. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. REGENERATION IN UROLEPTUS MOBILIS 539 more macronuclei and at least one micronucleus were able to reorganize and regenerate. In some instances, smaller pieces, although they con- tained sufficient nuclear material, were unable to regenerate completely, and perished. Their failure to do so was probably due to an insufficient amount of cytoplasm in which to undergo a reorganization. In all observed cases of functional regeneration, the stained portions indicated that some macronuclear and micronuclear material had been include
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. REGENERATION IN UROLEPTUS MOBILIS 539 more macronuclei and at least one micronucleus were able to reorganize and regenerate. In some instances, smaller pieces, although they con- tained sufficient nuclear material, were unable to regenerate completely, and perished. Their failure to do so was probably due to an insufficient amount of cytoplasm in which to undergo a reorganization. In all observed cases of functional regeneration, the stained portions indicated that some macronuclear and micronuclear material had been included in the living fragment. In addition, specimens of these re- generated individuals immediately after division exhibited a perfectly normal nuclear condition. DISCUSSION The results here reported on the effects of induced currents on injury and regeneration in Uroleptus inobilis bear out the findings of other investigators that mutilations in the hypotrichous ciliates are followed by reorganization changes comparable to those occurring at the time of division. Thus, it has been demonstrated that even after severe degrees of injury and partial cytolysis inflicted by electric cur- rents, Uroleptus organisms were able to regenerate and undergo pro- found reorganization changes involving a dedifferentiation and redif- ferentiation of the external motor organelles, such as was reported by Calkins (1911) and Young (1922) in Uronychia, Dembowska (1925) \riStylonychia, Taylor (1928) in Uronychia uncmata, Reynolds (1932) in Oxytriclia, and others. These results are perhaps more significant because they shed further light on the behavior of the nuclei during regeneration. Balbiani (1891), working with Stentor, was probably one of the earliest inves- tigators to point to the interesting fact that the macronucleus goes through precisely the same changes in regeneration as in fission. John- son (1893) subsequently confirmed this. More recently, Young (1926) found that when Stylonychia was t
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
