The dynamics of living matter . dynamicsofliving1906loeb2 Year: 1906 208 DYNAMICS OF LIVING MATTER Fig. 46. run parallel with the axis of symmetry of the animal from the tentacles to the foot. The number of these elements may be supposed to corre- spond to the number of the outer row of tentacles of the normal animal. Each such element behaves like a Tubu- larian, with this difference, however, that the elements in Cerianthus are more strongly polarized than Tubularia. No heteromor- phosis has thus far been produced in these elements in Cerianthus, and each one is able to form a tentacle a
The dynamics of living matter . dynamicsofliving1906loeb2 Year: 1906 208 DYNAMICS OF LIVING MATTER Fig. 46. run parallel with the axis of symmetry of the animal from the tentacles to the foot. The number of these elements may be supposed to corre- spond to the number of the outer row of tentacles of the normal animal. Each such element behaves like a Tubu- larian, with this difference, however, that the elements in Cerianthus are more strongly polarized than Tubularia. No heteromor- phosis has thus far been produced in these elements in Cerianthus, and each one is able to form a tentacle at its oral pole only. This fact can be nicely illustrated in the following way: if a square or oblong piece {abed, Fig. 46) be cut from the body wall of a Cerianthus in such a way that one side, ac, of the oblong is parallel to the longitudinal axis of the animal, tentacles will grow on one of the four sides only; namely, on the side ab* The three other free edges are not able to produce tentacles. If an incision be made in the body wall of a Cerianthus, tentacles will grow on the lower edge of the incision (Fig. 47). I have recently tried whether or not by tying a ligature round the middle of a piece of an Actinian this polarity could not be suppressed. But the experiments did not succeed, inasmuch as the cells compressed by the ligature died, and through bacterial action were liquefied so that the pieces in front and behind the ligature fell apart. It is therefore impossible to decide whether or not a condition of the nature of a current or a flow of substances in a certain direction through these elements is responsible for this polarity, though I consider this probable. I found, however, that one condition is necessary for the growth and regeneration of tentacles which also plays a role in the corresponding phenomena in plants; namely, turgidity. The tentacles of Cerianthus are hollow cylinders closed at the tip, and by liquid being pressed into them they can be stretched a
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