. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 2OO LEMON. [VOL. I. at least the following forms : Tubularia mesembryanthemum, Aglaophemia pluma, Plumularia pinnata, Eudendrium (rasimo- sum ?), Sertularia (polyzonias ?). Bickford and Driesch,1 cited by Morgan, have also shown that in the tubularian hydroids two heads may develop on opposite ends of a piece cut from a stem, especially if the piece be short. 3. Pseudoheteromorphosis.— By cutting a narrow strip from any part of the body so as partly to isolate it, a posteriorly directed head may be developed by the reversal
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 2OO LEMON. [VOL. I. at least the following forms : Tubularia mesembryanthemum, Aglaophemia pluma, Plumularia pinnata, Eudendrium (rasimo- sum ?), Sertularia (polyzonias ?). Bickford and Driesch,1 cited by Morgan, have also shown that in the tubularian hydroids two heads may develop on opposite ends of a piece cut from a stem, especially if the piece be short. 3. Pseudoheteromorphosis.— By cutting a narrow strip from any part of the body so as partly to isolate it, a posteriorly directed head may be developed by the reversal of the FIG. 10. FIG. ii. FIG. 13. FIG. 14. FIG. io. —The lines a show the nature of the cuts which produced heads at right angles to the body. FIG. ii. — A worm with heads lying at right angles to the main body. FIG. 12.—Pseudoheteromorphosis. FIG. 13. —The lines a, b, and c represent the cuts made to induce regeneration of heads in the tail region. FIG. 14.— A head regenerated on one of the tails. If by tension and growth this position becomes permanent, forms are produced which, to the casual observer, appear to be marked examples of heteromorphosis. Figs. 8, 12, 15, and 16 possess all the outward appearances of true heteromorphosis, but by the aid of Figs. 6, io, and 13 one can readily show that there is neither the reversal of axial relations nor the develop- ment of orie organ for another. Hence we do not have true heteromorphosis, but simply the swinging around of a portion 1 " Experimental Studies of the Regeneration of Planaria maculata," Separat- Abdruck aus dem Archiv fitr Entwickelungsmechanik dcr Organismcn. Bd. vii, P- 382-. 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 Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Ma
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
