. The biology of Stentor. Stentor. Fig. 54. Disturbances in heteropolar systems. A. Primordium sector of stage-4 reorganizer reversed in situ. Absence of stomatogenesis associated with posterior end of anlage lying now in the frontal field. The inverted patch {x) apparently was gradually resorbed but no regeneration occurred during 7-day survival. Nuclear distribution abnormal. B. Stage-2 regeneration primordium sector grafted hetero- polar to regenerating stentor in same stage. Both anlagen were resorbed; then two new ones produced the incomplete oral diflferentiations shown in the second ske
. The biology of Stentor. Stentor. Fig. 54. Disturbances in heteropolar systems. A. Primordium sector of stage-4 reorganizer reversed in situ. Absence of stomatogenesis associated with posterior end of anlage lying now in the frontal field. The inverted patch {x) apparently was gradually resorbed but no regeneration occurred during 7-day survival. Nuclear distribution abnormal. B. Stage-2 regeneration primordium sector grafted hetero- polar to regenerating stentor in same stage. Both anlagen were resorbed; then two new ones produced the incomplete oral diflferentiations shown in the second sketch as the shape became grossly abnormal. Specimen is re-regenerating with single primordium. Polar conflicts may be resolved by the larger part becoming dominant (Fig, 55A). A compromise may result in heteromorphosis, in which a secondary polarity is responsible for the formation of an extra set of feeding organelles but the lateral striping has, throughout, the polarity of the major portion of the specimen so that the secondary oral differentiation is of reversed asymmetry (b). These forms are however less frequent and less well-developed in Stentor than in other ciliates. When the major mid-section of the cell is reversed, all parts retain their original polarities and multiple formations occur (C). Shifting the head to the posterior end does not result in reversal of polarity. The most frequent result (unpublished) was that a new set of feeding organelles eventually regenerated at the original anterior end of the major cell body, and the displaced head became. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Tartar, Vance, 1911-. New York, Pergammon Press
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