. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. NOTES ON REGULATION IN STYLARIA LACUSTRIS. I85 10 C. 10 DESCRIPTION OF FIGURES. FIGS. 6 and 7. Failure of anterior regeneration in case of very short posterior pieces. Fig. 6 represents such a piece twenty-three days after it was severed, Fig. 7 a piece eighteen days after it was severed. It measured mm. Further observation was prevented. FIG. 8. Regeneration of a double-headed individual. The line in (a) indicates direction of cut. The smaller head was apparently destined to be absorbed at last observation. The spe
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. NOTES ON REGULATION IN STYLARIA LACUSTRIS. I85 10 C. 10 DESCRIPTION OF FIGURES. FIGS. 6 and 7. Failure of anterior regeneration in case of very short posterior pieces. Fig. 6 represents such a piece twenty-three days after it was severed, Fig. 7 a piece eighteen days after it was severed. It measured mm. Further observation was prevented. FIG. 8. Regeneration of a double-headed individual. The line in (a) indicates direction of cut. The smaller head was apparently destined to be absorbed at last observation. The specimen was lost before regeneration was complete. Stages (a) and (^) were six and ten days after the cut was made. FIG. 9. Regeneration of abnormal prostomium, a doubling of the organ. Later the lateral bud was absorbed. FIG. 10. Regeneration occurring in a direction normal to the cut surface. (&) represents the condition three days after the operation, (d] the complete regeneration. In (</) the right dorsal bundle of setae is not restored. In (c) scattered pigment cells resembling the chloragogue cells are present in the new tissue. II. REGENERATION OF THE SEXUAL FORMS. The sexual organs of Stylaria come to maturity during the months of October and November. In the height of the sexual stage the animals cease to multiply asexually. In the earlier stages budding animals are frequently seen. In the fully de- veloped sexual animal the formation of new segments in the anal proliferating region also ceases. As a result the animals attain larger size, since the segments in the budding region become fully differentiated. The clitellum is conspicuous, cover- ing the fifth and sixth segments, in which the testes and ovaries lie. This part becomes more opaque and loses its 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 th
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
