ABSTRACT
In the following pages, I wish to call attention to some remarkable events which I have observed in the life-history of Entamœba ranarum Grussi, an organism which I have been studying for some time, and whose life-cycle—so far as I had succeeded in following it—I have already described in a previous paper (2). I will divide my remarks into two sections —I, a description of the phenomena actually observed, and II, a discussion of their significance.
Prandtl (11) describes this as occurring in Amœba proteus.
Piundtl (11) apparently attributed the physiological degeneration which he observed in AmœBa proteus to active multiplication, through prolongation of suitable conditions, at a time when multiplication—in the ordinary course of events—would have ceased. The Amœbæ were collected in autumn—”also gegen Schluss der Vermeh-rungsperiode der meisten freilebenden Protozoen. Indem nun die Tiere durcli die gebotenen günstigen Vermehrungsbedingungen zu weiteren Teilungen veranlasst wurden, gingen sie ihrer pbysiologischen Degeneration entgegen.’’
See, for example, Popoff, “Experimentelle Zellstudien,” ‘Arch. f. Zellforschung,’ Bd. I, 1908. Lowering of temperature caused both an absolute and a relative increase in the size of the nucleus in the Infusoria studied.
-That the overgrowth of the nucleus is itself the primary cause of degeneration and death appears to me highly improbable. I would as soon argue that grey hairs are the cause of old age in man.
