Regeneration des Cortex bei Stentor coeruleus / Regeneration of the Cortex in Stentor coeruleus

Treatment of Stentor with very acid culture medium (pH 2.8) results in delamination of the cortex from the endoplasm . This procures the possibility to strip off the cortex with all its acid resistant organelles at minimum loss of endoplasm. Acid sensitive organelles react with dissolution or more or less damage. The endoplast may survive giving rise to a thin plasma membrane, which may be (even several times) shed and renewed. 10.5% of the decorticated cells regenerated a complete cortex. The ball-shaped and apparently apolar endoplast may pass through an ameboid stage. The visible part of the regeneration process begins with the appearance of a chaotic line system , which in regaining the polar order turns out to be the pigment free interstripe spaces. The ubiquitous appearing of foot anlagen underline the apolar situation. Nevertheless, the problem of endoplasmic preservation of polarity requires further, presently running, experiments. Obvious polarity begins to restore with the development of first membranelies and - approximately in opposite position with these - the definitive foot develops with the holdfast organelle. The ordering of stripe pattern starts from the foot and proceeds to the cells apex. With respect to Tartar’s contradicting result (death o fall decorticated cells) the new experiments do not refute Tartars conclusions, since the technique is different from his only micro-surgical method. This will be discussed in a following paper in context with the results of some other experiments. The here described total regeneration of the cortex in Stentor is not consummated as cytotactic differentiation depending on preformed structure.