. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. revolving to the left, and turning toward the aboral side when stimulated mechanically or chemically. 2. Posterior half, without oral groove or mouth (Fig. 4, b}. Much pains was taken to remove the entire oral groove and mouth, so that the posterior piece was usually a little less than one half the body. It was possible to distinguish the aboral side by the presence there of the contractile vacuole. The pos- terior half swims in a spiral, revolving, like the uninjured animal, to the left, and keeping the aboral side to the o
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. revolving to the left, and turning toward the aboral side when stimulated mechanically or chemically. 2. Posterior half, without oral groove or mouth (Fig. 4, b}. Much pains was taken to remove the entire oral groove and mouth, so that the posterior piece was usually a little less than one half the body. It was possible to distinguish the aboral side by the presence there of the contractile vacuole. The pos- terior half swims in a spiral, revolving, like the uninjured animal, to the left, and keeping the aboral side to the outside of the spiral. Its movements are slower than those of the an- terior half, and it is much less sensitive, not reacting so readily to stimuli. The reaction to mechanical and chemical stimuli is by jerk- ing backward and turning toward the aboral side, as in the uninjured individual. Thus the presence of the oral groove and oral cilia is not necessary in order that the usual move- ments and reactions may occur. 3. Middle third of Parainccinin (anterior with mouth and oral and posterior ends removed). — This behaves cilia. £, posterior half, . .. ... , . essentially like the anterior and posterior halves, or the entire FIG. 4. Parame- cium cut transverse- ly, a, anterior half, without mouth or oral cilia. SUMMARY AND CONCLUSIONS. In all the Ciliata studied, including several of the Hypotricha (Stylonycilia, Oxytricha, etc.), two of the Heterotricha (Stentor and Spirostomuni], and one of the Holotricha (Paramecium)> the' movements and reactions of pieces of the organisms, if these are not too minute or too irregular in form, are essentially similar to those of the entire animal. The pieces swim in a spiral, swerv- ing continually toward a certain side, just as do the entire organ- isms. They react to chemical and mechanical stimuli by back- ing and turning toward the same structurally defined side, as do the entire animals. This is true of pieces forming one f
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
