and lacked the ability to develop into plasmodia, existing only in the amoeboid form. The significance of the amoeboid form of mitosis in the heteroploid axenically cultured strain is discussed in relation to the difference in nuclear membrane behavior and the possible significance of such behavior.